The effect of different parameters on bioleaching of copper from PCBs using A. ferrooxidans has been studied by Willner . The experiments were carried out with daily regulation of pH at 2 using sulfuric acid (Willner 2013). Ilyas et al. studied the bioleaching of metals from e-waste using acidophilic bacteria. …

An indirect non-contact leaching approach using ferric iron generated by Acidithiobacillus ferrooxidans was compared to chemical ferric sulfate leaching of Cu, Ni, Zn and Al from milled high-grade PCBs at 1% pulp density at Fe 3+ concentrations of 5–20 g L −1 and at a pH range of 0.6–1.2. The roles of redoxolysis and acidolysis were ...

1 / 22. Microbial leaching of valuable metals from low-concentration ores is carried out in open-air leaching dumps for copper recovery, but in closed bioreactors for gold recovery because __________. more oxygen is required for copper leaching. the bioreactor prevents the loss of any valuable gold. the bioreactor prevents release of toxic ...

main passivation layers in the leaching of Cu minerals by A. ferrooxidans [54]. The sludge sample was leached at pH 1.6, 1.8, 2.0, and 2.2. The yields of heavy metals were

Acidithiobacillus ferrooxidans. A. ferrooxidans can remarkably promote the oxidation of chalcopyrite. SEM micrographs showed that the cells directly attached to …

Recent studies reported that the copper mobilization is mainly dependent on direct and indirect oxidation, and the microbial leaching of copper from WPCBs by A. ferrooxidans was accomplished mainly by the indirect oxidation of elemental copper through the prior oxidation of ferrous ions by A. ferrooxidans (Choi et al., 2004, Liang et …

Effect of pulp density in the range 5 - 20%(w/v) on the biodissolution of metal was investigated using 10% (v/v) isolate of A.ferrooxidans in 200 ml leaching medium with 50µm size particles at pH 2 and 35℃ while shaking at 100rpm.From the results shown in Fig.4, it is clear that the bio-recovery of copper is much higher at the lower pulp density …

In order to improve copper leaching efficiency from the flexible printed circuit board (PCB) by Acidithiobacillus ferrooxidans, it is necessary to quantitatively measure the bacteria bioleaching copper under extreme acidic condition from flexible PCB. The inductively coupled plasma-atomic emission spectroscopy (ICP-AES) is a very accurate way to …

The high density and even distribution of A. ferrooxidans on the surface of a mineral is believed to lead to high leaching rates of copper sulfides (Fu et al. 2014). ...

In particular, copper and zinc-containing raw materials are fed into a tank with a culture solution of A. ferrooxidans, and manganese-containing raw materials into a tank with a bicultural solution of A.ferrooxidans-R.phaseoli. S/L at leaching copper and zinc-containing raw material—1:3, at leaching manganese-containing raw material—1:5.

In the industrial leaching processes, microorganisms that are found in nature can be used. Dumps of sulphide ores, waste ... areas of bioleaching with Acidithiobacillus ferrooxidans in copper

Experiments were conducted to determine if acidophilic heterotrophic bacteria influence the ability of T. ferrooxidans to solubilize cobalt. Short term (7 day) flask leaching studies were conducted wherein 28 strains of T. ferrooxidans were each incubated with one of three different cobalt sulfides (CoS, cobaltite flotation concentrate, …

Biochemical oxidation technology with the use of Acidithiobacillus ferrooxidans bacterial culture, adapted to the composition of this ore, was also tested …

When the initial cell number ratio between A. ferrooxidans and R. phaseoli was 2 : 1, A. ferrooxidans attained the highest final cell number of approximately 2 × 10 8 cells/mL and the highest copper leaching rate of 29%, which is 7% higher than that in the group with A. ferrooxidans only. R. phaseoli may use metabolized polysaccharides from A ...

