Method of forming an insoluble phosphate mineral species

Abstract

The present invention discloses a method of forming phosphate mineral species of the apatite family, and the mineral species thus formed, by contacting soil or solid waste material containing leachable lead with a combination of a sulfate reagent that includes one or more reactive sulfate ions and a phosphate supplying reagent that includes one or more reactive phosphate ions. The mineral species are stable, substantially water insoluble and non-leachable under normal environmental conditions. The sulfate reagent is sulfuric acid or alum in liquid or powder form. The phosphate supplying reagent is phosphoric acid, trisodium phosphate, potassium phosphate, mono basic calcium phosphate or dibasic calcium phosphate. In a preferred embodiment, the phosphate supplying reagent is phosphoric acid and the sulfate reagent is sulfuric acid or liquid alum.

Dependencies are inferred from the claim text.