摘要 |
<p>Continuous separation of tin from minerals, slags etc. Process consists of forming briquettes with a mixture of the mineral with a carbonaceous material and sodium chloride sufficient to provide 1.1-7 times the chlorine stoichiometrically required by the Sn content, which are then heated in rotary furnace for 30-120 min at a sufficient temperature to evolve SnCl4 (above 750 degrees C). The volatilised SnCl4 is passed into a solution of Ca(OH)2 at above 60 degrees C, to yield SnO2 The furnace has a central burner fed with insufficient air for full combustion so as to provide an inert furnace atmosphere and surrounding burners supplied with excess air sufficient to complete the combustion.</p> |