| Abstract: | Solubilities of apatites isolated from random samples of Israeli phosphates were determined in citric acid, formic acid and neutral ammonium citrate. Minerals normally associated with the apatites in rock phosphates were then added and the solubility tests repeated. Calcite markedly reduced the apparent solubility in the three solvents but gypsum interfered only in the case of neutral ammonium citrate. The accepted solubility tests therefore favour phosphates containing inert accessory minerals such as quartz and do not reflect the solubility of apatite when it is associated with calcite. A method based on determining the solubility of apatite instead of rock phosphate is suggested. |
