A method for preparing manganese dioxide by photoelectrochemical metallurgy

Abstract

The invention discloses a method for preparing manganese dioxide through photo-electro-chemical metallurgy. The method comprises the following steps that A, an electrolyte solution containing manganese salt and acid is prepared, wherein anions of the manganese salt and anions of the acid are the same, and the anions comprise either the sulfate ions or the chloride ions; B, the electrolyte solution, a cathode and an anode are put into an electrolytic bath, light is applied to the anode, and manganese dioxide is subjected to electrolytic deposition through a continuous current, wherein the lightcontains photons of which the energy is larger than or equal to 0.58 eV; and C, the manganese dioxide is peeled from the anode and then subjected to smashing, washing, neutralizing and drying in sequence, and a manganese dioxide product is obtained. According to the technical scheme provided by the invention, the electrode Ohm voltage drop, the reaction impedance, the bath voltage and the electrolysis temperature are reduced, the adoptable anodic current density is improved, in addition, the bath voltage is not increased, accordingly, the deposition rate and productivity are improved, and energy consumption is reduced.

Description

technical field [0001] The invention relates to the field of photoelectric metallurgy, in particular to a method for preparing manganese dioxide by photoelectrochemical metallurgy. Background technique [0002] Manganese dioxide is a semiconductor oxide. With its high discharge rate and service life, it is used as an electrode material in chemical power sources such as alkaline-manganese batteries, zinc-manganese batteries, magnesium-manganese batteries, and lithium-manganese batteries. In recent years, two New power sources such as manganese oxide supercapacitors have also received extensive attention from researchers; manganese dioxide can also be used in catalysts, oxidants, ceramics and glass. [0003] Manganese dioxide can be divided into three categories: natural manganese dioxide (NMD), electrolytic manganese dioxide (EMD) and chemical manganese dioxide (CMD). In the past, natural manganese dioxide was widely used in my country, but the manganese ore was depleted due...

AI Technical Summary

Problems solved by technology

However, there are many problems in the extraction process, such as large tank voltage (2.5-3.0V), high energy consumption (up to 2000-2500kWh·t -1 ), low anode current density, slow deposition rate, etc. These problems are mainly due to the semiconductor properties of manganese dioxide

[0006] During the electrolysis process, when a thick layer of manganese dioxide is deposited on the anode, due to the poor conductivity of the semiconductor, the resistance of the electrode will rise rapidly, and a space charge region will be formed on the contact surface between the semiconductor and the electrolyte, thus Lead to an increase in the cell voltage, and only a lower current density can be used for electrolysis

Studies have shown that in the process of electrolyzing manganese dioxide, after electrolysis lasts for 35 hours, due to the deposition of a thicker manganese dioxide layer that completely covers the electrode on the anode, the anode potential will increase, and the cell voltage will increase by 0.5-0.6V; During the electrolysis process, it needs to be heated above 95°C to improve the semiconductor MnO 2 High conductivity to strengthen the electrodeposition process, which increases energy consumption and deteriorates the working environment