Study On Heavy Medium Separation Technology And Equipment Structure Parameters Of High Sulphur Gangue Pyrite

Coal gangue is the largest solid waste in the process of coal mine production.At present,more than 5 billion tons of coal gangue have been accumulated in China,among which pyrite of high sulfur coal gangue with sulfur S_t>6%is important sulfur resource in China.By sorting pyrite from high-sulfur gangue,the harm to environment can be reduced,the maximum recovery and utilization of sulfur resources can be realized,and the comprehensive utilization value of gangue can be improved.The paper focuses on taking the heavy medium separation technology recycling pyrite mine of high sulfur coal gangue,and large angle complex cone heavy medium cyclone is presented as select equipment.The stability and rheological properties of high density dense medium suspension prepared by-0.5mm high-sulfur gangue and primary magnetite powder are systematically studied in this paper.The effect of the equipment on the concentration degree of the heavy medium suspension and its structural parameters on the separation effect are studied.Finally,a kind of heavy medium separation process suitable for the equipment is proposed theoretically.Firstly,the paper systematically studies the high-density dense medium suspension for pyrite separation with 1.8-2.3g/cm~3,-0.5mm high-sulfur gangue content of 10%-35%,and analyzes the relationship between density and-0.5mm high-sulfur gangue content and its rheology and stability.The results show when the density or non-magnetic content of suspension is constant,the higher of non-magnetic content or density of suspension,the higher the viscosity and the better the stability,otherwise,vice versa;The density of high-density medium suspension for pyrite separation prepared with primary magnetite powder and-0.5mm high-sulfur gangue should be controlled at 2.0-2.2g/cm~3,and the content of-0.5mm high-sulfur gangue should be controlled at 15%-25%.Secondly,in order to explore the concentration degree of heavy medium suspension by the large angle double cone heavy medium cyclone,the single-factor test with different cone angles was designed.The relationship between the cone angle and the concentration degree of heavy medium suspension is analyzed through the changes of bottom and overflow density.The results show that the upper cone angle is the main factor affecting the concentration effect of the cyclone,and the lower cone angle is the secondary factor.From the point of the underflow concentration,when the combination of cone angle is 80°-30°,the density differencethe between bottom flow and filling is up to 0.41 g/cm~3,which is the largestenrichment,and the concentration is the highest.Then,through the orthogonal experiment of central pipe diameter,cone angle and bottom flow port diameter,the order and significance of the influence of these three structural parameters on the sulfur content and recovery of the bottom flow concentrate are analyzed,and then the relative optimal structural parameters are determined.The results show that from the point of sulfur grade of bottom flow products,the diameter of bottom flow orifice has the greatest influence on it,followed by cone angle,and the diameter of central pipe is the smallest.And when the diameter of bottom flow orifice is 60 mm,the diameter of center pipe is 120 mm and the cone Angle combination is 80°-20°,the sulfur grade of concentrate products is 26.26%,which is the highest;From the point of sulfur recovery rate of underflow products,the influence of cone angle combination is the greatest,the diameter of bottom flow orifice is the second,the diameter of center pipe is the smallest.And when the diameter of bottom flow orifice is 80 mm,the diameter of center pipe is 120 mm and the cone angle combination is 60°-30°,the sulfur recovery rate of bottom flow product is 51.23%,which is the higest.Considering the actual production requirements,the product grade and recovery rate,the optimum structure parameter combination is determined as follows:the diameter of bottom flow orifice is 70 mm,the diameter of center pipe is 80 mm and the cone angle combination is 80°-20°.The sulfur grade is 25.09%and recovery rate is 46.68%,which basically meet the requirements of the main products.Finally,on the basis of the experimental research results in the previous chapters,typical process analysis and coal preparation technology,a heavy medium separation process suitable for large angle double cone heavy medium cyclone is proposed,but it needs to be further studied and verified in semi-industry.