Research Article Characterization and Thermal Dehydration...

Research ArticleCharacterization and Thermal Dehydration Kinetics of HighlyCrystalline Mcallisterite Synthesized at Low Temperatures

Emek Moroydor Derun and Fatma Tugce Senberber

Department of Chemical Engineering Yildiz Technical University 34210 Istanbul Turkey

Correspondence should be addressed to Emek Moroydor Derun moroydorgmailcom

Received 18 November 2013 Accepted 19 January 2014 Published 25 February 2014

Academic Editors A L R Merce and E Mikuli

Copyright copy 2014 E Moroydor Derun and F T Senberber This is an open access article distributed under the Creative CommonsAttribution License which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

The hydrothermal synthesis of a mcallisterite (Mg2(B6O7(OH)

6)2sdot9(H2O)) mineral at low temperatures was characterized For

this purpose several reaction temperatures (0ndash70∘C) and reaction times (30ndash240min) were studied Synthesized minerals weresubjected to X-ray diffraction (XRD) fourier transform infrared (FT-IR) and Raman spectroscopies and scanning electronmicroscopy (SEM) Additionally experimental analyses of boron trioxide (B

2O3) content and reaction yields were performed

Furthermore thermal gravimetry and differential thermal analysis (TGDTA) were used for the determination of thermaldehydration kinetics According to the XRD results mcallisterite which has a powder diffraction file (pdf) number of ldquo01-070-1902rdquo was formed under certain reaction parameters Pure crystalline mcallisterite had diagnostic FT-IR and Raman vibrationpeaks and according to the SEM analysis for the minerals which were synthesized at 60∘C and 30min of reaction time particlesize was between 39830 and 70006 nm Its B

2O3content and reaction yield were 5080 plusmn 112 and 8580 plusmn 061 respectively

Finally average activation energies (conversion values (120572) that were selected between 01 and 06) were calculated as 10040 kJmoland 9831 kJmol according to Ozawa and Kissinger-Akahira-Sunose (KAS) methods respectively

1 Introduction

Boron most often occurs in nature as borates which canbe classified by the kind of metal it is complexed withMagnesium borate minerals which are a subclass of boronminerals are inorganic compounds containing magnesiumand boron They are excellent additives for industry due totheir high elasticity coefficient heat resistance and corro-sion resistance [1] Magnesium borates have specific appli-cations in modified glass compositions reinforcements inelectronic ceramics wide band gap semiconductors alu-minummagnesium matrix alloys antiwear additives such asthermoluminescence dosimeters catalysts for the conversionof hydrocarbons cathode ray tube screens and X-ray screens[2ndash5]

Many kinds of magnesium borates having 119909MgOsdot119910B2O3sdot

119911H2O compositions can be found naturally in mixture with

other metal borates or can be obtained in the laboratoryby synthetic methods Some examples of this type ofborate hydrate minerals that have been synthesized are

2MgOsdot3B2O3sdot17H2O MgOsdot3B

2O3sdot35H2O 2MgOsdotB

2O3sdot

H2O 2MgOsdot6B

2O3sdot15H2O and MgOsdot3B

2O3sdot7H2O [6ndash13]

Mcallisterite is a type of magnesium borate with the chemicalformula Mg

2[B6O7(OH)6]2sdot9H2O It has the appearance of

very fine aggregates and white-colorless crystals hardnessof 25 Mohs and low water solubility Mcallisterite reservesare found in Argentina China Kazakhstan and USAhowever in these reserves magnesium and calcium boratesare found in a mixture and purification is needed [14]General hydrothermal synthesis procedures for magnesiumborates involve the reactions of suitable raw materials athigh temperatures such as gt100∘C or by double salt phasetransformation The type of experimental procedure usedhas effects on the productrsquos crystal properties and size

In literature there are some examples ofmaterialsrsquo surfacemodification by changing the reaction temperatures andreaction times According to these studies nanoscale mate-rials can be synthesized as different crystal types [6ndash13 15]

Hydrothermal processes have several advantages overthe other types of conventional synthesis processes such as

Hindawi Publishing Corporatione Scientific World JournalVolume 2014 Article ID 985185 10 pageshttpdxdoiorg1011552014985185

2 The Scientific World Journal

Equipment and processes(1) Batch reactor(2) Vacuum filtration(3) Incubator (40∘C)(4) Washing(5) Incubator (40∘C)

Streams(1) MgO(2) BA(3) MgO(s) + MB(aq) + BA(aq)(4) MgO(s)(5) MB(aq) + BA(aq) + water(l)(6) Water(g)(7) MB(s) + BA(s)(8) Pure ethanol(l)(9) MB(s) + ethanol(l)(10) Ethanol(l) + BA(aq)(11) Ethanol(g)(12) Pure MB(s)

AbbreviationsMB magnesium borateBA boric acids solid

l liquid

1

1

2

2

3

3

4

4

5

5

6

7

8

9

10

11

12

aq aqueous

g gas

Figure 1 Synthesis procedure of magnesium borates

solid-state method in regard to energy conservation betternucleation control and lower temperature and pressure ofoperation [16 17] Higher reaction temperatures and longerreaction times cause increases in process cost

Dehydrations of crystalline solids represent an importantgroup of heterogeneous reactions Characteristic dehydrationfeatures of materials should be known in order to determinedesign parameters of equipment and to decrease mass ofrequired materials thus reducing the transportation costsThe decomposition process of the hydrated boron mineralwhich usually involves dehydration and dehydroxylation canbe explained by the removal of crystal water from structure[5ndash19] Dehydration behaviors of different types of metalborate minerals have been determined by thermogravimetricanalyses such as TGDTA [1]

The effects of different nonisothermal kineticmethods onthe thermal dehydration of inderite were examined by Zhuet al [7] Changes in ulexite structure resulting from heatingand the reaction kinetic parameters were studied by Ener etal [20] and Tunc et al [21] their results showed that ulexitecould be turned to amorphous phase of NaB

3O5at 855∘C

Waclawska [22] studied the effect of mechanical treatment onphase transitions of calcium borate and colemanite and inter-nal structure reconstitution processes of ground colemaniteThere have also been some studies regarding dehydrationkinetics of synthesized boron compounds Kanturk et al [23]studied dehydration kinetic parameters such as activationenergy and preexponential factors of synthesized sodiummetaborate tetrahydrate (NaB(OH)

4sdot2H2O) Kinetic analyses

of boric acid thermal decomposition were studied by ther-mogravimetric analysis and different kinds of nonisothermalkinetic methods were used for the calculation of parameters[24] Guo et al [25] have investigated the decomposition andoxidation behavior of MgB

2using TG XRD and SEM-EDS

In literature despite the extensively reported synthesis ofmagnesium borates only inderite mineralsrsquo kinetic behaviorhas been studied To date there have been no studiesregarding the kinetic behavior of mcallisterite

In this study the low temperature (0ndash70∘C) synthesisof a specific kind of magnesium borate mineral namelymcallisterite is aimed Therefore in literature Derun et al[1] studied the magnesium borates between 80 and 100∘Cand synthesized a specific kind ofmagnesium boratemineralnamely admontiteTheother aimof this study is to determinethe kinetic parameters (activation energy and coefficientfactor) of mcallisterite mineral which was not studied beforewith both Ozawa [26] and KAS [27 28] nonisothermalkinetic methods

2 Materials and Methods

21 Synthesis of Mcallisterite The raw materials used insynthesis were boric acid (H

3BO3) which was provided from

Kırka Boron Management Plant (ETi Mine Kırka Works)in Eskisehir Turkey and magnesium oxide (MgO) whichwas provided from Merck Chemicals H

3BO3was crushed

grinded and sieved and MgO was used as suppliedThe synthesis procedure of magnesium borates is given

in Figure 1 Experiments were carried out at the reactiontemperatures between 0 and 70∘C and reaction time between30 and 240minutes Each product was coded by initial lettersof the raw materials (M MgO and H H

3BO3) reaction

temperature and reaction time For instance ldquoMH-60-30rdquoindicated the product synthesized at a reaction temperatureof 60∘C and at a reaction time of 30min

22 Instrumental Analyses Philips PANalytical XRD wasused for identification of reaction products X-rays wereproduced from a Cu-K120572 tube at 45 kV and 40mA Theparameters used in the analyses were 0030∘ step 050 stime for step 0060∘Cs scan speed and 0ndash60∘ range ICSDpatterns were scanned using the inorganic library built intothe instrumentrsquos program Synthesized minerals were thensubjected to FT-IR analyses using a Perkin Elmer FT-IRwith universal attenuation total reflectance (ATR) sampling

