Development of borehole hydraulic jet mining device

The hydrogeological conditions in some domestic mining district are very complex and characterized with rich fissure-cavern water and large pit inflow of water.It is very difficult to operate in the district with traditional mining methods,so borehole hydraulic jet mining(BHM) method is one of the best schemes to solve this problem.After analyzing the work principle and structure of BHM device,the design scheme of its key component air lift pump was proposed.In order to obtain the operating parameters during lifting course,a small laboratory simulation test device was set up.The river sand served as the test particle,the influential laws of air inflow and submergence ratio on water drainage and sand discharge were studied.The results showed that the maximum water drainage and sand discharge occurred as the air inflow increased,and the positions of maximum water drainage were close to each other at all submergence ratios,but the positions of maximum sand drainage obviously shifted to left as the submergence ratio increased;the water drainage and the sand drainage increased as the submergence ratio increased.