Fluorspar mining is a multi-step process that involves extracting the raw ore from the ground and then processing it to achieve the high purity levels required by various industries
Mining Methods
The method used for fluorspar extraction depends on the geological characteristics of the deposit.
- Underground Mining: This is used for deep deposits where the ore is found in veins or stratified layers. Common techniques include shrinkage stoping and room-and-pillar mining, which involves creating a network of tunnels and leaving pillars of ore to support the mine roof. For example The Campbell-Crotser Fluorspar Project in Kentucky CleanTech Vanadium Mining Corp. (“CleanTech CTV”) is considered an underground mining style project.
- Open-Pit Mining: This method is more suitable for wide, shallow deposits. It involves removing the overburden (topsoil and waste rock) to expose the fluorspar ore, which is then extracted in a series of benches.
Mineral Processing (Beneficiation)
Once mined, the raw fluorspar ore must be processed to separate the calcium fluoride () from other minerals and impurities. This process is known as beneficiation and typically involves several stages:
- Crushing and Grinding: The raw ore is first crushed and ground into a fine powder to liberate the fluorspar from the surrounding gangue (waste rock).
- Flotation: This is the most common and effective method for processing fluorspar, especially for producing high-purity acid-grade fluorspar. The finely ground ore is mixed with water and specific chemical reagents (collectors, frothers, and inhibitors). Air is then bubbled through the slurry. The fluorspar particles attach to the bubbles and float to the surface, forming a froth that can be collected, while the waste minerals sink.
- Gravity Separation: This method separates minerals based on their density. Fluorspar is denser than some common impurities like quartz, so this technique can be used, often in combination with flotation, to produce a coarse-grained metallurgical-grade fluorspar.
- Magnetic Separation: If the ore contains magnetic impurities like magnetite, magnetic separation can be used to remove them, improving the purity of the final product.
- Thickening and Drying: After the separation process, the fluorspar concentrate is dewatered through thickening and filtering, and then dried to a low moisture content before being stored or shipped.
