A combination of bioleaching and electromagnetic separation in the treatment of quartz sands

Abstract

This contribution deals with the treatment of Slovakian eolic quartz sands by bioleaching and magnetic separation with the aim to remove iron. The X-ray study of sand patterns confirms that quartz occurs as a dominant mineral. Accompanying minerals are represented by smectite and feldspars. As to the sample of unground sand, bacterial leaching resulted in a Fe2O3 reduction to the content of 0.13 %. Similarly, in case of ground sample, the Fe2O3 content was decreased to the value of 0.19 %. Thus, biological leaching removed 60 % of Fe and by following leaching by oxalic acid total the iron removal was 70.5 %. Finally, the application of magnetic separation resulted in the total iron removal of 93 % and, in such combined way, the prepared product contained 0.024 % of Fe2O3. Achieved results on the iron removal points to the fact that the combination of leaching and magnetic separation enables to obtain a product usable in glass industry.

Keywords

• industrial minerals
• bioleaching
• Bacillus sp.
• heterotrophic bacteria
• iron