PROCESS FOR REMOVING METALLIC COMPOUNDS FROM DUST PRODUCED IN THE ELECTROTHERMIC PRODUCTION OF YELLOW PHOSPHORUS

Metallic constituents, especially heavy metal constituents are removed from dust electrostatically separated from a gas mixture consisting substantially of carbon monoxide and phosphorus in vapor form obtained during the electrothermal production of yellow phosphorus. To this end, the dust is initially calcined with continuous agitation under oxidizing conditions at temperatures of 300 DEG to 800 DEG C.; next, the resulting calcined matter is mixed with carbon and the mixture is treated at temperatures of 950 DEG to 1200 DEG C. under reducing conditions with volatilization of the metallic constituents; and the volatized metallic constituents are ultimately condensed and separated.