Novel Chemistry for Precious and Base Metals ... - CYTEC Industries
Novel Chemistry for Precious and Base Metals ... - CYTEC Industries
Novel Chemistry for Precious and Base Metals ... - CYTEC Industries
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<strong>Novel</strong> <strong>Chemistry</strong> <strong>for</strong><br />
<strong>Precious</strong> <strong>and</strong> <strong>Base</strong><br />
<strong>Metals</strong> Flotation
2<br />
Introduction<br />
Cytec has developed a novel family of collectors designed <strong>for</strong><br />
the flotation recovery of precious <strong>and</strong> base metals from primary<br />
<strong>and</strong> secondary ores. This family of collectors is based on the<br />
novel chemistry, MAXGOLD TM , which is a functionalized<br />
dithiocarbamate. This new chemistry is offered under the name<br />
AERO ® MAXGOLD TM 900 promoter <strong>and</strong> mineral-specific<br />
<strong>for</strong>mulations, the AERO MX-900 promoter series, developed<br />
using the FLOTATION MATRIX 100 TM approach <strong>for</strong> flotation<br />
recovery of:<br />
• Gold values from primary gold ores (free gold, auriferous<br />
pyrite, auriferous arsenopyrite <strong>and</strong> other gold-bearing<br />
sulfides)<br />
• Gold <strong>and</strong> copper values from copper/gold ores.<br />
• Nickel values from massive sulfides <strong>and</strong> ultramific ores<br />
• PGM values from a variety of ores<br />
MAXGOLD chemistry is a sustainable alternative to the<br />
traditionally used sulfide collectors such as xanthates. Some<br />
benefits of the MAXGOLD product line are:<br />
• They are liquids, which af<strong>for</strong>d greater flexibility in dosing.<br />
• They can be dosed directly into the mill, conditioners or<br />
stage-added to the flotation bank. They do not require<br />
reagent dosing systems traditionally required <strong>for</strong> xanthates.<br />
Improved reagent h<strong>and</strong>ling also provides significantly less<br />
chemical exposure to product.<br />
• They provide equivalent or superior metallurgical<br />
per<strong>for</strong>mance at lower dosages than the traditional<br />
collectors.<br />
• Their reduced dosage also translates directly to reduced<br />
residual reagent concentrations in the concentrate <strong>and</strong><br />
tailings. This, in turn, provides significantly better<br />
environmental profile over traditional collectors.<br />
In addition to the above listed benefits, MAXGOLD chemistry<br />
has been shown to offer the following improved per<strong>for</strong>mance<br />
characteristics in the flotation plants:<br />
• Demonstrated robustness in plant operation - reduced<br />
variability in plant recoveries, <strong>and</strong> improved overall gold<br />
recovery of 2-4% or greater.<br />
• A greener profile than st<strong>and</strong>ard products, especially<br />
xanthates.<br />
• Very effective in the flotation of pyrite <strong>and</strong> arsenopyrite in<br />
mildly acidic <strong>and</strong> neutral circuits.<br />
• Can operate in a broad pH range, thus it can be used <strong>for</strong><br />
copper/gold ores with selectivity against pyrite in mildly<br />
alkaline <strong>and</strong> alkaline pulps.<br />
• Provides greater flexibility in terms of addition point (mill,<br />
sumps, conditioners, regrind, etc).<br />
• Can also be also used as a secondary collector at low<br />
dosages (5g/t-15g/t), in conjunction with other collectors<br />
in the rougher or cleaner circuits.<br />
• Faster kinetics in the flotation of sulfides <strong>and</strong> precious<br />
metals than traditional collectors; this is an important<br />
advantage in circuits with shorter residence time.<br />
• Improved recovery of middlings or composite particles.<br />
• Effectiveness at significantly lower dose rates as compared<br />
to traditionally used collectors such as xanthates.<br />
• Greater flexibility in use as a partial replacement <strong>for</strong><br />
xanthates.<br />
• Excellent collector <strong>for</strong> bulk sulfide flotation <strong>and</strong> precious<br />
metal values including free gold, electrum, <strong>and</strong> tellurides.<br />
• Excellent collector <strong>for</strong> Cu, Au <strong>and</strong> Mo values from<br />
Cu-Mo-Au ores requiring no secondary collectors .<br />
• Can be used at low dosages (5g/t-10g/t) in flash float cells<br />
improving recovery of precious metals <strong>and</strong> gold-bearing<br />
iron sulfides.<br />
Case Study<br />
Overview<br />
A plant trial was conducted in a large epithermal gold<br />
operation located in North America that was facing significant<br />
losses of gold in fine particles. <strong>Base</strong>d on the FLOTATION<br />
MATRIX 100 approach <strong>for</strong> reagent selection <strong>and</strong> optimization<br />
<strong>and</strong> using AERO MAXGOLD 900 (AERO MX-900)<br />
promoter as part of the chemical system, improvements to<br />
the per<strong>for</strong>mance <strong>and</strong> significant benefits to the process were<br />
obtained when compared to the st<strong>and</strong>ard reagent Potassium<br />
Amyl Xanthate (PAX).<br />
Process Parameters <strong>and</strong> Flowsheet<br />
The circuit was composed of SAG <strong>and</strong> ball mill in closed<br />
circuit with a p80 set point of 150 µm. The ore passed through<br />
a gravity concentration circuit which the tails fed the flotation.<br />
The collector was added to a conditioning sump prior to the<br />
flotation circuit <strong>and</strong> the flotation was per<strong>for</strong>med at natural pH<br />
(7.5 – 8.5) using 125m 3 tank cells. The flotation concentrate<br />
reported to a cyanide leach.<br />
The trial was conducted using a combination of 40g/t of<br />
AERO MX6205 <strong>and</strong> 10g/t of AERO MX-900 promoters, as<br />
a full replacement <strong>for</strong> 50g/t of PAX in the flotation circuit <strong>for</strong><br />
five weeks.
