| 摘要 |
<p>PURPOSE:To provide the method for obtaining molten steel having a low tin concn. from iron and steel scrap contg. tin and cost-effectively recovering tin so as to make the tin reutilizable as a resource. CONSTITUTION:This method consists of a first stage for accelerating the evaporation of the tin by melting raw material scrap with a carbonaceous material as fuel by a melting furnace with which top blowing of oxygen is possible, under the conditions under which slag exists at >=200kg/t-metal and under which the secondary combustion rate of the atmosphere attains >=30% and the sulfur concn. in the molten metal >=0.03%, a second stage for separating and recovering the generated dust and a third stage for separating and recovering the tin as tin chloride. The conditions for the third stage are >=50kg/t-dust in the amt. as the chlorine of the chloride, 800 to 1200 deg.C heating temp. and <=1 CO2/CO ratio of the atmosphere. The dust contg. the chlorine is also usable as the chloride source for the third stage. The tin and copper are simultaneously separable and recoverable from the dust if the treatment is executed by adding the dust in which the copper and iron oxide coexist to the raw material scrap.</p> |
