Journal of Coal Science and Engineering (China)

In view of the deficiency of current gas monitoring systems in coal mine roadway excavation, a two-level information fusion technology, which adopted the adaptive weighted algorithm and the BP neural network technology, was applied to gas monitoring. The results show that the adaptive weighted algorithm can realize self-regulation by decreasing the weight value of the failed sensor automatically, so as to eliminate the effect of the failed sensor and ensure the effectiveness and accuracy of the gas monitoring system. The BP neural network can not only effectively predict the gas gush quantity of the excavation roadway, but also accurately calculate the gas concentration in the region where one or more sensors have failed, so as to provide the basis for judging the safety status of the roadway excavation. The experiments prove the superiority and feasibility of the application of information fusion in gas monitoring.

A more efficient mine ventilation system, the ventilation-on-demand (VOD) system, has been proposed and tested in Canadian mines recently. In order to supply the required air volumes to the production areas of a mine, operators need to know the cause and effect of any changes requested from the VOD system. The sensitivity analysis is developed through generating a cause and effect matrix of sensitivity factors on given parameter changes in a ventilation system. This new utility, which was incorporated in the 3D-CANVENT mine ventilation simulator, is able to predict the airflow distributions in a ventilation network when underground conditions and ventilation controls are changed. For a primary ventilation system, the software can determine the optimal operating speed of the main fans to satisfy the airflow requirements in underground workings without necessarily using booster fans and regulators locally. An optimized fan operating speed time-table would assure variable demand-based fresh air delivery to the production areas effectively, while generating significant savings in energy consumption and operating cost.

To control complex system’s safety effectively, safety control program was supported based on the principles of behavioral science that shapes organizational behavior, and organizational behavior produced individual behavior. The program can be structured into a model that consists of three modules including individual behavior rectification, organization behavior diagnosis and model of safety culture. The research result not only reveals the deep cause of complex system accidents but also provides structural descriptions with the accidents cause.

The odd axes resist pressure intensity with large quantity coal gangue was discussed and experimented on fly ash and coal gangue gel filling body between different concentration, proportion and additive dosage. The results show that forepart intensity of new gangue filling body is very low, and anaphase intensity have some increase which still go up after sixty days. The intensity of tao gangue can reach 1.0 MPa in seven days, and anaphase intensity can reach about 2.0 MPa. In the same term, the odd axes resist pressure intensity of gel filling body with tao gangue is higher than new gangue No.1 and No.2. To mix into proper additive dosage which occupied the quality point of cement and fly ash not more than 1.5% can improve the fluidity of slurry body and intensity of filling body.

The connection between blasting cost and comprehensive cost is the main concern. Some blasting effect factors (such as unit explosive consumption, uniformity of blockness, shape and porosity of blasting heap), which had an influence on electric shove loading efficiency, were analyzed. In the end a project to properly increase in blasting cost to decrease the comprehensive cost was put forward. At the same time, the hole-by-hole blasting is effective technology to improve blasting effect.

Presented a new coal dust control program that was airtight negative pressure dust-control technology at the transpersite, combining with analysis with the movement of air currents and numerical simulation of gas-solid flow at the transpersite, and proved the mechanism of precipitation and proliferation for coal dust-controlt in theory. The technology has made good economic results at the Heidaigou Clean Plant, not only dust concentration control within 10 mg/m3 to the work site, but also substantial energy savings and cost savings.

In order to settle the mining optimization design and safety problem of the above 1 150 m pillar of No.1 ore-body in No.II Mining Jinchuan, the lean-ore above 1 250 m, the 1 150 m horizontal pillar and the ore-body below 1 100 m regarded as research objects based on the original design project, and nine calculation schemes on different mining sequence and different fill body strength were put forward based on cement-sand ratio of 1: 4, 1: 12 and 1: 24. Calculation parameters were got by the back analysis method of field monitoring data, and the FLAC2D program was applied to compute for these schemes, stress and displacement of ground settlement, shaft and stope roof were analyzed, and some conclusions were got. Results show that the intensity of filling body and the mining technique have very important effect on controlling settlement and stability of surrounding rock; Developing of lean ore have some influences to the 16th return air filling shaft, especially for 1 500∼1 400 m of the shaft; The best project is the first project. This research supply some technique references and safety appraisals for the mining of lean-ore of No. II Mining Jinchuan.