UNDERSTANDING IN-SITU RECOVERY

A SUSTAINABLE APPROACH TO MINING

Thor mining is working to adapt an innovative, low impact mining technique to its copper projects ing South Australia. A move that could see Australia become a world-leader in sustainable mining practices.

The process is called in-situ recovery or I.S.R. Unlike traditional mining practices which rely on excavation and blasting to recover the ore – I S R has such a minimal impact on the surrounding environment that it can even take place alongside farms and communities.

In fact it is sometimes called the invisible mine.

This is how it works.

THE PROCESS

The process is relatively simple.

Once an ore-body has been identified and proven to have the right geology, a series of wells are drilled.

The key ones are the injection wells. They pump a specially formulated solution directly into the targeted rock.

LIXIVIANTS

In the past these solutions were a weak acidic liquid, but thanks to the pioneering work of the CSIRO and Curtin university, we now have new options that are 100% non-toxic and biodegradable options, known as lixiviants.

GETTING THE COPPER

The solution slowly permeates the targeted layer – rinsing the copper out of the rock. It’s a similar process to what happens when you make a cup of tea.

RECOVERING THE ORE

As the copper rich liquid spreads out the recovery wells start. They pump the solution back to the surface for processing.

MONITORING WELLS

Surrounded the entire area, are a number of monitoring wells. These wells collect ground water measurements and other data to make sure that nothing escapes the area being ‘mined’ and further minimises the risks to the surrounding environment.

THE INVISIBLE MINE

Once the copper has been recovered the rock is flushed with ground water, the wells are removed and the landscape quickly returns to normal as if the mine had never been there.