METHOD FOR PROCESSING NICKEL-CADMIUM SCRAP Russian patent published in 2007 - IPC C22B7/00 C22B17/02 C22B23/02 

FIELD: inorganic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for processing nickel-cadmium scrap in producing secondary non-ferrous metals, for example, scrap in aim for preparing nickel and cadmium from depleted nickel-cadmium accumulator batteries. Method involves heating scrap in furnace to temperature 200-300°C and its keeping at this temperature to distillate residual water followed by increasing temperature to 500-700°C and keeping dehydrated abovementioned scrap in reductive gaseous medium at this temperature to distillate residual non-metallic fractions and the following increasing temperature to 850-1000°C and keeping remained part of scrap at this temperature up to complete evaporation of cadmium. Evaporated cadmium is fed to condenser, cooled its in condenser up to transition to solid state followed by discharge of cadmium from condenser and nickel is discharged from furnace. Scrap is placed in furnace by at least one layer of thickness d satisfying the following ratio: wherein D is effective diffusion coefficient of cadmium in volume of nickel-cadmium scrap, m²/s; τ is duration of process in evaporation of cadmium, c; N_o is initial content of cadmium in scrap, weight%; N is amount of evaporated cadmium, weight%. Method provides enhancing extraction degree of cadmium and preparing highly pure nickel and cadmium.

EFFECT: improved processing method.

9 cl, 2 dwg, 1 tbl, 4 ex