CN-116676642-B - Device for strengthening zinc electrodeposition by magnetic field

CN116676642BCN 116676642 BCN116676642 BCN 116676642BCN-116676642-B

Abstract

The invention discloses a magnetic field enhanced zinc electrowinning device, wherein an anode is a Pb-Sn-Ca/alpha-PbO 2 /PbO 2 -carbon coated ferrite composite anode modified by carbon coated ferrite, a plurality of permanent magnets are integrated in an electrolytic tank, the permanent magnets are alternately arranged according to N poles and S poles, the direction of a magnetic field line is parallel to an electrolytic anode and an electrolytic cathode, so that the received Lorentz force is vertically downward, and the magnetic field strength is 1-5T. The device provided by the invention integrates the permanent magnet and the matched soft magnetic anode through the electrolytic tank, fully plays roles of the magnetic field in electrochemistry, including magnetocaloric effect, magnetohydrodynamic effect, maxwell stress effect, kelvin effect and self-selection selective effect, so that the problem of high oxygen evolution overpotential in zinc electrowinning is solved, the optimal energy-saving effect is achieved, meanwhile, the device has a certain improvement effect on the problems of serious concentration polarization and more floating anode slime, further, the zinc electrowinning process is strengthened, the purposes of reducing energy consumption and stabilizing product quality are achieved, and the device is applied to the zinc electrowinning field for the first time.

Inventors

WANG JUNE
CHEN CHEN
XUE XIANG
CHEN HANG
ZHONG SHUIPING
WU XINGLIN
KUANG CHEN

Assignees

紫金矿业集团股份有限公司
厦门紫金矿冶技术有限公司

Dates

Publication Date: 20260505
Application Date: 20230414

Claims (7)

1. The magnetic field enhanced zinc electrowinning device comprises an electrolytic tank, wherein an anode and a cathode are arranged in the electrolytic tank, and is characterized in that the anode is a Pb-Sn-Ca/alpha-PbO 2 /PbO 2 -carbon coated ferrite composite anode modified by carbon coated ferrite, a plurality of permanent magnets are integrated in the electrolytic tank, the permanent magnets are alternately arranged according to N poles and S poles, the direction of a magnetic field line is parallel to the electrolytic anode and the electrolytic cathode, so that the received Lorentz force is vertically downward, and the magnetic field strength is 1-5T; The Pb-Sn-Ca/alpha-PbO 2 /PbO 2 -carbon coated ferrite composite anode is prepared by the following steps: Adding the ferrite powder obtained by superfine grinding into a glucose solution, carrying out ultrasonic treatment to fully disperse the ferrite powder, then pouring the glucose solution into a reaction kettle to carry out hydrothermal reaction at the temperature of 180 ℃, centrifuging and separating after the reaction is finished, and finally calcining at the temperature of 600 ℃ under the protection of nitrogen, wherein the heating rate is 5 ℃ per min to obtain the carbon-coated ferrite powder; The preparation of Pb-Sn-Ca/alpha-PbO 2 , after polishing Pb-Sn-Ca alloy to be bright by sand paper, respectively immersing the Pb-Sn-Ca alloy into acetone, absolute ethyl alcohol and deionized water for ultrasonic treatment, then electroplating the Pb-Sn-Ca alloy which is obtained by treatment as an anode and stainless steel as a cathode in an electroplating solution containing 170g/L of NaOH and saturated PbO at the temperature of 40 ℃ and the current density of 60mA/cm 2 to obtain Pb-Sn-Ca/alpha-PbO 2 ; Preparing an electrolyte containing 250g/L of lead nitrate, 20g/L of nitric acid and 5g/L of carbon-coated ferrite powder, fully dispersing the electrolyte by ultrasound, and electroplating the electrolyte in the presence of stainless steel serving as a cathode and Pb-Sn-Ca/alpha-PbO 2 serving as an anode under the conditions of current density of 20mA/cm 2 and temperature of 30 ℃ to obtain the Pb-Sn-Ca/alpha-PbO 2 /PbO 2 -carbon-coated ferrite composite anode.
2. The device of claim 1, wherein the carbon-coated ferrite is one of carbon-coated zinc ferrite, carbon-coated cobalt ferrite, and carbon-coated manganese ferrite.
3. The apparatus of claim 1, wherein the outer wall of the electrolyzer is integrated with a means for circulating cooling water.
4. The device according to claim 1, further comprising a zinc electrolyte storage tank, wherein a zinc electrolyte outlet of the electrolytic tank is communicated with a zinc electrolyte inlet of the zinc electrolyte storage tank, a zinc electrolyte outlet of the zinc electrolyte storage tank is communicated with a zinc electrolyte inlet of the electrolytic tank, and a filter is arranged on a pipeline of the zinc electrolyte outlet of the zinc electrolyte storage tank, which is communicated with the zinc electrolyte inlet of the electrolytic tank.
5. The apparatus of claim 4, wherein a valve, a power pump and a flow meter are provided on a pipe in which a zinc electrolyte outlet of an electrolytic cell communicates with a zinc electrolyte inlet of the zinc electrolyte reservoir and a pipe in which a zinc electrolyte outlet of the zinc electrolyte reservoir communicates with a zinc electrolyte inlet of the electrolytic cell.
6. The apparatus of claim 4, further comprising a fresh liquid reservoir, wherein a fresh liquid outlet of the fresh liquid reservoir is connected to a zinc electrowinning liquid inlet of the zinc electrowinning liquid reservoir, and wherein a valve, a power pump, and a flow meter are disposed on a line connecting the fresh liquid outlet of the fresh liquid reservoir to the zinc electrowinning liquid inlet of the zinc electrowinning liquid reservoir.
7. The device according to claim 4, further comprising a zinc electrolyte buffer tank, wherein a waste zinc electrolyte inlet of the zinc electrolyte buffer tank is communicated with a waste zinc electrolyte outlet of the electrolytic tank, and a valve, a power pump and a flowmeter are arranged on a pipeline of the waste zinc electrolyte inlet of the zinc electrolyte buffer tank communicated with the waste zinc electrolyte outlet of the electrolytic tank.

