A method for the production of ceramic products with the use of glassy, not oxidized phosphorus slags and

摘要

A synthetic wollastonite is prepd. from the slag formed in the thermal prodn of P from crude phospahtes by soaking the slag in water and calcining, possibly after removing impurities, at least 1000 degrees C (1150-1200 degrees C) in an oxidising atmos. Before calcination there may be added, based on weight of slag, substances contg. 1-15% Al2O3 and/or 2-30% SiO2 and/or 0.5-10% alkaline oxide. Pigments may also be added. Uses incude ceramic objects, e.g. wall tiles, as additives in prodn of construction material based on Ca silicates, for brightening or marking road-surfaces, as fillers for plastics, paper or paints or as decorative gravel.