| In order to meet the large demand for uranium resources in China's rapid development of nuclear power and to solve the difficult mining problems in the conventional methods of sectional carbonaceous-siliceous-mudstone type uranium deposits in China,this paper,based on the characteristics of the drilling hydraulic mining technology,combined with the actual engineering geological conditions of a carbonaceous-siliceous-mudstone type uranium deposit in the Erlian Basin,for the first time carry out the model test of borehole hydraulic mining for carbonaceous-siliceous-mudstone type uranium deposit based on the similarity theory of model test.The feasibility,mining mechanism and mining efficiency of borehole hydraulic mining for carbonaceous-siliceous-mudstone type uranium deposit are discussed,and some useful conclusions are drawn.The specific contents are as follows:1.On the basis of the characteristics of borehole hydraulic mining studied by predecessors,in a setting of a carbonaceous-siliceous-mudstone type uranium deposit in the Erlian Basin,the similarity criteria suitable for model test of drilling hydraulic mining in carbonaceous-siliceous-mudstone type uranium deposits are derived,and according to the deduced similarity criterion of model test,the similarity are realized between the prototype test scheme for drilling hydraulic mining of carbonaceous-siliceous-mudstone type uranium deposit and geometric condition,boundary condition,high pressure water jet load and material of the model test through theoretical analysis and experimental research.2.Based on the model test similarity criterion of drilling hydraulic mining of carbonaceous-siliceous-mudstone type uranium deposit,the preliminary model test and optimization model test of drilling hydraulic mining are designed and implemented.By comparing and analyzing the data of hydraulic mining in model test,the influence laws of different water jet mining methods,water jet pressure and concrete similar model strength on mining efficiency are studied.The study results show that,under the same conditions,the rotating nozzle efficiency has 3 to 6 times higher than the direct-current(DC)nozzle efficiency,but the DC nozzle has a greater penetration force;increasing the water jet pressure has great influence on the mining depth and the mining efficiency per unit time,and only by increasing water consumption per unit has little effect on the mining efficiency.3.In order to explore the applicability of drilling hydraulic mining to other low-strength strata mining,select sand,cement,bentonite and gypsum as basic raw materials,the orthogonal test of three factors and three levels was carried out,and the influence laws of different ratios of similar materials on the strength and water softening characteristics of similar materials in ore body were studied by means of range sensitivity analysis.The results showed that: 1)with increasing of the age of the specimen,the single axial compression strength of the low strength similar material was compared with the main control effect from the conversion of gypsum to the main control function to the cement.2)with increasing of the amount of bentonite,the density of similar materials decreases gradually,and the size of aggregate is smaller and disintegration is more thorough after water disintegration of the specimen. |
PDF Full Text Request