Conventional mining methods are becoming increasingly uneconomical with declining ore grades. In-Situ Leaching (ISL) of minerals is one alternative technology that can be adapted to extract minerals from low-grade permeable mineral deposits. The susceptibility to ISL is dependent on the permeability of the host-rock formation. Although prevailing methods such as hydraulic fracturing and explosive blasting are used for host-rock preconditioning, these methods have limitations such as excessive formation damage around well fields and uncontrolled fracture propagation. Therefore, an alternative method is proposed to initiate fractures around an injection well using a patented hydrophobic, injectable, Soundless Cracking Demolition Agent (SCDA). The fracture performance of the compound was investigated by numerically simulating the fracture initiation and propagation using the Discrete Element Method. It was also tested in the laboratory to fracture multiple low permeability sandstone specimens under hydrostatic stresses up to 20MPa. Due to the fracturing nature of the agent, the fracture density can be significantly improved (by 116%) with increasing confining pressure (from 70kPa to 20MPa). Furthermore, the rock is subjected to a gradual fracturing process (10–25 hrs) facilitating safer, controlled fracture propagation, around the borehole. Afterwards, the fracture permeability of the specimen was calculated. Compared to the very low intact sandstone permeability (7.6⨯10-20 m2) an improved permeability of 9.79⨯10-13 m2 at a confining pressure of 30 MPa was observed following pre-conditioning. The radial fracturing observed using this method indicates that nonexplosive rock fragmentation is a potential catalyst to improve the permeability of host-rock formations for ISL among other applications.

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