Mineral composition and crystalline structure of iron-bearing components in metallurgical waste

Abstract

The waste stored in tailings and sludge pools at metallurgical enterprises—including wastes from raw-materials processing (extraction, enrichment, sintering, etc.), metallurgical processing, and ancillary processes—may be used for production purposes; in particular, it may prove valuable in ferrous metallurgy. With declining reserves of iron ore, the processing of industrial waste as a source of iron is of particular interest. For more than fifty years, production wastes—rock from coal enrichment, ash from coal combustion in the thermoelectric plant, gas-purification sludge, etc.—have been accumulating in the sludge pools at West Siberian Metallurgical Works (now OAO EVRAZ ZSMK). Since the sludge pools are now at the end of their working life, it is necessary to develop a technology for processing that waste. To assess the prospects for producing iron concentrates from the basic wastes in the sludge pool, the mineral composition and crystal-chemical structure of the iron-bearing minerals are investigated by means of Mossbauer spectroscopy, X-ray phase analysis, chemical analysis, and optical microscopy. Significant differences are observed in the types of iron in waste from different processes. That must be taken into account in developing the appropriate processing technology.