The Scientific World Journal 3

accessory with a diamondZnSe crystal The measurementrange was 1800ndash650 cmminus1 scan number was 4 and resolutionwas 4 cmminus1 For further analysis Perkin Elmer Brand RamanStation 400 F was used for Raman spectroscopy In theseanalyses the exposure time was 4 seconds and the numberof exposures was 4 Measurement range was 1800ndash250 cmminus1and the data interval was 2 cmminus1 During the experiments100 laser power was used Surface morphologies of synthe-sized minerals were obtained using a CamScan Apollo 300field-emission SEM (20 kV and magnification 20000)

23 B2O3Analyses and Reaction Yields Both B

2O3analyses

and calculations of reaction yields were performed accordingto Derun et al [1]

24 Thermal Dehydration Kinetics Thermal dehydrationbehavior of highly crystalline pure mcallisterite was studiedbetween the temperature ranges of 20 and 720∘C with aPerkin Elmer Diamond TGDTA Purely obtained mcallis-terite mineral was subjected to five different heating rates(2∘Cmin 5∘Cmin 10∘Cmin 15∘Cmin and 20∘Cmin) inan inert (nitrogen) atmosphere Kinetic parameters such asactivation energy (119864

119886) and coefficient constants (119896

0) were cal-

culated by Ozawa and KAS nonisothermal kinetic methodsIn the Ozawa kinetic method (1) values of 1119879 are plotted

against log120573 for each conversion value (120572) where 119879 is thethermodynamic temperature and120573 is heating rate Activationenergy (119864

119886) is calculated from the slope of parallel lines 119877 is

the gas constant Consider

log120573 = log(119896

0119864

119886

119877

) minus 2315 minus 04567 (

119864

119886

119877119879

) minus log (119892 (120572))

(1)

In the KAS kinetic method (2) the kinetic parametersare determined from the plot of 1119879 against the left side ofequation for each 120572 value

ln(

120573

119879

2) = ln(

119896

0119864

119886

119877 sdot 119892 (119909)

) minus

119864

119886

119877119879

(2)

25 Thermal Conversion of Mcallisterite In order to investi-gate and characterize the product obtained after the thermaldehydration kinetics study mcallisterite mineral was placedin a Protherm MOS 1804 high temperature furnace with10∘Cmin temperature increment to amaximum temperatureof 720∘C in nitrogen flowing (5mLmin) atmosphere Afterthe thermal conversion the product was analyzed by XRDwith the same parameters given in Section 22

3 Results and Discussion

31 XRD Results The magnesium and boron sources usedin the experiments were found to be periclase [MgO] andsassolite [H

3BO3] with powder diffraction file (pdf) numbers

of 01-087-0651 and 01-073-2158 respectively

XRD

scor

e

Reac

tion

time (

min

)

Reaction temperature (∘ C)

100

80

60

40

20

406080100120140160180200220240

7060 50 40 30 20 10

0

gt80

lt72

lt52

lt32

lt12

3D surface plot of XRD score against reaction temperature (∘C)

XRD score = distance weighted least squaresand reaction time (min) 10vlowast32c

Figure 2 Modeling graph of mcallisterite crystal scores which isdrawn using Statsoft Statistica

Products of the synthesis were determined to be mcallis-terite [Mg

2(B6O7(OH)6)2sdot9H2O] (pdf 01-070-1902) admon-

tite [MgO(B2O3)3sdot7H2O] (pdf 01-076-0540) andmagnesium

borate hydrate [MgB6O7(OH)6sdot3(H2O)] (pdf 01-073-0638)

XRD scores of synthesized minerals where a perfectcrystal structure is equal to 100 are given in Table 1 MH-0-60 MH-10-30 MH-60-30 and MH-70-60 were pure mcal-listerite MH-20-120 MH-20-240 MH-30-240 and MH-40-240 were pure admontite MH-70-240 was a mixture of threetypes of magnesium borate hydrate minerals

Mcallisterite formation as a function of reaction temper-ature and reaction time is presented in Figure 2 Mcallisteritecrystal formation decreased from 0∘C to 30∘C and increasedfrom30∘C to 70∘CAlsomcallisterite formation had a generaltendency to increase with decreasing reaction times exceptat the temperatures of 0∘C 30∘C 50∘C and 60∘C At 0∘Cand 50∘C the maximum formation was seen at 120minwhereas at 30∘C and 60∘C the maximum formation was seenat 60min

The highest mcallisterite crystal scores were seen in MH-60-30 and MH-70-60 with values of 84 and 85 respectivelySince the XRD crystal scores for MH-60-30 and MH-70-60were approximately the same according to green chemistryconcepts MH-60-30 was selected as the best reaction param-eter and subjected to TGDTA kinetic analyses


Table 1 XRD results of the synthesized magnesium borate minerals

Reaction temperature (∘C) Reaction time (min) XRD scores of01-070-1902 01-076-0540 01-073-0638

0

30 78 30 mdash60 80 mdash mdash120 84 25 mdash240 76 45 mdash

10

30 72 mdash mdash60 8 6 mdash120 69 61 mdash240 76 45 mdash

20

30 85 31 mdash60 77 51 mdash120 mdash 71 mdash240 mdash 73 mdash

30

30 77 70 mdash60 84 71 mdash120 50 79 mdash240 mdash 81 mdash

40


50

30 66 78 mdash60 86 59 mdash120 88 52 mdash240 45 79 mdash

60


70

30 87 18 mdash60 85 mdash mdash120 85 56 mdash240 57 84 23

pdf number = 01-070-1902 mcallisterite Mg2(B6O7(OH)6)2sdot9(H2O)pdf number = 01-076-0540 admontite MgO(B2O3)3sdot7(H2O)pdf number = 01-073-0638 MgB6O7(OH)6sdot3(H2O)

XRD patterns of synthesized pure mcallisterite mineralsare given in Figure 3 As seen in Figure 3 all the characteristicpeaks of mcallisterite were seen and higher count values wereobserved for MH-60-30 and MH-70-60 which is consistentwith their higher crystal scores

32 FT-IR and Raman Spectrum Results FT-IR spectrum ofproduct is given in Figure 4 The first peak at about 1650ndash1660 cmminus1 is the bending of HndashOndashH [120575(HndashOndashH)]The peaksat 1412ndash1337 cmminus1 can be explained by asymmetric stretch-ing of 3-coordinate boron [120592as(B(3)minusO)] The peak around1238 cmminus1 represents the bending of BndashOndashH [120575(BndashOndashH)]Asymmetric and symmetric stretching of 4-coordinate boron[120592as(B(4)minusO)] [120592s(B(4)minusO)] were seen between the peaks

of 1080ndash961 cmminus1 and 857ndash812 cmminus1 respectively The lastpeak of 671 cmminus1 was the bending of 3-coordinate boron[120575(B(3)

minusO)]Raman spectrum of the pure mcallisterite minerals is

given in Figure 5 From the Raman results symmetricstretching of 3-coordinate boron [120592s(B(3)minusO)] was seen atthe peaks between 951 and 879 cmminus1 120575(B

(3)minusO) was seen

at the peaks between 680 and 678 cmminus1 The characteristicpeaks of magnesium borates which are 120592

119901[B6O7(OH)6]2minus

and 120592

119901[B3O3(OH)4]minus were seen at the peak values around

640 cmminus1 At the peak of 528 cmminus1 120575(B(3)

minusO) and bendingof 4-coordinate boron [120575(B

(4)minusO)] were seen The last peaks

which are lower than the 490 cmminus1 can be explained by the120575(B(4)

minusO)


01000200030004000

7 17 27 37 47 57

Cou

nts

MH-70ndash60

Position (2120579 (∘)) (copper (Cu))

(a)

01000200030004000

7 17 27 37 47 57

Cou

nts

MH-60ndash30


(b)

0100200300400

7 17 27 37 47 57

Cou

nts

MH-10ndash30


(c)

0200400600800

7 17 27 37 47 57

Cou

nts

MH-0ndash60Position (2120579 (∘)) (copper (Cu))

(d)

Figure 3 XRD patterns of synthesized pure mcallisterite minerals

The FT-IR and Raman results are both consistent with theliterature [29 30]

33 SEM Results SEM surface morphologies of the synthe-sized pure mcallisterite minerals are given in Figure 6 At10∘C and 0∘C crystals were seen as rectangular shapes dueto overlapping of layers and single crystals Particle sizes ofthe crystals at 10∘C and 0∘C were between 348 nmndash132 120583mand 285ndash544 nm respectively Cylindrical crystal formationsoccurred at 60∘C and 70∘C where particle sizes were 344ndash719 nm and 398ndash700 nm respectively

34 B2O3Results and Reaction Yields B

2O3contents of the

synthesized minerals are given in Table 2 Highest and lowestB2O3were seen in MH-50-30 (5162 plusmn 107) and MH-0-30

