A method and a device for preparing a trivalent chromium salt by electrochemical oxidation of ferrochrome in an acidic system are provided. The method includes: putting ferrochrome as an anode and placing the anode into an acidic electrolyte together with a cathode, and then turning on a power supply for electrolysis reaction, until an electrolysis completion solution containing the trivalent chromium salt and a trivalent iron salt is directly prepared. Compared with the prior art, the one-step electrochemical synthesis of the trivalent chromium salt solution can be achieved without a hexavalent chromium salt stage, avoiding the generation of chromium-containing waste residue, shortening the process flow and significantly improving the production efficiency of the trivalent chromium salt; furthermore, the reaction can be carried out at room temperature and normal pressure without the use of fine chromium iron powders and a high-concentration acidic electrolyte.

To the extent that it should be deemed proper, necessary, or expedient (at the discretion of the Office), please amend the attorney docket number indicated in the header of the Abstract of the present Application as follows:

Attorney Docket No.: AGR2202QQ1U

Disclosed is a method for leaching lithium via an electrochemical apparatus including a multi-functional current collector, an electrode, an electrolyte, and a lithium-bearing material, wherein the lithium-bearing material is dispersed or suspended in the electrolyte or the lithium-bearing material is coated onto the current collector. The method involves applying voltage to the current collector to leach lithium from the lithium-bearing material. The method can involve adding promoter additive into the electrolyte to boost lithium extraction within the electrochemical apparatus.

Disclosed is a method for leaching lithium via an electrochemical apparatus including a multi-functional current collector, an electrode, an electrolyte, and a lithium-bearing material, wherein the lithium-bearing material is dispersed or suspended in the electrolyte or the lithium-bearing material is coated onto the current collector. The method involves applying voltage to the current collector to leach lithium from the lithium-bearing material. The method can involve adding promoter additive into the electrolyte to boost lithium extraction within the electrochemical apparatus.

The present invention discloses a method for recycling a spent lithium-ion battery, including the following steps: sandwiching a cathode of the spent lithium-ion battery with a conductive acid-resistant material as a cathode of a primary battery system; sandwiching an anode of the spent lithium-ion battery with a conductive acid-resistant material as an anode of the primary battery system; injecting an acid solution into a chamber of the primary battery system; and carrying out, after an electrochemical reaction is completed, solid-liquid separation on a mixed liquor in the chamber. The present invention further discloses an electrochemical system for recycling a spent lithium-ion battery.

Disclosed is a flexible electrode tube for electrified rare earth mining and an application method therefor. Flexible conductive plastic tubes, wires, and joint zones are included, outer walls of the flexible conductive plastic tubes are smooth, with spiral wires embedded inside tube walls, and the wires are led out at the joint zones and connected to cables. The method includes the steps of: S1, drilling fluid injection holes; S2, placing the flexible electrode tubes into bottoms of the fluid injection holes; S3, mounting fluid injection tubes; S4, connecting the wires and the cables to a direct current (DC) power supply, and fixing ropes connecting clamps; and S5, extracting the flexible electrode tubes by pulling the ropes for subsequent reuse after mining completion. The present disclosure has the advantages of excellent electrical conductivity, corrosion resistance, high strength, and ease of arrangement and retrieval.

In a method for recovering an active metal of a lithium secondary battery, a sulfuric acid solution is added to a lithium metal composite oxide so as to prepare a sulfated active material solution. A transition metal is extracted from the sulfated active material solution. A lithium precursor is recovered by adding a lithium extracting agent to the solution remaining after the transition metal has been extracted from the sulfated active material solution. In the method, the amount of impurities is reduced, and sulfuric acid and the neutralizing agent can be recycled so that a high-yield lithium precursor recovery is enabled.

In a method for recovering an active metal of a lithium secondary battery, a sulfuric acid solution is added to a lithium metal composite oxide so as to prepare a sulfated active material solution. A transition metal is extracted from the sulfated active material solution. A lithium precursor is recovered by adding a lithium extracting agent to the solution remaining after the transition metal has been extracted from the sulfated active material solution. In the method, the amount of impurities is reduced, and sulfuric acid and the neutralizing agent can be recycled so that a high-yield lithium precursor recovery is enabled.