Nornickel’s Polar Division: Modern approaches to metallurgical waste management within the ecological framework

A relevant trend of improvement of underground mining technology is broad introduction of stoping systems with backfill. Backfill ensures safety of mining operations at minimal loss and dilution. Generally, backfill preparation uses cement and very expensive purposeextracted aggregates. Meanwhile, mining regions accumulate large amounts of different production waste—tailings of sulfide sulfur flotation and dressing, metallurgical slag and other by-products. The laboratory testing results on preparation of experimental backfill mixes using gypsum pulp are described. The examples of implementation of the Sulfur Programme are given. The rate of curing, moisture and fineness of backfill using the absolutely novel material were collated, which allowed a mix formulation with maximum possible inclusion of gypsum pulp without increase in consumption of binders and at preserved properties required for hydraulic pipeline transport of the mixture by gravity. The laboratory testing results are discussed after experimental preparation of backfill mixes using nickel slag (NS) and sulfide sulfur flotation tailings of the Nadezhdinski Metallurgical Plant (NMP). In most cases, nickel slag has no deteriorative impact on the backfill mixture but improves its properties and increases strength characteristics within the control period of curing. This effect is especially noticeable in four-component mixes composed of anhydrite, granulated slag, break stone and cement (ASSC) but with break stone replaced by nickel slag. The analysis of the experimental backfill mixes with sulfide sulfur flotation tailings of NMP shows that the best results are achieved with the mixes composed of granulated slag, solid tailings and cement (STC) and with the mixes composed of anhydrite, granulated slag and cement (ASC). The authors describe promising trends of using overburden rocks such as dolomite and substandard limestone which are planned to become an alternative of break stone in production of backfill mixtures.