If you ask someone what mining looks like, they’ll probably describe a massive pit with giant yellow dump trucks and excavators moving tonnes of material – an ‘open cut’ mine – or dark underground passages packed with employees wearing helmets and lights – an ‘underground’ mine. These mines have traditionally been – and continue to be – the most common types of mines found across the world.
Others include in situ recovery (ISR) mining, which has been used to mine potash, salt, uranium, and copper in Australia, the United States, Kazakhstan, China, and Russia since the 1970s.
What is in situ recovery mining?
The most important thing to understand about ISR mining is that it is unlike traditional mining in that there is no ‘mine’ in the traditional sense in that there is no pit or mine-site. A borehole is drilled below the orebody, and a well-like structure is dug around it. Water is pumped into the well, dissolving the salt or other minerals underground, which is then pumped to the surface.
The main advantage of ISR mining is that there is no need to remove the overburden (the surface material that must be removed before the ore is reached) to reach the ore body, which is a significant advantage as the depth and level of overburden can vary dramatically, which can make the costs of traditional mining unpredictable.
In the case of ISR mining, once the ore body is reached, the rest of the process is very similar to traditional mining. Rock is removed to reach the salt, and the salt is then ground and washed to remove impurities. The water is then processed and recycled.
Other advantages of ISR mining:
• It is less expensive than traditional mining because there is no need for overburden removal
• It is less disruptive to the environment
• It is much better for the environment and, as we have seen in the case of the Great Artesian Basin, can be used to help rehabilitate previously mined areas
• It is easier to plan with predictable costs.
Disadvantages of ISR mining
• It has high start-up costs
• As it takes place in small pockets, it would have to be done one small area at a time, which can make ISR mining a slow process
• It takes more time to get the ore to the surface than traditional mining.
Why Isn’t Every Mine Implementing ISR Mining?
Simply said, all mineral deposits are unique and are found in unique settings; therefore, in situ recovery is only a viable mining process in certain circumstances.
In situ recovery mining is applicable in the following circumstances:
- Water can freely travel through the geology that contains the minerals, and the minerals quickly dissolve into solution and may be transferred using water and other chemicals.
- The minerals can be recovered from that solution; the solution can be confined and rigorously regulated in the local environment; the process can be handled without causing unacceptable environmental harm; the whole process can be carried out inexpensively.
- Because in situ recovery technologies are not appropriate for every mineral deposit, the technical effort required by a firm and the government to analyze potential in situ recovery mines is significant.
Years of inquiry are generally required for studies, including drilling into and around the mineral deposit, sampling and mapping groundwater in and around the local region, and comprehensive laboratory work to determine if in situ recovery is an appropriate strategy for a specific deposit.
If preliminary studies are favourable, a carefully controlled trial is usually conducted to confirm the results of those investigations and to demonstrate that the deposit can be mined successfully and safely before any decision to allow mining to proceed is made.
ISR mining may not be the right solution for every mine and every mine owner, but it can play a vital role in the future of mining and, if done right, is better for the environment and the community it serves.
Group 11 Technologies provides solutions for In-Situ Recovery Mining. Our mission is to facilitate environment-friendly mining operations, and we can achieve that through our non-invasive technology that’s FDA-approved, meaning our methods are up to standard. Contact us today to learn more!