(4459 plusmn 134) Pure mcallisterite minerals B2O3contents

MH-0ndash60

MH-10ndash30

MH-60ndash30

MH-70ndash60Tran

smiss

ion

()

Wavenumber (cmminus1)

1653

1412 13381238

1054 964857

812671

1652

1409 13391236

1080 962 857

811670

1662

1413 13381238

1073962

857

85781316601411

13371239

1054 965813 672

1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 650

Figure 4 FT-IR spectrum of synthesized pure mcallisterite miner-als

MH-0ndash60

MH-10ndash30

MH-60ndash30

MH-70ndash30

Raman shift (cmminus1)

Inte

nsity

1800 1600 1400 1200 1000 800 600 400 250

951

880 679

640

528490

409

351

321295

951

879 676

640

528

409

349

322295

951

676

641

528 466

409351322295

951

682

640

528 490

409

351322

295

Figure 5 Raman spectrum of synthesized pure mcallisterite miner-als

were 5325 plusmn 120 in MH-70-60 5417 plusmn 087 in MH-60-30 4991 plusmn 128 inMH-10-30 and 4592 plusmn 054 inMH-0-60 These results were in mutual agreement with theoreticalB2O3content of mcallisterite mineral (5435)

Average reaction yield of the MH-60-30 was 8580 plusmn

061 as calculated from the four repeated syntheses

35 Kinetic Analysis Results TG and DTG analyses of MH-60-30 are shown in Figures 7 and 8 respectivelyThe analysesshowed that mcallisterite lost its crystal water via a two-stepprocess at the heating rate of 2∘Cmin and by a single-stepprocess at heating rates of greater than 2∘Cmin (5∘Cmin10∘Cmin 15∘Cmin and 20∘Cmin)

The first step at the heating rate of 2∘Cmin was a rapiddehydration where the initial peak and final temperatureswere 9081∘C 15064∘C and 15594∘C respectively In the sec-ond step initial peak and final temperatures were 15594∘C16579∘C and 30000∘C Weight decreases were 16416 and19359 for the first and second steps respectively Totalweight loss was 35775

The initial peak and final temperatures andweight lossesat other heating rates are given in Table 3 The averageweight loss calculated using all of the heating rates was35379 which is close to structural water content (3516)of mcallisterite mineral


MH-70ndash60

71901 nm

45746nm44470nm

36514 nm

34497nm

57395nm

(a)

MH-60ndash30

39830nm

70006 nm

55344nm

72503 nm

66721 nm48433nm

(b)

MH-10ndash30

35241nm

67734nm

34801 nm48388 nm

132120583m

54254nm

88090nm

57379nm

(c)

MH-0ndash60

54770nm25330nm

27042nm

39072nm34087 nm

54383 nm

28513 nm

48786 nm

(d)

Figure 6 SEM surface morphologies of synthesized pure mcallisterite minerals at 20000x magnification

Wei

ght (

)

100

95

90

85

80

75

70

65

60

Temperature (∘C)

20 100 200 300 400 500 600 700 720

2∘Cmin5∘Cmin10∘Cmin

15∘Cmin20∘Cmin

Figure 7 TG curve of synthesized pure mcallisterite

Ozawa and KAS nonisothermal kinetic methods wereapplied for conversion values (120572) between 01 and 09 In theOzawa kinetic method log(120573) values were plotted against1119879 values for each 120572 value (Figure 9) For each heating ratekinetic parameter of 119864

119886was calculated from the slope of the

curvesLikewise in the KAS kinetic method ln(1205731198792) was

plotted against 1119879 for each 120572 value (Figure 10) Kinetic

Der

ivat

ive w

eigh

t (

min

)

Temperature (∘C)

0

minus1

minus2

minus3

minus4

minus5

minus6

minus7

minus8

minus9minus95

20 100 200 300 400 500 600 700 720


15∘Cmin20∘Cmin

Figure 8 DTG curve of synthesized pure mcallisterite

parameters of 119864119886and 119896

0for each heating rate were calculated

from the intercept and slopes of the curves respectively119864

119886 1198960 and the correlation coefficient (1198772) values obtained

for each curve are shown in Table 4The activation energy values were calculated as 4781ndash

10118 kJmol and 5391ndash10395 kJmol according to Ozawaand KAS methods respectively 119896

0values were between

00002 and 291389 according to KAS


02

04

06

08

1

12

14

00016 00018 0002 00022 00024 00026

log(120573

)

a = 01

a = 02

a = 03

a = 04

a = 05

a = 06

a = 07

a = 08

a = 09

1T

Figure 9 Ozawa analysis of mcallisterite

00016 00018 0002 00022 00024 00026

a = 01

a = 02

a = 03

a = 04

a = 05

a = 06

a = 07

a = 08

a = 09

minus9

minus95

minus10

minus105

minus11

minus115

minus12

ln(120573

(T

2))

1T

Figure 10 KAS analysis of mcallisterite

Average activation energies of mcallisterite mineral cal-culated for the conversion values between 01 and 06 were10040 kJmol and 9831 kJmol according to Ozawa and KASrespectively

36 Thermal Conversion Results of Mcallisterite Thermalconversion results showed that mcallisterite mineral lost3574 plusmn 032 of its weight This was in agreement with theTG analyses and mcallisteritersquos theoretical structural watercontent of 3516 which is equal to 15 molar equivalent ofwater

Also XRD analysis showed that the mcallisterite mineralhad lost all of its structure water and changed to dehydrated

Table 2 B2O3 contents () of the synthesized magnesium borateminerals

Reactiontemperature (∘C)

Reaction time(min) B2O3 content ()

0

30 4458 plusmn 134

60 4592 plusmn 054

120 4706 plusmn 054

240 4573 plusmn 027

10

30 4991 plusmn 128

60 4706 plusmn 054

120 4592 plusmn 054

240 4763 plusmn 081

20

30 4782 plusmn 107

60 4953 plusmn 027

120 4972 plusmn 054

240 4801 plusmn 081

30

30 4554 plusmn 115

60 4754 plusmn 013

120 4611 plusmn 081

240 4820 plusmn 168

40

30 4896 plusmn 107

60 4820 plusmn 107

120 4706 plusmn 054

240 4668 plusmn 161

50

30 5162 plusmn 107

60 4896 plusmn 107

120 5086 plusmn 054

240 5143 plusmn 081

60

30 5417 plusmn 087

60 5287 plusmn 125

120 5318 plusmn 094

240 5017 plusmn 124

70

30 5083 plusmn 084

60 5325 plusmn 120

120 4962 plusmn 106

240 5384 plusmn 134

magnesium minerals Mg(B2O3)2(pdf 01-076-0666) and

B2O3(pdf 01-072-0626) The obtained Mg(B

2O3)2and B

2O3

crystal scores were 71 and 24 respectively At this step inorder to obtain pure Mg(B

2O3)2 the mixture was washed

with pure ethanol and then filtered and dried at 40∘C Driedmineral was again subjected to XRD analyses and found asthe same dehydrated magnesium mineral Mg(B

2O3)2with a

crystal score of 83The increase in the crystal scoremeans thatthe excess B

2O3content was removed and pure Mg(B

2O3)2

was obtained Also according to the weight changes beforeand after the washing step Mg(B

2O3)2and B

2O3were found

to be equimolarThe crystallographic data obtained from XRD are shown

in Table 5 for mcallisterite and Mg(B2O3)2 The Mg(B

2O3)2


Table 3 Dehydration temperatures and weight losses of pure mcallisterite (MH-60-30)

Heating rate (∘Cmin) 2 5 10 15 20Step 1st 2nd 1st 1st 1st 1st119879

119894(oC) 9081 15594 10000 10651 11188 11974

119879

119901(oC) 15064 16579 17214 18294 18486 18622

119879

119891(oC) 15594 30000 34779 39436 39680 49795

Δ119898 () 16416 19359 35109 35537 35517 34958ΣΔ119898 () 35775 35109 35537 35517 34958AverageΔ119898 () 35379119894 initial 119901 peak 119891 final119898 weight

Table 4 Calculated kinetic parameters for KAS and Ozawa method

120572

MethodOzawa KAS

119864

119886(kJmol) 119877

2119864

119886(kJmol) 119896

0119877

2

01 9749 09909 9558 291389 0989602 9842 09888 9638 169583 0987203 10002 09871 9795 159202 0985204 10224 09869 10018 189934 0984905 10395 09889 10187 196544 0987206 10026 09914 9788 47080 0990007 8307 09794 7964 30520 0975008 6407 09736 5932 00106 0965609 5391 09674 4781 00002 09533120572 Average 119864

119886(kJmol) Average 119864

119886(kJmol)

01ndash06 10040 9831

0200400600800

1000

7 17 27 37 47 57

Cou

nts


Figure 11 XRD pattern of Mg(B2O3)2

XRD pattern is given in Figure 11 where in Figure 11 all thecharacteristic peaks of Mg(B

