Improvement in Metal Recovery from Laterite Tailings by Bioleaching

Abstract

In previous studies it has been showed that sulphuric bio-acid is a good leaching agent for laterite tailings. In this work we evaluated nickel and cobalt recoveries from tailings of Caron technology process using sulphuric acid produced by Acidithiobacillus thiooxidans cultures under different conditions. In studies where tailings were initially added to the cultures, high nickel and cobalt recoveries (about 60 % for cobalt and 85-100 % for nickel) were reached after 13 days when low pulp densities (1 % and 2.5 %) of laterite tailings were used. These high recoveries fitted very well with the low pH values measured in these cultures. However, metal recoveries were negligible when higher pulp densities were used. Due to such reason, the performance of pre-cultivation configuration was evaluated; for that laterite tailings were added to the cultures after 24 or 48 hours of bacterial growth. This configuration was very efficient even at high pulp density (like 10 %) reaching recoveries (almost 50 % for cobalt and 80 % for nickel) close to those observed where tailings at low pulp densities were initially added to the cultures.

Different strategies for recovering metals from CARON process residue

“…Earlier studies by Hernández et al [27] showed that bioleaching of Ni and Co from CARON process residue with A. thiooxidans in a one-stage batch system was inversely proportional to the increase in pulp density (1%, 2.5%, 5% and 10%). Leaching was not observed at the highest concentration added (10%) and the results with 10% pulp density were identical to the abiotic control.…”

“…For this reason, A. thiooxidans has been widely used in the bioleaching of low-grade and concentrates of sulphide minerals on both laboratory and industrial scales [21][22][23]. This bacterium has also been used to solubilise nickel and cobalt from wastes from the mining-metallurgy industry, including lateritic overburden [24] and tailings [25][26][27]. The aim of the work described here was to evaluate the capacity of A. thiooxidans DMS 11478 to recover the heavy metals contained in the residues 0304-3894/$ -see front matter © 2011 Elsevier B.V. All rights reserved.…”

Review of Biohydrometallurgical Metals Extraction from Polymetallic Mineral Resources

“…• direct bioleaching in which an autotrophic acidophile supplied with sulfur or another RISC produced sulfuric acid for the extraction of metals from mine waste or tailings [344,[396][397][398][399][400]];…”

Aplicación de técnicas de biorremediación para el tratamiento de residuos industriales con alto contenido de metales pesados

“…Chen y Lin 63 también informaron que el aumento de la cantidad de azufre da como resultado un aumento de la tasa de acidificación, la producción de sulfato y solubilización de metales. Los datos aportados por Hernández Díaz et al64 muestran que el incremento en la densidad de pulpa de azufre de los cultivos, produce una mayor solubilización de metales. Pero a pesar de que un aumento de la cantidad de azufre agregada genera una acidificación eficiente y solubilización de metales en el proceso de biolixiviación, también implica un aumento en los costes operativos y obstaculiza la eliminación de los sedimentos tratados63 .…”