Gradient functional inert anode material used for zinc electrodeposition and its preparation method

Abstract

The invention puts forward a gradient functional inert anode material used for zinc electrodeposition and its preparation method. Through the operations of alkaline degreasing, pickling and dipulse electrodeposition, etc., a gradient functional inert anode material Pb-(0.2wt%)Ag / Pb-PANI(polyaniline)-WC(tungsten carbide) is prepared on the matrix surface of an alloy Pb-(0.2wt%)Ag in an electrolyte solution. The total thickness of the anode material is 3.44-3.74mm, wherein, the thickness of the alloy matrix is 3mm, the unilateral thickness of a Pb-PANI-WC deposition layer on the matrix surface is 0.22-0.37mm, and the bilateral thickness of the Pb-PANI-WC deposition layer is 0.44-0.74mm. Compared with traditional Pb-0.8wt%Ag alloy, on the basis of not changing the electrolytic tank structure, the electrolyte solution composition as well as operation standards, the gradient functional inert anode material prepared in the invention has the tank voltage of zinc electrodeposition reduced by 280-290mV and the direct current consumption reduced by 60-80kWh / t.Zn.

Description

technical field [0001] The invention relates to a gradient functional inert anode material for zinc electrowinning and a preparation method thereof, which belongs to the scientific and technical fields of composite electrodeposition, metal matrix composite material, and hydrometallurgical electrowinning extraction. Background technique [0002] In the hydrometallurgical electrodeposition process of Zn, the anode material is one of the key components of the electrodeposition process. The direction and kinetics of the electrode process, the structural type of the electrolytic cell, the power consumption and the quality of the cathode product largely depend on the properties of the anode material. Anode materials must meet the requirements of good electrical conductivity, mechanical strength and processability, high electrocatalytic activity, strong corrosion resistance, long life and low cost. However, because the electrowinning process is carried out in a sulfuric acid mediu...

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Problems solved by technology

Among them, magnetic iron oxide has high oxygen evolution overpotential, high brittleness and limited size; platinum and platinum group metal oxides consume significantly at high current density and are expensive; titanium-based PbO2 composite is inert Anode materials have been a research hotspot for a time, but the internal stress generated by the inherent electrodeposition distortion of β-PbO2 leads to poor bonding between the deposited layer and the substrate, and the PbO2 Oxidation effect is easy to passivate the titanium matrix and cause difficulty in conduction, but it is only in the laboratory research stage; Pb-(0.5~1)wt%Ag alloy inert anode material has the characteristics of easy forming and high electrocatalytic activity in sulfuric acid medium, and is favored Widely used in the electrowinning of Zn, but its performance also has some aspects that need to be improved

For example, the anode material has a high oxygen evolution overpotential in a high-concentration H2SO4 electrolyte, resulting in a useless power consumption of nearly 1000kWh / t Zn, accounting for Zn About 30% of the total electricity consumption

The existence of the above factors lead to higher cell voltage, lower current efficiency, higher DC power consumption and anode dissolution and contamination of the electrolyte leading to a decline in the quality of cathode products in the zinc electrowinning process.

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