| The Mengqiguer deposit is a large sandstone-type uranium deposit on the southern margin of the Yili Basin.Due to the thick surface coverage of the mining area and the close physical properties between the ore-bearing strata and the surrounding rock,no suitable geophysical method can be used in the working zone.Uranium generates chemical potential in the process of activation,migration,precipitation and enrichment of the interlayer oxidation zone,so the natural potential method should be used to explore this type of deposits with good results.Up to now,the formation mechanism of the spontaneous potential of sandstone-type uranium deposits in the interlayer oxidation zone is still unclear.Researches to understand the formation mechanism of the natural potential of the deposit were conducted in the paper with the theme.The relationship between the mine and anomalies were analyzed and the inversion of the natural potential data of the particle swarm optimization algorithm were also discussed.In terms of deposit geology,hydrogeology,complement-diameter-exhaust system,and interlayer oxidation zone development characteristics,the research work thoroughly elaborated the formation conditions of the Mengqigur sandstone-type uranium deposit,and summarized the unique characteristics of the Mengqigur uranium deposit cause pattern.Based on the systematic analysis of the geochemical zoning characteristics of the interlayer oxidation zone of the deposit,the geochemical behaviors of the two metallogenic standard elements,Fe and S,are closely analyzed,and the mechanism of the spontaneous potential generation of sandstone-type uranium deposits is deeply analyzed.U activates and migrates under oxidizing conditions,precipitates and concentrates under reducing conditions,and the redox reaction that occurs in the interlayer oxidation zone not only provides an electrochemical environment for U ore formation,but also at the weak oxidation zone-redox transition The zone produces a mixed potential difference,which creates a current field in the surrounding rock.After clarifying the generation mechanism of the spontaneous potential of the sandstone-type uranium deposit in the interlayer oxidation zone,in order to quantitatively delineate the shape and location of the underground ore body,the paper simulates the underground ore body with simple geometry,analyzes the relationship between the ore and anomaly,and further explores The SP data inversion method based on particle swarm algorithm is proposed.The paper improves the particle swarm algorithm by introducing the convergence factor and simulated annealing method,and improves the inversion effect,thereby more accurately determining the spatial position of the ore body.The mechanism explanation is inseparable from experimental data,and the explanation results also need to be verified through practice.Four SP anomaly curves were accurately measured in the northeast of the mining area.Through the analysis of anomalous characteristics,it was found that the mine and the anomaly had a good corresponding relationship,thus verifying the reliability of the mechanism interpretation.Using the particle swarm optimization inversion method,the three spontaneous potential curves in the southwest of the mining area were inversely studied,and the spatial position of the underground natural polarization body was successfully delineated,which was consistent with the borehole data.The research work of the thesis has certain theoretical and practical value for the theory and ore deposit positioning of the interlayer oxidation zone sandstone type uranium deposit in the southern margin of the Yili Basin. |
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