beneficiation of brannerite
DESCRIPTION
A copy of the presentation I gave at the AusIMM 2009 International Uranium Conference. It outlines some testing I conducted on a Brannerite ore to beneficiate it.TRANSCRIPT
June 2009AusIMM International Uranium Conference
Mineral Laboratories
Amdel is a member of the Bureau Veritas
Group
Contents
1. Disclaimers
2. Mineralogy – know your enemy
3. Heavy Liquid Separations
4. Spiralling
5. Flotation
6. Magnetic Separations
7. Summary
Beneficiation of Uranium Brannerite Ores
Acknowledgement and Disclaimer
• Thanks to our client who has kindly allowed me to release this information.
• The client has requested their identity NOT be disclosed so as to comply with ASX disclosure requirements. So any information thatcould reveal this has been withheld.
• The information presented is based on lab scale testing and not plant scale.
• No technicians were harmed in the production of these test results.• Copious quantities of beer were consumed in the production of this
presentation and hence don’t believe anything you read.
• Further for those who DON’T ask any difficult questions, the beers are on me at the bar at 5.30pm today.
Beneficiation of Uranium Brannerite Ores
Brannerite – an introduction
• (U4+,Ca)(Ti,Fe3+)2O6 complex• Radioactive
• SG 4.2 - 5.4
• Refractory ore – more difficult to leach• Paramagnetic
In our case we have 5 bulk composites from different sections of the ore body.
Courtesy: Mindat.org
Indicative Head Grades – Fusion ICP (OES & MS)
Beneficiation of Uranium Brannerite Ores
Bulk Chemistry of our Samples
MnO (<0.01%)P2O5 (0.8%)
Th (150-310ppm)Fe2O3 (1.5%)
MgO (1.8%)
CaO (1.5%)
U (100-395ppm)
TiO2 (0.5%)
Na2O (6.3%)
K2O (1.8%)
Al2O3 (14.3%)
SiO2 (70%)
Head grade of U from 100 to 395 ppm.
Beneficiation of Uranium Brannerite Ores
Bulk Mineralogy of our Samples - QEMSCAN
• Brannerite predominantly liberated or high grade middling in -1.0mm sample
• Average grain size from 5 – 25 microns, but up to 250 microns top size
Brannerite0%
Mica8%
Fe Mn Oxides0% Pyrite
0%
Others1%
Calcite0%
Rutile/anatase1%
Apatite2%
Thorite0%
Other Silicates1%
Feldspar63%
Quartz24%
Beneficiation of Uranium Brannerite Ores
Assay by Size
Observed
• High grade U in the -20 micron fractions
• U in the large size fractions
• Cumulative grade by size shows U evenly distributed by mass
0
200
400
600
800
1000
1200
1400
0.000 0.025 0.050 0.075 0.100 0.125 0.150 0.175 0.200 0.225 0.250 0.275 0.300
Size (mm)
U (
pp
m)
Sample 1 Sample 2 Sample 3 Sample 4 Sample 5
• Screened from 3.35mm to 20 microns
Beneficiation of Uranium Brannerite Ores
Processing Implications from Mineralogy
• Beneficiation prior to grinding unlikely to be successful• High SG likely to favour gravity separation
• Concentration Criterion of 1.9-2.7 depending on SG value of Brannerite
• Leach likely to involve high free acid levels 50g/L• Acid consuming minerals present in significant proportions
• Presence of Mica likely to affect flotation performance
• Presence of Phosphate has some possible implications for flotation• Paramagnetic properties presents magnetic separation potential
Recovery the driver for this client
Density Gradient
Beneficiation of Uranium Brannerite Ores
Heavy Liquid Separations for Gravity Separation Assessment
• Gradient of heavy liquids from low SG at top to higher SG at bottom
• Eye-ball technique - qualitative• -150, +75 micron fraction
• Showed potential for separation at an SG of 2.7
Beneficiation of Uranium Brannerite Ores
Heavy Liquid Separations for Gravity Separation Assessment
• Likely to quantify the maximum performance for gravity separation
• Each sample subjected to HLS at SG of 2.7
• Results include -20 micron fraction
89.70% 89.30%
78.90%81.30%
11.80% 11.70%12.60%11.70%7.80%
