Research And Application Of Multi Strength Combined Filling To Control Ground Pressure In Mining Thick And Large Ore Body

Presidengt XI pointed out that“green water and green mountains are golden mountains and silver mountains”At present,the government stipulates that metal mines and non-metal underground mines must conduct feasibility studies on filling mining methods,and give priority to the implementation of filling mining methods.Filling mining method has attracted more and more attention in the mining industry because of its green,ecological,efficient and safe role.Based on the filling mining method,this paper analyzes the ground pressure in the goaf in the middle section of+680m～+740m in the opposite row of copper molybdenum mine.The parameters of the ore body in the goaf in the middle section are 85m long,40m thick,60m high and 75°inclined.It belongs to a steeply inclined thick large ore body.The main research contents and achievements of this paper are as follows:（1）Based on the theoretical analysis of fuzzy mathematics,following the principles of safe production,economic rationality and high ore recovery rate,and combined with the actual situation of the mine,three mining schemes are preliminarily selected.After fuzzy comprehensive evaluation,the evaluation results show that,The advantages and disadvantages of the three mining schemes are as follows:the room subsequent tailings cemented filling method in the stage of sublevel drilling（85.87%）is better than the room subsequent filling method in the stage of vertical deep hole caving,and the VCR method（80.79%）is better than the upward horizontal layered drift filling method（78.14%）,The optimal mining method for the opposite row copper molybdenum mine is the sublevel drilling stage room followed by tailings cemented filling method.The stope production capacity of this scheme is 750t/D,ore loss rate:15%,ore dilution rate:10%,mining cutting ratio:6.2m/kt,and mining cost:75.3 yuan/t（2）Through the physicochemical and proportioning optimization test of the mine’s full tailings,it is analyzed that the true density of the mine’s full tailings is 2.667g/cm3,the bulk density is 1.005g/cm3,the void ratio is 62.31%,the p H value of the full tailings mortar is 7,there are no obvious harmful impurities in the tailings,the particle size distribution belongs to medium and fine tailings,and the compressive strength of the filling test block increases with the increase of proportioning and concentration,The growth of curing age shows a positive correlation.Considering the transportation performance,72%of the filling body that can actually reach the mass concentration after passing through the deep cone thickener is selected as the main object of this study.The test parameters provide data basis for numerical simulation,and can also smoothly guide the design and construction of mine practical engineering.（3）FLAC^3D numerical simulation is used to study the stability of goaf.36 schemes are analyzed from two different filling sequences of filling one by one and filling every other,five different ratios of cement powder and tailings 1:6～1:20 and three combinations of different filling heights.By comparing the safety factor,the displacement and deformation of goaf roof and floor and plastic failure,Finally,it is determined to use the ash sand ratio of 1:6,1:12 And 1:20 to fill the goaf at the height of 20m in the lower part,20m in the middle and17m in the upper part of the single free face.（4）When the filling scheme is applied to the field project of the mine filling system,the comprehensive cost is equivalent to 23.7 yuan/T,which meets the requirements of 24.5yuan/T on the premise of ensuring the stability of the goaf,and realizes the purpose of green,safe,efficient and sustainable development of the mine.