Next Article in Journal
Towards Zn-Dominant Tourmaline: A Case of Zn-Rich Fluor-Elbaite and Elbaite from the Julianna System at Piława Górna, Lower Silesia, SW Poland
Next Article in Special Issue
Comparison of Wet and Dry Grinding in Electromagnetic Mill
Previous Article in Journal
World-Class PGE-Cu-Ni Talnakh Deposit: New Data on the Structure and Unique Mineralization of the South-Western Branch
Previous Article in Special Issue
A Preliminary Investigation into Separating Performance and Magnetic Field Characteristic Analysis Based on a Novel Matrix
Article Menu
Issue 4 (April) cover image

Export Article

Open AccessArticle

Removal of Potassium and Iron in Low Grade Bauxite by a Calcination-Acid Leaching Process

School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou 450046, China
Research Institute of Henan Energy and Chemical Industry Group, Zhengzhou 450046, China
Henan Province Industrial Technology Research Institute of Resources and Materials, Zhengzhou 450046, China
Authors to whom correspondence should be addressed.
Minerals 2018, 8(4), 125;
Received: 18 January 2018 / Revised: 12 March 2018 / Accepted: 16 March 2018 / Published: 22 March 2018
(This article belongs to the Special Issue Sustainable Mineral Processing Technologies)
PDF [8745 KB, uploaded 3 May 2018]


In order to explore the commercialized applications of the low-grade bauxite in the refractory industry, a calcination integrated with acid leaching method was adopted to remove the potassium (K) and iron (Fe) from the diaspore-illite (DI) type low-grade bauxite. Following calcining the bauxite at different temperatures, the leaching parameters, including the sulfuric acid concentration, temperature, sulfuric acid to bauxite ratio, and reaction time were systematically studied. The appropriate and economical conditions for removing the impurities were found to be calcining the bauxite at 550 °C, and leaching it with a sulfuric acid solution of 1.2 mol/L, sulfuric acid/bauxite ratio of 9 mL/g at a reaction temperature of 70 °C and reaction time of 2 h, under these conditions, the removal efficiency of K and Fe from the bauxite can reach 30.32% and 47.33%, respectively. The treated bauxite was examined by XRD analysis, SEM observations, and chemical analysis. Kinetics of the removing process were calculated by two models, and the results showed that the leaching process was controlled by the mixed shrinking core model, which was affected by both the diffusion through solid layer and the interface transfer. In summary, the approach in this work presents a promising process for comprehensive utilization of the low-grade bauxite. View Full-Text
Keywords: low-grade bauxite; potassium and iron removal; calcination; acid leaching; kinetics low-grade bauxite; potassium and iron removal; calcination; acid leaching; kinetics

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Li, Z.; Cao, Y.; Jiang, Y.; Han, G.; Fan, G.; Chang, L. Removal of Potassium and Iron in Low Grade Bauxite by a Calcination-Acid Leaching Process. Minerals 2018, 8, 125.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Minerals EISSN 2075-163X Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top