Method of breaking down hard phosphate minerals - by heating, in order to extract the phosphate economically

摘要

Hard phosphate minerals are free from carbonate material by the following process. The mineral is crushed to a particle size of 2 mm or less, then heated at a temp. which is varied according to the nature of the carbonate- 600-850 deg.C for calcitic minerals, 450-750 deg.C for calcaro-dolomitic minerals, and 350-700 deg.C for dolomitic minerals. The phosphate and carbonate phases are then sepd. by known methods. The process enables phosphate to be extracted economically from minerals that could not otherwise be worked satisfactorily.