Development of the technological schemes for layered mining of the third potash seam for the deep sections of the fourth production unit mine field of JSC “Belaruskali”

Taking into account the practical experience gained at the Starobinski Deposit, the four variants of technological schemes for layered extraction of the Third Potash Seam at a depth of over 900 m were developed. The comparison of the presented variants of technological schemes was carried out according to the following indicators: the specific volume of the mining and preparation work; the average content of potassium chloride and insoluble residue in the ore; the volume of ore extraction in the standard; the coefficient of the useful component extraction from the subsoil. It was noted that technological schemes with a sequential order of extraction pillars mining, where extraction (panel) workings are carried out separately for the upper and lower longwalls are more effective, and the presence of an inclined section in the upper longwall is a significant disadvantage that complicates the operation of the face conveyor and leads to a deterioration in ore quality. It is proposed to select a specific variant of layered extraction of the Third Seam with the involvement of the 4th sylvinite layer in the development at depths of more than 900 m taking into account the mining-geological and mining-technical conditions of a specific section of the mine field, since the data presented in the work indicate an insignificant difference in the variants of technological schemes for all accepted indicators for comparison. The process flow charts will be used in the development of projects for the development of mining pillars using layered longwalls and will be included in the relevant regulatory documents of JSC “Belaruskali”.