2O3)2were matched

4 Conclusions

From the results of this study it is seen that the pure mcallis-teriteminerals can be synthesized at a reaction temperature of60∘C with a 30min reaction time by a hydrothermal methodfrom the raw materials of MgO and H

3BO3

According to the XRD results ldquo01-070-1902rdquo codedmcal-listerite mineral [Mg

2(B6O7(OH)6)sdot9H2O] was synthesized

FT-IR and Raman spectrum had the characteristic bands ofmagnesium borates [29 30] Surface morphologies revealedthat proper crystals in nanoscale were obtained with particlesize ranges of 39830ndash70006 nm The B

2O3content of the

MH-60-30 was 5417 plusmn 087 which is very close to the the-oretical value of mcallisterite (5435) The average reactionyield of MH-60-30 was 8580 plusmn 061

In thermal analysis at 2∘Cmin mcallisterite lost its struc-ture water content in a two-step process with the reactionscheme shown in (3) and (4)

1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O

997888rarr Mg2(B6O7(OH)

6)

2sdot 2H2O+ sim 7H

2O

(3)

2nd step

Mg2(B6O7(OH)

6)

2sdot 2H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ sim 8H

2O

(4)

In the first step mcallisterite lost approximately 7 molesof its structure water and in the second step the remaining 8moles of structural water were lost According to the thermalconversion results the final components were equimolarMg(B

2O3)2and B

2O3

In the thermal analyses at heating rates greater than2∘Cmin mcallisterite lost all 15 moles of structure water


Table 5 Crystallographic data of synthesized mcallisterite and MgO(B2O3)2

Mineral name Mcallisterite Magnesium boratepdf number 01-070-1902 01-076-0666Chemical formula Mg2(B6O7(OH)6)2sdot9(H2O) MgO(B2O3)2Molecular weight (gmole) 76856 17955Crystal system Rhombohedral OrthorhombicSpace group Pr3c (No 167) Pbca (No 61)119886 (A) 115490 137300119887 (A) 115490 79700119888 (A) 355670 86200120572 (∘) 9000 9000120573 (∘) 9000 9000120574 (∘) 12000 9000119911 600 800Density (calculated) (gsdotcmminus3) 186 253

Characteristic peaks 119868 ()2120579 (∘)100010139 10002229135715332 9441703332931875 80919921

content in a single step turning into Mg(B2O3)2and B

2O3

by the reaction scheme shown in (5)

1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ 15H

2O

(5)

In the kinetic study for the conversion values between 01and 06 1198772 values varied in the range of 09909ndash09869 and0990ndash09849 in Ozawa and KASmethod respectively Aver-age 119864119886values of Ozawa and KAS methods were calculated as

10040KJmol and 9831 KJmol respectivelyIn conclusion the kinetic study of mcallisterite was

reasonable considering that the Ozawa and KAS methodsactivation energy values were approximately the same

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authors would like to express their deepest gratitude toProfessor Dr Sabriye Piskin and Dr A Seyhun Kıpcak fortheir contribution to the study

References

[1] E M Derun A S Kipcak F T Senberber and M S Yil-maz ldquoCharacterization and thermal dehydration kinetics ofadmontite mineral hydrothermally synthesized from magne-sium oxide and boric acid precursorrdquo Research on ChemicalIntermediates 2013

[2] E I Kamitsos M A Karakassides and G D ChryssikosldquoVibrational spectra of magnesium-sodium-borate glasses 2

Raman and mid-infrared investigation of the network struc-turerdquo Journal of Physical Chemistry vol 91 no 5 pp 1073ndash10791987

[3] W Zhu Q Zhang L Xiang et al ldquoFlux-assisted thermalconversion route to pore-free high crystallinity magnesiumborate nanowhiskers at a relatively low temperaturerdquo CrystalGrowth and Design vol 8 no 8 pp 2938ndash2945 2008

[4] M Prokic ldquoMagnesium borate in TL dosimetryrdquo RadiationProtection Dosimetry vol 17 no 1ndash4 pp 393ndash396 1986

[5] M B Piskin and H E Figen ldquoDehydroxylation ReactionKinetic Mechanism of Inderite Mineralrdquo IPCBEE vol 10 2011

[6] A K Figen M S Yilmaz and S Piskin ldquoStructural charac-terization and dehydration kinetics of Kirka inderite mineralApplication of non-isothermal modelsrdquo Materials Characteri-zation vol 61 no 6 pp 640ndash647 2010

[7] W Zhu G Li Q Zhang L Xiang and S Zhu ldquoHydrothermalmass production ofMgBO

2(OH) nanowhiskers and subsequent

thermal conversion toMg2B2O5nanorods for biaxially oriented

polypropylene resins reinforcementrdquo Powder Technology vol203 no 2 pp 265ndash271 2010

[8] L Zhihong andHMancheng ldquoSynthesis and thermochemistryof MgOsdot3B

2O3sdot35H2OrdquoThermochimica Acta vol 403 pp 181ndash

184 2003

[9] L Zhihong and H Mancheng ldquoSynthesis characterizationand thermochemistry of a new form of 2MgO3B

2O317H2Ordquo

Thermochimica Acta vol 414 no 2 pp 215ndash218 2004[10] A S Kipcak F T Senberber E M Derun and S Piskin

ldquoHydrothermal synthesis of magnesium borate hydrates fromMgO and H

3BO3at 80∘Crdquo Research Bulletin of the Australian

Institute of High Energetic Materials Australian Institute of HighEnergetic Materials vol 1 p 47 2011

[11] A S Kipcak F T Senberber E M Derun and S PiskinldquoCharacterization of Magnesium Borate Hydrates Producedfrom MgO and H

3BO3at 80∘Crdquo in Proceedings of the 12th

Mediterranean Congress of Chemical Engineering November2011


[12] H Niitsuma and T Kikuchi ldquoAn experimental study on thephase relations in the systems MgO-B

2O3and MgO-B

2O3-

H2Ordquo Journal of Mineralogical and Petrological Sciences vol 97

no 6 pp 285ndash288 2002[13] C L Christ ldquoCrystal chemistry and systematic classification of

hydrated borate mineralsrdquo The American Mineralogist vol 45pp 334ndash340

[14] W T Schaller A C Vlisidis and M E Mrose ldquoMcallisterite2MgO6B

2O315H2O A new hydrous magnesium borate min-

eral from the Death Varry reigion Inyo Country CaliforniardquoThe American Mineralogist vol 50 p 629 1965

[15] Y Zheng Y Tian H Ma et al ldquoSynthesis and performancestudy of zinc borate nanowhiskersrdquoColloids and Surfaces A vol339 no 1ndash3 pp 178ndash184 2009

[16] W Zhu L Xiang Q Zhang X Zhang L Hu and SZhu ldquoMorphology preservation and crystallinity improvementin the thermal conversion of the hydrothermal synthesizedMgBO

2(OH) nanowhiskers to Mg

2B2O5nanowhiskersrdquo Jour-

nal of Crystal Growth vol 310 no 18 pp 4262ndash4267 2008[17] W L Suchanek and R E Riman ldquoHydrothermal synthesis of

advanced ceramic powdersrdquo Advances in Science and Technol-ogy vol 45 pp 184ndash193 2006

[18] Y Saito K Kawahira N Yoshikawa H Todoroki and STaniguchi ldquoDehydration behavior of goethite blended withgraphite by microwave heatingrdquo Journal of the Iron and SteelInstitute of Japan vol 51 no 6 pp 878ndash883 2011

[19] A K Galwey ldquoStructure and order in thermal dehydrations ofcrystalline solidsrdquoThermochimica Acta vol 355 no 1-2 pp 181ndash238 2000

[20] S Ener G O Lu and A Demirci ldquoChanges in the structure ofulexite on heatingrdquo Thermochimica Acta vol 362 no 1-2 pp107ndash112 2000

[21] M Tunc H Ersahan S Yapici and S Colak ldquoDehydrationkinetics of ulexite from thermogravimetric datardquo Journal ofThermal Analysis vol 48 no 2 pp 403ndash411 1997

[22] IWaclawska ldquoThermal behaviour of mechanically amorphizedcolemanite II Internal structure reconstitution processes ofground colemaniterdquo Journal of Thermal Analysis vol 48 no 1pp 155ndash161 1997

[23] A Kanturk M Sari and S Piskin ldquoSynthesis crystal structureand dehydration kinetics of NaB(OH)

4sdot2H2Ordquo Korean Journal

of Chemical Engineering vol 25 no 6 pp 1331ndash1337 2008[24] F Sevim F Demir M Bilen and H Okur ldquoKinetic analysis of

thermal decomposition of boric acid from thermogravimetricdatardquo Korean Journal of Chemical Engineering vol 23 no 5 pp736ndash740 2006

