Process for recovering components from alkaline batteries
AssigneeFortum Oyj
InventorsPeik Ekman, Kenneth Ekman, Pasi Kauppinen, Paula Kivelä, Elina Lappalainen
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Abstract
The present invention relates to separation and recovery of metals from ground alkaline batteries using anode mud (zinc electrolysis waste) and other manganese and zinc containing materials. The material commonly referred to as alkaline black (AKB) is solubilized into sulfate media and the manganese to zinc ratio is adjusted. The solution containing metals is processed using crystallization and ion exchange methods to produce manganese sulfate and zinc sulfate solutions for several possible applications.
Claims19
A method for recovering metals from ground alkaline batteries comprising the steps of:
- a. selectively leaching under reductive conditions manganese and zinc from alkaline black by mixing the alkaline black and a manganese oxide-containing material and/or manganese sulfate with a sulfuric acid solution at a leaching temperature of 15-40° C., for 1-5 hours to obtain a mixture,
- b. filtering the mixture to obtain a manganese and zinc sulfate filtrate and a Pb/Ca/organics as a filter cake, wherein the manganese and zinc sulfate filtrate obtained in the filtering step (step b) has a manganese to zinc ratio between 10:1 and 3.6:1,
- c. heating the manganese and zinc sulfate filtrate to a crystallization temperature of 70-100° C. and keeping the crystallization temperature under reflux cooling for at least 30 minutes to precipitate manganese in a form of manganese sulfate crystals,
- d. filtrating the manganese sulfate crystals and obtaining a manganese-depleted filtrate, and
- e. solubilizing the manganese sulfate crystals in water to obtain a zinc-containing manganese sulfate solution and separating manganese and zinc from the zinc-containing manganese sulfate solution by a chelating ion exchange.
Dependencies are inferred from the claim text.