Research On Sodium Removal Influence Factors And Disciplines Of The Extracted Vanadium Residue After Water Leaching

At present,the actual production of vanadium extraction process for the main business of sodium roasting-water extraction of vanadium,in this production process inevitably produce a large amount of sodium extracted vanadium residue.As the water extracted vanadium residue contains a large amount of valuable metal elements,such as:iron,chromium and vanadium,it is necessary to recycle.But because of water extracted vanadium residue combine with a large amount of the sintering raw materials,resulting in sodium content increasing,thereby increasing sodium content in the blast furnace,leading to sodium in the blast furnace cycle enrichment,greatly improving the blast furnace nodulation probability,seriously affect the life and operation of blast furnace.In this paper,sodium-vanadium residue come from Chengde Jianlong Iron and Steel Company are used as raw material,so that it can be used as raw material to return to blast furnace process without adversely affecting the equipment.Remove the sodium element to achieve the reuse of solid waste resources.In this paper,sodium element is removed by mixed acid leaching method.The influence of sulfuric acid concentration,hydrofluoric acid concentration,leaching temperature,liquid-solid ratio and leaching time on sodium leaching rate in water extracted vanadium residue;the influence degree of the factors and the interaction between them,and the leaching kinetics of mixed acid leaching were studied by means of XRD,SEM,XRF and so on.The main conclusions and results are as follows:(1)According to the chemical composition analysis and phase analysis of the extracted vanadium residue shows that the main phase are iron oxide,pyroxene solid solution,in which sodium main packages in the pyroxene solid solution,otherwise a small amount of sodium exists in silicate phase.(2)The addition of hydrofluoric acid can effectively destroy the pyroxene solid solution structure and the silicate phase.The sodium in the water extracted vanadium residue can be effectively leached,and the removal rate of sodium is increased by about 20 percentage points compared with the sulfuric acid alone.(3)Under the condition of mixed acid leaching with sulfuric acid and hydrofluoric acid,the removal rate of sodium in water extracted vanadium residue increased obviously with the increase of hydrofluoric acid concentration,and reached 75.34%when the concentration of hydrofluoric acid was 15%.With the increasing of the ratio of liquid to solid,the sodium removal rate of water extracted vanadium residue increased fast and then increased slowly.With the prolongation of reaction time,the sodium removal rate of water extracted vanadium residue increased slowly.The effect of sulfuric acid concentration and reaction temperature on the removal rate of sodium was not obvious.(4)Combined with single factor experiment and Box-Behnken response surface experiment to study the factors which are influent the sodium leaching rate of extracted vanadium residue,and the interaction between various factors.The leaching process is optimized.It is concluded that:the influences of factors on leaching rate are as follows:hydrofluoric acid concentration>leaching temperature>sulfuric acid concentration>leaching time.The interactions between sulfuric acid concentration and hydrofluoric acid concentration are strong;sulfuric acid concentration and the leaching time,sulfuric acid concentration and the leaching temperature exist certain interaction;hydrofluoric acid concentration and the leaching time,hydrofluoric acid and leaching temperature,leaching temperature and leaching time are weak.According to the response surface optimization we obtain the optimum process conditions:sulfuric acid concentration is 15%,hydrofluoric acid concentration is 15%,leaching temperature is 45?,liquid-solid ratio is 10:1,leaching time is 90 min,raw material granularity is smaller than 75 ?m.Sodium leaching rate is as high as 91.7%,and TFe can reach 35.19%after this leaching conditions.(5)According to the study of extracted vanadium residue leaching kinetics,we can conclude that the leaching process can be described by a diffusion-chemical hybrid control which is belong to shrinking core model.The apparent activation energy is 16.29 kJ/mol,sulfuric acid and the reaction series of sucrose are 0.48 and 1.68,the macroscopic reaction kinetics equation is:[(1-x)1/3-1]+1/3ln(1-x)=C([H2SO4])0.48C([HF])1.68 exp((-16.29)/(RT))t...