MINING CHEMICALS
Additional laboratory trials are being conducted
by Clariant’s mining development laboratory in
Australia on copper and gold mine flotation plants
to evaluate HOSTAFLOT xanthate replacements, in
all cases to replace potassium amyl xanthate, the
company said.
In South Africa, it is platinum and palladium
producers currently interested in HOSTAFLOT
xanthate replacement products, according to
Clariant.
At one platinum producer, the HOSTAFLOT
xanthate replacement showed the new product
can operate at a lower dosage than xanthate and
result in reduced chrome content in the
concentrate – an undesirable metal in this case, as
it increases the slag liquid temperature in the
subsequent smelting process, Clariant noted.
There are also indications from the plant trial that
frother consumption can be reduced, which will
lead to additional reagent savings for the operator.
Further, there are lab trial qualifications for
HOSTAFLOT xanthate replacements ongoing in the
new Clariant mining development lab in
Johannesburg, South Africa, with the aim of
moving to plant trials later in 2020.
It’s clear from the breadth of testing to replace
the likes of sodium isopropyl xanthate, sodium
ethyl xanthate, potassium amyl xanthate and
other xanthate collectors that there is no one-size-
fits-all flotation solution. It is also apparent some
of these replacement chemistries positively
impact more than just the effectiveness of the
collectors, the environment and personnel.
Phosphine-based flotation
alternatives
When it comes to the adoption of Solvay’s
AEROPHINE 3418A xanthate replacement chemical
technology, the company also sees three market
forces leading to further market adoption.
First, with base metal prices subdued, the likes
of copper, zinc and lead miners are exploring ways
to effectively extract precious metals that can be
sold as by-products. AEROPHINE enables mine
operators to maximise their net smelter returns for
concentrate, the Solvay says.
Separation efficiency is another key selling
point, with AEROPHINE enabling increased
selectivity against gangue and penalty elements,
while lowering the ore treatment cost. This
potentially increases revenue at the same time as
reducing operating expenses, the company says.
Lastly – and a point already picked up on –
AEROPHINE technology helps mines limit operator
exposure to harmful chemicals.
AEROPHINE 3418A, Solvay says, is a unique,
phosphine-based chemistry originally developed
for the flotation of copper and activated zinc minerals.
More recently, it has demonstrated selectivity
towards complex, polymetallic and massive
sulphide ores, the company said, adding that
AEROPHINE is highly selective for lead/zinc and
lead/silver minerals and exhibits strength yet
selectivity against iron sulphides (pyrite,
pyrrhotite, marcasite and arsenopyrite), non-
activated sphalerite and penalty elements.
The company has provided a few examples to
back this up.
In an application where ore from a chalcopyrite-
sphalerite deposit was being milled at a rate of
around 10,000 t/d – with the concentrator using a
conventional flowsheet of copper flotation
followed by copper sulphate activation and zinc
flotation – Solvay carried out laboratory tests on
the use of AEROPHINE.
After these lab tests were deemed successful,
the AEROPHINE 3418A promoter was introduced
for a full-scale 10-day plant trial, replacing the
standard sodium amyl xanthate and methyl
isobutyl carbinol mill promoter and frother,
respectively. This saw copper recovery increase by
around 8% and reagent dosage decrease by 30%,
according to Solvay.
The AEROPHINE 3418A promoter also induced
minor improvements in zinc grades and recoveries,
according to the company, with zinc recovery in
the copper concentrate and copper recovery in the
zinc concentrate “essentially equal” for both
collectors, it noted.
Solvay said: “The improvement in copper
metallurgy alone translates into a substantial
monthly increase in the value of copper recovered
at the mill.”
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MAY 2020 | International Mining 37