[25] Y Guo W Zhang D Yang and R L Yao ldquoDecompositionand oxidation of magnesium diboriderdquo Journal of the AmericanCeramic Society vol 95 no 2 pp 754ndash759 2012

[26] T Ozawa ldquoA new method of analyzing thermogravimetricdatardquo Bulletin of the Chemical Society of Japan vol 38 no 11pp 1881ndash1886 1965

[27] H E Kissinger ldquoReaction kinetics in differential thermalanalysisrdquo Analytical Chemistry vol 29 no 11 pp 1702ndash17061957

[28] T Akahira and T Sunose ldquoTrans Joint convention of fourelectrical institutesrdquo Chiba Institute of Technology vol 16 pp22ndash31 1971

[29] J Yongzhong G Shiyang X Shuping and L Jun ldquoFT-IR spec-troscopy of supersaturated aqueous solutions of magnesiumboraterdquo SpectrochimicaActaA vol 56 no 7 pp 1291ndash1297 2000

[30] S Li D Xu H Shen J Zhou and Y Fan ldquoSynthesis and Ramanproperties of magnesium borate micronanorodsrdquo MaterialsResearch Bulletin vol 47 no 11 pp 3650ndash3653 2012

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Carbohydrate Chemistry

International Journal of


Journal of

Chemistry


Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of


Chromatography Research International


Applied ChemistryJournal of



Theoretical ChemistryJournal of


Journal of

Spectroscopy

Analytical ChemistryInternational Journal of


Journal of


Quantum Chemistry


Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


Equipment and processes(1) Batch reactor(2) Vacuum filtration(3) Incubator (40∘C)(4) Washing(5) Incubator (40∘C)

Streams(1) MgO(2) BA(3) MgO(s) + MB(aq) + BA(aq)(4) MgO(s)(5) MB(aq) + BA(aq) + water(l)(6) Water(g)(7) MB(s) + BA(s)(8) Pure ethanol(l)(9) MB(s) + ethanol(l)(10) Ethanol(l) + BA(aq)(11) Ethanol(g)(12) Pure MB(s)

AbbreviationsMB magnesium borateBA boric acids solid

l liquid

1

1

2

2

3

3

4

4

5

5

6

7

8

9

10

11

12

aq aqueous

g gas

Figure 1 Synthesis procedure of magnesium borates

solid-state method in regard to energy conservation betternucleation control and lower temperature and pressure ofoperation [16 17] Higher reaction temperatures and longerreaction times cause increases in process cost

Dehydrations of crystalline solids represent an importantgroup of heterogeneous reactions Characteristic dehydrationfeatures of materials should be known in order to determinedesign parameters of equipment and to decrease mass ofrequired materials thus reducing the transportation costsThe decomposition process of the hydrated boron mineralwhich usually involves dehydration and dehydroxylation canbe explained by the removal of crystal water from structure[5ndash19] Dehydration behaviors of different types of metalborate minerals have been determined by thermogravimetricanalyses such as TGDTA [1]

The effects of different nonisothermal kineticmethods onthe thermal dehydration of inderite were examined by Zhuet al [7] Changes in ulexite structure resulting from heatingand the reaction kinetic parameters were studied by Ener etal [20] and Tunc et al [21] their results showed that ulexitecould be turned to amorphous phase of NaB

3O5at 855∘C

Waclawska [22] studied the effect of mechanical treatment onphase transitions of calcium borate and colemanite and inter-nal structure reconstitution processes of ground colemaniteThere have also been some studies regarding dehydrationkinetics of synthesized boron compounds Kanturk et al [23]studied dehydration kinetic parameters such as activationenergy and preexponential factors of synthesized sodiummetaborate tetrahydrate (NaB(OH)

4sdot2H2O) Kinetic analyses

of boric acid thermal decomposition were studied by ther-mogravimetric analysis and different kinds of nonisothermalkinetic methods were used for the calculation of parameters[24] Guo et al [25] have investigated the decomposition andoxidation behavior of MgB

2using TG XRD and SEM-EDS

In literature despite the extensively reported synthesis ofmagnesium borates only inderite mineralsrsquo kinetic behaviorhas been studied To date there have been no studiesregarding the kinetic behavior of mcallisterite

In this study the low temperature (0ndash70∘C) synthesisof a specific kind of magnesium borate mineral namelymcallisterite is aimed Therefore in literature Derun et al[1] studied the magnesium borates between 80 and 100∘Cand synthesized a specific kind ofmagnesium boratemineralnamely admontiteTheother aimof this study is to determinethe kinetic parameters (activation energy and coefficientfactor) of mcallisterite mineral which was not studied beforewith both Ozawa [26] and KAS [27 28] nonisothermalkinetic methods

2 Materials and Methods

21 Synthesis of Mcallisterite The raw materials used insynthesis were boric acid (H

3BO3) which was provided from

Kırka Boron Management Plant (ETi Mine Kırka Works)in Eskisehir Turkey and magnesium oxide (MgO) whichwas provided from Merck Chemicals H

3BO3was crushed

grinded and sieved and MgO was used as suppliedThe synthesis procedure of magnesium borates is given

in Figure 1 Experiments were carried out at the reactiontemperatures between 0 and 70∘C and reaction time between30 and 240minutes Each product was coded by initial lettersof the raw materials (M MgO and H H

3BO3) reaction

temperature and reaction time For instance ldquoMH-60-30rdquoindicated the product synthesized at a reaction temperatureof 60∘C and at a reaction time of 30min

22 Instrumental Analyses Philips PANalytical XRD wasused for identification of reaction products X-rays wereproduced from a Cu-K120572 tube at 45 kV and 40mA Theparameters used in the analyses were 0030∘ step 050 stime for step 0060∘Cs scan speed and 0ndash60∘ range ICSDpatterns were scanned using the inorganic library built intothe instrumentrsquos program Synthesized minerals were thensubjected to FT-IR analyses using a Perkin Elmer FT-IRwith universal attenuation total reflectance (ATR) sampling




2O3analyses




0) were cal-





log120573 = log(119896

0119864

119886

119877

) minus 2315 minus 04567 (

119864

119886

119877119879

) minus log (119892 (120572))

(1)


ln(

120573

119879

2) = ln(

119896

0119864

119886

119877 sdot 119892 (119909)

) minus

119864

119886

119877119879

(2)






XRD

scor

e

Reac

tion

time (

min

)


100

80

60

40

20

406080100120140160180200220240

7060 50 40 30 20 10

0

gt80

lt72

lt52

lt32

lt12














0


10


20


30


40


50


60


70








(3)minusO) was seen


119901[B6O7(OH)6]2minus

and 120592






minusO)


01000200030004000

7 17 27 37 47 57

Cou

nts

MH-70ndash60


(a)

01000200030004000

7 17 27 37 47 57

Cou

nts

MH-60ndash30


(b)

0100200300400

7 17 27 37 47 57

Cou

nts

MH-10ndash30


(c)

0200400600800

7 17 27 37 47 57

Cou

nts


(d)





2O3contents of the



MH-0ndash60

MH-10ndash30

MH-60ndash30

MH-70ndash60Tran

smiss

ion

()


1653

1412 13381238

1054 964857

812671

1652

1409 13391236

1080 962 857

811670

1662

1413 13381238

1073962

857

85781316601411

13371239

1054 965813 672

1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 650


MH-0ndash60

MH-10ndash30

MH-60ndash30

MH-70ndash30


Inte

nsity

1800 1600 1400 1200 1000 800 600 400 250

951

880 679

640

528490

409

351

321295

951

879 676

640

528

409

349

322295

951

676

641

528 466

409351322295

951

682

640

528 490

409

351322

295









MH-70ndash60

71901 nm

45746nm44470nm

36514 nm

34497nm

57395nm

(a)

MH-60ndash30

39830nm

70006 nm

55344nm

72503 nm

66721 nm48433nm

(b)

MH-10ndash30

35241nm

67734nm

34801 nm48388 nm

132120583m

54254nm

88090nm

57379nm

(c)

MH-0ndash60

54770nm25330nm

27042nm

39072nm34087 nm

54383 nm

28513 nm

48786 nm

(d)


Wei

ght (

)

100

95

90

85

80

75

70

65

60

Temperature (∘C)

20 100 200 300 400 500 600 700 720


15∘Cmin20∘Cmin






Der

ivat

ive w

eigh

t (

min

)

Temperature (∘C)

0

minus1

minus2

minus3

minus4

minus5

minus6

minus7

minus8

minus9minus95

20 100 200 300 400 500 600 700 720


15∘Cmin20∘Cmin











02

04

06

08

1

12

14

00016 00018 0002 00022 00024 00026

log(120573

)

a = 01

a = 02

a = 03

a = 04

a = 05

a = 06

a = 07

a = 08

a = 09

1T


00016 00018 0002 00022 00024 00026

a = 01

a = 02

a = 03

a = 04

a = 05

a = 06

a = 07

a = 08

a = 09

minus9

minus95

minus10

minus105

minus11

minus115

minus12

ln(120573

(T

2))

