Application effect of block stone cementing process in a mine in the USSR and Australia

Since the 1970s,countries such as the Soviet Union and Australia have used the empty field method to return to the mining house,filling with stone,and then injecting cement mortar into the stone to form a block of concrete;or pouring the gravel into the goaf.At the same time,the cement mortar is transported by pipeline to form a block stone concrete.Then carry out the mining of the pillars.
Soviet Czech Magnitogorsk copper ore open cells with good Sublevel Room case,stope width of 10~20m,a width of pillar 20~22m.After the mining house is finished,the gravel is filled with gravel,and the gravel filling material accounts for 45-55%of the space.Then,the gob is sealed and pressed into the cement slurry at a pressure of 0.5 to 0.6 MPa(cement:slag:water=1:1.6:2.6 to 1:3:3.5).Depending on the structure of the mining method,two or six closed points of cement slurry are placed at the height of the mine.The filling body strength can reach 2.4 to 2.6 MPa,and the filling cost is only about 50%of the same strength concrete.