Method for producing briquettes, method for producing reduced metal, and method for separating zinc or lead

Abstract

Disclosed is a method for producing briquettes, by which briquettes having enhanced strength can be produced even when the amount of a binder used therefor is reduced as much as possible. Specifically disclosed is a method for producing briquettes, which comprises: a step of forming a primary granular material having an apparent density of 1,000 to 4,000 kg/m 3 using a powder of metal oxides including iron oxide and one or more oxides selected from among of zinc oxide, lead oxide, and titanium oxide; and a step of forming a secondary granular material by compressing a plurality of primary granular materials, while having the primary granular materials contain one or more metal oxides selected from among the zinc oxide, lead oxide, and titanium oxide.

1 . A method for producing a briquette, the method comprising:
 (a) forming a primary granular material having an apparent density in a range from 1,000 to 4,000 kg/m 3  from a powder of metal oxides comprising iron oxide and at least one metal oxide selected from the group consisting of zinc oxide, lead oxide, and titanium oxide; and   (b) pressing a plurality of the primary granular materials comprising the at least one metal oxide, to obtain a secondary granular material.   
     
     
         2 . The method of  claim 1 , wherein the forming (a) is carried out by tumbling granulation, kneading granulation, or pressure compaction. 
     
     
         3 . The method of  claim 1 , wherein a total content of at least one metal oxide in the secondary granular material is 10% by mass or more, based on a total mass of the secondary granular material. 
     
     
         4 . The method of  claim 1 , wherein the primary granular material comprises a reducing agent. 
     
     
         5 . The method of  claim 1 , wherein the primary granular material comprises water. 
     
     
         6 . The method of  claim 5 , wherein a water content of the primary granular material when pressed is 4 to 20% by mass, based on a total mass of the primary granular material. 
     
     
         7 . The method of  claim 5 , further comprising, prior to (b):
 drying the primary granular material.   
     
     
         8 . The method of  claim 7 , wherein the drying decreases a water content of the primary granular material by 50 to 95% by mass of an initial water content before drying, based on a total mass of the primary granular material. 
     
     
         9 . The method of  claim 2 , wherein the forming (a) is carried out with a tumbling granulator, and the metal oxide remains in the granulator for 15 seconds or more. 
     
     
         10 . The method of  claim 1 , further comprising:
 drying the secondary granular material.   
     
     
         11 . The method of  claim 1 , wherein a volume of the primary granular material is 1/500 or more of an inner volume of a die, which forms the secondary granular material. 
     
     
         12 . A method for producing a reduced metal, the method comprising:
 reducing a briquette obtained by the method of  claim 1 .   
     
     
         13 . A method for separating zinc, the method comprising:
 heating and reducing a briquette comprising zinc oxide and obtained by the method of  claim 1 , thereby evaporating zinc.   
     
     
         14 . A method for separating lead, the method comprising:
 heating or heating and reducing a briquette comprising lead oxide and obtained by the method of  claim 1 , thereby evaporating lead.   
     
     
         15 . The method of  claim 1 , wherein the primary granular material comprises zinc oxide. 
     
     
         16 . The method of  claim 1 , wherein the primary granular material comprises lead oxide. 
     
     
         17 . The method of  claim 1 , wherein the primary granular material comprises titanium oxide. 
     
     
         18 . The method of  claim 1 , wherein a total content of the at least one metal oxide in the secondary granular material is 15% by mass or more, based on a total mass of the secondary granular material. 
     
     
         19 . The method of  claim 1 , wherein the primary granular material has an apparent density in a range from 1,500 to 4,000 kg/m 3 . 
     
     
         20 . The method of  claim 1 , wherein the primary granular material has an apparent density in a range from 2,000 to 4,000 kg/m 3 .