Evaluation Of Typical Pyrite Tailings Resources In Northwest Guizhou Province

The Northwest region of Guizhou province is one of the main sulfur-iron mining areas in China.However,prolonged mining and ore processing activities have led to the accumulation of a large amount of sulfur-iron tailings along the slopes surrounding the mining areas.This not only occupies land but also causes certain environmental impacts.Additionally,due to the limitations of technology and equipment at that time,the produced tailings contain enormous potential resources,which are worth further exploration.Therefore,this study selected the Linkou town of Qixingguan,Maochang town of Dafang,and Heishu town of Zhenxiong in northwest Guizhou province as the research areas.By conducting field investigations and sample collection,the geometric method and production report method were employed to estimate the amount of sulfur-iron tailings.Moreover,various analytical techniques such as optical microscopy,X-ray diffraction analysis,scanning electron microscopy energy spectrum analysis,and analyses of major,trace,and rare earth elements,as well as phase analysis,were used to investigate the mineral composition,chemical composition,and distribution of useful elements in the tailings.Finally,a mathematical model was established to evaluate the resources of sulfur-iron tailings in Northwest Guizhou province.The study obtained the following insights:（1）The main chemical components of sulfur-iron ore tailings in Linkou,Maochang,and Heishu towns are TFe₂O₃,Si O₂,Al₂O₃,and Ti O₂.Among them,from the perspective of the content of valuable elements,the TFe content in the three regions is 26.95 wt%,18.21 wt%,and 22.22 wt%,respectively,all of which have reached the secondary flotation grade.The Ti O₂ content is 3.51 wt%,2.31 wt%,and 4.84 wt%,respectively,which have also reached the boundary grade and have potential utilization value.The trace element contents differ slightly among the three regions.The V element in the sulfur-iron ore tailings in Linkou town and Heishu town is874.73 ug/g and 621.69 ug/g,respectively,which have reached the boundary grade.Other elements have no immediate utilization value,but heavy metals such as Cu,Cd and As are enriched in the sulfur-iron ore tailings（slag）,and should be given more attention when considering comprehensive utilization due to environmental factors.At the same time,the rare earth element contents in the sulfur-iron ore tailings in the three regions are relatively high and have potential utilization value.Moreover,it can be inferred from the rare earth partition curve that the sulfur-iron ore tailings in the three regions have a similar source,which is conducive to the development and utilization of the tailings.（2）The sulfur-iron tailings mainly consist of hematite,magnetite,pyrite,rutile,quartz,molybdenite,kaolinite,and plagioclase.From the mineral phase analysis,the valuable element iron mainly exists in the form of hematite,which is the product of high-temperature calcination.The degree of crystallization is low,and due to long-term stacking,the minerals generally suffer from varying degrees of pollution and corrosion,resulting in impurities in the composition of hematite,and a large variation coefficient in particle size.Through monomer dissociation experiments,it was found that increasing the sample’s grinding fineness can effectively improve the iron recovery rate.（3）After conducting field measurements,reviewing production materials and geological reports,and using geometric and production report methods,we estimated the storage volumes of sulfur-iron mine tailings in Linkou,Maochang,and Heishu towns to be 73.3572 million tons,26.2297 million tons,and 3.3313 million tons respectively.Based on the element content in the tailings,we also calculated the resource reserves of the valuable elements TFe and Ti O₂.The reserves in Linkou town are19.1998 million tons and 2.5748 million tons respectively,while those in Maochang town are 4.7764 million tons and 0.7712 million tons respectively.The reserves in Heishu town are 0.7402 million tons and0.1612 million tons respectively.（4）Ten evaluation indicators were selected from the sulfur-iron tailings in the northwestern part of Guizhou province.A four-level evaluation set was established with"excellent","good","average",and"poor".The fuzzy comprehensive evaluation model was used,and a comprehensive evaluation model for sulfur-iron tailings resources was established by combining the comprehensive index method and the analytic hierarchy process.The results showed that the comprehensive evaluation indexes of Linkou Town,Heishu Town,and Maochang Town were 3.046,1.466 and 2.735,respectively.Therefore,from the evaluation results,the sulfur-iron tailings in the areas where Linkou Town and Heishu Town are located have excellent development potential.