Silica removal from waste of ilmenite concentrate pyrometallurgical processing

Abstract

The article presents the study results for alkaline leaching of fine ilmenite concentrate dusts from electric smelting. The physical and chemical properties of the dusts were studied using chemical and instrumental analysis methods. The dust composition was determined, X-ray phase analysis showed that the dust sample substance is in the X-ray amorphous state, iron is present in the trivalent state, and silicon is bound to magnesium. The dust sample study using a scanning electron microscope showed that part of the titanium is bound in a hard-to-disclose anasovite encapsulated in amorphous silicon oxide. The leaching study of electric smelting dust with sodium hydroxide solutions included the study of the effect of sodium hydroxide concentration, process duration, temperature, S: L ratio. The optimal conditions for dust leaching from electric smelting of ilmenite concentrate have been established: temperature 80-90 °C, duration 90-120 min, ratio S: L = 1: 5, the concentration of sodium hydroxide solution 110-115 g/dm3. The silicon extraction degree into the solution under these conditions was 77.7%. The behavior of accompanying components of chromium, zinc, iron, and manganese during dust leaching was also studied. X-ray phase analysis of the cake after leaching shows almost complete amorphization of the leached product, the main phase is a solid solution of Fe2O3·TiO2.

A novel low‐energy approach to leucoxene concentrate desiliconization by ammonium bifluoride solutions

“…The coefficient of determination of the obtained equation is 0.9883. Obtained results are almost 15% higher compared to leaching by NaOH after 120 min and a temperature of 80–90 °C 31 …”

“…Obtained results are almost 15% higher compared to leaching by NaOH after 120 min and a temperature of 80-90 °C. 31 Equation ( 9) refers to Fig. 2: where C is the concentration of NH 4 NF 2 in wt% and t is the time in the range 0-250 min.…”