| Vanadium-bearing titanomagnetite is associated with polymetallic typical mineral resource of iron, vanadium, titanium and other metals. The current study mainly focuses on the utilization of high-grade vanadium-bearing titanomagnetite and few research reports about the utilization of ultra-low grade vanadium-bearing titanomagnetite. It mostly concentrates in the early research of geological and prospecting, mineral composition, mineral characteristics and mineral beneficiation. However, the research about extraction and separation of valuable metals and other aspects have not been reported. In this paper, the raw material is the vanadium-bearing titanomagnetite bulk concentrate after the beneficiation of ultra-low grade vanadium-bearing titanomagnetite. The paper aims at the characteristics of high content vanadium and titanium, low content iron which do not apply to the blast furnace ironmaking. The mineral characteristics of ultra-low grade vanadium-bearing titanomagnetite, hydrochloride selective leaching behavior, the preparation of rich titanium product and other key issues are investigated. The following innovative results are achieved:(1) The mineralogy characteristic and ore component of ultra-low grade vanadium-bearing titanomagnetite in Liaoning Province are studied. The independent mineral of iron is vanadium-bearing titanomagnetite, independent mineral of titanium is ilmenite and sphene, most of the iron and a small number of titanium exsit in silicate minerals, vanadium mainly exsits in titanomagnetite (the subject of vanadium-bearing titanomagnetite) in the form of isomorphous. The vanadium-bearing titanomagnetite disseminates coarse particle size and its composition contains high vanadium. It is a new type of strategic resources of vanadium-bearing titanomagnetite.(2) The efficient leaching of iron, vanadium and titanium of vanadium-bearing titanomagnetite bulk concentrate by hydrochloric acid leaching is investigated and the optimum conditions are obtained. The leaching behavior of Ti of bulk concentrate is investigated by simulation of the crystal structure and other analysis. The results are as follows:20 wt.% hydrochloric acid,4:1 liquid-to-solid mass ratio,110℃ leaching temperature,4 h leaching time and 300 r/min stirring rate. Under the optimal leaching conditions, the leaching efficiencies of Fe, V are 91.8% and 95.0%, respectively and the loss rate of Ti is 0.3%. It can be described the mechanism of firstly dissolving and then hydrolysis-precipitation during the hydrochloric acid leaching.(3) Desilication of the hydrochloric acid leaching residue by alkaline leaching for the preparation of rich titanium product has been systematically studied. The mechanism of desilicification from hydrochloric acid leaching residue is studied. The optimum process conditions are obtained. The results are as follows:initial NaOH concentration 15%, liquid-to-solid mass ratio 5:1, alkaline leaching temperature 80℃, alkaline leaching time 60 min. The amorphous silicon of hydrochloric acid leaching residue is easily removed during alkaline leaching. A small amount of silicon in the Ti-riched phase, feldspar, hedenbergite, diopside and other silicate phase cannot be removed by alkaline leaching. The sulfuric acid decomposition rate of TiO2 of obtained rich titanium product is 98.2% and it can be used as raw materials of titanium white by sulfuric acid process because of good acid soluble. |
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