| China is rich in boron resources,but only 8.98%of the country’s total reserves are available for direct development and utilization.Therefore,it is urgent to develop complex boron and magnesium resources.Fengcheng in Liaoning Province is a super large boron resource base in China.Its paigeite is rich in iron,boron,magnesium and other elements,and has a high value of comprehensive utilization.However,on one hand,with many kinds of minerals,complex structure and close symbiosis,paigeite belongs to the fine-grained uneven distribution,which greatly limits the efficient application of paigeite.On the other hand,the comprehensive and efficient utilization of boron iron ore can not only alleviate the dilemma of less and more rich iron ore in China,but also give full play to the advantages of boron iron ore resources in China,which is of great significance.In view of the economic value,strategic significance and sintering research blank of paigeite resources,this paper studies the raw material characteristics,sintering characteristics and metallurgical properties of paigeite in Fengcheng,Liaoning Province,and draws the following conclusions:(1)Paigeite powder is a kind of low iron,low boron and high magnesium iron concentrate,which has a lot of symbiosis,low iron grade,high MgO content and low B2O3 content.With loose structure,small particle size and low specific surface area for the paigeite ore powder,this mineral resource is not easy to make particles,and it is not conducive to the permeability of the subsequent sinter layer.(2)The result of the experiment shows that the homemade mixed powder has relatively lower assimilation temperature(1200℃),bad liquid liquidity(with a liquidity index of-0.042),high self-intensity of binding phase(6486N/sample),and good quality of crystal consolidation strength(compression strength 11048N/sample).(3)The order of influence on vertical sintering speed of paigeite is:basicity,carbon content,common ore ratio.The order of influence on the yield is:ratio of common ore,carbon content,basicity.The order of influence on the drum strength(T)of boron sinter is carbon content,common ore ratio and basicity.The order of influence on RDI+3.15 is:ratio of common ore,basicity,carbon content.The optimal ore blending scheme considering only the vertical sintering speed is as follows:basicity 2.1,common ore ratio 30%,carbon content 5%,The optimal ore blending scheme considering only the yield is as follows:basicity 1.9,general ore ratio 60%,carbon content 5.5%.The optimal ore blending scheme only considering the drum strength(T)is:basicity 2.1,ore blending 60%,and carbon blending 5%.The optimal ore blending scheme considering RDI+3.15 is alkalinity 1.7,common ore ratio 60%and carbon content 5%.Considering the vertical sintering speed,yield,drum strength and low temperature reduction pulverization index,the sequence of main influencing factors is the ratio of common ore,carbon content and basicity.The optimal ore blending scheme is:basicity 1.7,ore blending 60%and carbon blending 5%.(4)The order of influence on the total characteristic number Sn and the maximum pressure difference ΔPmax of paigeite sinter is:ratio of common ore,basicity and carbon content.the order of influence on the softening start temperature,melting start temperature and dripping start temperature of paigeite sinter is:ratio of common ore,carbon content and basicity.The order of influence on the permeability of paigeite sinter is:ratio of common ore,carbon content and basicity.The order of influence of softening and melting-dripping range of boron iron ore sinter is carbon content,basicity and common ore ratio.The optimal ore blending scheme considering only the total characteristic number SN of permeability is:basicity 2.1,ore blending ratio 60%,coke powder 5%.The optimal ore blending scheme considering only the maximum pressure difference ΔPmax is:basicity 1.9,ore blending ratio 60%,coke powder 5.5%.The optimal ore blending scheme considering only the softening start temperature is:basicity 1.9,common ore ratio 60%,and carbon content 5.5%.The optimal ore distribution scheme only considering melting start temperature is:basicity 2.1,common ore ratio 60%,and carbon content 5.5%.The optimal ore distribution scheme only considering dropping start temperature is:basicity 1.9,common ore ratio 30%,and carbon content 5.5%.The optimal ore distribution scheme only considering softening zone is:basicity 1.9,common ore ratio 60%,and carbon content 5%.The optimal ore blending scheme considering only the dropping interval is:basicity 1.7,ore blending 60%and carbon blending 5.5%.Considering the softening-melting-dripping characteristics,the sequence of influencing factors is carbon content,common ore ratio and basicity.The optimal scheme of ore blending:basicity 1.9,ore blending 60%and carbon blending 5.5%.Considering low temperature reduction pulverization index,cold metallurgical properties and softening-melting-dripping characteristics,the sequence of influencing factors is carbon content,common ore ratio and basicity.The optimal scheme of ore blending:basicity 1.9,ore blending 60%and carbon blending 5.5%.(5)After burden sintering,reduction,softening and dripping,slag and iron separation,the migration behavior of boron component is Mg2Fe(BO3)O2-Fe3BO6-FeB.The migration behavior of magnesium component is Mg2Fe(BO3)O2/MgFe2O4MgFe2O4/MgO-MgAlO4/MgSiO3(in slag). |
PDF Full Text Request