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VIDEO: Meet mining engineering grad student Fazl Jahromi

Learn more about the Robert M. Buchan Department of Mining and read more about Jahromi's supervisor, Queen's engineering Professor Ahmad Ghahreman.

 

Video transcript:

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

water table.

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.