EFFECT OF pH, MINING TAILINGS CONCENTRATION AND CULTURE MEDIUM ON THE PERFORMANCE OF POLYMETALLIC BIOLEACHING AT FLASK LEVEL

Abstract

The aim of this research was to evaluate bioleaching of Mn, As, Pb and Zn from mining tailings using two different sets of variable processing conditions. In the first set pH (2.0, 4.0 and 6.0), tailings concentrations (10, 20 y 30 %, w/v [111.11, 250.00 and 428.57 g/L, respectively]), and two types of culture medium (9K [with nitrogen source] and nonN (nitrogen-free medium) were evaluated; in the second set the evaluation focused on continuous supplementation of biogenic H2SO4 oxidized with two types of culture medium (9K and nonN) at different tailings concentrations (10, 20 y 30 %, w/v [111.11, 250.00 and 428.57 g/L, respectively]), with continuous supplementation of the media previously described (9K and nonN) oxidized by the native strains Leptospirillum ferriphilum and Leptospirillum ferrooxidans. In the first set, the highest removal of Mn (93.49 %), As (13.92 %) and Pb (> 99 %) was observed in both media at 10 % of tailings and initial pH of 2.0. In the second experimental set, the highest removal of Mn (99 %), As (> 85 %), Pb (> 99 %) and Zn (67 %) was found with both media at 10 % of tailings and initial pH 6.0. Continuous supplementation of biologically acidified and oxidized culture media enhanced the metals removal from solid waste or tailings. Similar metals removal in media without nitrogen compared to medium with nitrogen was observed in this research.

Evaluation of manganese bioleaching and silver extraction in mining tailings by native bacteria using a flooded system

“…A Box-Behnken experimental design was used with the following variables: ferrous ion concentration (2-14 g/L), pH (2-6), and agitation time at 100 rpm (2-6 min/day). Experimentation was performed for 18 days (Zazueta-Álvarez et al 2018). Analyzed responses (in percentage) were manganese removal and silver extraction.…”

Effect of Polysaccharides on the Physical, Rheological and Thermal Properties of a Balanced Canine Food

“…The composition of the diet was 40.5% corn flour, 18% chicken flour, 15% bean flour, 10% rice flour, 9% beet pulp, 3% canola oil, 2% fish oil, 2% vitamins and minerals, and 0.5% structure agent (inulin, sodium alginate or polysaccharide of microbial origin). Exopolysaccharide was synthesized by a native microbial consortium isolated from mining waste that showed 99 and 97% of DNA similarity with Leptospirillum ferriphilum and Leptospirillum ferrooxidans, respectively (Zazueta et al, 2018).…”

Bioleaching of Iron and Zinc from a galvanized steel waste from automotive industry using Acidithiobacillus thiooxidans: a case of study of the bajío area in México

“…These bio-processing technologies are distinguished by the utilization of biocatalysts, such as microorganisms or enzymes, and are generally regarded as more sustainable and eco-friendly approaches of existing processes (Wang et al, 2009). Bioleaching, in particular, has been attributed with advantages such as low cost, easy operation and maintenance, possibility to implement native consortia adapted to a medium containing different metals, and the potential to leach various metals from a polymetallic source (Zazueta-Álvarez et al, 2018). Furthermore, bioleaching allows for greater removal efficiencies in shorter operation times, when compared to traditional hydrometallurgical processes.…”

“…For instance, a study conducted by Ye et al (Ye et al, 2017), which aimed to evaluate the effects of pH and solid concentration in the bioleaching of heavy metals from lead-zinc mine tailings, demonstrated recovery efficiencies of 3.47%, 3.75% and 26.1% for Fe, Pb and Zn, respectively, in a control group after 50 days of treatment, where the solubilization of metals could be attributed to sulfuric acid in the medium at a pH of 2; in comparison, in an experimental group with inoculation of Acidithiobacillus ferrooxidans and under optimal conditions determined by the authors (Ye et al, 2017), recoveries of 85.45%, 4.12% and 97.85% of Fe, Pb and Zn, respectively, were obtained within the same timeframe of 50 days. Another example is an experiment by Zazueta-Álvarez et al (Zazueta-Álvarez et al, 2018), which demonstrated a removal of 93.49% Mn, 66.45% Zn and >99% Pb from mine tailings at flask level in just 17 days employing native consortia, composed of Leptospirillum ferriphilum and L. ferrooxidans, in a 9K medium with an initial pH of 2. Due to these characteristics, these processes may contribute in the generation of future technologies, including those related to the treatment of waste, such as that coming from the electronics industry (Wang et al, 2009), and as a plausible option to recover valuable metals from alternative sources in view of their ever growing demand (Zazueta-Álvarez et al, 2018).…”

“…Another example is an experiment by Zazueta-Álvarez et al (Zazueta-Álvarez et al, 2018), which demonstrated a removal of 93.49% Mn, 66.45% Zn and >99% Pb from mine tailings at flask level in just 17 days employing native consortia, composed of Leptospirillum ferriphilum and L. ferrooxidans, in a 9K medium with an initial pH of 2. Due to these characteristics, these processes may contribute in the generation of future technologies, including those related to the treatment of waste, such as that coming from the electronics industry (Wang et al, 2009), and as a plausible option to recover valuable metals from alternative sources in view of their ever growing demand (Zazueta-Álvarez et al, 2018).…”