scholarly journals Leaching/Bioleaching and Recovery of Metals

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1732
Author(s):  
Laura Castro ◽  
María Luisa Blázquez ◽  
Jesús Ángel Muñoz
Keyword(s):  
Metal Extraction ◽  
Valuable Metals ◽  
The World ◽  
Ore Grades

Hydrometallurgical processes for metal extraction are becoming more and more popular as average ore grades are declining and huge tonnages of tailings and recycle materials containing valuable metals are being accumulated all around the world [...]

scholarly journals Application of a cashew-based oxime in extracting Ni, Mn and Co from aqueous solution

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Chi M. Phan ◽  
Son A. Hoang ◽  
Son H. Vu ◽  
Hoang M. Nguyen ◽  
Cuong V. Nguyen ◽  
...  
Keyword(s):  
Organic Phase ◽  
Extraction Efficiency ◽  
Acidic Solution ◽  
Lithium Ion ◽  
Metal Extraction ◽  
Economic Potential ◽  
Cashew Nut ◽  
Valuable Metals ◽  
Loaded Organic Phase ◽  
Cashew Nut Shell

Abstract Background Cashew nut shell is a by-product of cashew (Anacardium occidentale) production, which is abundant in many developing countries. Cashew nut shell liquor (CNSL) contains a functional chemical, cardanol, which can be converted into a hydroxyoxime. The hydroxyoximes are expensive reagents for metal extraction. Methods CNSL-based oxime was synthesized and used to extract Ni, Co, and Mn from aqueous solutions. The extraction potential was compared against a commercial extractant (LIX 860N). Results All metals were successfully extracted with pH0.5 between 4 and 6. The loaded organic phase was subsequently stripped with an acidic solution. The extraction efficiency and pH0.5 of the CNSL-based extractant were similar to a commercial phenol-oxime extractant. The metals were stripped from the loaded organic phase with a recovery rate of 95% at a pH of 1. Conclusions Cashew-based cardanol can be used to economically produce an oxime in a simple process. The naturally-based oxime has the economic potential to sustainably recover valuable metals from spent lithium-ion batteries. Graphic abstract

Marine Authigenic Deposits Mineral - New Fields for the Development of Rare Earth Resources

2011 ◽  
Vol 291-294 ◽  
pp. 1748-1751
Author(s):  
Ying Zhang ◽  
Chang Shui Liu ◽  
Lian Feng Gao ◽  
Zhen Guo Zhang ◽  
Peng Zhang
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Mineral Resources ◽  
Resource Depletion ◽  
Polymetallic Nodules ◽  
Growth History ◽  
Valuable Metals ◽  
The World ◽  
Development And Utilization ◽  
Rare Earth Mineral

Rare earth metals are an important strategic resource. Due to scarce reserves, and large consumer demand, it is facing the crisis of resource depletion. Marine are the largest deposits sites in the world. In the long growth history, marine autogenic sedimentary mineral, such as polymetallic nodules, crusts with large quantities, not only contain the enrichment of Mn, Fe, Co, Cu, Ni and other valuable metals, but also contain extremely rare earth elements (REE) in the crust. Thus, in the process of developing marine mineral resources, Mn, Fe, Co, Cu, Ni and other metals are used, while it is possible for the development and utilization of the associated rare earth mineral. Marine may become a new field of rare earth resources development.

scholarly journals The Recovery of Valuable Metals from Ocean Polymetallic Nodules Using Solid-State Metalized Reduction Technology

Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 20 ◽  
Author(s):  
Feng Zhao ◽  
Xunxiong Jiang ◽  
Shengdong Wang ◽  
Linyong Feng ◽  
Da Li
Keyword(s):  
Solid State ◽  
Magnetic Separation ◽  
Ferrous Metal ◽  
Mineral Resources ◽  
Metal Extraction ◽  
Metallic State ◽  
Ferrous Metals ◽  
Polymetallic Nodules ◽  
Valuable Metals ◽  
Pre Treatment

