Post Lab Discussion
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![Page 1: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/1.jpg)
Bond Ball Mill Work Index
Procedure
![Page 2: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/2.jpg)
Work Indices
• Measures of the energy necessary to break a particular type of ore
• Relates the power input and the reduction ratio in comminuting ore
• Generally dependent on material; but some equipment factors should be considered when using different methods for determining WI
![Page 3: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/3.jpg)
Bond’s Energy Equation• Derived from FC Bond’s 3rd theory of
Comminution
• Generally used for all equipment!
EFFP
WE i
1110
E = energy input, in KWh/MT or HP F = Feed size in microns P = Product size in microns EF = Efficiency Factor
![Page 4: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/4.jpg)
Bond Ball Mill Grindability Index
• This parameter controls the calculation of the basic energy requirements of the comminution circuit
• It can be used to determine the grinding power required for a given throughput of material under ball mill grinding conditions
• It is the most important parameter
![Page 5: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/5.jpg)
Bond Ball Mill Grindability Index
• 12-in diameter by 12-in long (internal dimensions) horizontal axis mill with rounded corners and a smooth lining. There are no lifters. The mill rotates at 70 rpm
![Page 6: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/6.jpg)
Bond Ball Mill Grindability Index• BWI Equipment
• Data obtained: Grindability
![Page 7: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/7.jpg)
Grindability
• A material property• Defined as the ease at which a mineral particle
is reduced to a prescribed size, given the amount of energy input
• For BMWI test, grindability is the net grams of undersize product per revolution of mill
![Page 8: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/8.jpg)
Bond Ball Mill Grindability Index• Equation is given as:
FPGp
W
bpi
i 11
45.4
82.023.0
pi = test sieve size in microns Gbp = grindability P = product size in microns F = Feed size in microns
![Page 9: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/9.jpg)
Procedure
1. Set the test sieve size (100 mesh = 150μm)2. Prepare 10 kg of 100% passing -6 mesh of
sample (the FEED)3. Obtain an initial particle size distribution
– Should be representative!
4. Determine % of undersize of the FEED
![Page 10: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/10.jpg)
Procedure
5. Pack fill a 1000-mL plastic graduated cylinder to 700mL level,
– This fraction shall be the constant charge weight
6. Set aside the remaining sample for replenishment
7. Determine the weight and bulk density
![Page 11: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/11.jpg)
Procedure
8. Determine the intended product passing (IPP) by dividing the 700mL material weight by 3.5
![Page 12: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/12.jpg)
Intended Product Passing
• The target weight of material as 100% PRODUCT UNDERSIZE with 250% circulating load
• Illustrative example:– Feed weight of 700mL sample = 1050 grams
![Page 13: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/13.jpg)
Intended Product Passing
– 300 grams is the 100% (target undersize weight)– 750 grams is the 250% (target circulating load)– 300 + 750 = 1050– 100% + 250% = 350% = 3.5!
gramsIPP
gramsIPP
3005.3
1050
3.5
700mL Weight,Feed
![Page 14: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/14.jpg)
Procedure
9. Run in the ball mill for 100 revolutions (initial, arbitrary)
10. remove the charge from the ball mill, ensuring that all material is recovered
11.Screen the material using test screen for oversize and undersize
12.Fill-in the table
![Page 15: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/15.jpg)
Bond Work Index TablePeriod Weight, grams # of
revsWeight, Grams Net Under
size per Rev
% Circu-lating Load
Fresh Feed Undersize, fresh feed
Over size Under size
Net Undersize
1
2
3
4
5
6
7
8
9
10
![Page 16: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/16.jpg)
Example
• Sample: 10 kg of Calcite (Limestone) from Camp 6, Benguet
![Page 17: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/17.jpg)
Example
• PSA of feed Calcite (100% Passing 6 mesh)
![Page 18: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/18.jpg)
Example
• PSA of feed Calcite (100% Passing 6 mesh)
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Formulae
• Fresh feed = weight of fresh feed = weight of 700mL material
(for period 1 only!)
• Weight of 700 mL sample = 1,285 grams
![Page 20: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/20.jpg)
Bond Work Index TablePeriod Weight, grams # of
revsWeight, Grams Net Under
size per Rev
% Circu-lating Load
Fresh Feed Undersize, fresh feed
Over size Under size
Net Undersize
1 1,285
2
3
4
5
6
7
8
9
10
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Formulae
• Undersize Fresh Feed
* Based on PSA of feed, 15.28%
35.196
1528.0285,1
*Undersize%FeedFresh ofWeight
![Page 22: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/22.jpg)
Bond Work Index TablePeriod Weight, grams # of
revsWeight, Grams Net Under
size per Rev
% Circu-lating Load
Fresh Feed Undersize, fresh feed
Over size Under size
Net Undersize
1 1,285 196.35
2
3
4
5
6
7
8
9
10
![Page 23: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/23.jpg)
Formulae
• # of Revolutions = 100– Arbitrary, for the 1st period only!
