Study on the influence of greater pitching to top coal caving law in complex conditions;

NO_X emission behavior of different types of coal;

In this paper, chemical forms, release rules and their affecting factors of phosphorus in the sediments of eutrophic water were discussed.

Release concentration of HCHO and tripbenzene after house fitment is monitored,then release rules are found out.

In order to know the release law of heavy metals and make sure whether it would pollute water, the distribution characteristics of nickel & zinc and their release law were studied.

The stopes structure by using mining method of"induced inbreak und pillarless sublevel caving with recovery access",the features of this mining method and the regular pattern of ore drawing by this method are studied,thus the means for calculating the cut\|off grade of ore are determined that are the basis for optimun exploitation of mineral resource.