Description

Device for strengthening zinc electrodeposition by magnetic field Technical Field The invention relates to the technical field of zinc electrodeposition, in particular to a magnetic field reinforced zinc electrodeposition device. Background In the zinc hydrometallurgy field, the zinc electrowinning section has the problems of overhigh ton zinc electricity consumption (3000-3200 kWh/t), easily exceeding cathode product impurities, serious cathode dendrite, low current efficiency (-88%), and the like for a long time, and the main reasons are that (1) the anode oxygen evolution reaction is a four-electron transfer process controlled by slow dynamics, but Pb-Ag alloy anode oxygen evolution catalytic activity is poor, and has a higher oxygen evolution overpotential, (2) a small amount of lead on the anode is easy to dissolve and separate out on the cathode, (3) the mechanical strength of the anode is low, and easy to bend to cause short circuit, and (4) inherent concentration polarization in the electrochemical process causes serious cathode zinc product dendrite. The magnetic field is used as a physical field and generally plays an unexpected role when applied in other fields, in electrochemistry, the magnetic field is applied to mainly play roles of magnetocaloric effect, magnetohydrodynamic effect, maxwell stress effect, kelvin effect and self-selection selective effect, wherein the magnetocaloric effect is generated by the action of an external high-frequency alternating magnetic field on Magnetic Nano Particles (MNPs), the magnetohydrodynamic effect is macro and micro convection caused by the interaction of the magnetic field and local current density (Lorentz force driving), the Maxwell stress effect is caused by the interaction of the magnetic field and dipole moment, the shape of paramagnetic drops is magnetically expanded and contracted due to the stress of a magnetic field source, the Kelvin effect is mass transfer and can drive convection of paramagnetic substances due to the magnetic field gradient force, so that a diffusion layer is thinned, limiting current is increased, the reaction rate near an electrode is improved, and the spin selective effect is that the magnetic field can induce spin turnover of an intermediate adsorbed on the surface of a magnetic catalyst, the reaction path is optimized, and the reaction efficiency is improved. For the application of a magnetic field in zinc electrodeposition, chinese patent application CN111676490A discloses a method for optimizing zinc electrodeposition process, and proposes adding a magnetic field at a liquid inlet pipe of an electrolytic tank, thinning the thickness of chemical hydration layers of Zn 2+ and other positive and negative ions through magnetizing electrolyte, and increasing the thickness of hydration layers of paramagnetic ions such as H +、Co2+、Ca2+、Mg2+, thereby reducing tank voltage, reducing the formation of calcium sulfate and magnesium sulfate, and reducing burning and reflow of cathode zinc. However, CN111676490a only can pre-magnetize the electrolyte to change the property of the electrolyte, and the high oxygen evolution overpotential of the anode in the electro-deposition process is the biggest challenge of high energy consumption, and CN111676490a cannot effectively improve the oxygen evolution problem in the electro-deposition process. In addition, a nonmagnetic Pb-Ag alloy anode was used in CN 111676490A. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a magnetic field reinforced zinc electrowinning device. In order to achieve the above purpose, the present invention adopts the following technical scheme: The magnetic field enhanced zinc electrowinning device comprises an electrolytic tank, wherein an anode and a cathode are arranged in the electrolytic tank, the anode is a Pb-Sn-Ca/alpha-PbO 2/PbO2 -carbon coated ferrite composite anode modified by carbon coated ferrite, a plurality of permanent magnets are integrated in the electrolytic tank, the permanent magnets are alternately arranged according to N poles and S poles, the direction of a magnetic field line is parallel to the electrolytic anode and the electrolytic cathode, the acted Lorentz force is vertically downward, and the magnetic field strength is 1-5T; The Pb-Sn-Ca/alpha-PbO 2/PbO2 -carbon coated ferrite composite anode is prepared by the following steps: Adding the ferrite powder obtained by superfine grinding into a glucose solution, carrying out ultrasonic treatment to fully disperse the ferrite powder, then pouring the glucose solution into a reaction kettle to carry out hydrothermal reaction at the temperature of 180 ℃, centrifuging and separating after the reaction is finished, and finally calcining at the temperature of 600 ℃ under the protection of nitrogen, wherein the heating rate is 5 ℃ per min to obtain the carbon-coated ferrite powder; The preparation of Pb-Sn-Ca/alpha-PbO 2, after polishing Pb-Sn-Ca alloy