| Lanjian iron mine is main raw material production base of Pangang group mining co., Ltd. The original design was 1.5 million tons/year by open pit mining, in 1965 started construction, put into production in 1972, reaches producing in 1978. After 40 years of strip mining, jianshan mine open-pit mining already can not meet the requirement of the economic and reasonable mining, open end in March 2011.Caving constitute was founded in August 2007, construction began in November 2009. On June 30,2011, started the first underground mining, marked the jianshan mine officially entered the underground mining. The design production is 2 million tons/year, the bottomless pillar sublevel caving mining method is adopted, sublevel height 20 m, stoping approach span is 18 m, stoping mining design is divided into three sections:open bottom of more than 1300 m elevation for ore exploration area, within the scope of 1020 m ～ 1300 m elevation lower orebody exploration area, and the deep exploration area under 1020 m elevation.1300 m elevation above hang for ore exploration area, led panel.Mine was founded in August 2007 jianshan mining into underground mining engineering team, began in November 2009 jianshan opencast mining into underground mining infrastructure construction, on June 30,2011, started the first underground mining, marked the jianshan mine officially entered the underground mining. To design production 2 million tons/year, the bottomless pillar sublevel caving mining method is adopted, sublevel height 20 m, stoping approach span is 18 m, stoping mining design is divided into three sections: open bottom of more than 1300 m elevation for ore exploration area, within the scope of 1020 m ～ 1300 m elevation lower orebody exploration area, and the deep exploration area under 1020 m elevation.1300 m elevation above hang for ore exploration area, led panel, this cover is the major target of the study of the formation process.Jianshan to collected from mass production on June 30,2011 began, the construction of the construction technology level, detonator crural line length limit, and I mine underground blasting technology constraints, orifice is blasting in deep hole blasting has been adopted, at the same time, in order to enhance the reliability of priming, has adopted the hole along the depth of the entire installation detonating cord and orifice to primer adding auxiliary detonation detonating cord measures. After more than a year of blasting practice and the outgoing inspection, we found the fan on the I mine underground deep hole blasting in the hole (positive) initiation and detonating cord laying within the following deficiencies, one is the large rate is high; The second is the eyebrow destroyed; Three is the construction efficiency is low; Four is to join the detonating cord in blasting site risk coefficient increases and the blasting cost is high. How to solve the initiation body well placed to the bottom of the hole, and other aspects such as construction technical problems of processing each are not identical, but on the bottom of the hole blasting relative collar priming in improving the blasting quality and the advantages of identity in the eyebrow line protection is consistent.The research is to explore the guide and explosive devices, auxiliary materials and construction technology for the use of hole bottom reverse initiation in the mine. Through the original condition of the underground construction, we have designed a "primer protection shell" for the hole bottom initiation, and the optimal blasting parameters and construction technology of the deep hole blasting are realized. And the original hole and blasting quality has improved significantly, the explosive unit consumption decreased 0.29kg/m3, protecting the integrity of the stoping eyebrow line, bulk rate, vertical slot rate and suspended top rate is close to, with good economic and social benefits. |
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