Novel Chemistry for Precious and Base Metals ... - CYTEC Industries

Novel Chemistry for
Precious and Base
Metals Flotation

2
Introduction
Cytec has developed a novel family of collectors designed for
the flotation recovery of precious and base metals from primary
and secondary ores. This family of collectors is based on the
novel chemistry, MAXGOLD TM , which is a functionalized
dithiocarbamate. This new chemistry is offered under the name
AERO ® MAXGOLD TM 900 promoter and mineral-specific
formulations, the AERO MX-900 promoter series, developed
using the FLOTATION MATRIX 100 TM approach for flotation
recovery of:
• Gold values from primary gold ores (free gold, auriferous
pyrite, auriferous arsenopyrite and other gold-bearing
sulfides)
• Gold and copper values from copper/gold ores.
• Nickel values from massive sulfides and ultramific ores
• PGM values from a variety of ores
MAXGOLD chemistry is a sustainable alternative to the
traditionally used sulfide collectors such as xanthates. Some
benefits of the MAXGOLD product line are:
• They are liquids, which afford greater flexibility in dosing.
• They can be dosed directly into the mill, conditioners or
stage-added to the flotation bank. They do not require
reagent dosing systems traditionally required for xanthates.
Improved reagent handling also provides significantly less
chemical exposure to product.
• They provide equivalent or superior metallurgical
performance at lower dosages than the traditional
collectors.
• Their reduced dosage also translates directly to reduced
residual reagent concentrations in the concentrate and
tailings. This, in turn, provides significantly better
environmental profile over traditional collectors.
In addition to the above listed benefits, MAXGOLD chemistry
has been shown to offer the following improved performance
characteristics in the flotation plants:
• Demonstrated robustness in plant operation - reduced
variability in plant recoveries, and improved overall gold
recovery of 2-4% or greater.
• A greener profile than standard products, especially
xanthates.
• Very effective in the flotation of pyrite and arsenopyrite in
mildly acidic and neutral circuits.
• Can operate in a broad pH range, thus it can be used for
copper/gold ores with selectivity against pyrite in mildly
alkaline and alkaline pulps.
• Provides greater flexibility in terms of addition point (mill,
sumps, conditioners, regrind, etc).
• Can also be also used as a secondary collector at low
dosages (5g/t-15g/t), in conjunction with other collectors
in the rougher or cleaner circuits.
• Faster kinetics in the flotation of sulfides and precious
metals than traditional collectors; this is an important
advantage in circuits with shorter residence time.
• Improved recovery of middlings or composite particles.
• Effectiveness at significantly lower dose rates as compared
to traditionally used collectors such as xanthates.
• Greater flexibility in use as a partial replacement for
xanthates.
• Excellent collector for bulk sulfide flotation and precious
metal values including free gold, electrum, and tellurides.
• Excellent collector for Cu, Au and Mo values from
Cu-Mo-Au ores requiring no secondary collectors .
• Can be used at low dosages (5g/t-10g/t) in flash float cells
improving recovery of precious metals and gold-bearing
iron sulfides.
Case Study
Overview
A plant trial was conducted in a large epithermal gold
operation located in North America that was facing significant
losses of gold in fine particles. Based on the FLOTATION
MATRIX 100 approach for reagent selection and optimization
and using AERO MAXGOLD 900 (AERO MX-900)
promoter as part of the chemical system, improvements to
the performance and significant benefits to the process were
obtained when compared to the standard reagent Potassium
Amyl Xanthate (PAX).
Process Parameters and Flowsheet
The circuit was composed of SAG and ball mill in closed
circuit with a p80 set point of 150 µm. The ore passed through
a gravity concentration circuit which the tails fed the flotation.
The collector was added to a conditioning sump prior to the
flotation circuit and the flotation was performed at natural pH
(7.5 – 8.5) using 125m 3 tank cells. The flotation concentrate
reported to a cyanide leach.
The trial was conducted using a combination of 40g/t of
AERO MX6205 and 10g/t of AERO MX-900 promoters, as
a full replacement for 50g/t of PAX in the flotation circuit for
five weeks.

