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VIDEO: Meet mining engineering grad student Fazl Jahromi
Hi my name is Fazl Jahromi and I'm working
under the supervision of Dr Ahmad Ghahreman.
My research is about copper mostly.
As you know 70 percent of copper is in
form of chalcopyrite and one of most
major chalcopyrite contaminants is enargite.
Enargite is one of the minerals contains about
eight percent of arsenic in concentrate and
it's a major concern for environmental issues.
So, because enargite contains arsenic,
it makes most of the processing methods
unviable. We are trying to develop a process
based on using activated carbon and hydrochloric
acid which is good for the environment and also
viable for industry.
So, in this experiment I'm running here, we have
some sort of reactor with heater jacket to
keep the temperature up. One of the temperatures
we are working on is mostly about 80 degrees C to
90 degrees C and is viable to apply in industry.
And, we have a copper solution, as we can see
the green-black colour is from the copper
which is dissolved into the acid medium here.
So, we have our activated carbon beads to help
us to improve the process of leeching.
These carbon beads help us to oxidize more and
more of those minerals into the hydrochloric acid
and we are also sparging oxygen to this
reactor to improve the oxidation process.
The medium of leeching is mostly hydrochloric
acid with some ferric sulfate solution in it to
improve the leeching.
When we put enargite concentrate inside
our solution, this enargite concentrate starts to
dissolve in the presence of activated carbon
and oxygen sparging.
And the copper leeches into to the
solution and makes this nice green colour
here for us.
With this method, we are separating all
of the copper from the enargite material
and also we dissolve all the arsenic and separate
it from the gain. After that the arsenic precipitation
is happening autonomously inside the solution
and making a ferric arsenic, or scorodite
which is very safe for the environment and
can be safely dumped in the environment.
The contamination decreases a lot with this kind
of method and we recover all the copper from
anargite. We reached about 99 percent of copper
recovery after four days of operation, which is pretty
good for us.
When we dissolve arsenic into the
solution, we need to change the arsenic three
to arsenic five to be safer for the environment
after the change in arsenic three to five, with
the help of this activated carbon beads
we precipitate out the arsenic in the form of
scorodite, which is much safer for the environment
So, when we have scorodite, it doesn't dissolve
into the ground water system or come into the
This is exactly what we're getting out of the process
which is the safe form or arsenic.
We have already separated the copper in the
solution and recovered the copper.