Regenerating and recycling method for ferric trichloride etching liquid

Abstract

The invention provides a regenerating and recycling method of a ferric trichloride etching liquid. The method provides a "membrane-one time passing process" technology. An electrolytic cell is dividedinto a cathode chamber and an anode chamber by a membrane, waste liquid in the anode chamber oxidizes Fe<2+> into Fe<3+>, and all the waste liquid is regenerated and recycled. A liquid in the cathodechamber adopts a conductive electrolyte, the membrane is utilized, anions in the electrolyte and the anode liquid can generate exchange, so that the charge balance and the material balance are achieved; an oxidation reverse process that the Fe<3+> is reduced into the Fe<2+> does not occur, so that the cathode liquid does not need the secondary electrolysis and the subsequent treatment, the cleanliness and the low consumption are achieved, and the regenerating efficiency is greatly improved; meanwhile, a chemical impurity removal method is combined, so that the production cost is further reduced; the online regeneration or offline regeneration can be carried out; the process flow adopts automatic control; and the actual application requirement of ferric trichloride etching liquid recyclingis achieved.

Description

technical field [0001] The invention relates to a regeneration method and recycling use of a recyclable ferric chloride etching solution, and is especially suitable for regeneration and recycling of iron, steel, copper and other etching waste solutions. Background technique [0002] Metal etching such as iron and steel is widely used in various fields of national life, and FeCl 3 The etchant has a mature etching technology for various grades of steel, iron, copper, etc., and can be used to manufacture printing metal plates, flower rolls, etc., and etch thin parts that are difficult to machine, such as metal screens, small holes, Gratings, etc., used for plaques, graphic engraving on metal surfaces of instruments and equipment, etc. FeCl during etching 3 Fe in etchant 3+ Gradually become Fe 2+ However, the etching ability is lost, and the total iron content increases at the same time, and the output of ferric chloride etching waste liquid is large. In addition to being ri...

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Problems solved by technology

The extraction method (patents CN1470674 and CN101497484) mainly obtains the separation of iron, nickel, etc. through organic solvent extraction, and then back-extracts to obtain FeCl 3 Reuse, there are problems such as complicated process, high cost, and the extraction agent needs to be further processed, so it is not suitable for large-scale industrial applications

In recent years, electrochemical methods (patents CN106958021A, CN107059011A, CN206872948U, CN206033893U, CN104131285A, CN104451688A, CN103710706A) have been applied to ferric chloride waste liquid regeneration technology. Fe in area waste 2+ Oxidized to Fe 3+ , to realize the regeneration and recycling of part of the waste liquid, while the waste liquid in the cathode area is due to the occurrence of Fe 3+ reduced to Fe 2+ In the reverse oxidation process, the waste liquid in the cathode chamber must be re-used after anodic secondary oxidation treatment, or discarded after subsequent treatment (such as precipitation iron powder replacement or extraction), which increases the regeneration cost and solid waste discharge. The overall recycling rate of liquid is low, and it is difficult to meet the requirements of production and application

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