Ocean polymetallic nodules are oxide ores rich in Ni, Co, Cu, and Mn, which are valuable metals found in deep-sea mineral resources. Such non-ferrous metals do not exist in isolation, and producing concentrates using conventional mineral separation techniques is challenging without pre-treatment. We propose an effective, environmentally-friendly recovery technology combined with solid-state metalized reduction treatment and magnetic separation to recycle these metals from ocean polymetallic nodules. We conducted single-factor tests to investigate the effects of additives, anthracite dosage, duration, and reduction temperature on metal recovery and to obtain optimal operating parameters. We found that valuable metals in ocean polymetallic nodules may be selectively reduced to a metallic state. Only a fraction of Mn was reduced to metal. The reduced metals were recovered to concentrates using magnetic separation. More than 80% of these metals were concentrated to magnetic concentrates with mass ratios of 10–15%. The recovery rates of Ni, Co, Cu, Mn, and Fe in concentrates were optimum at 86.48%, 86.74%, 83.91%, 5.63%, and 91.46%, respectively, when using CaF2 4%, anthracite 7%, SiO2 dosage 5%, and FeS 6% at 1100 °C for 2.5 h. This approach to non-ferrous metal extraction using conventional hydrometallurgical processes could be a step toward practical industrial-scale techniques for the recovery of metals from polymetallic nodules.

The Effect of pH on Bioleaching of Deerni Pyrite Roasting Residues as Magnetic Materials

2017 ◽  
Vol 730 ◽  
pp. 226-230 ◽  
Author(s):  
Xing Lan Cui ◽  
Hao En Zuo ◽  
Jian Kang Wen
Keyword(s):  
Sulfuric Acid ◽  
Magnetic Materials ◽  
Bacterial Growth ◽  
Culture Condition ◽  
Ph Value ◽  
Copper Deposit ◽  
Metal Extraction ◽  
Valuable Metal ◽  
Steel Making ◽  
Valuable Metals

The experiment focused on the Deerni pyrite roasting residues mainly made of magnetic materials such as hematite and magnetite in Qinghai Deerni Copper Deposit. The method of bioleaching sulfuric acid residue by bacteria was proposed for roasting residues desulfurization and valuable metal extraction. First of all, the study systematically performed multi-elements analysis, which provided scientific and technique basis for extraction of valuable metals. Subsequently, the effect of the pH value on the bacterial growth was investigated. The data revealed that pH at 1.2 was the optimum culture condition for the bacteria. The concentration of the bacteria at the best culture condition reached 8.5×107 cells/mL. Finally, the bioleaching experiments were performed to explore the ability of the NB bacteria to oxidize the Deerni pyrite roasting residues. The study demonstrated that the microorganism was able to effectively extract valuable metals such as copper and zinc. The total Fe and sulfur contents of the bioleaching residues account for 68.38% and 0.39%, respectively. The desulfurization effects are evident and bioleaching residues meet the requirements as magnetic materials in steel making industry.

scholarly journals Development of a Laboratory-Scale Leaching Plant for Metal Extraction from Fly Ash by ThiobacillusStrains

1998 ◽  
Vol 64 (4) ◽  
pp. 1237-1241 ◽  
Author(s):  
Christoph Brombacher ◽  
Reinhard Bachofen ◽  
Helmut Brandl
Keyword(s):  
Fly Ash ◽  
Thiobacillus Ferrooxidans ◽  
High Capacity ◽  
Waste Incineration ◽  
Laboratory Scale ◽  
Metal Extraction ◽  
Vacuum Filter ◽  
Valuable Metals ◽  
Filter Unit ◽  
Reaction Vessels

ABSTRACT Semicontinuous biohydrometallurgical processing of fly ash from municipal waste incineration was performed in a laboratory-scale leaching plant (LSLP) by using a mixed culture of Thiobacillus thiooxidans and Thiobacillus ferrooxidans. The LSLP consisted of three serially connected reaction vessels, reservoirs for a fly ash suspension and a bacterial stock culture, and a vacuum filter unit. The LSLP was operated with an ash concentration of 50 g liter−1, and the mean residence time was 6 days (2 days in each reaction vessel). The leaching efficiencies (expressed as percentages of the amounts applied) obtained for the economically most interesting metal, Zn, were up to 81%, and the leaching efficiencies for Al were up to 52%. Highly toxic Cd was completely solubilized (100%), and the leaching efficiencies for Cu, Ni, and Cr were 89, 64, and 12%, respectively. The role of T. ferrooxidans in metal mobilization was examined in a series of shake flask experiments. The release of copper present in the fly ash as chalcocite (Cu2S) or cuprite (Cu2O) was dependent on the metabolic activity of T. ferrooxidans, whereas other metals, such as Al, Cd, Cr, Ni, and Zn, were solubilized by biotically formed sulfuric acid. Chemical leaching with 5 N H2SO4 resulted in significantly increased solubilization only for Zn. The LSLP developed in this study is a promising first step toward a pilot plant with a high capacity to detoxify fly ash for reuse for construction purposes and economical recovery of valuable metals.

