Assessment of environmental hazard of accumulated mineral processing waste of closed mining enterprises in the Amur river region and Primorye

The subject of research was technogenic waste systems formed in the last century due to the activities of presently closed mining enterprises in the Amur River Region and Primorye of the Far Eastern Federal District of the Russian Federation. Experimental studies allowed to establish that toxic sulphidized mineral processing waste accumulated for the 20th century in tailings storage facilities (TSF) in large quantities produce negative impact on the environment. It was revealed that their conservation and reclamation were not carried out. However, they pose huge threat not only to the environment, but also to public health. In this regard, the research goal was to assess environmental hazard of the accumulated toxic waste and substantiate the possibility of mitigating their negative impact on biosphere components and human health. Based on the research goal, the following tasks were set: 1) analysis and generalization of the existing experience of studying the problem in Russia and abroad; 2) identification of the main sources of crisis situations at closed mining enterprises, indicators and criteria for assessing the environmental hazard of the accumulated mineral processing waste; 3) assessment of the environmental hazard of the accumulated mineral processing waste; 4) development of principles and measures aimed at ensuring environmental safety of TSF comprising toxic waste. The following methods were used: physical-chemical, biological, as well as mathematical modeling, GIS technologies, etc.Based on the study of the TSF current state, assessment of the level of technogenic environment pollution, and patent search, the authors substantiate the need for effective solution to this problem. It was found that the waste belongs to the second hazard class (highly hazardous). The excess of 4 to 46 times above the regional background indicators (metal concentrations), and more than 200 times above MPC was revealed. It has been proven that the TSF surface does not naturally run wild for 30 years. Patent search and our own experimental research allowed developing measures to ensure environmental safety of sulfidized tin ore processing waste, novelty of which was confirmed by patents of the Russian Federation.