1T








0

30 4458 plusmn 134

60 4592 plusmn 054

120 4706 plusmn 054

240 4573 plusmn 027

10

30 4991 plusmn 128

60 4706 plusmn 054

120 4592 plusmn 054

240 4763 plusmn 081

20

30 4782 plusmn 107

60 4953 plusmn 027

120 4972 plusmn 054

240 4801 plusmn 081

30

30 4554 plusmn 115

60 4754 plusmn 013

120 4611 plusmn 081

240 4820 plusmn 168

40

30 4896 plusmn 107

60 4820 plusmn 107

120 4706 plusmn 054

240 4668 plusmn 161

50

30 5162 plusmn 107

60 4896 plusmn 107

120 5086 plusmn 054

240 5143 plusmn 081

60

30 5417 plusmn 087

60 5287 plusmn 125

120 5318 plusmn 094

240 5017 plusmn 124

70

30 5083 plusmn 084

60 5325 plusmn 120

120 4962 plusmn 106

240 5384 plusmn 134



2O3)2and B

2O3




2O3)2with a



2O3)2


2O3)2and B

2O3were found



2O3)2




119894(oC) 9081 15594 10000 10651 11188 11974

119879

119901(oC) 15064 16579 17214 18294 18486 18622

119879

119891(oC) 15594 30000 34779 39436 39680 49795



120572

MethodOzawa KAS

119864

119886(kJmol) 119877

2119864

119886(kJmol) 119896

0119877

2

01 9749 09909 9558 291389 0989602 9842 09888 9638 169583 0987203 10002 09871 9795 159202 0985204 10224 09869 10018 189934 0984905 10395 09889 10187 196544 0987206 10026 09914 9788 47080 0990007 8307 09794 7964 30520 0975008 6407 09736 5932 00106 0965609 5391 09674 4781 00002 09533120572 Average 119864


119886(kJmol)

01ndash06 10040 9831

0200400600800

1000

7 17 27 37 47 57

Cou

nts




2O3)2were matched

4 Conclusions


3BO3




2O3content of the



1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O


6)

2sdot 2H2O+ sim 7H

2O

(3)

2nd step

Mg2(B6O7(OH)

6)

2sdot 2H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ sim 8H

2O

(4)


2O3)2and B

2O3







2O3


1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ 15H

2O

(5)






Acknowledgments


References














184 2003


2O317H2Ordquo










2O3and MgO-B

2O3-





































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




2O3analyses




0) were cal-





log120573 = log(119896

0119864

119886

119877

) minus 2315 minus 04567 (

119864

119886

119877119879

) minus log (119892 (120572))

(1)


ln(

120573

119879

2) = ln(

119896

0119864

119886

119877 sdot 119892 (119909)

) minus

119864

119886

119877119879

(2)






XRD

scor

e

Reac

tion

time (

min

)


100

80

60

40

20

406080100120140160180200220240

7060 50 40 30 20 10

0

gt80

lt72

lt52

lt32

lt12














0


10


20


30


40


50


60


70








(3)minusO) was seen


119901[B6O7(OH)6]2minus

and 120592






minusO)


01000200030004000

7 17 27 37 47 57

Cou

nts

MH-70ndash60


(a)

01000200030004000

7 17 27 37 47 57

Cou

nts

MH-60ndash30


(b)

0100200300400

7 17 27 37 47 57

Cou

nts

MH-10ndash30


(c)

0200400600800

7 17 27 37 47 57

Cou

nts


(d)





2O3contents of the



MH-0ndash60

MH-10ndash30

MH-60ndash30

MH-70ndash60Tran

smiss

ion

()


1653

1412 13381238

1054 964857

812671

1652

1409 13391236

1080 962 857

811670

1662

1413 13381238

1073962

857

85781316601411

13371239

1054 965813 672

1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 650


MH-0ndash60

MH-10ndash30

MH-60ndash30

MH-70ndash30


Inte

nsity

1800 1600 1400 1200 1000 800 600 400 250

951

880 679

640

528490

409

351

321295

951

879 676

640

528

409

349

322295

951

676

641

528 466

409351322295

951

682

640

528 490

409

351322

295









MH-70ndash60

71901 nm

45746nm44470nm

36514 nm

34497nm

57395nm

(a)

MH-60ndash30

39830nm

70006 nm

55344nm

72503 nm

66721 nm48433nm

(b)

MH-10ndash30

35241nm

67734nm

34801 nm48388 nm

132120583m

54254nm

88090nm

57379nm

(c)

MH-0ndash60

54770nm25330nm

27042nm

39072nm34087 nm

54383 nm

28513 nm

48786 nm

(d)


Wei

ght (

)

100

95

90

85

80

75

70

65

60

Temperature (∘C)

20 100 200 300 400 500 600 700 720


15∘Cmin20∘Cmin






Der

ivat

ive w

eigh

t (

min

)

Temperature (∘C)

0

minus1

minus2

minus3

minus4

minus5

minus6

minus7

minus8

minus9minus95

20 100 200 300 400 500 600 700 720


15∘Cmin20∘Cmin











02

04

06

08

1

12

14

00016 00018 0002 00022 00024 00026

log(120573

)

a = 01

a = 02

a = 03

a = 04

a = 05

a = 06

a = 07

a = 08

a = 09

1T


00016 00018 0002 00022 00024 00026

a = 01

a = 02

a = 03

a = 04

a = 05

a = 06

a = 07

a = 08

a = 09

minus9

minus95

minus10

minus105

minus11

minus115

minus12

ln(120573

(T

2))

1T








0

30 4458 plusmn 134

60 4592 plusmn 054

120 4706 plusmn 054

240 4573 plusmn 027

10

30 4991 plusmn 128

60 4706 plusmn 054

120 4592 plusmn 054

240 4763 plusmn 081

20

30 4782 plusmn 107

60 4953 plusmn 027

120 4972 plusmn 054

240 4801 plusmn 081

30

30 4554 plusmn 115

60 4754 plusmn 013

120 4611 plusmn 081

240 4820 plusmn 168

40

30 4896 plusmn 107

60 4820 plusmn 107

120 4706 plusmn 054

240 4668 plusmn 161

50

30 5162 plusmn 107

60 4896 plusmn 107

120 5086 plusmn 054

240 5143 plusmn 081

60

30 5417 plusmn 087

60 5287 plusmn 125

120 5318 plusmn 094

240 5017 plusmn 124

70

30 5083 plusmn 084

60 5325 plusmn 120

120 4962 plusmn 106

240 5384 plusmn 134



2O3)2and B

2O3




2O3)2with a



2O3)2


2O3)2and B

2O3were found



2O3)2




119894(oC) 9081 15594 10000 10651 11188 11974

119879

119901(oC) 15064 16579 17214 18294 18486 18622

119879

119891(oC) 15594 30000 34779 39436 39680 49795



120572

MethodOzawa KAS

119864

119886(kJmol) 119877

2119864

119886(kJmol) 119896

0119877

2

01 9749 09909 9558 291389 0989602 9842 09888 9638 169583 0987203 10002 09871 9795 159202 0985204 10224 09869 10018 189934 0984905 10395 09889 10187 196544 0987206 10026 09914 9788 47080 0990007 8307 09794 7964 30520 0975008 6407 09736 5932 00106 0965609 5391 09674 4781 00002 09533120572 Average 119864


119886(kJmol)

01ndash06 10040 9831

0200400600800

1000

7 17 27 37 47 57

Cou

nts




2O3)2were matched

4 Conclusions


3BO3




2O3content of the



1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O


6)

2sdot 2H2O+ sim 7H

2O

(3)

2nd step

Mg2(B6O7(OH)

6)

2sdot 2H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ sim 8H

2O

(4)


2O3)2and B

2O3







2O3


1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ 15H

2O

(5)






Acknowledgments


References














184 2003


2O317H2Ordquo










2O3and MgO-B

2O3-





































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




0


10


20


30


40


50


60


70








(3)minusO) was seen


119901[B6O7(OH)6]2minus

and 120592






minusO)


01000200030004000

7 17 27 37 47 57

Cou

nts

MH-70ndash60


(a)

01000200030004000

7 17 27 37 47 57

Cou

nts

MH-60ndash30


(b)

0100200300400

7 17 27 37 47 57

Cou

nts

MH-10ndash30


(c)

0200400600800

7 17 27 37 47 57

Cou

nts


(d)





2O3contents of the



MH-0ndash60

MH-10ndash30

MH-60ndash30

MH-70ndash60Tran

smiss

ion

()