Tail g/t Au
Data Analysis and Trial Results
In order to understand the variability in the flotation circuit,
four months of historical data were analyzed, see Figure 1.
This baseline data represents gold in the final tails when PAX
was used as the collector. The average Au in the tails for this
period was 0.25g/t as presented in Figure 1. This will be used
as a baseline for comparison with the trial data.
The Au content in the tails during the trial period is presented
in Figure 2, it can be observed that the average Au in the tails
during the trial period dropped to 0.19 g/t.
When combining the historical data (Figure 1) with the trial
period (Figure 2), the trend in the gold tails is readily evident:
Time Series Tail g/t Au
0.4
Time Series Tail g/t Au
0.35
0.3
0.25
Tail g/t Au
0.2
0.15
Tails, g/t
0.4
0.35
0.3
0.25
0.2
• Significant drop in the Au values in the flotation tails:
from an average of 0.25 g/t using PAX to 0.19g/t.
• More robust performance with the new collector system
with reduced swings in tails value.
This improvement is estimated to generate an additional one
million dollars of revenue to this operation, representing a
return on the investment (ROI) of about 480%. An additional
benefit observed was that more gold reported to the gravity
circuit than when PAX was used. This can be attributed to the
activation of auriferous pyrite in the gravity circuit by PAX,
which leads to gold reporting to flotation instead of being
recovered in the gravity circuit.
0
0.15
50 100 150
Time
200 250 300
Time Series Tails g/t
0.5
Time Series Tails g/t
0.4
0.
Tails, g/t
0.2
0.1
0 50 100 150 200 250 300
0.5
0.4
0.
0.2
FIGURE 1 - Historical Data - Au in Final Tails
Time
FIGURE 2 - Trial Data - Au in the Final Tails
0 10 20 30 40 50 60
0.1
Time
0 10 20 30
Time
40 50 60
3

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Shipping
AERO MAXGOLD 900 and the series AERO MX-900
promoters are shipped in drums, totes or bulk containers.
For information on bulk delivery, contact your Cytec sales
representative.
Storage and Handling
AERO MAXGOLD 900 and the series AERO MX-900
promoters are combustible liquids. Provide adequate
ventilation. Do not heat with an open flame or place in the
presence of an ignition source or contact it with an oxidizing
material with which it may react. The material should be
stored in a cool, well ventilated area away from any sources of
ignition. If product is spilled, remove sources of ignition, cover
with an absorbent material, sweep up and place in a properly
covered waste disposal container. Flush area with water and
dispose of properly.
Health and Safety
Before handling these materials, read the appropriate Cytec
Material Safety Data Sheet for more detailed information on
physical properties, safety, health and environmental data.
Causes burns of eyes and skin. May cause allergic skin
reaction.
Combustible liquid and vapor.
Reagent Selection and Optimization –
FLOTATION MATRIX 100
FLOTATION MATRIX 100 is a new holistic approach
to mineral flotation optimization that combines Cytec 100
years of experience in flotation, unique chemicals, and our
unmatched expertise and insights to consistently deliver
measurable improvements in metallurgical, operational and
financial performance.
FLOTATION MATRIX 100 is designed to deliver a range of
measurable results by taking into consideration the dynamic
interaction of the ore body and plant characteristics with the
chemicals in the flotation process. The benefits that can be
experienced by following this approach are:
• Optimized reagent performance
• Enhanced recovery of all value minerals
• Increased yield
• Improved concentrate grades
• Accelerated implementation of recommendations
following needs assessment
• Significant cost savings
Contact your Cytec sales representative for more information
on Cytec products.
• Email: custinfo@cytec.com Worldwide Contact Info: www.cytec.com US Toll Free: 800-652-6013 Tel: (+1) 973-357-3193 •
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