Effect of Partial Acidulation of Purulia Rock Phosphate on Water Soluble and Citrate Soluble Phosphorus

The rock phosphate (RP) mined in Purulia in West Bengal was partially acidulated with sulphuric, nitric, hydrochloric and phosphoric acids individually at 10 and 20 per cent degrees of acidulation. All the acidulants increased water soluble, citrate soluble and available P content of partially acidulated rock phosphates (PARP) prepared at either 10 or 20 per cent degrees of acidulation, 20 per cent being better than 10 per cent acidulation. Only phosphoric acid increased total P content of PARP. All other acids decreased it. A curing time of 12 hours was found to have an advantage over other timings.