Creation of a high-strength backfill composite based on sulfide-bearing technogenic waste from mining production

Introduction. The application of technogenic waste in the composition of backfill composites not only reduces the cost of mining operations but also minimizes the environmental impact of technogenic activities. However, the presence of sulfides in the technogenic waste from mining and processing operations has a detrimental effect on the cement rock. The main objective of this study is to reduce the negative impact of sulfide-containing components on the cement rock in the developed hardening backfill composite based on sulfide-bearing technogenic waste. Materials and methods. As the sulfide-bearing technogenic waste, current enrichment tailings taken from the Buribay mining and processing plant were used. Two types of fibers were employed as reinforcing components: polypropylene (pp) and glass fiber (gf), with lengths of 3 mm and 12 mm. During the study, a comparative analysis of samples with different recipes was conducted to examine the effect of the reinforcing additives on the strength characteristics of the composite after solidification and the dynamics of strength gain over various storage periods. Results. 1. In the first two ranges (from 7 to 60 days) of the study, an increase in the strength characteristics of the tested samples for all recipes was observed. 2. Increasing the storage time of the samples leads to a negative impact of sulfur on the cement rock and results in a decrease in the strength characteristics of the samples for all investigated sulfur content ranges. 3. The maximum strength characteristics of the samples are achieved at 60 days, regardless of the type of reinforcing material and its size. 4. The introduction of additives into the backfill composite leads to increased strength characteristics of the solidificated samples for all formulations and storage periods. Discussion. Reinforcement of the backfill composite increases its strength characteristics, regardless of the type of reinforcing component and its size. Samples reinforced with glass fiber showed a more intense strength development compared to samples with polypropylene fiber in their recipe. Conclusion. 1. Reinforcement of the backfill composite made from sulfide-bearing enrichment tailings leads to increased strength characteristics of the artificial mass at all stages of solidification. 2. The use of reinforcing materials did not eliminate the negative impact of sulfur on the cement rock. 3. The type of reinforcing material, its dimensions (length), and its proportion in the total volume of the backfill composite have a direct impact on the strength characteristics of the created artificial mass. Resume. 1. The results of this study enable the creation of a strong artificial mass based on sulfide-bearing technogenic waste, considering the completion of work in the stoping block no later than 60 days. 2. A further direction of research is the search for materials that ensure the reduction or complete elimination of the influence of sulfides (sulfur) on cement rock.