Elaboration and implementation technology of concentration of Magnitogorsk steel-works slime tailings

Abstract

The problems of processing iron ore tailings of wet concentration plants and wastes with high content of iron, contaminated by oil products are actual from both points of view of ecology and economy. One of the reasons restraining solving the problem is absence of technologies ensuring to involve such wastes into industrial turnover. In the process` of the research, composition and opening degree of ore and non-metallic minerals of concentration slime tailing of Magnitogorsk steel-works (MMK) were studied and technology of their concentration was elaborated. Taking into consideration the contamination of initial slime tailings of MMK, it was proposed to accomplish their preliminary de-sliming to remove vegetable remains and clay slimes by disintegration in a screw-toothed crusher and washing in a spiral classifier. Results of wet magnetic separation (WMS) of the initial slime tailings of MMK, made at JSC “Uralmekhanobr” presented, the slimes having natural coarseness of –2.0+0.0 mm. It was established that WMS at the magnetic field intensity of 1500 Oe ensures effective removal of magnetite, aggregates magnetite-hematite-goetite into magnetic product. Iron content in the magnetite concentrate was varying from 61.5 to 62.6%. For processing of slime tailings of MMK, magnetic separation was proposed by high-gradient magnetic separator with permanent magnets, created specially for these purposes by “ERGA” company. To increase iron extraction degree, it was proposed to apply gravitation methods of concentration of nonmagnetic product, obtained at high-gradient WMS. It enabled to increase iron content in the final magnetite-hematite concentrate up to 59%. A technological diagram of oiled slimes processing presented. Tests with oiled slimes of bottom deposits of metallurgical production under pilot-industrial conditions of MMK exhibited a possibility to obtain additional iron concentrate with total iron content of 62.47% while oil content in it was less 0.3%.