Research On Coal Mine Water Decontamination Process Underground For Coal Mines

Guided by the national opinion on the high-quality development of the coal industry,the treatment and reuse of wastewater generated from coal mine operations is of paramount importance in reducing the incidence of underground water damage and alleviating water scarcity.As a crucial water storage unit in coal mines,the stability of the operational status of water tanks determines the efficiency of underground water treatment.Due to the complex working environment of underground coal mines,the problem of water bin dredging has always been a crucial concern for coal mining enterprises.Therefore,this thesis designs the underground coal water decontamination process system for coal mines in front of the water tank and carries out decontamination pretreatment before the coal water enters the water tank to reduce the solid particle content of the coal water entering the water tank,thus extending the cleaning cycle of the underground water tank and ensuring safe production in coal mine.Based on the environmental conditions of underground coal mine tunnels and the characteristics of coal water quality,this paper designs a coal mine underground decontamination process with a coal picker,coagulation sedimentation pool,stacked-screw sludge dewatering equipment,and belt conveyor as the main elements.The dewatering efficiency of the stacked-screw sludge dewatering equipment determines the solid particle interception rate of the decontamination process.The method of theoretical analysis verifies the applicability of the filtration mechanism and anti-clogging performance of the stacked-screw sludge dewatering equipment in the coal water decontamination process.Based on the conclusion of mechanical and kinematic analysis of solid particles in coal water inside the spiral chute,and combined with the established spiral chute processing capacity calculation model,the key component spiral shaft was designed with structural selection,shaft diameter,and pitch,and the compression ratio was checked accordingly.To tackle the issue of reduced dewatering efficiency in dynamic-static screens caused by the working condition and susceptibility to deformation of the static ring,finite element analysis was performed on static rings with different structural forms using ANSYS software.The analysis focused on the deformation and stress of the static ring.Based on the results of the analysis,preliminary improvements were made to the structure of the static ring and validated.Using the DOE method,a three-factor,three-level orthogonal experiment was designed to investigate the impact of the number of support holes,improved static ring thickness,and loading on the performance of the static ring.The experiment was based on two indicators: maximum deformation and maximum stress of the improved static ring.The results were used to determine the primary and secondary order of factors affecting the structural performance of the improved static ring.Based on the conclusion of the orthogonal test,a quadratic regression orthogonal combination test with the thickness of the improved static ring,the load as the influencing factor,and the maximum deformation as the test index was designed to reasonably predict the optimal value of the thickness of the improved static ring;a multiple regression model to predict the optimal value of the improved static ring thickness was established based on regression analysis,residual analysis,analysis of variance,and significance test.The accuracy of the multiple regression model was validated by predicting and verifying the optimal thickness of the improved static ring,Using the optimal thickness of the improved static ring,the theoretical improvement in the dewatering efficiency of the screw sludge dewatering equipment was evaluated.The results of the research indicate that the establishment of a coal water decontamination pretreatment process in front of the underground water bunker has a significant effect on extending the cycle time of water tank desilting;The filtration characteristics of the stackedscrew sludge dewatering equipment and its excellent anti-clogging properties have excellent applicability in the underground coal water decontamination process for coal mines.The design of a suitable spiral shaft with variable shaft diameter and pitch inside the spiral tank has a significant impact on the treatment capacity of the stacked-screw sludge dewatering equipment.Based on ANSYS finite element analysis of deformation and stress of static ring can guide the direction of structural improvement of the static ring,and the preliminary conclusion of the analysis shows that the improvement of the static ring can greatly improve the installation efficiency of static and dynamic ring filters,in addition to the improvement of filtration efficiency of static and dynamic ring filters.The DOE-based three-factor,three-level,twoindicator orthogonal test design of the improved static ring determined the order of influencing factors as the number of support holes,thickness,and load,and determined the maximum deformation of the improved static ring as the main test index.The multiple regression model obtained by a quadratic regression orthogonal combination test and verified through correction was used to predict the optimal thickness of the improved static ring under different loading conditions.Experimental verification confirmed the high accuracy of the regression model,and it was found that the optimized thickness of the improved static ring has a significant impact on the filtration performance of the dynamic-static filter screen.