Research Of The Huangmailing Phosphate Safe And Smooth Transfer Technology From Open-pit To Underground Mining

As shallow resources depleted, many open-pit mine are or will be underground mining, which faces many important technical problems that need to be solved urgently. It will be important to smooth transition of open-air to underground mining and stability of mining yield and economic benefit. Aiming at the mining technical conditions of HuangMaiLing Phosphorous Chemical Industry Group Company, and some methods such as field investigation, laboratory test, theoretical analysis, numerical simulations and program design have been used, and some key technologies of open-pit to underground have been also analyzed and researched deeply. Research results have obtained as follows:(1) Through testing and redacting mechanics parameters of open-are to underground rock, this paper obtains reasonable numerical simulation parameters, which provides base material for the determination of safety isolation layer thickness and stope structure parameters;(2) By using of comprehensive formula method and numerical analysis, conclusion that ore bodies in+5m above from den elevation is permanent confinement tiberium spikes in HuangMaiLing phosphate open-air pithas has been made;(3) Through comparing some suitable exploit system solutions, WangGuShan shaft exploit system solution is finally adopted. The paper has also researched and designed several main exploit systems, such as mine pit waterproof and drainage, ventilation systems affect open-are to underground mining smoothly. Through investment estimate to the whole system, the final investment amount of this system is firmed, which is 377,589,400 yuan.(4) Based on the fuzzy mathematics theory, and optimizing a variety of suitable for mine mining methods, horizontal stratified filling method has been finally chose as the subject of mine mining method. This method has many advantages, such as high mechanization level, great capacity of production, ore loss and dilution ratio, these make it protect open pit, surface main structures well, such as the mill, highway, waste stone field, etc. Moreover, it can also ensure open-are to underground mining alternate safely and smoothly.Through the research and improvement to the key technology of open-are to underground mining in replacing safely and smoothly, this article solved the special joint technical problems which are brought by open-air and underground mining. This result of the study can not only offer important guarantee for mining stable transition and realize sustainable development, but also provide the beneficial reference to other similar mines.