Slide 1

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2RECYCLING OF IRON FROM RED MUD BY MAGNETIC SEPARATION AFTER CO-ROASTING WITH PYRITE

3GROUP MEMBER: M .ANUS 14MN36(G.L)IMRAN 14MN06TANVEER AHMEED 14MN20KHALID HUSSAIN 14MN29TAHIR ALI 14MN60

4 OBJECTIVES

5OBJECTIVE

Recycling of Iron from Aluminas tailing

Make Toxic Red Mud environment friendly

To make the Tailing Profitable

6INTRODUCTION

7WHAT IS RED MUD ?Red mud is a toxic iron rich residue of Industrial process of Bauxite

Highly Basic pH 10-13

Effects the air,land and water environment of surrounding area

At present,77 Million Tones of red mud is generated annually worldwide

Contain Gibbsite ,Boehmite, Goethite, Hematite (-Fe203), Anatase and Clay Minerals

8What is RED MUD ?

Red mud contain 10-30% hematite

Hematite is being recovered by RED MUD

Hematite in red mud being transformed into MAGNETITE (the highest gade iron ore) with the help of Pyrite

Remaining 2-3% Iron used as REFRACTORY

9Flow-sheet diagram of recycling of Iron from red mud

10XRD (X-Ray diffraction): for mineralogy & crystallography

XRF (X-Ray Fluorescence): for elemental analysis

TGA (Thermogravimetric Analysis): thermo-analytic technique,works on increasing temprature (heating rate)

TERMINOLOGY

DTA (Differential Thermal Analysis): thermo-analytic technique,records temprature difference between Sample & Reference

Anaerobic roasting: heated below melting point in absence of air

11TERMINOLOGY

12Experiment

13Red mud samples dried at 110 C for 4 h before testing

30 g of red mud contain the mole ratio of FeS2 to Fe2 O3 was 1:4 or 1:8 roasted at 600 C for 30 min under N2 atmosphere.

The thermogravimetric analysis (TG) and differential thermal analysis (DTA) of the samples were performed on a thermal analyzer SAMPLING

14 In Fig. the (a)TG-(b)DTA curves showing three weight-loss stages in the range of 500750 c

23% of weight-loss

Desulfurization of pyrite at 280C

Thermo-chemical behavior of pyrite

(a)TGA curve(b)DTA curve14

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TGA-DTA Curves at different mole ratiosThe XRD patterns of (a) the anaerobic decomposed residue of pyrite at 700 C; and (b) the co-roasting product of the above residue with hematite at 600 C.

a=mole ratio of 1:1 b=mole ratio of 1:5c=mole ratio of 1:10d=mole ratio of 1:20

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a= from a Alumina plant in Shanxi,China.b= from a Alumina plant in Henan,China.17

Production processRed mud samplesAl2O3(%)SiO2(%)Fe2O3(%)TiO2(%)CaO(%)Na2O(%)Sintering Process1a2b5.5112.204.5920.379.78.83.813.7442.3938.000.615.76Bayers Process3a4b23.2022.3622.0919.0513.219.46.245.1318.4013.315.648.24

The main chemical compositions of the collected red mud samples

18Co-roasting of Pyrite and HematiteThe mixture of hematite and pyrite with different mole ratios are heated at 500C for 1h (pyrite decomposes into iron monosulphide FeS)

When the temprature reaches from 525-600C hematite could be transformed into roasted Magnetite

FeS2 + 4Fe2O3 = 3Fe3O4 + 2S2S + 12Fe2O3 = 8Fe3O4 + 2SO2

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a=mole ratio of pyrite to hematite in red mud is 1:4b=mole ratio of pyrite to hematite in red mud is 1:8Red mud sample no.Pyrite mixed with 30g red mudMagnetic part Mass (g)Magnetic partFe (%)Non-magnetic partMass (g)Non-magnetic partFe(%)112340.55a0.28b0.51a0.74a1.10a3.32.73.04.56.236.433.835.236.938.724.326.225.022.520.01.072.041.190.611.65

20INDUSTRIAL APPLICATION

211 ton red mud (Fe 15%)+40 kg pyrite is needed to get 232 kg Fe3 O4 upon magnetic separation.

At least 10 kg pyrite is needed to guarantee the transformation, but 167 mol SO2 might be released.INDUSTRIAL APPLICATION

22CONCLUSION

23Hematite can be transformed into magnetite at 525 C

The released SO2 used for sulfuric acid production

This method is expected to be applied in industry only if the amount of the pyrite is calculated based on the content of Fe2 O3 in red mud.CONCLUSIONS

24THANKS FOR YOUR TIME