scholarly journals Investigation of indium and other valuable metals leaching from unground waste LCD screens by organic and inorganic acid leaching

2021 ◽  
pp. 119659
Author(s):  
Jonas Schuster ◽  
Burçak Ebin
Keyword(s):  
Acid Leaching ◽  
Inorganic Acid ◽  
Valuable Metals

scholarly journals Recovery of Zinc and Silver from Zinc Acid-Leaching Residues with Reduction of Their Environmental Impact Using a Novel Water Leaching-Flotation Process

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 586
Author(s):  
Yunpeng Du ◽  
Xiong Tong ◽  
Xian Xie ◽  
Wenjie Zhang ◽  
Hanxu Yang ◽  
...  
Keyword(s):  
Hazardous Waste ◽  
Acid Leaching ◽  
Copper Recovery ◽  
Water Leaching ◽  
Flotation Process ◽  
Metal Levels ◽  
Valuable Metals ◽  
Leaching Experiments ◽  
Zinc Hydrometallurgy ◽  
Poor Stability

Zinc-leaching residue (ZLR) is a strongly acidic hazardous waste; it has poor stability, high heavy metal levels, and releases toxic elements into the environment. ZLR has potential as a valuable resource, because it contains elevated levels of zinc and silver. In this paper, the recovery of zinc (Zn) and silver (Ag) from ZLR wastes from zinc hydrometallurgy workshops using water leaching followed by flotation was studied. During water leaching experiments, the zinc and copper recovery rates were 38% and 61%, respectively. Thereafter, various flotation testing parameters were optimized and included grinding time, reagent dosages, pulp density, flotation time, and type of adjuster. Experimental results demonstrated this flotation method successfully recycled Ag and Zn. A froth product containing more than 9256.41 g/t Ag and 12.26% Zn was produced from the ZLR with approximately 80.32% Ag and 42.88% Zn recoveries. The toxicity characteristic leaching procedure (TCLP) results indicated the water-leaching flotation process not only recycled valuable metals such as zinc and silver in zinc-containing hazardous wastes but lowered the hazardous waste levels to those of general wastes and recycled wastes in an efficient, economical, and environmentally friendly way.

Leaching Behavior Analysis of Valuable Metals from Lithium-Ion Batteries Cathode Material

2018 ◽  
Vol 775 ◽  
pp. 419-426 ◽  
Author(s):  
Wei Sheng Chen ◽  
Hsing Jung Ho
Keyword(s):  
Cathode Material ◽  
Lithium Ion Batteries ◽  
Acid Leaching ◽  
Lithium Ion ◽  
Activation Energies ◽  
Mass Ratio ◽  
Solid Mass ◽  
Environmental Technology ◽  
Valuable Metal ◽  
Valuable Metals

The paper concerns an approach about using environmental technology and hydrometallurgical process to the recovery of valuable metal from waste cathode material produced during the manufacture of lithium-ion batteries. It is noteworthy that the content of nickel, manganese and cobalt from cathode material are in the extraordinary large proportion. In the acid leaching step, the essential effects of H2SO4 concentration, H2O2 concentration, leaching time, liquid-solid mass ratio and reaction temperature with the leaching percentage were investigated. The cathode material was leached with 2M H2SO4 and 10 vol.% H2O2 at 70 °C and 300 rpm using a liquid-solid mass ratio of 30 ml/g and the leaching efficiency of cobalt was 98.5%, lithium was 99.8%, nickel was 98.6% and manganese was 98.6% under optimum conditions. Kinetic study demonstrates the activation energies for those analyzed metals with Arrhenius equation and manifests the data with hybrid reaction control mechanism. The process was proved from activation energies ranged from 27.79 to 47.25 kJ/mol. Finally, the valuable metals will be leached in sulfuric acid effectively.

scholarly journals The Reduction Behavior of Ocean Manganese Nodules by Pyrolysis Technology Using Sawdust as the Reductant

