The optimization method of structure parameters for sublevel caving method without floor pillar was discussed in theory, through the success experience of similar mines at home and abroad, and by the practical analysis of Meishan iron mine, it was shown that increasing the stope advance interval for was an effective way to reduce mining costs.

According to the practice of the first phase output of 600,000t/a in Xinqiao Pyrite Mine and high mining costs,and the issues of optimum technical plan in first phase extend engineering,the measures of reducing production costs,and improving comprehensive utilization of mineral resource are provided in this paper.

The experimental study on the beforehand control-roof downward slicing all-round mining jointly operated by Kunming University of Science & Technology and Tong-guan-shan Copper Mine is made which reaches the goal to upgrade the production capacity, increases the ore recovery, lowers the ore dillution, reduces mining costs and improves mine benefits.

In the paper,in terms of the real situation of the open pits,the parameters of drilling and blasting are studied under the complex condition and the complex geological situation in open pits beach by applying controlled blasting, so that it guarantees the safety of the prime tunnel beneath the blasting place,the stability of the lasting road and the high slope, reduces ore dilution rate, lump rate, mining costs, and it brings a better project profit.

Based on analysis of mining costs, a formula for calculating the optimum length of fully mechanized longwall faces is derived and the relationship between the longitudinal length of the blocks and the cost of relocation of the face equipments and also that of driving of headings are listed.

For small working place and large quantity water flush in deep mining, upper banch understripping, and no deep dewatering in Shilu open pit mine,the mining efficiency declined, mining costs increased largely, and loss in economy.

Based on ores deposit condition,it makes some exploratio n about how to improve mining efficie ncy,enhance stope roof and rock press safety management,make the roof or bottom p illar effectively and safely,decre ase ores loss and povertification,r educe mining costs,recover mineral resou rces as much as possible.

Based on the study of the prices of mining outputs and the analysis of the uncertainties of mining costs and revenue,and by means of Option Pricing Theory(OPT),an dynamic programming model is developed to provide a helpful approach and quantitative tools for mining projects evaluation and investment.

Declining trends in average ore grades, increasing mining costs and environmental considerations will ensure that this situation will remain in the foreseeable future.

Reserve characteristics and mining costs An empirical study of the phosphate industry

An operational equation which takes into account the number of ventures, probability factors P1, P2, P3 and the estimated mining costs for a given region has been employed to assess the likely returns.

When people consider technological change and its role in reducing mining costs, they focus on the impact of such change on production processes.

Very large cavities in flexible geometries can be created at very low mining costs in the well-studied salt rock at WIPP.

The conventional longwall mining system has been now widely adopted in underground mining of mildly dipping and thin orebodies with feeble immediate roofs in China and abroad, however, this method has defects inherent in its geomechanical properties. For instance, it suffers a comparatively higher mining cost due to large consumption of fine grade timber; moreover, the production output in tons per manshift decreases noticeably with the increase in roof pressure. With the view of overcoming...

The conventional longwall mining system has been now widely adopted in underground mining of mildly dipping and thin orebodies with feeble immediate roofs in China and abroad, however, this method has defects inherent in its geomechanical properties. For instance, it suffers a comparatively higher mining cost due to large consumption of fine grade timber; moreover, the production output in tons per manshift decreases noticeably with the increase in roof pressure. With the view of overcoming of these shortcomings, the author proposes a new conception of improvement in the filling in rooms and pillars method. A structural layout is shown to give clear idea of the methodology. Size of rooms and pillars is determined chiefly by roof characteristics. Roofs subjected to tremendous gravitational force require larger pillars with smaller rooms and vice versa. In mining process, ore is blasted and mucked out at first, then the immediate roof is shot off by retreating blast to fill the emptied rooms. Haulage of broken ore is performed by either scrapers or LHD machines depending on the dip inclination of the orebodies. Mechanical loaders are suitable to the dip less than 15°, while scrapers may be used for dip steeper than 15°. The advantages of the new method are: (1) no timber consumption, (2) higher productivity at lower cost, and (3) further improvement in ore recovery.

This paper deals with an analysis of parameters in regard to rational extent of working area for underground hydraulic coal mining. It expounds the functional relation between the mining cost and the parameters of the working area. A discussion is made on the interrelationship among the driving cost, capacity of hydromonitor, rate of recovery and interval between drawing headings. A preliminary study is also conducted of the relation between the capacity of hydromonitor and the distance of...

This paper deals with an analysis of parameters in regard to rational extent of working area for underground hydraulic coal mining. It expounds the functional relation between the mining cost and the parameters of the working area. A discussion is made on the interrelationship among the driving cost, capacity of hydromonitor, rate of recovery and interval between drawing headings. A preliminary study is also conducted of the relation between the capacity of hydromonitor and the distance of its nozzle from the coal face.

Based on analysis of mining costs, a formula for calculating the optimum length of fully mechanized longwall faces is derived and the relationship between the longitudinal length of the blocks and the cost of relocation of the face equipments and also that of driving of headings are listed. Taking into consideration of the current mining method, the performance and price of the equipments, the labour cost, the working and management levels etc., the optimum size of the blocks of fully...

Based on analysis of mining costs, a formula for calculating the optimum length of fully mechanized longwall faces is derived and the relationship between the longitudinal length of the blocks and the cost of relocation of the face equipments and also that of driving of headings are listed. Taking into consideration of the current mining method, the performance and price of the equipments, the labour cost, the working and management levels etc., the optimum size of the blocks of fully mechanized longwall faces can be determined.