![Page 24: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/24.jpg)
Bond Work Index TablePeriod Weight, grams # of
revsWeight, Grams Net Under
size per Rev
% Circu-lating Load
Fresh Feed Undersize, fresh feed
Over size Under size
Net Undersize
1 1,285 196.35 100
2
3
4
5
6
7
8
9
10
![Page 25: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/25.jpg)
Formulae
• Weight Oversize– Weight of material retained on test screen
• Weight Undersize– Weight of material passing the test screen
• Screening is done AFTER the prescribed revolutions are applied!
![Page 26: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/26.jpg)
Bond Work Index TablePeriod Weight, grams # of
revsWeight, Grams Net Under
size per Rev
% Circu-lating Load
Fresh Feed Undersize, fresh feed
Over size Under size
Net Undersize
1 1,285 196.35 100 850 435
2
3
4
5
6
7
8
9
10
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Formulae
• Net Undersize
65.238
35.196435
FeedFresh ersize,Weight UndersizeWeight Und
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Bond Work Index TablePeriod Weight, grams # of
revsWeight, Grams Net Under
size per Rev
% Circu-lating Load
Fresh Feed Undersize, fresh feed
Over size Under size
Net Undersize
1 1,285 196.35 100 850 435 238.65
2
3
4
5
6
7
8
9
10
![Page 29: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/29.jpg)
Formulae
• Net Undersize per Revolution
39.2100
65.238
sRevolution of #
izeNet Unders
![Page 30: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/30.jpg)
Bond Work Index TablePeriod Weight, grams # of
revsWeight, Grams Net Under
size per Rev
% Circu-lating Load
Fresh Feed Undersize, fresh feed
Over size Under size
Net Undersize
1 1,285 196.35 100 850 435 238.65 2.39
2
3
4
5
6
7
8
9
10
![Page 31: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/31.jpg)
Formulae
• % Circulating Load
40.195435
850
ersizeWeight Und
OversizeWeight
![Page 32: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/32.jpg)
Bond Work Index TablePeriod Weight, grams # of
revsWeight, Grams Net Under
size per Rev
% Circu-lating LoadFresh Feed Undersize,
fresh feedOver size
Under size
Net Undersize
1 1,285 196.35 100 850 435 238.65 2.39 195.40
2
3
4
5
6
7
8
9
10
![Page 33: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/33.jpg)
Procedure
13. Discard ALL the screened undersize14. Replenish the oversize from the set-aside
sample, with the SAME AMOUNT discarded* to maintain the total weight of charge (1285 grams)
*ensure that proper representative sampling is performed to obtain replenishment mass!
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Bond Work Index TablePeriod Weight, grams # of
revsWeight, Grams Net Under
size per Rev
% Circu-lating LoadFresh Feed Undersize,
fresh feedOver size
Under size
Net Undersize
1 1,285 196.35 100 850 435 238.65 2.39 195.40
2 435 66.47
3
4
5
6
7
8
9
10
![Page 35: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/35.jpg)
Procedure
15. Determine the # of Rev for Period 2 using the formula:
*IPP is computed as 367.14 grams (1285/3.5)
Revper izeNet Unders previous
feedfresh Undersize,-*IPP Rev of #
![Page 36: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/36.jpg)
Procedure
126 Rev of #2.39
66.47-367.14 Rev of #
Revper izeNet Unders previous
FeedFresh Undersize,-*IPP Rev of #
![Page 37: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/37.jpg)
Bond Work Index TablePeriod Weight, grams # of
revsWeight, Grams Net Under
size per Rev
% Circu-lating LoadFresh Feed Undersize,
fresh feedOver size
Under size
Net Undersize
1 1,285 196.35 100 850 435 238.65 2.39 195.40
2 435 66.47 126
3
4
5
6
7
8
9
10
![Page 38: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/38.jpg)
Procedure
16. return the replenished charge (previous oversize + replenishment = 1285 grams) to the ball mill
17. run the mill based on the computed # of revolutions
18. repeat steps 10-17, until convergence is reached!
