Technical achievement appraisal conference of "the Second Blasting of 15,000 t/day Open-pit Mining Expansion Works" and "Research on Extremely Complex Large Scale Vacant Area of Cavern Blasting Processing" passed through expert appraisal organized by Luoyang Scientific and Technical Bureau smoothly on 25^th.

　　Group Company respects knowledge, focuses on talents, vigorously implements application of revitalizing the mine through science and technology in the enterprise, and obtains obvious effect in recent years. To accelerate enterprise development and form scaled open-pit mining as soon as possible, Group Company successfully implemented the second blasting of 15,000 t/day open-pit mining expansion with 675t powder charging and 1.065 million m³ rock blasting on May 22, 2004. Jointly designed by CMOC and Henan Wanshun Blasting Engineering Corporation, the blasting adopts strip type chamber powder charging and non-electric millisecond blasting technology. With 20 design pitheads, 80 chambers and 2,990m total cavern length (890m heading and 2,100m chamber), it is the largest blasting in Henan Province throughout history. It realizes even lumpiness, high throw rate and other effects, and receives uniform affirmation from authoritative sources in Henan Province blasting industry.

　　There are large areas of regular and irregular deep and shallow mining vacant areas at the lower part of 30,000t/day open-pit mining, which have large span, overlapping and staggering. With descending of operation steps, collapse may occur. According to the safety thickness from scientific research unit, safety of vacant area processing can be guaranteed only after penetrating 40m ultra-deep hole at the upper part of vacant area top. However, some vacant areas have thin tops and not suitable for operation of large punching equipment. Under the circumstance, engineering technicians of Mining Company decide to and succeed in using cavern blasting method for vacant area processing after full demonstration. Currently, vacant area processed by the method is up to 12,800 m2 and volume is up to 140,800 m³. This not only guarantees smooth work safety but also creates obvious social and economic benefits.

　　After listening to research report of Group Company, reviewing technical documents and conducting appraisal and discussion, the expert group believes two achievements have complete appraisal documents, and full, accurate and reliable indexes and data, meeting appraisal requirements. With practical and promotion values, "the second blasting of 15,000 t/day open-pit mining expansion" project develops in detonation network reliability, strip type chamber application and filling technology, and is up to advanced domestic level in application of strip type blasting cartridge and non-electric network. "Research on Extremely Complex Large Scale Vacant Area of Cavern Blasting Processing" project has new significant progress in processing technology of complex large scale vacant area in China. Featuring simple application, safety, reliability and low cost, the vibration belt effect technology has higher promotion and application values in similar mines both at home and abroad.

　　It is known that the appraisal is authorized by Henan Province Scientific and Technology Department and the appraisal committee is organized by Luoyang City Scientific and Technology Bureau, which consists of 7 authoritative sources in domestic blasting industry such as Professor Chen Shouru from Central South University and senior engineer Ding Yuezhang from Engineering Military Scientific Research Institute III of the Headquarters of the General Staff. Yu Songhe, Achievement Management Department Head of Henan Province Scientific and Technology Department, Wu Zhenqing, Director of Luoyang Scientific and Technical Bureau, Du Quanxian, Deputy Director of Luoyang Scientific and Technical Bureau, Li Faben, Standing Deputy General Manager of Group Company, Zhang Wuxing, Manager of Mining Company, Cheng Xiusheng, Deputy Chief Engineer, Qin Yuhui, Head of Mining Department and Yi Lin, Head of Safety and Security Department attended the appraisal conference.