1653

1412 13381238

1054 964857

812671

1652

1409 13391236

1080 962 857

811670

1662

1413 13381238

1073962

857

85781316601411

13371239

1054 965813 672

1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 650


MH-0ndash60

MH-10ndash30

MH-60ndash30

MH-70ndash30


Inte

nsity

1800 1600 1400 1200 1000 800 600 400 250

951

880 679

640

528490

409

351

321295

951

879 676

640

528

409

349

322295

951

676

641

528 466

409351322295

951

682

640

528 490

409

351322

295









MH-70ndash60

71901 nm

45746nm44470nm

36514 nm

34497nm

57395nm

(a)

MH-60ndash30

39830nm

70006 nm

55344nm

72503 nm

66721 nm48433nm

(b)

MH-10ndash30

35241nm

67734nm

34801 nm48388 nm

132120583m

54254nm

88090nm

57379nm

(c)

MH-0ndash60

54770nm25330nm

27042nm

39072nm34087 nm

54383 nm

28513 nm

48786 nm

(d)


Wei

ght (

)

100

95

90

85

80

75

70

65

60

Temperature (∘C)

20 100 200 300 400 500 600 700 720


15∘Cmin20∘Cmin






Der

ivat

ive w

eigh

t (

min

)

Temperature (∘C)

0

minus1

minus2

minus3

minus4

minus5

minus6

minus7

minus8

minus9minus95

20 100 200 300 400 500 600 700 720


15∘Cmin20∘Cmin











02

04

06

08

1

12

14

00016 00018 0002 00022 00024 00026

log(120573

)

a = 01

a = 02

a = 03

a = 04

a = 05

a = 06

a = 07

a = 08

a = 09

1T


00016 00018 0002 00022 00024 00026

a = 01

a = 02

a = 03

a = 04

a = 05

a = 06

a = 07

a = 08

a = 09

minus9

minus95

minus10

minus105

minus11

minus115

minus12

ln(120573

(T

2))

1T








0

30 4458 plusmn 134

60 4592 plusmn 054

120 4706 plusmn 054

240 4573 plusmn 027

10

30 4991 plusmn 128

60 4706 plusmn 054

120 4592 plusmn 054

240 4763 plusmn 081

20

30 4782 plusmn 107

60 4953 plusmn 027

120 4972 plusmn 054

240 4801 plusmn 081

30

30 4554 plusmn 115

60 4754 plusmn 013

120 4611 plusmn 081

240 4820 plusmn 168

40

30 4896 plusmn 107

60 4820 plusmn 107

120 4706 plusmn 054

240 4668 plusmn 161

50

30 5162 plusmn 107

60 4896 plusmn 107

120 5086 plusmn 054

240 5143 plusmn 081

60

30 5417 plusmn 087

60 5287 plusmn 125

120 5318 plusmn 094

240 5017 plusmn 124

70

30 5083 plusmn 084

60 5325 plusmn 120

120 4962 plusmn 106

240 5384 plusmn 134



2O3)2and B

2O3




2O3)2with a



2O3)2


2O3)2and B

2O3were found



2O3)2




119894(oC) 9081 15594 10000 10651 11188 11974

119879

119901(oC) 15064 16579 17214 18294 18486 18622

119879

119891(oC) 15594 30000 34779 39436 39680 49795



120572

MethodOzawa KAS

119864

119886(kJmol) 119877

2119864

119886(kJmol) 119896

0119877

2

01 9749 09909 9558 291389 0989602 9842 09888 9638 169583 0987203 10002 09871 9795 159202 0985204 10224 09869 10018 189934 0984905 10395 09889 10187 196544 0987206 10026 09914 9788 47080 0990007 8307 09794 7964 30520 0975008 6407 09736 5932 00106 0965609 5391 09674 4781 00002 09533120572 Average 119864


119886(kJmol)

01ndash06 10040 9831

0200400600800

1000

7 17 27 37 47 57

Cou

nts




2O3)2were matched

4 Conclusions


3BO3




2O3content of the



1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O


6)

2sdot 2H2O+ sim 7H

2O

(3)

2nd step

Mg2(B6O7(OH)

6)

2sdot 2H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ sim 8H

2O

(4)


2O3)2and B

2O3







2O3


1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ 15H

2O

(5)






Acknowledgments


References














184 2003


2O317H2Ordquo










2O3and MgO-B

2O3-





































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


01000200030004000

7 17 27 37 47 57

Cou

nts

MH-70ndash60


(a)

01000200030004000

7 17 27 37 47 57

Cou

nts

MH-60ndash30


(b)

0100200300400

7 17 27 37 47 57

Cou

nts

MH-10ndash30


(c)

0200400600800

7 17 27 37 47 57

Cou

nts


(d)





2O3contents of the



MH-0ndash60

MH-10ndash30

MH-60ndash30

MH-70ndash60Tran

smiss

ion

()


1653

1412 13381238

1054 964857

812671

1652

1409 13391236

1080 962 857

811670

1662

1413 13381238

1073962

857

85781316601411

13371239

1054 965813 672

1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 650


MH-0ndash60

MH-10ndash30

MH-60ndash30

MH-70ndash30


Inte

nsity

1800 1600 1400 1200 1000 800 600 400 250

951

880 679

640

528490

409

351

321295

951

879 676

640

528

409

349

322295

951

676

641

528 466

409351322295

951

682

640

528 490

409

351322

295









MH-70ndash60

71901 nm

45746nm44470nm

36514 nm

34497nm

57395nm

(a)

MH-60ndash30

39830nm

70006 nm

55344nm

72503 nm

66721 nm48433nm

(b)

MH-10ndash30

35241nm

67734nm

34801 nm48388 nm

132120583m

54254nm

88090nm

57379nm

(c)

MH-0ndash60

54770nm25330nm

27042nm

39072nm34087 nm

54383 nm

28513 nm

48786 nm

(d)


Wei

ght (

)

100

95

90

85

80

75

70

65

60

Temperature (∘C)

20 100 200 300 400 500 600 700 720


15∘Cmin20∘Cmin






Der

ivat

ive w

eigh

t (

min

)

Temperature (∘C)

0

minus1

minus2

minus3

minus4

minus5

minus6

minus7

minus8

minus9minus95

20 100 200 300 400 500 600 700 720


15∘Cmin20∘Cmin











02

04

06

08

1

12

14

00016 00018 0002 00022 00024 00026

log(120573

)

a = 01

a = 02

a = 03

a = 04

a = 05

a = 06

a = 07

a = 08

a = 09

1T


00016 00018 0002 00022 00024 00026

a = 01

a = 02

a = 03

a = 04

a = 05

a = 06

a = 07

a = 08

a = 09

minus9

minus95

minus10

minus105

minus11

minus115

minus12

ln(120573

(T

2))

1T








0

30 4458 plusmn 134

60 4592 plusmn 054

120 4706 plusmn 054

240 4573 plusmn 027

10

30 4991 plusmn 128

60 4706 plusmn 054

120 4592 plusmn 054

240 4763 plusmn 081

20

30 4782 plusmn 107

60 4953 plusmn 027

120 4972 plusmn 054

240 4801 plusmn 081

30

30 4554 plusmn 115

60 4754 plusmn 013

120 4611 plusmn 081

240 4820 plusmn 168

40

30 4896 plusmn 107

60 4820 plusmn 107

120 4706 plusmn 054

240 4668 plusmn 161

50

30 5162 plusmn 107

60 4896 plusmn 107

120 5086 plusmn 054

240 5143 plusmn 081

60

30 5417 plusmn 087

60 5287 plusmn 125

120 5318 plusmn 094

240 5017 plusmn 124

70

30 5083 plusmn 084

60 5325 plusmn 120

120 4962 plusmn 106

240 5384 plusmn 134



2O3)2and B

2O3




2O3)2with a



2O3)2


2O3)2and B

2O3were found



2O3)2




119894(oC) 9081 15594 10000 10651 11188 11974

119879

119901(oC) 15064 16579 17214 18294 18486 18622

119879

119891(oC) 15594 30000 34779 39436 39680 49795



120572

MethodOzawa KAS

119864

119886(kJmol) 119877

2119864

119886(kJmol) 119896

0119877

2

01 9749 09909 9558 291389 0989602 9842 09888 9638 169583 0987203 10002 09871 9795 159202 0985204 10224 09869 10018 189934 0984905 10395 09889 10187 196544 0987206 10026 09914 9788 47080 0990007 8307 09794 7964 30520 0975008 6407 09736 5932 00106 0965609 5391 09674 4781 00002 09533120572 Average 119864


119886(kJmol)

01ndash06 10040 9831

0200400600800

1000

7 17 27 37 47 57

Cou

nts




2O3)2were matched

4 Conclusions


3BO3




2O3content of the



1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O


6)

