Metallochlorophosphates-Perspective Binders for Heat Resistive Compositions

New ways of synthesizing aluminium, magnesium and chromium phosphate binders with phosphorous metal ratio of 1:l were discovered. It was found that the viscous solution of met-allochlorophosphate binders and powdered chlorophosphate aluminium, magnesium and chromium can be used as a component for heat resistive materials. Viscous binders increase the mechanical strength, while powdered chlorophosphates ensure safe storage, usage and transportation. Investigation of formation conditions, constituent, pnysico-chemical properties and thermal treatment of liquid binders and precipitated from it aluminium, chromium and magnesium chlorophosphate showed the presence of MHPO 4 · nH 2 O where M-Al, Cr and MgH 2 PO 4 Cl·nH 2 O where n = 2-6. It was found that similar compounds are formed by the reaction of metallic chloride with phosphoric acid and metallic hydrooxide, the mixture of phosphoric and hydrochloric acids having M:P:Cl = 1:1:1.1-1.8 ratio. The latter method is more technological. It was stated that the viscosity, density and stability of liquid chlorophosphate binders depend on the nature of cations: viscosity increases, while density decreases from Cr-Mg-Al, precrystallization period increases from 1 to 3 days for magnesium up to 3-5 months for aluminium, and a year for chromium. As a result of thermal treatment metallic orthophosphate without water of crystallization is produced. Highly effective heat resistive materials with compressive strength of 70-106 MPa, refrectoriness 1300-1800°C oped. −1800°C and hardening temperature of 150-350°C are developed.