This leaching process can be modeled by the shrinking core model, showing that it is controlled by diffusion. In order to obtain a detailed and fundamental understanding about leaching copper from WPCBs by ILs, five typical ionic acids were selected and the results were compared with published data using [Bmim]HSO 4. Factors that affect …

(reaction 7) can also cause leaching of copper oxide ores (reaction 8). Thiobacillus ferrooxidans is found in acid drainage waters from deep strip LEACHING OF COPPER ORE 361 John Lennox is an associate professor of microbiology at Penn State Altoona Campus, Altoona, PA 16601-3760. Tho-mas Blaha is a graduate student in the

The new strategy developed improved the kinetic reaction rate and overcomes transport limitations for the leaching solution, thus improving copper recoveries from 50 …

The bioleaching of five different copper sulfide minerals (djurleite, bornite, covellite, massive sulfide copper and porphyry chalcopyrite) by Acidithiobacillus ferrooxidans (At.f LD-1) and the adsorption behavior of At.f LD-1 on mineral surfaces were investigated. Bioleaching experiments show that the copper extraction of the five …

1. INTRODUCTION The leaching is connected with the action of chemilithotrophic bacteria capable of oxidizing sulphide minerals, ferrous iron and …

In this study, using several types of acidic ionic liquids as the leaching reagents, the leaching behaviors of the copper present in waste printed circuit boards (WPCBs) were investigated. The effects of various parameters on the copper leaching rate were studied, such as the particle size of the sh …

The efficiency of copper leaching is improved by bacteria attached to chalcopyrite. Therefore, the study of the attachment mechanism to control leaching is important. The adhesion of three species of leaching microorganisms including Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and …

Dissolution of copper and zinc present in a complex sulfide concentrate were examined by applying bioleaching technique with aid of the pure Acidithiobacillus ferrooxidans. The leaching rate of ...

Application of bioleaching process for metal recovery from electronic waste has received an increasing attention in recent years. In this work, a column bioleaching of copper from waste printed circuit boards (WPCBs) by Acidithiobacillus ferrooxidans has been investigated. After column bioleaching for 28 d, the copper recovery reached …

Acidothiobacillus ferrooxidans (A. ferrooxidans), an iron-oxidizing bacteria oxidizes Fe(II) to Fe(III), which is an excellent leaching agent to leach out rare earth …

Bioleaching of metals from PCB primarily focuses on copper leaching due to the high content of copper in PCB. A. ferrooxidans can recover more than 94.8% of copper from PCB in batch or tank leaching system (Chen et al. 2015; Yang et al. 2014). The leaching efficiency of copper from PCB was markedly enhanced but with shortened …

A novel isolated strain Acidithiobacillus ferrooxidans BMSNITK17 has been investigated for its bioleaching potential from lateritic soil and the results are presented. System conditions like pH, feed mineral particle size, pulp density, temperature, rotor speed influences bioleaching potential of Acidithiobcillus ferrooxidans BMSNITK17 in leaching …

The shake flasks with growth medium were inoculated with 0, 5, 10, 20, 30 and 50% (v/v) of A. ferrooxidans, A. thiooxidans and mixed culture (A. ferrooxidans + A. thiooxidans). Figure 5 showed the influence of inoculation quantity on leaching copper, nickel, zinc and aluminum from metal concentrate of waste PCBs.

on the bioleaching of copper sulfide ores with pure and mixed cultures of mesophilic bacteria was performed by POGLIANI et al [26]. It has also been reported that copper extractions by the pure and mixed cultures achieved 14.87% and 20.11%, respectively, over a period of 117 days, including 15 days of acid pre-leaching and

The initial bio-leaching solution, for copper extraction, consists of ferric ions, generated by A. ferrooxidans-assisted oxidation of Fe 2+. To maximize the Cu recovery, the factors that were examined for column-leaching were initial Eh, pH, and flow-rate using the statistical design of experiments. 96% Cu recovery was accomplished in …

Bioleaching of Copper Biological copper leaching is practiced in many countries in­ cluding Australia, Canada, Chile, Mexico, Peru, Russia and the United States of America. Copper recovery from bioleaching accounts for about 25% of the world copper production. Follow­ ing the initial isolation of Acidithiobacillus ferrooxidans from coal­