Prepn. of partially solubilised super:phosphate fertilisers - by treating phosphate with aq. phosphoric acid, then with more phosphate

摘要

Partially solubilised granular superphosphate or superphosphopotassium fertilisers are prepd. by the following process: natural phosphate is solubilised with phosphoric acid at a predetermined concn., the slurry is passed to a granulator where it is mixed with powdered natural phosphate, recycled prods., and opt. a potassium salt. The acid concn. is selected according to the water content required in the granulator. Mfr. and storage of superphosphate is not necessary, gas evolved may be recycled, the control of the process is simple, and economies of energy are possible.