![Page 39: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/39.jpg)
Bond Work Index TablePeriod Weight, grams # of
revsWeight, Grams Net Under
size per Rev
% Circu-lating LoadFresh Feed Undersize,
fresh feedOver size
Under size
Net Undersize
1 1,285 196.35 100 850 435 238.65 2.39 195.40
2 435 66.47 126 870 415 348.53 2.77 209.64
3 415 63.41 110 915 370 306.59 2.79 247.30
4 370 56.54 111 915 370 313.46 2.82 247.30
5 370 56.54 110 915 370 313.46 2.84 247.30
6 370 56.54 109
7
8
9
10
![Page 40: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/40.jpg)
Procedure
• Convergence is reached when:– The last three (3) entries for % Circulating Load is
at 250 ± 5%– The Weight Undersize approaches the IPP value
(367.14 grams)
![Page 41: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/41.jpg)
Bond Work Index TablePeriod Weight, grams # of
revsWeight, Grams Net Under
size per Rev
% Circu-lating LoadFresh Feed Undersize,
fresh feedOver size
Under size
Net Undersize
1 1,285 196.35 100 850 435 238.65 2.39 195.40
2 435 66.47 126 870 415 348.53 2.77 209.64
3 415 63.41 110 915 370 306.59 2.79 247.30
4 370 56.54 111 915 370 313.46 2.82 247.30
5 370 56.54 110 915 370 313.46 2.84 247.30
6 370 56.54 109
7
8
9
10
![Page 42: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/42.jpg)
Procedure
19. When convergence is reached, DO NOT DISCARD the last screened Undersize
20. Determine the particle size distribution of the last screened Undersize
![Page 43: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/43.jpg)
Example
• PSA of the last screened Undersize
![Page 44: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/44.jpg)
Example
• PSA of the last screened Undersize
![Page 45: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/45.jpg)
Procedure
21. Compute the average of the last three (3) entries for the Net Undersize per Revolution
22. this value is taken as the GRINDABILITY of the sample!
![Page 46: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/46.jpg)
Bond Work Index TablePeriod Weight, grams # of
revsWeight, Grams Net Under
size per Rev
% Circu-lating LoadFresh Feed Undersize,
fresh feedOver size
Under size
Net Undersize
1 1,285 196.35 100 850 435 238.65 2.39 195.40
2 435 66.47 126 870 415 348.53 2.77 209.64
3 415 63.41 110 915 370 306.59 2.79 247.30
4 370 56.54 111 915 370 313.46 2.82 247.30
5 370 56.54 110 915 370 313.46 2.84 247.30
6 370 56.54 109
7
8
9
10
![Page 47: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/47.jpg)
Example
• Test sieve = 100 mesh = 150 μm• Grindability = 2.818 grams/rev• 80% Passing size of feed = 1,654.40 μm • 80% Passing size of product = 97.89 μm
![Page 48: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/48.jpg)
Example
• Equation is given as:
FPGp
W
bpi
i 11
45.4
82.023.0
pi = test sieve size in microns Gbp = grindability P = product size in microns F = Feed size in microns
![Page 49: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/49.jpg)
Example
• Substituting the values:
Mt
kWhr 86.7
40.654,1
1
89.97
1818.2150
45.4
82.023.0
i
i
W
W
![Page 50: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/50.jpg)
Mesh of Grind
![Page 51: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/51.jpg)
Procedure
1. Obtain 1-kg of 100% passing 6-mesh sample2. Determine the ball loading of the ball mill3. Grind the sample for 5 minutes4. Perform particle size analysis of the sample5. Determine the cumulative 80% passing6. Repeat steps 3-5 for an additional 5, 5, 5, 10,
15, and 15 minutes
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Data Processing
0 2000 4000 6000 8000 10000 12000 140000.00
20.00
40.00
60.00
80.00
100.00
15 mins
30 mins
45 mins
60 mins
Microns
Cu
mu
lati
ve
% P
as
sin
g
![Page 53: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/53.jpg)
Data Processing
1.5000 2.0000 2.5000 3.0000 3.5000 4.0000 4.50000.0000
0.5000
1.0000
1.5000
2.0000
2.5000
f(x) = 0.320920332811502 x + 0.649853133588051f(x) = 0.35934139282703 x + 0.464774812086754f(x) = 0.362065725088539 x + 0.415169569378266f(x) = 0.437253546602284 x + 0.0475020990195434
Log Size, microns
Lo
g C
um
ula
tiv
e %
Pa
ss
![Page 54: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/54.jpg)
Data Processing
Time, min Log 80% Pass, um
Initial
15 17,510.09
30 12,854.59
45 10,332.51
60 8,039.61
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Data Processing
1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 3.0000
3.5000
4.0000
4.5000
f(x) = − 0.329264725751256 x + 4.64083772097153
Log10 (Time, minutes),
Lo
g1
0(C
um
80
%P
as
s,
um
)
![Page 56: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/56.jpg)
Dense Medium Separation
![Page 57: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/57.jpg)
Dense Media Separation
• Prepare SG 1.3 and 1.7 solutions of ZnCl2
• Obtain 10-g of powdered coal sample• Place solution in 500-mL graduated cylinders• Place sample in solution• Scoop out the “float” samples• Filter out the “sink” samples• Burn the samples in the muffle furnace for 1
