Low Grade Pyrolusite Leaching Process Of Manganese In The Smelting Of Manganese Dust

Manganese is an important strategic metal that has several industrial used, for steel production, non-ferrous alloys, carbon-zinc batteries and some chemical reagents. It has very large unprecedent space and potential requirement. Manganese sulfate are mainly used in the preparation of manganese matel by electrolysis in industrial production. So, the preparetion of manganese sulfate become the key point in the production of manganese metal. The current production of manganese sulfate are roasting and leaching. Manganese sulfate production technology makes the development by leaps and bounds in domestic and internation through years of precipitation and accumulation. In order to improve the leaching ratio of manganese ore and reduce the environmental pollution in the production process, the preparation of new manganese sulfate production process is still of great significance.This paper analyzes the technology at home and abroad status, base on the method of dealing with low grade manganese ore and electric furnace dust and it's thermodynamic and kinetic properties on the foundation of consulting a large amount of the ripe and forward-looking information, which prepare manganese sulfate. It has analyzed the theory of producing manganese sulfate and enriched the theory of the preparation of acid leaching of manganous sulfate under pressure. So as to simplify process and energy-saving purpose when combining traditional manganese hydrometallurgical and pressure acid leaching.This experimental study is small-scale experiment that carries on pressure acid leaching the low grade manganese ore powder and electric furnace dust. By single factor condition experiment, the author has studied the influence on leaching rate to find out the optimal conditions through the temperature, the air pressure, the leaching time, the initial acidity of sulfuric acid, the liquid-solid ratio and the proportion of manganese ores and pyrites. It also has confirmed the optimal conditions by four group comprehensive experiment. The result showed that the optimal conditions of the low grade manganese ore are the temperature is 120℃, the air pressure is 0.5 MPa, the leaching time is 80 min, the initial acidity of sulfuric acid is 120 g/L, the liquid-solid ratio is 5:1, the proportion of manganese ores and pyrites is 1:0.6, the stirring rate is 500 r/min. The optimal conditions of the electric furnace dust are the temperature is 95℃, the air pressure is normal pressure, the leaching time is 120 min, the initial acidity of sulfuric acid is 120 g/L, the liquid-solid ratio is 5:1, the proportion of manganese ores and pyrites is 1:0.5, the stirring rate is 200 r/min. Under these conditions, the leaching efficiencies of the low degree of manganese ore and electric furnace dust were 99.18% and 97.62%, respectively.On the fundation of the experimental the pressure acid leaching process of manganese were discussed. The results is that the pressure leaching not only can improve Mn leaching ratio but also shorten production cycle and improve the environment. It has also offered reference for industrial study in future.