Study of the effects of thermal treatment on chemical and physical characteristics of phosphates

Via the thermal treatment of natural phosphates and their analysis, it was proved that the decrease in their solubility in the interval 400–550°C is an indication of the degree of incorporation of OH groups into the apatite structure of phosphates, whereas the solubility at 950°C is an indication of the degree of incorporation of the non-volatile components. The higherR ₉₅₀, the more extensive this substitution, and the more reactive the natural phosphate.