There are two primary methods for Rare Earth Elements mining. The first involves removing topsoil with mineralised rock (ore) from the ground, breaking it up and treating it to remove the minerals being sought. The second method, which we adopted in our mines in Kenering, Hulu Perak, is In Situ Leaching (ISL) method.
In-Situ Leaching (ISL) Method:
ISL involves leaving the ore where it is in the ground, and recovering the minerals from it by dissolving them and pumping the pregnant solution to the surface where the minerals can be recovered. ISL mining include the construction of hydrometallurgical plants and establishment of injection holes and piping system for the in situ leaching. There is little surface disturbance and no tailings or waste rock generated.
Ionic lanthanide ISL uses the native groundwater in the orebody which is fortified with Ammonium Sulphate. It is then pumped through the underground orebody to recover the minerals in it by leaching. The pregnant solution is collected via collection tunnels, diversion holes and collection drains. Once the pregnant solution is returned to the surface, it is pumped to hydrometallurgical plant for processing. Our project will reuse all the collected supernatant with no discharge during the operation. Lanthanide carbonate is our final product.