Method for removing magnesium in sulfuric acid leaching process of rhodochrosite

Abstract

A method for removing magnesium in sulfuric acid leaching process of rhodochrosite comprises the steps that electrolytic manganese returned anode liquor is added in a leaching tank, and then rhodochrosite powder and concentrated sulfuric acid are added to carry out high acid leaching; after sufficient leaching is carried out, liquid ammonia is added for neutralization, and a solution system is made to be neutral; air is blown into the solution system, dimethyl carbamodithioic acid is added after aeration is carried out for a while; after sufficient stirring, solid and liquid separation is carried out on obtained pulp; the filtrate obtained through the solid and liquid separation is circularly used for electrolytic manganese production; separated solid residues are recycled separately. The method is easy and convenient to operate and easy to implement, the manganese leaching rate in the electrolytic manganese production can be increased, and the concentration of magnesium in the electrolytic manganese returned anode liquor can be reduced.

Description

technical field [0001] The invention belongs to the field of nonferrous metal hydrometallurgy or chemical environmental protection, and in particular relates to a method for removing magnesium in the leaching process of rhodochrosite. Background technique [0002] In the current industrial production of electrolytic manganese, the raw material rhodochrosite contains about 2% magnesium oxide, most of which are dissolved in the leaching process, and the leaching solution is recycled electrolytic manganese anolyte, which leads to the MgSO in the system 4 The accumulative total reaches more than 150g / L, which brings many difficulties to production, such as: (1) the viscosity and density of the electrolyte increase, and the conductivity decreases, which hinders the diffusion of ions in the electrolyte and increases the cell voltage; (2) Affect the purity and quality of manganese products; (3) Irregular precipitation of substances in electrodes, equipment and pipelines will seriou...

AI Technical Summary

Problems solved by technology

Liu Honggang and others chose MnF 2 As a precipitant, the MnSO-containing 4 The magnesium removal test was carried out on the leaching solution, and the precipitation rates of calcium and magnesium reached 96% and 99% respectively (see Liu Honggang et al.: Manganese fluoride precipitation removes calcium and magnesium in the leach solution of reduced manganese oxide ore[J]. Mining and Metallurgy, 2007, 16 (4 ):25-28.), the precipitation effect is very good, but the MnF used in this method 2 The purity requirement is high, and the preparation cost is also high. In the test, MnSO 4 with NH 4 The F reaction is self-made, and there is no ready-made product. At the same time, the excess coefficient of fluoride salt is large, and the residual fluoride ion content increases, which has a strong corrosion effect on the cathode plate and shortens the service life of the cathode plate.

[0004] At present, there is no method for direct magnesium removal in rhodochrosite leaching process