Preamble

Reduction and smelting are two independent unit processes employed in mental extraction through pyromettallurgical route. Reduction is carried mostly by carbon. For example reduction of . Whereas smelting consists in heating the products to a temperature above the melting point to separate liquid metal from liquid slag. Both unit processes can be carried out simultaneously in one reactor or in two independent interconnected reactors.

Typically lead, zinc and hot metal are produced in a single reactor called blast furnace. In Korex process two independent interconnected reactors are used to produce hot metal.  Shaft furnace is connected with a smelter–gasifies unit.

Salient features of lead reduction smelting

In the following lecture we will deal with production of lead. A salient feature of lead blast furnace will be given and the lecture is followed by material balance. A detailed description can be found in the references given at the end of this lecture.

•  is produced by carbon reduction of the sinter containing lead oxide in a lead blast furnace. Sinter consists of
  
  
• Height of blast furnace 8m, top dia 3m, crucible depth. and stack height 5 m.
  
  
• Temperature at bosh .
  
  
• Air is blown in through 15 tuyeres(15-20) around the bosh to oxidize C charged with sinter which produces required heat.
  
  
• At top of furnace bag houses are provided to collect lead furnaces from outgoing gases.
  
  
• Limestone and quartz are added to make a slag.

Scrap iron is charged. The following reactions occurs,





The products of smelting are liquid lead, matte, speiss, slag and gases. Lead has density 11 g/cm3, matte containing copper has density 5 g/cm3, whereas speiss has density 6 g/cm3