Leaching Behaviors of Impurities in Titanium-Bearing Electric Furnace Slag in Sulfuric Acid

Wenlin Nie,Qicheng Feng,Qian Zhang,Junbo Liu,Shuming Wen,Dan Liu

doi:10.3390/pr8010056

Wenlin Nie, Qicheng Feng + Show 4 more

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https://doi.org/10.3390/pr8010056

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Abstract

Titanium-bearing electric furnace slag (TEFS) was prepared from vanadium titanomagnetite and leached with sulfuric acid. The Ti leaching rate of vanadium titanomagnetite TEFS is significantly lower than that of ilmenite TEFS. The impurity content in vanadium titanomagnetite TEFS is higher than that in ilmenite TEFS. This might be one of the main factors resulting in the low leaching rate of Ti, so the leaching behaviors of various impurities under different conditions (temperature, acid/solid weight ratio, particle size, and initial sulfuric acid concentration) were investigated. The following trends were observed under different leaching conditions: The leaching rate of Fe increased rapidly and reached equilibrium quickly, that of Si increased quickly in the early stage and then decreased in the later stage, that of Ca increased initially and reached equilibrium later, and the leaching rates of Mg and Al increased gradually until the equilibrium was reached. The leaching rate of Fe was too rapid to be able to investigate its leaching kinetics, and the insoluble leached products of Si and Ca interfered with their leaching. The effects of leaching parameters on the leaching of impurities were further analyzed by X-ray diffraction (XRD) and scanning electron microscopy analysis. XRD data indicated that spinel is the major Mg- and Al-bearing mineral in TEFS. Mg and Al showed similar leaching behaviors, and their leaching conformed to a new model based on interface transfer and diffusion across the product layer, both of which affect the leaching rate.

Highlights

The Panzhihua–Xichang region of China is rich in vanadium titanomagnetite resources with ore reserves of approximately 10 billion tons
It is of great significance to develop effective methods to utilize the vanadium titanomagnetite concentrate, and many methods such as sodium salt roasting/direct reduction/electric furnace smelting, direct reduction/electric furnace smelting, and direct reduction/magnetic separation have been studied toward this goal [3,4,5]
The comparison of Ti leaching rates in Conditions (b) and (c) shows that a comparison of Ti leaching rates in Conditions (a) and (c) shows that a larger average particle size led lower acidolysis temperature is unfavorable to the Ti leaching rate

Summary

Introduction

The Panzhihua–Xichang region of China is rich in vanadium titanomagnetite resources with ore reserves of approximately 10 billion tons. Vanadium titanomagnetite concentrates obtained by mineral beneficiation methods contain approximately 52.0%. Of the titanium of the vanadium titanomagnetite ore [2]. It is of great significance to develop effective methods to utilize the vanadium titanomagnetite concentrate, and many methods such as sodium salt roasting/direct reduction/electric furnace smelting, direct reduction/electric furnace smelting, and direct reduction/magnetic separation have been studied toward this goal [3,4,5]. Titanium-bearing electric furnace slag from the direct reduction/electric furnace smelting method has a high Ti grade of 48–60.68 wt% and is easier to extract than the products from other methods [2,6].

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