Method for co-producing manganese hydroxide and sulfuric acid or ammonium sulfite by electrolytic manganese waste slag

Abstract

The invention relates to a method for co-producing manganese hydroxide and sulfuric acid or ammonium sulfite with electrolytic manganese waste slag, comprising the following steps: A. slurrying electrolytic manganese metal waste slag, leaching, adjusting pH to 6.0-6.4, removing iron, and pressing filtration to obtain Press filter block A and press filter liquid A, press filter press block A after water washing, obtain press filter block B and press filter liquid B; Regulate the pH of press filter liquid A to 11.5-12, press filter, obtain press filter block C and press filter liquid C, press filtrate C circulation treatment, after potassium and sodium enrichment, remove calcium sulfate, evaporate and crystallize, separate potassium sulfate and sodium sulfate; B. calculate according to production needs and add the required substances to the press block B, dry Drying, pre-decomposition, and calcination to obtain cement additives or solids. The sulfur dioxide produced by calcination is separated from the dedusting ash for powder gas separation. The sulfur dioxide gas is used to make sulfuric acid. The dedusting ash and filter press block B are calcined together to enrich selenium and zinc; C. Slurry the filter block C, leaching, adjust the pH to 6.0-6.4, remove impurities, stand still, and press filter to obtain the filter block D and the filter liquid D, adjust the pH of the filter liquid D to 8.8-9, and continue to adjust the solution pH to 11.4‑11.8. This method realizes the joint output of multiple products.

Description

technical field [0001] The invention belongs to the technical field of electrolytic production and recovery of manganese by a solution electrolysis method, and in particular relates to a method for co-producing manganese hydroxide and sulfuric acid or ammonium sulfite by electrolyzing metal manganese waste residue. Background technique [0002] At present, the electrolytic manganese metal industry mainly adopts manganese carbonate ore dilute sulfuric acid leaching method or manganese oxide roasting dilute sulfuric acid leaching method to obtain manganese metal flakes by electrolysis. During the production process, a large amount of harmful substances such as heavy metals and high concentrations of carbon dioxide, ammonia, and chlorine will be produced. and other impurity gases. The commonly used treatment method is to build a large leak-proof slag silo, and overflow water treatment facilities are installed in front of the slag dam to treat overflow sewage, and the slag dam c...

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Problems solved by technology

Through the above technical means, most of the water-soluble manganese and waste residues are recovered, and these water-soluble manganese and waste residues become cement additives, and sulfuric acid is produced at the same time, but the manganese element content in the obtained cement additives is relatively high. Manganese has adverse effects on the combustibility of raw meal and the compressive strength of cement additives (“Application of manganese slag in the calcination of cement additives”, Zou Li, Sichuan Cement, 2007, July, 33) and the obtained cement additives The magnesium content in the medium exceeds the standard; the slag washing water is recycled, and the water balance will be affected after the slag washing is too many times; the sulfidic slag produced in the process of sulfur removal and air iron removal in the production process of electrolytic manganese will take away 3.16%-10.5% manganese, resulting in a waste of resources; at the same time, this method can only deal with water-soluble manganese, can not deal with acid-soluble manganese and acid-insoluble manganese; in the process of operation, some manganese exists in the waste residue, which has not been fully recycled

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