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 850 ◽  
Author(s):  
Xiang-yi Deng ◽  
Dong-sheng He ◽  
Ru-an Chi ◽  
Chun-qiao Xiao ◽  
Jin-gang Hu
Keyword(s):  
Activation Energy ◽  
High Efficiency ◽  
Acid Leaching ◽  
Reduction Process ◽  
Reduction Reaction ◽  
Pyrolysis Process ◽  
Manganese Nodules ◽  
Valuable Metals ◽  
Shrinking Core ◽  
Isothermal Kinetic

Ocean manganese nodules, which contain abundant Cu, Co, Ni and Mn resources, were reduced using biomass (sawdust) pyrolysis technology. Valuable metals were further extracted by acid leaching after the reduction process with high efficiency. The effects of sawdust dosage, reduction temperature, and time were investigated to obtain optimal operating parameters. The extraction rates of Mn, Cu, Co, and Ni reached as high as 96.1%, 91.7%, 92.5%, and 94.4%, respectively. Results from TGA show that the main pyrolysis process of sawdust occurs at temperature range of 250–375 °C with a mass loss of 59%, releasing a large amount of volatile substances to reduce the ocean manganese nodules. The pyrolysis activation energy of sawdust was calculated to be 52.68 kJ∙mol−1 by the non-isothermal kinetic model. Additionally, the main reduction reaction behind the main sawdust pyrolysis process was identified by the comparison of the assumed and actual TG curve. The thermodynamic analysis showed that the high valence manganese minerals were gradually reduced to Mn2O3, Mn3O4, and MnO by CO generated from sawdust pyrolysis. The shrinking core model showed that the reduction process is controlled by the surface chemical reaction with activation energy of 45.5 kJ∙mol−1. The surface of reduced ore and acid leached residue exhibited a structure composed of relatively finer pores and rougher morphology than the raw ore.

scholarly journals Recycling the GaN Waste from LED Industry by Pressurized Leaching Method

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 861 ◽  
Author(s):  
Wei-Sheng Chen ◽  
Li-Lin Hsu ◽  
Li-Pang Wang
Keyword(s):  
Energy Gap ◽  
Light Emitting Diode ◽  
Economic Value ◽  
Acid Leaching ◽  
High Hardness ◽  
High Energy ◽  
Light Emitting ◽  
Valuable Metals ◽  
Leaching Solution ◽  
Leaching Efficiency

In recent years, with the increasing research and development of the light-emitting diode (LED) industry, which contains gallium nitride (GaN), it is expected that there will be a large amount of related wastes in the future. Gallium has an extremely high economic value, therefore, it is necessary to establish a recycling system for the GaN waste. However, GaN is a direct-gap semiconductor and with its high energy gap, high hardness, and high melting point, these make it difficult to recycle. Therefore, this study will analyze the physical characteristics of LED wastes containing GaN and carry out various leaching methods to leach the valuable metals from the waste optimally. Different acids are used to find out the best reagent for gallium leaching. Different experimental parameters are discussed, such as the effect of the different acid agents, concentration, pressure, liquid-solid mass ratio, temperature and time, which influence the leaching efficiency of gallium. Finally, acid leaching under high pressure is preferred to leach the GaN waste, and hydrochloric acid is used as the leaching solution because of its better leaching efficiency of gallium. Optimally, the leaching efficiency of gallium can reach 98%.

Study on Recovering of Value Metals from Acid Leaching Solution of Roasted Electroplating Sludge

2012 ◽  
Vol 524-527 ◽  
pp. 1951-1955 ◽  
Author(s):  
Xiao E Dang ◽  
Xin Zhe Lan ◽  
Yuan Dong
Keyword(s):  
Recovery Rate ◽  
Acid Leaching ◽  
Recovery Process ◽  
Zinc Powder ◽  
Environmental Benefits ◽  
Pollution Problem ◽  
Valuable Metals ◽  
Electroplating Sludge ◽  
Environmental Pollution Problem ◽  
Leaching Solution

