Treatment of Phosphorus-Containing Raw Materials with Alkaline Solutions

Abstract— The work describes a method for recovery of phosphorus compounds from phosphorus-containing raw materials. The possibility of autoclave leaching of phosphorus from phosphorite in the form of a solution of sodium phosphates with an alkaline solution was experimentally tested. The optimal process parameters were determined (temperature 250–300°C, leaching time 3 h, NaOH concentration 150–300 kg m^–3), under which calcium silicate with a unique nano-sized needle-shaped structure, widely used in many industries, is formed in the solid residue. The research results make it possible to involve raw materials with low phosphorus content in waste-free processing.