Study On Pre-enrichment-Magnetization Roasting Of Sijiaying Integrated Tailings

As a large steel producing country,the storage of iron tailings piles has been increasing,the cost and difficulty of tailings treatment have increased and the national environmental protection policy has become increasingly strict.The benign development of mining enterprises is facing many challenges.The development and comprehensive utilization of tailings resources has become an inevitable requirement for the sustainable development of mining enterprises.This study takes Sijiaying integrated tailings as the research object,and explores the optimal process parameters of the magnetization roasting-weak magnetic separation process of Sijiaying integrated tailings based on system research.Firstly,the systematic process mineralogy of Sijiaying integrated tailings was carried out by means of optical microscopy,X-ray diffraction,chemical composition analysis and iron chemical phase detection.On the basis of the exploration of the ore properties,the preenrichment process exploration of Sijiaying integrated tailings was carried out and the optimal process parameters were gained.At the same time,the physicochemical properties of preenriched products were studied in detail.At last,it was carried out to the suspension magnetization roasting-weak magnetic separation process of the pre-enrichment product,the test also determined the optimal magnetization roasting-weak magnetic separation process and conditions for pre-enriched products.While the detailed study was carried out on the reaction characteristics during the roasting process and the magnetic transformation of the roasted product.The Sijiaying integrated tailings process mineralogical research shows that the total iron grade of the ore is 9.84%,the iron in the ore is mainly in the form of iron in hematite and magnetite,and the distribution rates are 68.25%and 15.20%,respectively.The iron-bearing minerals in the ore are mainly hematite and magnetite,with contents of 9.32%and 2.17%,respectively.The gangue minerals are mainly quartz with a content of 87.67%.The hematite and magnetite in the integrated tailings are mainly in the form of disseminated,and some hematite and magnetite are associated with each other and the gangue minerals are intertwined to form a continuous body.The pre-enrichment process test of Sijiaying integrated tailings shows that the integrated tailings adopts the low intensity magnetic-high intensity magnetic-re-grinding-igh intensity magnetic pre-enrichment process,with a low intensity magnetic field strength of 100kA/m and a two-stage high intensity magnetic rough selection magnetic field strength of 320 kA/m.The strength of 320kA/m,re-grinding particle size-0.038mm particle size content of 95%,after a low intensity magnetic field,two sections of high intensity magnetic,can obtain TFe 20.94%grade,the recovery rate of 64.08%pre-concentrated concentrate.The iron minerals in the preenriched concentrate are mainly hematite and magnetite,and the-25 μm content in the preenriched concentrate is as high as 54.34%.The test of roasting-low intensity magnetic separation of Sijiaying integrated tailings preenrichment product shows that the reaction of hematite to magnetite is spontaneously carried out in the roasting process and the reaction is easy to realize,but the temperature and CO gas concentration need to be strictly controlled to avoid the occurrence of overreduction phenomenon during the reaction.The best roasting-magnetic separation process parameters for the pre-enriched concentrate arethe experiment determined that the roasting temperature of 540℃,CO concentration of 20%,reduction time of 15 min,total gas volume of 350mL/min,grinding fineness-0.025mm content of 70%is optimal process parameters for roastingmagnetic separation of pre-enriched products.At this time,a good index of 65.61%TFe grade,53.68%iron recovery rate and 82.31%magnetic conversion rate can be obtained.The research results of this paper have certain guiding significance for the recovery of useful iron minerals in Sijiaying comprehensive tailings and the development of similar iron tailings.