Process for producing a concentrated potassium solution from solutions of certain lakes and defined types of ground water in a desert area for the recovery of potassium salts by utilising solar energy.

摘要

The present invention relates to a process for producing a concentrated potassium solution, which allows the winning of potassium over a large area from a potassium solution. The physical principle on which this invention is based is the Darcy-Hubbert-Hsü principle: DELTA Qw = K . dh/dl This process, called "evaporative pumping", produces the desired potassium solution as a side effect due to the interaction of the ground water with the host rock. Hitherto, the potassium-winning areas were restricted to sites, where the ground water level had by chance "naturally" reached the optimum level for this process. The invention is characterised in that the hydraulic gradient is (artificially) adjusted in accordance with the geological and climatic conditions in such a way that the chemical interaction is optimised. This can be accomplished by levelling the ground water level: that is to say, especially by excavation or piling-up of soil. In addition, there is a supplementary process. The latter is characterised in that, in order to assist the separation of magnesium and hence to produce a purer, more concentrated potassium solution, a carbonate is added as an additive to the host rock.