88.10%
3633
1367
2194 2159
4386
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Sample 1 Sample 2 Sample 3 Sample 4 Sample 5
Rec
ove
ry t
o +
2.7
SG
Fra
ctio
n
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
U G
rad
e (p
pm
)
Wt% U Recovery U Grade
• Significant rejection of mass by gravity separation possible
Beneficiation of Uranium Brannerite Ores
Spirals
• -1.0mm feed material• Deslime at 250 microns
prior to spiral• Bulk Density 30%
• Flowrate ~1000kg/hour wet
65.9%
72.5%74.0%
76.3%
84.8%85.5%
73.2%
79.6%78.0%
90.2%
519
271
138
305 299
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Sample 1 Sample 2 Sample 3 Sample 4 Sample 5
Rec
ove
ry (
%)
0
100
200
300
400
500
600
U G
rad
e (p
pm
)
Wt% U Recovery U Grade
Beneficiation of Uranium Brannerite Ores
Spiral Enhancement
• Observed tail was dominated by large white grains
• Deslime the tail post spiral at 250 microns
• +250 micron tail comprised 90% of the mass and assayed at 89 ppm U
65.9%69.0%
85.5%
94.9%
519534
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Sample 1 Sample 1 with Tail Deslimed at 250 microns
Rec
ove
ry %
0
100
200
300
400
500
600
U G
rad
e (p
pm
)
Wt% U Recovery U Grade
• Suggests potential for sequential scavenger/cleaner spiral arrangement
Range of Collectors Tested
Beneficiation of Uranium Brannerite Ores
Sighter Flotation – 2.5L cell
• Anionic collectors performed better than the cationic one• Fatty acid achieved 79.4% recovery at a grade of 1096ppm in 26.6% of the weight.
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 10 20 30 40 50 60 70 80 90 100
U Recovery (%)
U G
rad
e (p
pm
)
mono/di phosphoric acid esther (-) fatty acid (-) alkyl hydroxamate (-) talow diamine acetate (+)
Beneficiation of Uranium Brannerite Ores
Bulk Flotation – 15L cell
• Average U recovery 89%, peaking at 95%
• Average U grade 1096 ppm
• Average mass rejected 78%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 5 10 15 20 25 30 35 40 45 50
Float Number
Rec
ove
ry (
%)
0
200
400
600
800
1000
1200
1400
1600
U G
rad
e (p
pm
)
Wt Recovery (%) U Recovery (%) U Grade (ppm)
• Increased float time to 40 minutes
• 45 floats conducted to produce a bulk concentrate
Conducted as part of our new WHIMS commissioning
Beneficiation of Uranium Brannerite Ores
Magnetic Separation
• Very visual split achieved• Initial Frantz testing done on a 38-212 micron split of Sample 4
• U grade 2571ppm in 9.6% of the mass but only 61.5% recovery
Beneficiation of Uranium Brannerite Ores
SAMPLE
WHIMS Pass 1
TAIL
WHIMSScavenger
WHIMSCleaner 1
WHIMSCleaner 2
WHIMSCleaner 3
MIDS CON
Non Mags
Non Mags
Mags
Mags
Mags
Mags
Non Mags
Non Mags
Non Mags
AMDEL WHIMS Standard Test Sequence
Mags
Beneficiation of Uranium Brannerite Ores
Magnetic Separation
• Test at 2 magnetic intensities, 10kG and 18kG
• High intensity expected to be required for paramagnetic Brannerite
20.9%
34.7%
43.3%
73.7%
83.7%
74.1%
18.0%
87.9%
2436
2930
833 811
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Sample 1 - WHIMS 10kG Sample 1 - WHIMS 18kG Sample 4 - WHIMS 10kG Sample 4 - WHIMS 18kG
Rec
ove
ry (
%)
0
500
1000
1500
2000
2500
3000
3500
U G
rad
e (p
pm
)
Wt% U Recovery U Grade
• Significantly different behaviour amongst the two samples tested
Beneficiation of Uranium Brannerite Ores
Quick Comparison of the Three Beneficiation Techniques
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Spiral Flotation Magnetic Separation
Beneficiation Method
Rec
ove
ry %
)
0
200
400
600
800
1000
1200
U G
rad
e (p
pm
)
Wt% U Recovery U Grade
Leach, IX and SX
Beneficiation of Uranium Brannerite Ores
Glimpse of Next Stage
• Up to 95% U extraction but at some significant acid consumptions ~254kg/T
• IX and SX results to come
Questions…
PS don’t forget beers on me at 5.30pm today.