Tail g/t Au<br />
Data Analysis <strong>and</strong> Trial Results<br />
In order to underst<strong>and</strong> the variability in the flotation circuit,<br />
four months of historical data were analyzed, see Figure 1.<br />
This baseline data represents gold in the final tails when PAX<br />
was used as the collector. The average Au in the tails <strong>for</strong> this<br />
period was 0.25g/t as presented in Figure 1. This will be used<br />
as a baseline <strong>for</strong> comparison with the trial data.<br />
The Au content in the tails during the trial period is presented<br />
in Figure 2, it can be observed that the average Au in the tails<br />
during the trial period dropped to 0.19 g/t.<br />
When combining the historical data (Figure 1) with the trial<br />
period (Figure 2), the trend in the gold tails is readily evident:<br />
Time Series Tail g/t Au<br />
0.4<br />
Time Series Tail g/t Au<br />
0.35<br />
0.3<br />
0.25<br />
Tail g/t Au<br />
0.2<br />
0.15<br />
Tails, g/t<br />
0.4<br />
0.35<br />
0.3<br />
0.25<br />
0.2<br />
• Significant drop in the Au values in the flotation tails:<br />
from an average of 0.25 g/t using PAX to 0.19g/t.<br />
• More robust per<strong>for</strong>mance with the new collector system<br />
with reduced swings in tails value.<br />
This improvement is estimated to generate an additional one<br />
million dollars of revenue to this operation, representing a<br />
return on the investment (ROI) of about 480%. An additional<br />
benefit observed was that more gold reported to the gravity<br />
circuit than when PAX was used. This can be attributed to the<br />
activation of auriferous pyrite in the gravity circuit by PAX,<br />
which leads to gold reporting to flotation instead of being<br />
recovered in the gravity circuit.<br />
0<br />
0.15<br />
50 100 150<br />
Time<br />
200 250 300<br />
Time Series Tails g/t<br />
0.5<br />
Time Series Tails g/t<br />
0.4<br />
0.<br />
Tails, g/t<br />
0.2<br />
0.1<br />
0 50 100 150 200 250 300<br />
0.5<br />
0.4<br />
0.<br />
0.2<br />
FIGURE 1 - Historical Data - Au in Final Tails<br />
Time<br />
FIGURE 2 - Trial Data - Au in the Final Tails<br />
0 10 20 30 40 50 60<br />
0.1<br />
Time<br />
0 10 20 30<br />
Time<br />
40 50 60<br />
3
4<br />
Shipping<br />
AERO MAXGOLD 900 <strong>and</strong> the series AERO MX-900<br />
promoters are shipped in drums, totes or bulk containers.<br />
For in<strong>for</strong>mation on bulk delivery, contact your Cytec sales<br />
representative.<br />
Storage <strong>and</strong> H<strong>and</strong>ling<br />
AERO MAXGOLD 900 <strong>and</strong> the series AERO MX-900<br />
promoters are combustible liquids. Provide adequate<br />
ventilation. Do not heat with an open flame or place in the<br />
presence of an ignition source or contact it with an oxidizing<br />
material with which it may react. The material should be<br />
stored in a cool, well ventilated area away from any sources of<br />
ignition. If product is spilled, remove sources of ignition, cover<br />
with an absorbent material, sweep up <strong>and</strong> place in a properly<br />
covered waste disposal container. Flush area with water <strong>and</strong><br />
dispose of properly.<br />
Health <strong>and</strong> Safety<br />
Be<strong>for</strong>e h<strong>and</strong>ling these materials, read the appropriate Cytec<br />
Material Safety Data Sheet <strong>for</strong> more detailed in<strong>for</strong>mation on<br />
physical properties, safety, health <strong>and</strong> environmental data.<br />
Causes burns of eyes <strong>and</strong> skin. May cause allergic skin<br />
reaction.<br />
Combustible liquid <strong>and</strong> vapor.<br />
Reagent Selection <strong>and</strong> Optimization –<br />
FLOTATION MATRIX 100<br />
FLOTATION MATRIX 100 is a new holistic approach<br />
to mineral flotation optimization that combines Cytec 100<br />
years of experience in flotation, unique chemicals, <strong>and</strong> our<br />
unmatched expertise <strong>and</strong> insights to consistently deliver<br />
measurable improvements in metallurgical, operational <strong>and</strong><br />
financial per<strong>for</strong>mance.<br />
FLOTATION MATRIX 100 is designed to deliver a range of<br />
measurable results by taking into consideration the dynamic<br />
interaction of the ore body <strong>and</strong> plant characteristics with the<br />
chemicals in the flotation process. The benefits that can be<br />
experienced by following this approach are:<br />
• Optimized reagent per<strong>for</strong>mance<br />
• Enhanced recovery of all value minerals<br />
• Increased yield<br />
• Improved concentrate grades<br />
• Accelerated implementation of recommendations<br />
following needs assessment<br />
• Significant cost savings<br />
Contact your Cytec sales representative <strong>for</strong> more in<strong>for</strong>mation<br />
on Cytec products.<br />
• Email: custinfo@cytec.com Worldwide Contact Info: www.cytec.com US Toll Free: 800-652-6013 Tel: (+1) 973-357-3193 •<br />
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