Mining without having to move a single rock from the surface is called in-situ mining. In-situ mining employs the use of good technology to dissolve the ore that is underground and pump the dissolved material to the surface where the minerals can be separated and processed. The most common process used in in-situ mining is acidization.
The whole method requires less moving equipment and machinery, reducing the amount of used resources and emissions produced. Using a process called flushing, in-situ miners dissolve the ore underground by injecting a mixture of water and chemicals into the ground. The mixture is pumped into the mine and then extracted, leaving behind a void under the surface. The void is then filled in with cement to create a flat surface so that buildings can be constructed.
For in-situ mining to be economically viable, an adequate amount of ore must be extracted. In-situ mining also takes expertise to plan and execute. In-situ mining does not result in the destruction of habitat or the movement of large rocks, which is a positive for the environment.
There are certain criteria that need to be met in order for in-situ mining to be done. Below are just a few examples.
1. Must have ore that is sufficient in quantity. For example, if there is a layer of ore that is less than 2 feet thick.
2. There must be sufficient open space and access to the ore layer.
3. There must be favourable geology. If the geology is not favourable, then the mineral will not be able to be dissolved by the chemicals and injected into the ground.
4. There must be little to no thermal or mechanical barriers.
5. The ground must be suitable and stable for cement backfill. The ground will need to be stable enough to support the buildings and infrastructure that will be constructed.
6. The ground must have good vadose permeability. This refers to the ability to drain excess water. If there is not enough permeability, then the water will not be able to drain out. This will result in water build-up and in groundwater contamination.
7. There must be favourable environmental conditions.
Industries commonly associated with the in-situ mining process include:
Coal, oil and gas, potash, uranium, gold and diamond are a few examples of minerals found in-situ. The most common use of in-situ mining is to process rock and ore deposits that have not been able to be extracted from surface mining methods.
While it is not as common as surface mining, there are many countries that employ the use of in-situ mining. China and the United States are two countries that use this method of mining. One facility in China used the in-situ process to extract oil from shale. In the United States, the in-situ process is used to extract oil and natural gas.
Though in-situ mining is not as widespread as surface mining, it is definitely a good alternative to surface mining since it leaves no visible signs of damage on the land. It also does not require the movement of large amounts of earth.
There has been a lot of discussion over the years concerning surface mining and its environmental impact. While there have been benefits from it, there have also been a large number of negative impacts on the environment in many different areas: water contamination, air pollution, human health, wildlife and the land itself.
On the other hand, with the advancement of technology, we have seen improvements in in-situ mining, as it helps to keep the land intact, reduces air and water pollution, lowers greenhouse gas emissions and preserves natural habitats.
If you want to know more about the advantages of in-situ mining, look no further than our company overview here at Group 11 Technologies. We are committed to the development and application of environmentally and socially responsible mineral extraction. Call us today for more information about our eco-friendly mining innovations and services.