Geological and mineralogical study of ore tailings for bio-leaching

Abstract

In this paper, the geological conditions of accumulation and the material composition of the ore tailings from the processing plants of Kazakhstan were studied. The results of studying the material of unused tailings are presented. Accumulated tailings were studied on natural exposures and on the materials of cartographic wells. In the three tailing dumps of the Zhezkazgan enrichment plant, after processing, more than 1.2 billion tons of tailings are accumulated in the form of effluent pulp, of which about 1 billion tons are in two inactive tailing dumps, and the third tailing dump is operational. When the content of the main copper ore component in tailing dump is about 0.1-0.3%, the total geological reserves of metals can be at least 2.0 million tons. More than 630 million tons of ground material with a copper content of 0.1 to 0.4% is accumulated in the tailing site of another large facility – Balkhash enrichment plant. Thus, in the tailing ponds of only two considered processing plants, there are more than 1.5 billion tons of technogenic raw ore material, where the geological reserves of copper are about 3 million tons. Mineralogical studies provide a determination of the distribution and content of basic (copper, lead, zinc) and associated (noble and rare metals) useful components in the tailings. The tailings of the processing plant can be considered promising for processing technogenic deposits of mineral raw materials. This type of technogenic ore is underexplored from both a geological and technological point of view. In this regard, it was necessary to conduct full-scale scientific research in order to study the material composition of tailings as technogenic deposits with the establishment of variability in the distribution of useful components in them and the technological properties of their processing. The results of studying the chemical, mineral and granulometric content of the tailings can serve as reliable initial data for technological studies on the extraction of metals from this technogenic raw ore material. The mineral and granulometric content of copper ore processing tailings has been studied. Microscopic descriptions of polished sections made of loose tailings are given. Sulfide ore minerals are microscopic in size, they are distributed mainly inside the grains of the host rocks and are rush in nature. Using the results of geological studies, a methodology for technological research was selected and laboratory experiments were conducted on the bioleaching of copper from the tailings.