Process for working up dusts which are produced in the electrothermalproduction of phosphorus

Abstract From the Canadian patent

Process for working up dusts which are produced in the electrothermal production of phosphorus Abstract of the disclosure, A process is provided for working up dusts which have been precipitated electrostatically from the gas mixture composed essentially of carbon monoxide and phosphorus vapor produced in the electrothermal production of yellow phosphorus, which process comprises converting the dusts into a calcinate at 300 to 800°C under oxidizing conditions in a first step, leaching the calcinate with phosphoric acid in a second step, adjusting the pH of the solution in phosphoric acid to 0 to 1.5 with sodium hydroxide solution in a third step, precipitating the sulfides of lead, copper …