Abstract: There is provided a method for recovering lead from copper smelting dust according to the present invention includes an alkali leaching step of leaching lead contained in copper smelting dust with an alkali solution, a step of performing a solid liquid separation on a post-leaching solution and a leaching residue after the alkali leaching step, a neutralization step of adding an acid to the separated post-leaching solution to precipitate a lead, and a step of recovering a precipitate containing the lead by performing a solid liquid separation.

Abstract: A method of treating recyclable raw materials containing valuable metals is provided, the method including the steps of feeding recyclable raw materials (W) containing valuable metals into a rotary kiln furnace (2) in which a refractory product having an Al2O3—Cr2O3 content of 70% or greater is used for an inner wall; feeding an additive (A) containing SiO2 as a major component into the rotary kiln furnace (2) so as to increase a viscosity of a slag (S) flowing along the inner wall, thereby the recyclable raw materials (W) are attached on the slag (S) having a high viscosity such that at least part of the recyclable raw materials (W) is exposed to the inside of the rotary kiln furnace; and burning/melting the recyclable raw materials (W) attached on the slag (S) in the rotary kiln furnace (2).

Abstract: A method of treating recyclable raw materials containing valuable metals is provided, the method including the steps of feeding recyclable raw materials (W) containing valuable metals into a rotary kiln furnace (2) in which a refractory product having an Al2O3—Cr2O3 content of 70% or greater is used for an inner wall; feeding an additive (A) containing SiO2 as a major component into the rotary kiln furnace (2) so as to increase a viscosity of a slag (S) flowing along the inner wall, thereby the recyclable raw materials (W) are attached on the slag (S) having a high viscosity such that at least part of the recyclable raw materials (W) is exposed to the inside of the rotary kiln furnace; and burning/melting the recyclable raw materials (W) attached on the slag (S) in the rotary kiln furnace (2).

Abstract: A method, for charging anode(s) into a furnace, comprises bending anode(s) having a roughly rectangular plate shape at the end of the charging direction, and charging the anode(s) into a melt stored in the furnace through a slope. When the depth of melt is taken to be D (cm), the height of the slope is taken to be H (cm), the inclination angle of the slope is taken to be &bgr; (°) and the thickness of the anode is taken to be b (cm), the bending angle &agr; (°) of the anode and the length c (cm) of the bent end of the anode are set to satisfy the following relationship: Equation (1): D>A×(c sin &agr;/b)B +0.06(H-190), provided that A and B are given by: Equation (2): A=−1051(sin &bgr;)2 +2028 sin &bgr;−839.3, and Equation (3): B=7.378(sin &bgr;)2−11.64 sin &bgr;+3.806.

Abstract: The present invention provides a magnesia-spinel refractory in which corrosion resistance and slag penetration resistance are significantly improved. The magnesia-spinel refractory is obtained by mixing magnesia granulated powder having a particle diameter of 10 to 150 &mgr;m and alumina powder having a particle diameter of 0.1 to 5 &mgr;m, molding the resultant mixture, and then burning the molded product to form a dense and strong combined structure of periclase and spinel. The mixture of magnesia and alumina contains powders of both components, or a powder of one of the components and a granulated powder of the other component. It is preferable to use a spray dryer method as granulating means, and a hydrostatic pressing method as molding means. These mixtures are used for producing magnesia-spinel protecting tube and crucible, bricks for copper smelting and converting furnaces, and magnesia-spinel protecting tube and crucible for copper smelting and converting furnace slag.