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

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.

A flotation combined extraction process for improving the whiteness of phosphogypsum

“…2, 3). Other impurities such as SiO2 and carbon that cannot be dissolved by sulfuric acid can be extracted using TBP (Christensen, 2008;Nie, 2020).…”

Intensification of Sulfuric Acid Leaching of Altered Ilmenite via Adding Fluoride Activator

“…The formed gaseous HF goes from the reactor (11) to the absorber (13), which contains NaOH. The resulting sodium fluoride is fed to the storage hopper (14), where NaF can flow through the dosing reactor (12) into the reactor (11); thus, the fluoride reagent can be recycled.…”

“…The most common industrial methods of processing titanium-bearing raw materials are hydrochloric [6][7][8][9][10][11] and sulfuric acid [12][13][14][15][16][17][18][19][20][21][22][23] leaching. The hydrochloride method is limited to the use of high-quality raw materials (concentrates must have an ilmenite content of 98-99%), because impurities can affect the stability of the process and the quality of the target product.…”