Chelating electroplating sludge contains high grade of toxic metals or heavy metals, so this sludge should be treated and recovered of valuable metals from it. This paper mainly studied on the recovery process of Copper, Nickel and Zinc process from sulfuric acid leaching solution of roasted chelating electroplated sludge. It provided an effective technique for recovery of valuable metals from acid leaching solution. The efficiency of the process had been measured with the metal recovery rate. Experimental results showed that recovery rate of Copper and Nickel can respectively achieve at 99.30% and 97.00% from acid leaching solution after removal iron with zinc powder used reducing agent. The process has simple operation and high recovery rate. It can solve the environmental pollution problem of electroplating sludge and valuable metals can be recovered from which. It could bring better economic and environmental benefits to the enterprise.

scholarly journals Recycling the Gan Waste from LED Industry by Pressurized Leaching Method

2018 ◽  
Author(s):  
Wei-Sheng Chen ◽  
Li-Lin Hsu ◽  
Li-Pang Wang
Keyword(s):  
Energy Gap ◽  
Acid Leaching ◽  
High Hardness ◽  
High Energy ◽  
Advantages And Disadvantages ◽  
Valuable Metals ◽  
Leaching Solution ◽  
Leaching Methods ◽  
Solid Liquid ◽  
Leaching Efficiency

In recent years, with the increasing research and development of the LED industry which contains GaN, it is expected that there will be a large amount of related wastes in the future. Especially the gallium has extremely high value of economic, therefore, it is necessary to establish the recycling system of the GaN waste. However, GaN is a direct-gap semiconductor and with high energy gap, high hardness, and high melting point make it difficult to recycle. Therefore, this study will analyze the physical characteristics of LED wastes containing GaN and carry out various leaching method to leach the valuable metals from the waste optimally. Different acids are used to find out the best reagent for leaching the gallium. Different experimental parameters are discussed such as the effect of the different acid agents , concentration, pressure, solid-liquid mass ratio, temperature, and time which influence the leaching efficiency of the gallium. In this study, various leaching methods which effect the leaching efficiency of the gallium are compared and the advantages and disadvantages are discussed. Finally, pressurized acid leaching method is preferred to leach the GaN waste, and hydrochloric acid is used as the leaching solution because of its better leaching efficiency of gallium. Eventually, the leaching efficiency of the gallium can reach to 98%.

Recovering Valuable Metals from Spent Lithium Ion Battery via a Combination of Reduction Thermal Treatment and Facile Acid Leaching

2018 ◽  
Vol 6 (8) ◽  
pp. 10445-10453 ◽  
Author(s):  
Yang Yue ◽  
Sun Wei ◽  
Bu Yongjie ◽  
Zhang Chenyang ◽  
Song Shaole ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Lithium Ion Battery ◽  
Acid Leaching ◽  
Lithium Ion ◽  
Valuable Metals

Investigating of a Low-Grade Copper Concentrate Desilication by Alkali Pressure Leaching

2019 ◽  
Vol 946 ◽  
pp. 608-614 ◽  
Author(s):  
Andrey A. Shoppert ◽  
Irina V. Loginova ◽  
V.N. Pismak
Keyword(s):  
Raw Materials ◽  
Acid Leaching ◽  
Pressure Leaching ◽  
Low Grade ◽  
X Ray Diffraction ◽  
Copper Concentrate ◽  
Valuable Metals ◽  
Alkali Leaching ◽  
Wet Chemical ◽  
Promising Source

Low grade copper concentrate, composed mainly of plagioclase, quartz, pyrite, chlorite, chalcopyrite, glauconite, is a promising source for the future recovery of copper and other valuable components, which processing by existing methods are not economical. An alkali pressure leaching method, followed by acid leaching for extraction of aluminum and silica from such low-grade copper concentrate with the aim to enrich other valuable metals content, was explored in this research. The samples were characterized by using wet chemical analysis and X-ray diffraction. An alkali pressure leaching, followed by dilute acid leaching for enrichment of low-grade copper concentrate, allows to extract in a solution of 90,4% Si, 83.82% Al and 7.73% of Cu with the following optimal parameters: NaOH/concentrate-1 mass ratio = 65%, alkali leaching temperature = 240 °C, the alkali leaching time = 90 min. The content of copper in the final concentrate was 19.17%. Consequently, the technology of processing of low-grade copper raw materials is proposed, that allows to increase the comprehensiveness of raw materials usage.

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