The process of environmentally safe biochemical recycling of phosphogypsum

Abstract

This paper focuses on the determining of biochemical treatment feasibility of phosphogypsum with the extraction of useful components, particularly rare earth metals. The possibility of phosphogypsum use as a mineral substrate by various groups of microorganisms in environmental protection technologies allows the application of bioleaching. The results of research show that biochemical leaching is carried out by aerobic bacteria and it arches capable of oxidizing sulfide minerals. The representatives of the genera Acidithiobacillus, Leptospirillum, Sulfobacillus, Sulfolobus, Acidianus, Metallosphaera, Ferroplasma are leading in these processes. Biochemical formalization of the kinetics process and study of the data bank of current developments dealing with using the waste treatment processes have been carried out. The main ecological and biochemical researches, and various mechanisms of microbiological investigation, biochemical modelling have been studied for assessment of biomass productivity of phosphogypsum. Technological scheme of biological leaching of rare-earth metals from PG dumps has been developed. The optimal parameters have been determined under pH = 1.5–2.5 and T = 278–308 K and the efficiency of bioleaching has been estimated.