Salt borehole mining

Potassium ore resources in Stebnyk would be enough for further hundred years.. Annual potash fertilizers demand in Ukraine is about 2 mln. t of active substance. Underground mining of potash salts is non-profitable but to destroy the prepared reserves. is not reasonable. It is more proper to settle the problem by solution mining of the potash salts and obtaining mineral fertilizers from the brine
Salt mining by way of leaching is widely used from old times. A production borehole consists of several pipes: a wellhead, a brinepipe, a casing, a water injecting pipe and a brine pipe. Water being less dense than the solution goes up and the brine runs down the borehole walls to the bottom from where it is forced out up to the surface. To prevent dissolution of the upper part of the deposit some non-solving liquid is pumped into the casing. Mining is carried out in steps from bottom to the top controlling room development with non-solvent level. Insoluble inclusions fall down to the room's bottom. Inclined boreholes are used to intensify the process of dissolution.
A chamber process of leaching was used on the Stebnyk deposit prior to 1941. Workings were driven on two horizons and a chamber which was connected with the lower horizon through a vertical drainage working. Water delivered by the pipeline passing through the upper working dissolved the chamber's walls and the roof. The brine was evacuated through the drainage working to the lower horizon. Insoluble impurities accumulated at the bottom. Solubility of potassium ore minerals makes it possible to process the ore to finished products in situ without its extraction to the surface. This will considerably improve the economy and ecology of mining and processing