MINING CHEMICALS
n Increasing the lean electrolyte acid
n Increasing the extractant concentration
Recommendations are issued to help the
customer achieve their Cu recovery and
production targets. Using the strip electrolyte
acid as an example, MINCHEM ® defines how the
% recovery and net transfer changes as a
function of the sulphuric acid concentration. In
one example, the % recovery could be increased
from 94% to the customer’s target of 95% by
increasing the sulphuric acid concentration from
182 g/l to 200 g/l.
Intelligent gold processing
Maximising gold recovery relies on constant
adjustment of variables throughout the process,
often without the necessary tools to quantify and
react in a timely manner. The inability to respond
to this variability undoubtedly has a cost to the
industry, but how much? Top-down information
from published recoveries, combined with Orica’s
intelligence database estimated the scale of
global gold losses to be in the order of $16-20
billion at a gold price of $1,200/oz. Based on
observed experience at the time, Orica further
estimated the scale of ‘avoidable losses’ –
defined as solution losses plus gold leachable in
a 24-hour bottle roll on process plant tailings – to
be in the range of $2-5 billion globally.
In a concerted effort to use big data to define
best-practice gold processing, Orica’s Cyanide
Customer Solutions team leveraged detailed
operational data across 50 sites in the
development of an intelligent system, LeachIT™
that is capable of validating industry estimates,
determining the drivers behind gold losses and
delivering insights to accelerate the capture of
these losses.
Since 2014, LeachIT™ has been enabling
customers to maximise economic recovery
through identifying shortcomings at site and
confidently predicting the recovery impacts of
process changes and variability. The intelligent
software also allows metallurgists to see how
their process will respond to changes without
time-consuming and expensive experiments.
Aimed at enabling best practice leaching,
LeachIT™ simulates changes to the process and
presents the impact on tails grade. Adjustments
could be made based on feed, tank, or tail
measurements. Alternatively, they may include
changes to the physical plant such as simulating
a tank going offline for maintenance. The
software harnesses this information not only to
calculate but also visualise gold recovery and
cyanide consumption. Rapid scenario modelling
of commonly observed process changes is
brought to life through an easy to use digital
interface, giving Orica’s customers and site teams
a clearer understanding of the benefits that any
proposed changes will bring to their operations.
44 International Mining | MAY 2019
Orica Cyanide Customer Solutions Lead, Peter
Leckie said: “We aim to take our customers’
operations data and combine it with our
expansive global Cyanide process data gathered
over time, and then interpret that data into
insights, delivered visually so that our customers
can make more rapid and confident decisions.
“The LeachIT™ simulation software simply
provides a tool to empower the people who know
your process best.”
The simulation software can be harnessed to
provide insights for a one-off exercise or installed
onsite to allow discovery of insights on an
ongoing basis. This way, customers can
continually turn everyday information and data
into actionable insights that improves their
bottom line.
Improving efficiency & safety:
replacing xanthates in copper mining
Copper remains one of the most valuable
industrial metals due to its high electrical and
thermal conductivity. In parallel with other
sectors, the mining industry has been focussed
on the challenges of improving
operational efficiency while
increasing sustainability and
safety performance.
Xanthates are used in
the flotation process
within the copper and
gold mining industry as
collectors for recovery of
metal sulphides. The most
popular are sodium ethyl
xanthate (SEX), sodium
isopropyl xanthate (SIPX),
sodium isobutyl xanthate
(SIBX) and potassium amyl xanthate
(PAX).
Sodium xanthates have a
hydrocarbon chain and a polar
group. In the flotation process,
the polar group molecules attach to the ore
particles, with the non-polar hydrocarbon part
sticking out, forming a hydrophobic film. With
the addition of air and a flotation frothing agent,
air bubbles are created, the hydrophobic film
attaches to the bubbles and is carried to the
surface. The float can then be collected and
dried. At this point, most of the xanthate is
attached to the concentrate, however small
amounts may be contained within the process
water and tailings waste material.
Because of the hazardous nature of xanthate
and difficulties associated with storage,
handling, and disposal, mining companies have
sought a cost-effective alternative for
years. Clariant told IM it has been working on
replacement technology for the use of xanthate.
Its answer is HOSTAFLOT ® , part of the company’s
high-performing, highly sustainable
EcoTain ® range of products.
The HOSTAFLOT family of phosphates can
replace the many forms of xanthates that are
currently used in mineral processing. The
numerous benefits of this application include
environmental performance, cost reduction, and
safety. On the environmental front, it is available
in liquid form, unlike xanthates that are supplied
as pellets or powder, reducing the need for
product handling to create a solution. An
additional benefit is that there is no extraneous
packaging in contrast to xanthates whose boxes
or cartons are difficult to dispose. As HOSTAFLOT
is non-flammable, there are no special storage
requirements, unlike xanthates that are highly
flammable and need special treatment.
It has similar recovery levels at the same
dosage as SIPX with a 12-15% better cost
performance and further savings from
preparation because of its liquid state. With the
production of xanthates limited to the countries
of China and South Africa, security of supply
concerns linked to long distance logistics are
The Clariant
HOSTAFLOT family
of phosphates can
replace the many
forms of xanthates
that are currently
used in copper
mineral processing
alleviated. Lastly, HOSTAFLOT can replace
xanthates as both a primary and secondary
collector, improving metallurgy recovery during
both processes.
The product has already proven its worth in
two extensive trials that Clariant has conducted
in South America. At a Brazilian copper ore
mining operation, the company mines bornite
and chalcocite as prominent copper-bearing
minerals with chalcopyrite occurring in lower
percentages.
The Clariant application development team
created and tested several chemistries from the
HOSTAFLOT collector series, using the customer’s
ore as feed material. After laboratory trials
showed satisfactory results, Clariant supplied
four tonnes of HOSTAFLOT for the plant trials.