In this work, acetic and citric acids were used along with ammonium chloride in the removal of iron from reduced Hatinh ilmenite. Iron removal was carried out at 70ºC, 4 liter/min of air flow rate, 7/1 of liquid/solid ratio and 0.5% NH<sub>4</sub>Cl as catalyst. After 9 hours, metallic iron was decreased from 30.3% in reduced ilmenite to 0.5% in synthetic rutile. The addition of 0.4% acetic acid into NH<sub>4</sub>Cl solution reduces removal time to 5 hours, residual metallic iron (RMI) was also 0.5%. The addition of 0.4% citric acid also reduces removal time to 5 hours, RMI was reduced to 0.33%. The rusting rate of metallic iron increased when acid concentration increased from 0.1 to 1%. The results indicated that acetic and citric acids could be used as additional catalysts along with NH<sub>4</sub>Cl in the removal of metallic iron in reduced ilmenite. The acid have the capability to form complexes with iron and also showed impact on the formation of precipitated iron compounds.
Aeration step, one of the major stages in the Becher process was carried out on reduced Hatinh (Vietnam) ilmenite in NH4Cl solution and the effect of several processing parameters were thoroughly investigated including the temperature, time, liquid/solid weight ratio (L/S), air flow rate and concentration of NH4Cl solution. The obtained results showed that longer rinsing time, higher liquid/solid ratio and air flow rate facilitated metallic iron rusting. The rusted iron amount increased when the temperature increased and reached the highest value at 70°C. Variation of NH4Cl concentration showed similar impact as that of temperature. The highest amount of rusted iron achieved at 0.5% NH4Cl. Chemical analysis and XRD results indicated that 98% of metallic iron in reduced ilmenite has been transformed to iron oxides at an aeration condition (70°C, 8 h, L/S=7/1, air flow rate = 4 l/min and 0.5% NH4Cl). Consequently, TiO2 content from approximately 60% in the reduced ilmenite increased up to approximately 80% in the aerated rutile.
<p class="AMSmaintext">Acetic acid and sodium acetate mixture (AASAM) was used as an aeration catalyst in the removal of metallic iron in reduced ilmenite. The efficiency of the catalyst was then compared to the standard ammonium chloride catalyst used in industry. Obtained results show that faster rate of iron removal could be achieved with AASAM while the molar concentrations of both AASAM and ammonium chloride were 0.1M. The highest rate of iron removal was achieved at the mixture proportion of 0.025M CH<sub>3</sub>COONa and 0.075M CH<sub>3</sub>COOH, aeration parameters of 70 °C, solid/liquid ratio of 1/7 and air flow rate of 4.0 lit/min. At those experimental conditions, the aeration time was shortened from 9 hours when NH<sub>4</sub>Cl was used to 6 hours when AASAM was used. In both cases, the obtained rutile contains approx. 82% TiO<sub>2</sub> and less than 0.5% metallic iron. The results indicated that AASAM could be used as a replacement for the NH<sub>4</sub>Cl catalyst in the aeration of reduced ilmenite. </p>
Becher process was applied for upgrading Ha Tinh ilmenite concentrate (54-55% TiO2) to synthetic rutile. The process includes reduction of ilmenite concentrate using anthracite coal as reductant, followed by aeration of reduced ilmenite in ammonium chloride solution (NH4Cl). The controlled parameters were temperature and NH4Cl concentration. The results showed that the degree of iron metallization was 83% after 4 hours of reduction at 1150 °C. Most of the metallic iron (98%) was successfully rust after 9 hours of aeration at 70°C, 7/1 of liquid/solid ratio (L/R), 4 liter/minutes (L/min) of air flow rate and 0.5% of NH4Cl concentration. The addition of acetic acid or citric acid in to the aeration solution has facilitated the aeration process. The aeration time could be vastly reduced when ammonium chloride solution used in aeration was replaced by the mixture of CH3COOH 0.075M and CH3COONa. Leaching with H2SO4 15% has improved TiO2 content from 82% in the aerated ilmenite to approximately 89% in synthetic rutile. The research work has proved that Becher process is applicable for the beneficiation of Ha Tinh ilmenite concentrate.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.