If you are planning to design a new mine or extending the life of a current open-pit system, one of the top alternatives is block cave mining. The mining method is recommended when the targeted minerals are located too deep to economically mine using the open-pit method. Here is a closer look at the factors you should consider before adopting block cave mining.
What is Block Cave Mining?
This is an underground mining method where the ore body is undermined so that it eventually collapses under its weight. The process involves undercutting a section of the rock through blasting or drilling to form a sort of a cave that will eventually collapse and fill with own rubble. The broken ore falls into pre-constructed funnels. Then, underneath access tunnels are used to mine them continuously.
Benefits of Block Cave Mining
If you take a closer look at open surface mines started decades ago, most of them are nearing exhaustion. For others, the remaining mineral deposits are located deep in the earth. Therefore, continuing to extract them using open-pit method is not viable. Block cave mining is considered a good alternative because it is cheap. Typically, the cost of block cave mining is approximately 1/10 of what other underground mining methods cost. This is largely driven by economies of scale.
Another notable benefit of cave block mining is the reduction in the need for surface waste disposal requirements. In open-pit mining, the generated waste rocks have to be moved and stored in a different area. However, rock cave mining only generates a small amount of rock waste. This helps to reduce the surface land impact and keep related cost low.
What to Consider before Adopting Block Cave Mining
In the mining industry, as mentioned here, investors have to progressively look for new technology to reduce the impact on the environment and remain profitable. Therefore, if you are considering adopting block cave mining, here are the factors to consider:
- An area with massive mineral deposit and ample height. It should also be wide enough to initiate natural caving of the rocks.
- Beneficial characteristics of in-situ rocks such as natural fractures to promote fragmentation the block caving process.
- Ore deposits under consideration should be able to cover your operating costs.
- The accepted level of surface disturbance. This should factor things such as planned infrastructure and the environment.
As many open pit mines near their exhaustion points, mining firms are exploring the option of shifting to low-cost and extensive underground mining. Block cave mining is one of the top options. Make sure to factor the above considerations when planning to adopt block cave mining.