Purpose. Justification of possibility to create the hardening mixtures with filler based on tailings of the Akshatau mining and processing complex for strengthening the quarry benches, inter-chamber pillars and excavation roofs and producing building materials. Methodology. The complex approach is applied including experimental methods of physical and chemical and mechanical analysis of the phase composition and properties of ore processing wastes. The practicability of using the tailings of polymetallic ore processing as an inert filling of hardening mixtures is estimated; the compressive and bending strength of samples is determined after the mixture solidification as well. Findings. Based on X-ray phase analyses, differential thermal and chemical analyses, the ore tailings composition was determined. The optimal qualitative composition of the hardening mixture with specified rheological and strength properties, as well as the technological mode of its preparation, have been determined. Originality. The peculiarities of hydration processes in the cement-water-limestone system are clarified and a new formulation of a hardening mixture with specified rheological and strength properties have been developed. Practical value. The proposed composition of hardening mixtures with filler based on ore processing waste is aimed at strengthening the fractured area of the rock mass. This increases the stability of rock openings and provides safety of mining. The involvement of ore processing waste in the production of hardening mixtures and other building materials is a positive solution in terms of the disposal of these wastes. Reducing the amount of accumulated waste contributes to minimizing environmental risks in mining regions. The obtained results are significant for the construction industry. They provide the expansion and reproduction of the raw material base through using the waste of processing the ore of Akzhal deposit.