scholarly journals Mechanism and Kinetics of Ammonium Sulfate Roasting of Boron-Bearing Iron Tailings for Enhanced Metal Extraction

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 812
Author(s):  
Xiaoshu Lv ◽  
Fuhui Cui ◽  
Zhiqiang Ning ◽  
Michael L. Free ◽  
Yuchun Zhai
Keyword(s):  
Particle Size ◽  
Ammonium Sulfate ◽  
Metal Extraction ◽  
Molar Ratio ◽  
Orthogonal Experimental Design ◽  
Optimal Processing ◽  
Valuable Metals ◽  
Roasting Temperature ◽  
Apparent Activation Energies ◽  
Roasting Time

The large amount of boron-bearing iron tailings in China is a resource for metals that needs to be more completely and efficiently utilized. In this evaluation, the ammonium sulfate roasting process was used to make a controllable phase transformation to facilitate the subsequent extraction of valuable metals from boron-bearing iron tailings. The effects of roasting temperature, roasting time, the molar ratio of ammonium sulfate to tailings, and the particle size on the extraction of elements were investigated. The orthogonal experimental design of experiments was used to determine the optimal processing conditions. XRD (X-Ray Diffractomer), scanning electron microscope (SEM), and simultaneous DSC–TG analyzer were used to assist in elucidating the mechanism of ammonium sulfate roasting. The experimental results showed that nearly all Fe, Al, and Mg were extracted under the following conditions: (1) the molar ratio of ammonium sulfate to iron tailings was 3:1; (2) the roasting temperature was 450 °C; (3) the roasting time was 120 min.; and, (4) the particle size was less than 80 μm. The kinetics analysis indicated that the sulfation of metals was controlled by internal diffusion, with the apparent activation energies of 17.10 kJ·mol−1, 17.85 kJ·mol−1, 19.79 kJ·mol−1, and 29.71 kJ·mol−1 for Fe, Al, Mg, and B, respectively.

scholarly journals Evolution of Environmentally Friendly Strategies for Metal Extraction

Separations ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 4 ◽  
Author(s):  
Govind Sharma Shyam Sunder ◽  
Sandhya Adhikari ◽  
Ahmad Rohanifar ◽  
Abiral Poudel ◽  
Jon R. Kirchhoff
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Environmentally Friendly ◽  
Metal Extraction ◽  
Phase Extraction ◽  
Aquatic Life ◽  
Valuable Metals ◽  
Recent Developments ◽  
Sorbent Materials ◽  
The Impact

The demand for the recovery of valuable metals and the need to understand the impact of heavy metals in the environment on human and aquatic life has led to the development of new methods for the extraction, recovery, and analysis of metal ions. With special emphasis on environmentally friendly approaches, efforts have been made to consider strategies that minimize the use of organic solvents, apply micromethodology, limit waste, reduce costs, are safe, and utilize benign or reusable materials. This review discusses recent developments in liquid- and solid-phase extraction techniques. Liquid-based methods include advances in the application of aqueous two- and three-phase systems, liquid membranes, and cloud point extraction. Recent progress in exploiting new sorbent materials for solid-phase extraction (SPE), solid-phase microextraction (SPME), and bulk extractions will also be discussed.

