Processing and recycling of iron-bearing copper–nickel production waste

Abstract

The importance of production waste recycling toward sustainable development of the society is defined. The world’s experience in processing and reusing of metallurgical waste from nonferrous metallurgy works are briefly described. Examples of the use of slag and cake in the construction industry are presented, and a number of technologies for the extraction of nonferrous metals and iron from them are described. To organize efficient utilization of waste slag from Kola MMC, a mixed processing method has been developed based on their sulfuric acid leaching with 5-10% sulfuric acid, transferring most of silica into the solution in the form of silicic acid and concentrating the bulk of nickel and all copper in an insoluble residue, followed by flotation of nonferrous metal sulfides, providing flotation concentrates containing more than 4.5% copper and nickel. Processing of the leaching solution produces mesoporous silica with a specific surface area of 700-800 m2/g, which is used as an active additive in cement. The possibility of hydrometallurgical processing of afterburning products after carbonyl nickel decomposition using hydrochloric acid solutions and liquid extraction method for separating nickel and iron by organic reagents to obtain pure solutions of ferric chloride is demonstrated. A scheme is proposed for the joint processing of solutions from leaching of ferruginous cakes and residues of carbonyl nickel afterburning, as well as nickel raffinates of cobalt production of Kola MMC, which ensures production of commercial ferric chloride. To reduce the volume of dumped iron cakes, the technology and regulation are developed for the extraction of iron(III) from concentrated nickel solutions using high molecular weight aliphatic ketones and their mixtures with fatty alcohols instead of its hydrolytic precipitation.The authors appreciate participation of Leading Researcher, Candidate of Geological and Mineralogical Sciences Yu. N. Neradovskiy and Researcher E. V. Chernousenko from the Tananaev Institute of Chemistry and Technology of Rare Elements and Minerals, Kola Science Center, Russian Academy of Sciences in these studies.