Influence of moisture content on the shape of isolated movement zone in mesoscale
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摘要: 為從細觀尺度研究礦巖含水率對自然崩落法放礦松動體形態的影響,對非飽和礦巖顆粒間的受力進行了分析,并分別將放礦場內細顆粒流與大塊離散礦巖利用格子波爾茲曼法與離散元法處理,基于格子波爾茲曼法-離散元法耦合算法建立自然崩落法放礦模型,得出含水率與放礦松動體形態間的關系,并通過將模擬結果與已有研究結論進行對比分析,驗證了基于格子波爾茲曼法-離散元法耦合算法的放礦模型準確性及可靠性.研究表明:礦巖含水率對放礦松動體形態影響顯著,在同等礦巖放出質量分數情況下,隨著含水率的增大,放礦松動體高度呈先增大后減小的趨勢,放礦松動體形態先逐漸變為細長型再逐漸恢復,放礦松動體形態變化的含水率臨界值在10%左右.Abstract: Block caving mining has the advantages of large production capacity, safe operation, low mining cost, and easy organization and management. Therefore, it is considered as one of the natural alternatives to the current open cut mining. The migration law of ore-rock and the design of ore drawing parameters during ore drawing are the key to block caving mining. The caving rocks usually contain pore water between the fine particles, therefore, the caving rock in an unsaturated state is a solid-liquid-gas three-phase coupling field. The electric double layer force as well as the ionic hydration force, electrostatic force, and Van der Waals force result in the interaction between adjacent particles on a molecular scale. However, the interaction is also resulted in the force of the liquid bridge. To explore the influence of moisture content on the shape of an isolated movement zone in block caving method under ore drawing in mesoscale, the stress between unsaturated ore particles was analyzed. The fine particles flow and discrete bulks of ore-rocks were investigated using lattice Boltzmann method (LBM) and discrete element method (DEM), respectively. Based on the LBM-DEM coupling algorithm, the ore-drawing models of the block caving method were constructed, and the relationship between the moisture content and the shape of the isolated movement zone was obtained. The accuracy and reliability of the ore-drawing models based on the LBM——DEM coupling algorithm were verified by comparing the simulation results with the existing research results. The results indicate that the moisture content of ore-rock has significant effects on the shape of the isolated movement zone. When the same ore-rock mass fraction is discharged, with an increase of moisture content, the height of isolated movement zone increases and then decreases, and the shape of isolated movement zone becomes slender and then is restored gradually. The critical value of moisture content during the change of isolated movement zone shape is about 10%.
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Key words:
- block caving /
- ore drawing /
- moisture content /
- non-Newtonian fluid /
- isolated movement zone
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參考文獻
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