A New Biohydrometallurgical Method for Processing of Deep-Sea Mineral Resources

2009 ◽  
Author(s):  
Yasuhiro Konishi ◽  
Norizoh Saitoh ◽  
Takashi Ogi
Keyword(s):  
Deep Sea ◽  
Mineral Resources ◽  
Environmentally Friendly ◽  
Sulfide Minerals ◽  
Experimental Results ◽  
Metal Extraction ◽  
Valuable Metals ◽  
Oxide Minerals ◽  
Hydrothermal Sulfides

This paper concentrates on the application of a biohydrometallurgical method for processing deep-sea mineral resources. Bioleaching technologies developed for terrestrial sulfide minerals now can be applied for metal extraction from deep-sea hydrothermal sulfides. However, little attention has been given to the bioleaching of terrestrial oxide minerals. A potentially attractive bioleaching system using the Fe(III)-reducing bacterium has recently been proposed for manganese crusts and nodules. Experimental results obtained from these systems demonstrate that bioleaching is an economical and environmentally friendly processing avenue to recover valuable metals from deep-sea mineral resources.

scholarly journals Metal Extraction and Recovery from Mobile Phone PCBs by a Combination of Bioleaching and Precipitation Processes

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1004
Author(s):  
Arrate Santaolalla ◽  
Piet N. L. Lens ◽  
Astrid Barona ◽  
Naiara Rojo ◽  
Ainhoa Ocio ◽  
...  
Keyword(s):  
Mobile Phone ◽  
Printed Circuit Boards ◽  
Metal Extraction ◽  
Copper Extraction ◽  
Secondary Source ◽  
Circuit Boards ◽  
Metal Recycling ◽  
Effective Removal ◽  
Valuable Metals ◽  
Synthetic Solution

Bearing in mind the metal rich composition of printed circuit boards (PCBs), this material represents a secondary source of valuable metals and offers an entrepreneurial opportunity in the metal sales market. Based on the ability of microorganisms to regenerate and produce the chemical oxidants that are responsible for metal leaching, bioleaching has become an efficient and affordable alternative to conventional metal recycling technologies, although further research is still necessary before industrial implementation. This study focuses on the recovery of metals contained in mobile phone PCBs through a combined process. Two different PCB pre-treatments were evaluated: grinding the whole piece and removing the epoxy cover from the piece without grinding. The benefit of A. ferrooxidans activity on the metal solubilization rate was analyzed. Additional chemical leaching assays were also conducted for comparison purposes and the reagents ferric iron (Fe3+) and sulfuric acid (H2SO4) were selected for these experiments. The copper extraction results obtained in Fe3+ experiments with and without bacteria (A. ferrooxidans) were similar after 260 h of operation, indicating the need for alternative strategies to ensure a controlled and continuous metal biodissolution rate. The contribution of H2SO4 to the leaching processes for copper and nickel was almost negligible during the first 50 h, and more significant thereafter. The recovered metals were precipitated from a synthetic solution simulating a real ferric leaching by adding sodium hydroxide (NaOH) and sodium sulfide (Na2S). The combination of both precipitants allowed an effective removal of metals from the leachate.

Green chemistry in mineral processing: chemical and physical methods to enhance the leaching of silver and the efficiency in cyanide consumption

2018 ◽  
Vol 90 (7) ◽  
pp. 1109-1120 ◽  
Author(s):  
Alejandro Alarcón ◽  
Carlos Segura ◽  
Carlos Gamarra ◽  
Juan Carlos F. Rodriguez-Reyes
Keyword(s):  
Green Chemistry ◽  
Mineral Processing ◽  
Metal Extraction ◽  
Complex Nature ◽  
Valuable Metals ◽  
Low Efficiency ◽  
Chemical Pretreatments ◽  
Extractive Economies ◽  
Cyanide Consumption ◽  
Silver Extraction

Abstract The leaching of valuable metals from mineral ores is the basis of several extractive economies around the world, but the strategies employed often need to rely on dangerous compounds such as cyanides. Due to the complex nature of most ores, leaching processes are slow and have a low efficiency in noble metal extraction, which is usually improved by fine-milling the mineral. In this manuscript, we consider this strategy, demonstrating that it may increase the amount of silver leaching, but at the expense of a higher consumption of cyanide, which renders the process inefficient (only 2% of consumed cyanide is employed to complex silver). The increase in the yield of the desired product without the smarter use of dangerous compounds is shown as a paradigm of the need to insert green chemistry principles in industrial processes. We further present the result of two potential strategies for greener mineral processing: the use of ultrasound to eliminate passivating layers formed during the leaching process and the use of chemical pretreatments to eliminate possible sources of passivation. These strategies can increase the amount of silver extraction and simultaneously increase the efficiency in cyanide consumption. The convenience of these pretreatments in the framework of the green chemistry principles, as well as the challenges towards their implementation at industrial scale, is discussed.

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