MINING CHEMICALS
A flotation cell at Kennecott Utah Copper’s
Bingham Canyon copper concentrator. Bulk
chemicals such as xanthates will continue to
dominate base metal sulphide flotation, though
regulation is increasing in China, the largest
producer
Challenges for China
Paul Moore reports on a new update on the Cyanide Code,
and gets commentary from leading players on bulk and
speciality mining chemicals markets. The big news is
rising demand and prices due to increasing environmental
regulation for producers in China
n the mining chemicals market, there are
both bulk chemicals that are ubiquitous in
the industry, such as sodium cyanides for
gold processing and xanthates from sulphide
flotation as well as sulphuric acid for heap
leaching; and then increasingly there are
speciality focussed chemicals for processing of
particular ore and mineral types as well as other
uses such as chemical thickeners and
flocculants. These chemicals are supplied both
by global multinationals and regional players as
well as trading companies. Bulk chemicals will
still play a major role in the industry for the
foreseeable future. There have been attempts to
try to get away from cyanide to using
thiosulpates but so far this has not really been
done to any great degree. Also, the use of NaHS
is increasing as pulp chemistry is a crucial part
of optimisation of flotation.
In terms of bulk chemicals versus speciality
chemicals there are some important trends,
notably in China. Frank Cappuccitti is President
of Flottec, a global major in mining chemicals
supply through its Flottec sites as well as its
Kemtec operations in Asia. It has companies in
Africa, Canada, US, Mexico, South America and
Australia and China. He told IM: “Although ores
are getting more difficult, xanthates are still
predominant in sulphide flotation. The use of
specialty chemicals are on the rise but so are
xanthates. The split is not that different than it
used to be. A lot of that is driven by gold and
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24 International Mining | MAY 2018
pyrite flotation where xanthate is still the best
overall bulk sulphide reagent and this segment
has grown. That is not to say that specialty
chemicals are not being used extensively. There
was a big switch to thionocarbamates in zinc
flotation but a lot of that was due to the
lowering of the price of this specialty. What will
be interesting is to see what will happen now
that the cost of the specialty chemicals is rising
tremendously as China (the main if not only
producer) struggles through the new standards
and taxes that have been introduced to protect
the environment. The costs are going up and the
supply is going down as many companies that
were producers no longer operate as they
cannot meet the new standards.”
Another interesting area is the ramp up of
demand and therefore project development for
commodities such as cobalt, lithium, graphite,
PGMs, REOs etc, and universities have been
working in this area for a long time. Cappuccitti
states: “I think that the issue now is to switch to
transfer of technology. A good example is the
use of hydroxamates as collectors. There is
much more interest in this chemistry than
before especially in the REOs. So the focus now
is on applications of chemical technology. There
is also a lot of work being done on new
disruptive technology where flotation will be
done differently as well as many new ideas for
different types of cells. Some of these
technologies are focusing on coarse and fine
particle flotation which is where the bulk of the
improvements will come from.”
There is also a lot of work being done on
bioreagents that would be much better for the
environment. These products would be more
environmentally friendly and be based on
natural materials rather than sulphur based.
There is also a move again to test bioreagents
for settling slow settling clays that are a big
problem in oil sands and phosphate. The work
here is focused on the whole process of dry
stacking versus conventional ponds and the
equipment used. but the reagents are still
standard flocculants.
More detail on the China problem
This is a crucial issue in the current market, as
due to the problems in China, mining chemicals
demand now exceeds supply. So the power is
moving from the mining customers to the
suppliers. Cappuccitti states: “Prices are moving
up tremendously and miners must now focus on
security of supply rather than lower prices. We
predict that chemicals will go on allocation and
some mines will have to slow down or even shut
down for lack of product. The industry has
allowed China to be the predominant
manufacturer of sulphide reagents so as they
struggle to meet new regulations, they will no
longer be a low cost producer of reagents. The
big companies are just as dependent on the
Flottec argues that a big factor that will influence chemical demand in mining is flotation technology.
A lot of work being done on new disruptive technology where flotation will be done differently as
well as many new ideas for diffe