hour @ 9000C
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Findings
• Separation by density– Separate coal by grade– Higher grade, higher density– Separate other minerals
• Determination of ash content– Verify coal grade by ash residue after burning
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Hand Panning
![Page 60: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/60.jpg)
Hand Panning
• Prepare 100 grams chromite @ 100% passing 30 mesh, 100% retained 50 mesh
• Prepare 100 grams silica @ 100% passing 10 mesh, 100% retained 20 mesh
• Mix the two minerals• Separate by hand panning• Collect the concentrate and tails and screen to
separate the two minerals
![Page 61: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/61.jpg)
Findings
• Determine separation of minerals by gravity and particle size
![Page 62: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/62.jpg)
Findings
• Behavior of minerals:
![Page 63: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/63.jpg)
Bubble Pick-up
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Bubble Pick-up
1. Obtain 1-gram of ore sample2. Place in 100-mL beaker 3. Fill with water4. Ultra-sonicate for 3 minutes5. Discard water6. Repeat steps 3-5 until water is clear7. Condition pH8. Add collector
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Bubble Pick-up
9. Condition pH10. Add frother11. Lower the glass tube into the pulp12. Press the rubber plunger13. Without releasing the plunger, raise the glass tube
and apply the bubble into a glass slide14. Repeat steps 11-13 until 10 droplets were recovered15. Dry and perform particle counting using the
microscope
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Findings
• Simulate flotation response using a single bubble
• Determine best dosage parameters before froth flotation test
![Page 67: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/67.jpg)
Froth Flotation
![Page 68: Post Lab Discussion](https://reader035.fdocuments.us/reader035/viewer/2022081504/55160a7f497959111e8b5169/html5/thumbnails/68.jpg)
Froth Flotation
1. Obtain 1-kg sample2. Grind, at the grinding time determined in the
MOG experiment3. Place sample in flotation cell4. Add enough water to cover5. Pulp for 5 minutes6. Add pH modifier7. Condition for 5 minutes8. Repeat steps 6-7 until proper pH is achieved
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Froth Flotation
9. Add collector10.Condition for 10 minutes11.Check the pH, make adjustments if necessary12.Add frother13.Condition for 10-30 seconds14.Scrape froth15.After flotation, scoop out tailings solids16.Perform assay of concentrate and tailings
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Findings
• Determine the proper steps in performing flotation– Art vs. science
• Determine the effects of dosage parameters to recovery
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Flocculation
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Flocculation
1. Prepare a 1000 mL 20:1 water-ore pulp using 100% passing 200-mesh ore from BWI undersize
2. Prepare 10 dosages of flocculant3. Agitate pulp for 5 minutes4. Determine the settling rate without flocculant5. Mark the lowest settling level of solids6. Add 1 dose of flocculant and agitate for 5 minutes
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Flocculation
7. Determine settling rate8. Mark the lowest settling level of solids9. Repeat steps 6-8 until no change in settling
rate is observed10.Graph the settling rates vs. time
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Findings
• Determine the minimum dosage of flocculation
• Observe stearic stabilization• Observe “swelling” of flocculated solids
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Sedimentation
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Sedimentation
1. Prepare 1000 mL of 5, 10, 15, and 20% solids pulp using 100% passing 200-mesh from BWI undersize
2. Agitate for 5 minutes3. Mark the level of the solids-water interface at
specified intervals4. Mark the lowest settling level of solids
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Findings
H1
H2
H3
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Findings
• Determine thickener area using Kynch’s formula:
00CH
tA u
A = thickener areatu = settling timeH0 = initial pulp heightC0 = pulp consistency
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Findings
• Determine thickener retention time using Robert’s formula
cu ttt t = retention timetu = settling timetc = time to compression zone
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Findings
• Determine the depth of compression zone:
A
xtd
24
1
d = depth of compression zonetu = retention timex = average dilution of pulp at compression zonex = average dilution of pulp between the compression zone and final underflow is reachedA = thickener area