Increasing environmental safety by reducing technogenic load in mining regions

One of the most problematic points in technology for storing ore enrichment waste materials with hardener admixture into underground mined space and tailing dumps are the tailings of hydrometallurgical plant (HMP). They are supplied through a slurry pipeline to the tailing dump in form of pulp with solid to liquid mass ratio of 1:2. Liquid phase of the pulp after gravity separation and clarification in tailing dump is returned to technological cycle of HMP. Storage technology under consideration has several disadvantages: high nonrecurrent capital costs for construction of tailing dump at full design capacity; high probability of harmful chemicals migration into groundwater if protective shields of the base or sides of tailings are damaged. The authors have used data from literature and patent documentation considering storage parameters, laboratory and production experiments, physical modeling and selection of compositions of hardening mixtures. Analytical studies, comparative analysis of theoretical and practical results by standard and new methods were performed. Possibility of using hardening mixtures with adjacent production wastes used as binders was established. Optimal composition of ingredients per 1 m3 of hardening mixture is proposed as follows: 1350 – 1500 kg of HMP tailings; 50 - 70 kg of binder (cement); 350 liters of mixing water. Proposed technology of ore enrichment waste storage into underground mined space and tailings with hardener admixture application allows using underground mined space at the enterprise production capacity of 1,500 thousand tons per year to store 50 – 55 % of tailings, and store the rest wastes cemented by binding material in repository. When filling the entire area of the tailing dump mirror of 10 m height with cemented tails and HMP capacity of up to 1.5 million tons per year, its operation life is extended by 50 years.