Integrated technology study on mining for inclined orebodies with low grade and moderate thickness
Inclined orebodies with medium thickness are always regarded as hard to mine. Firstly, due to the flat dips of these orebodies, blasted ore can not be drawn out from the bottom by gravity, nor favorouble to the application of self-walking machinery as well. Therefore, it causes higher cutting engineering and higher operational cost. Secondly, the roof controlling is rather difficult when these orebodies, are mined, which needs large amount of permanent pillars to be left resulting in much loses and potential safety problems.
From May, 2008 to November, 2009, Changchun Gold Research Institute conducted a technology research on the main problems of these similar orebodies in Nalin Gold Mine of Hongyi Mining Company, where of upwards fan-pattern medium long hole, and the tunnel support technology of shotcreting with wire-mesh were tested on the basis of 3D finite-elementary analysis, which integrated many ore loss and dilution controlling technologies, the structural parameters of the stope were optimized, and an ore drawing method of “footwall first and hangingwall later” was introduced. The sequence detonating and smooth blast technologies improved moving effect of the ore, the ore loss and dilution controlling technologies such as recovery of the residual ore in the footwall by crossing drift method, increasing the stoping capacity by 4-5 times, with the ore dilution being 21.87%, decreasing 37.51% compared with previous mining method, and the recovery being 71.98%, increasing by over two times, bringing significant economic and social benefits.
This project was awarded the first prize for science and technology development by China Gold Association in 2009.