Purpose. The solution to one of the important problems of the underground mining method is to substantiate cost-effective, technologically feasible and safe variants for mining steeply dipping low-thickness ore bodies. Methods. Mining systems are substantiated on the basis of a detailed analysis of the developed and existing experiential variants for mining steeply dipping ore bodies, identifying production and economic disadvantages, as well as their causes. Findings.As a result of the research, the pillar raise performance in the mining system with ore shrinkage has been substantiated. The main parameters of the proposed variants for mining systems with ore shrinkage, intended for expansion-type supports and borehole breaking, have been substantiated. A design has been developed of fastening the material-running raises (MRR) and ventilating raises (VR) on the working and ventilation horizons to ensure their performance in the mining system with ore shrinkage. Originality. For the first time, dependences of dilution and labour productivity on the ore body thickness and the type of ore breaking for blast-hole stoping and borehole breaking for a single and “twinned block” have been obtained. In addition, a certain dependence of the loading and delivery performance on the average fractional composition, as well as on the delivery distance, has been obtained. Practical implications. The research is characterized by scientific innovations created for the first time, which are able to ensure the efficiency and safety of mining operations, while creating the ability to manage the loss of minerals and dilution in the block, as well as reaching their calculated optimal ratio in order to achieve the most cost-effective production rate.

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The results of studies of the stability of the microemulsion of an ultramicroheterogeneous flotation reagent obtained from a mixture of oil from the Zhanazhol field and butyl xanthate (BX) in the following ratios are presented: oil: BX = 1: 1; oil: BX = 2: 1; oil: BX = 4: 1. It was found that the microemulsion has the greatest stability when the ratio of oil: BX = 4: 1, which was 99.3% after 120 hours of exposure. The supposed emulsifying effect of butyl xanthate in symbiosis with natural emulsifiers of the oil itself over newly formed globules of ultrasonic (US) dispersion was found. At an ultrasonic treatment power of 250 W for 10 min, a microemulsion with an average globule size of 123.4 nm was obtained. It is shown that an increase in the duration of ultrasonic treatment for more than 10 minutes does not have a significant effect on the stability of the obtained microemulsion of an ultramicroheterogeneous reagent.

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