2sdot 2H2O+ sim 7H

2O

(3)

2nd step

Mg2(B6O7(OH)

6)

2sdot 2H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ sim 8H

2O

(4)


2O3)2and B

2O3







2O3


1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ 15H

2O

(5)






Acknowledgments


References














184 2003


2O317H2Ordquo










2O3and MgO-B

2O3-





































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


MH-70ndash60

71901 nm

45746nm44470nm

36514 nm

34497nm

57395nm

(a)

MH-60ndash30

39830nm

70006 nm

55344nm

72503 nm

66721 nm48433nm

(b)

MH-10ndash30

35241nm

67734nm

34801 nm48388 nm

132120583m

54254nm

88090nm

57379nm

(c)

MH-0ndash60

54770nm25330nm

27042nm

39072nm34087 nm

54383 nm

28513 nm

48786 nm

(d)


Wei

ght (

)

100

95

90

85

80

75

70

65

60

Temperature (∘C)

20 100 200 300 400 500 600 700 720


15∘Cmin20∘Cmin






Der

ivat

ive w

eigh

t (

min

)

Temperature (∘C)

0

minus1

minus2

minus3

minus4

minus5

minus6

minus7

minus8

minus9minus95

20 100 200 300 400 500 600 700 720


15∘Cmin20∘Cmin











02

04

06

08

1

12

14

00016 00018 0002 00022 00024 00026

log(120573

)

a = 01

a = 02

a = 03

a = 04

a = 05

a = 06

a = 07

a = 08

a = 09

1T


00016 00018 0002 00022 00024 00026

a = 01

a = 02

a = 03

a = 04

a = 05

a = 06

a = 07

a = 08

a = 09

minus9

minus95

minus10

minus105

minus11

minus115

minus12

ln(120573

(T

2))

1T








0

30 4458 plusmn 134

60 4592 plusmn 054

120 4706 plusmn 054

240 4573 plusmn 027

10

30 4991 plusmn 128

60 4706 plusmn 054

120 4592 plusmn 054

240 4763 plusmn 081

20

30 4782 plusmn 107

60 4953 plusmn 027

120 4972 plusmn 054

240 4801 plusmn 081

30

30 4554 plusmn 115

60 4754 plusmn 013

120 4611 plusmn 081

240 4820 plusmn 168

40

30 4896 plusmn 107

60 4820 plusmn 107

120 4706 plusmn 054

240 4668 plusmn 161

50

30 5162 plusmn 107

60 4896 plusmn 107

120 5086 plusmn 054

240 5143 plusmn 081

60

30 5417 plusmn 087

60 5287 plusmn 125

120 5318 plusmn 094

240 5017 plusmn 124

70

30 5083 plusmn 084

60 5325 plusmn 120

120 4962 plusmn 106

240 5384 plusmn 134



2O3)2and B

2O3




2O3)2with a



2O3)2


2O3)2and B

2O3were found



2O3)2




119894(oC) 9081 15594 10000 10651 11188 11974

119879

119901(oC) 15064 16579 17214 18294 18486 18622

119879

119891(oC) 15594 30000 34779 39436 39680 49795



120572

MethodOzawa KAS

119864

119886(kJmol) 119877

2119864

119886(kJmol) 119896

0119877

2

01 9749 09909 9558 291389 0989602 9842 09888 9638 169583 0987203 10002 09871 9795 159202 0985204 10224 09869 10018 189934 0984905 10395 09889 10187 196544 0987206 10026 09914 9788 47080 0990007 8307 09794 7964 30520 0975008 6407 09736 5932 00106 0965609 5391 09674 4781 00002 09533120572 Average 119864


119886(kJmol)

01ndash06 10040 9831

0200400600800

1000

7 17 27 37 47 57

Cou

nts




2O3)2were matched

4 Conclusions


3BO3




2O3content of the



1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O


6)

2sdot 2H2O+ sim 7H

2O

(3)

2nd step

Mg2(B6O7(OH)

6)

2sdot 2H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ sim 8H

2O

(4)


2O3)2and B

2O3







2O3


1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ 15H

2O

(5)






Acknowledgments


References














184 2003


2O317H2Ordquo










2O3and MgO-B

2O3-





































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


02

04

06

08

1

12

14

00016 00018 0002 00022 00024 00026

log(120573

)

a = 01

a = 02

a = 03

a = 04

a = 05

a = 06

a = 07

a = 08

a = 09

1T


00016 00018 0002 00022 00024 00026

a = 01

a = 02

a = 03

a = 04

a = 05

a = 06

a = 07

a = 08

a = 09

minus9

minus95

minus10

minus105

minus11

minus115

minus12

ln(120573

(T

2))

1T








0

30 4458 plusmn 134

60 4592 plusmn 054

120 4706 plusmn 054

240 4573 plusmn 027

10

30 4991 plusmn 128

60 4706 plusmn 054

120 4592 plusmn 054

240 4763 plusmn 081

20

30 4782 plusmn 107

60 4953 plusmn 027

120 4972 plusmn 054

240 4801 plusmn 081

30

30 4554 plusmn 115

60 4754 plusmn 013

120 4611 plusmn 081

240 4820 plusmn 168

40

30 4896 plusmn 107

60 4820 plusmn 107

120 4706 plusmn 054

240 4668 plusmn 161

50

30 5162 plusmn 107

60 4896 plusmn 107

120 5086 plusmn 054

240 5143 plusmn 081

60

30 5417 plusmn 087

60 5287 plusmn 125

120 5318 plusmn 094

240 5017 plusmn 124

70

30 5083 plusmn 084

60 5325 plusmn 120

120 4962 plusmn 106

240 5384 plusmn 134



2O3)2and B

2O3




2O3)2with a



2O3)2


2O3)2and B

2O3were found



2O3)2




119894(oC) 9081 15594 10000 10651 11188 11974

119879

119901(oC) 15064 16579 17214 18294 18486 18622

119879

119891(oC) 15594 30000 34779 39436 39680 49795



120572

MethodOzawa KAS

119864

119886(kJmol) 119877

2119864

119886(kJmol) 119896

0119877

2

01 9749 09909 9558 291389 0989602 9842 09888 9638 169583 0987203 10002 09871 9795 159202 0985204 10224 09869 10018 189934 0984905 10395 09889 10187 196544 0987206 10026 09914 9788 47080 0990007 8307 09794 7964 30520 0975008 6407 09736 5932 00106 0965609 5391 09674 4781 00002 09533120572 Average 119864


119886(kJmol)

01ndash06 10040 9831

0200400600800

1000

7 17 27 37 47 57

Cou

nts




2O3)2were matched

4 Conclusions


3BO3




2O3content of the



1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O


6)

2sdot 2H2O+ sim 7H

2O

(3)

2nd step

Mg2(B6O7(OH)

6)

2sdot 2H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ sim 8H

2O

(4)


2O3)2and B

2O3







2O3


1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ 15H

2O

(5)






Acknowledgments


References














184 2003


2O317H2Ordquo










2O3and MgO-B

2O3-





































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




119894(oC) 9081 15594 10000 10651 11188 11974

119879

119901(oC) 15064 16579 17214 18294 18486 18622

119879

119891(oC) 15594 30000 34779 39436 39680 49795



120572

MethodOzawa KAS

119864

119886(kJmol) 119877

2119864

119886(kJmol) 119896

0119877

2

01 9749 09909 9558 291389 0989602 9842 09888 9638 169583 0987203 10002 09871 9795 159202 0985204 10224 09869 10018 189934 0984905 10395 09889 10187 196544 0987206 10026 09914 9788 47080 0990007 8307 09794 7964 30520 0975008 6407 09736 5932 00106 0965609 5391 09674 4781 00002 09533120572 Average 119864


119886(kJmol)

01ndash06 10040 9831

0200400600800

1000

7 17 27 37 47 57

Cou

nts




2O3)2were matched

4 Conclusions


3BO3




2O3content of the



1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O


6)

2sdot 2H2O+ sim 7H

2O

(3)

2nd step

Mg2(B6O7(OH)

6)

2sdot 2H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ sim 8H

2O

(4)


2O3)2and B

2O3







2O3


1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ 15H

2O

(5)






Acknowledgments


References














184 2003


2O317H2Ordquo










2O3and MgO-B

2O3-





































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of






2O3


1st step

Mg2(B6O7(OH)

6)

2sdot 9H2O

997888rarr 2 (MgO(B2O3)

2) + 2B

2O3+ 15H

2O

(5)






Acknowledgments


References














184 2003


2O317H2Ordquo










2O3and MgO-B

2O3-





































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of



2O3and MgO-B

2O3-





































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of










Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

Research Article Characterization and Thermal Dehydration...

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Transcript of Research Article Characterization and Thermal Dehydration...