SUSPENSION FOR MAKING SHELL MOLDS IN CASTING ON MOLTEN MODELS Russian patent published in 2019 - IPC B22C1/02 B22C9/04 

FIELD: technological processes.

SUBSTANCE: invention relates to the foundry. Suspension contains (wt%) ethyl silicate (8.0–15.0), water (1.0–5.5), hydrochloric acid (0.2–0.8), dispersed silica in form of dust from electrostatic precipitators of ferroalloy furnaces (0.5–5.0), organic solvents in the form of acetone or ethyl alcohol (11.0–18.0), orthophosphoric acid (0.2–1.5), liquid waste of chemical treatment of zinc-plated steel scrap from the zinc coating in form of an aqueous solution of zinc chloride (1.5–6.0) and pulverized fire-resistant filler (rest). When drying the shells, the aqueous solution of zinc chloride is hydrolysed to form colloidal zinc hydroxide, which provides faster drying of the suspension in air, increases water resistance and strength of shells in hot water, leads to stress relaxation during tempering and pouring of ceramic molds.

EFFECT: higher strength, heat resistance, gas permeability, reduced gas output of shells.

1 cl, 2 tbl, 1 ex