Advances on jarosite residue detoxification and reutilization: a review.

Jarosite residues are typical hazardous waste byproducts generated during the iron removal process in hydrometallurgical solutions. The jarosite process is widely used for iron removal in zinc hydrometallurgy; jarosite disposal has become a significant barrier to sustainable development in the industry. During this process, jarosite residues entrain and co-precipitate with heavy metals, which are hazardous but valuable.

Iron separation from iron-rich manganese ore leachate: Comprehensive optimization of operating parameters and economic viability.

In the current electrolytic manganese industry, iron separation and reuse from iron-rich manganese ore leachate (IRMOL) has become one of the most pressing challenges. This study aimed to investigate the optimal conditions for iron separation from IRMOL and to assess the economic and practical advantages of iron separation or removal in industrial manufacturing. To identify more cost-effective and technologically advanced production circumstances, we examined five key elements that weaken Fe(OH) colloidal production conditions in enterprises: reaction temperature, pH, crystal species, aging and reaction time.

Chlorine and heavy metals removal from municipal solid waste incineration fly ash by electric field enhanced oxalic acid washing.

Electric field enhanced oxalic acid (HCO) washing was conducted to examine the simultaneously removal efficiency of heavy metals (HMs) and chlorine, especially insoluble chlorine from municipal solid waste incineration fly ash (MSW FA). Results show that chlorine and HMs can be effectively removed with a total chlorine, As, Ni and Zn removal rate of 99.10%, 79.

Application of Machine Learning in a Mineral Leaching Process-Taking Pyrolusite Leaching as an Example.

In this study, several machine learning models were used to analyze the process variables of electric-field-enhanced pyrolusite leaching and predict the leaching rate of manganese, and the applicability of those models in the leaching process of hydrometallurgy was compared. It showed that there was no correlation between the six leaching conditions; in addition to the leaching time, the concentrations of sulfuric acid and ferrous sulfate had great influences on the leaching of pyrolusite. The results of the prediction models showed that the support vector regression model has the best prediction performance, with regression index ( ) = 0.

Enhanced removal of Pb from electrolytic manganese anode slime and preparation of chemical MnO.

Electrolytic manganese anode slime (EMAS) is produced during the production of electrolytic manganese metal. In this study, a method based on vacuum carbothermal reduction was used for Pb removal in EMAS. A Pb-removal efficiency of 99.

Electrolytic manganese residue disposal based on basic burning raw material: Heavy metals solidification/stabilization and long-term stability.

Solidification/stabilization (S/S) is an option for the treatment of electrolytic manganese residue (EMR). Basic burning raw material (BRM) could successfully solidify/stabilize EMR, though heavy metals S/S mechanism and long-term stability remain unclear. Herein, Mn and NH S/S behavior, hydrated BRM and S/S EMR characterization, Mn long-term leaching behavior, phase and morphology changes for long-term leaching were discussed in detail to clarify these mechanisms.

Toxic footprint and materials profile of electronic components in printed circuit boards.

Waste printed circuit boards (WPCBs) contain valuable material resources and hazardous substances, thereby posing a challenge for sustainable resource recovery and environmental protection initiatives. Overcoming this challenge will require mapping the toxic footprint of WPCBs to specific materials and substances used in manufacturing electronic components (ECs). Therefore, this work collected 50 EC specimens from WPCBs in five ubiquitous consumer products, such as television, refrigerator, air conditioner, washing machine and computer.

Synergistic solidification/stabilization of electrolytic manganese residue and carbide slag.

Electrolytic manganese residue (EMR) contains high concentrations of NH and heavy metals, such as Mn, Zn, Cu, Pb, Ni and Co, while carbide slag (CS) contains high amount of OH and CO, both posing a serious threat to the ecosystem. In this study, EMR and CS synergistic stabilization/solidification (S/S) was discussed science CS could stabilize or solidify EMR and simultaneously reduce its corrosive. The results showed that after the synergistic S/S for 24 h when liquid-solid ratio was 17.

A critical review on approaches for electrolytic manganese residue treatment and disposal technology: Reduction, pretreatment, and reuse.

Electrolytic manganese residue (EMR) has become a barrier to the sustainable development of the electrolytic metallic manganese (EMM) industry. EMR has a great potential to harm local ecosystems and human health, due to it contains high concentrations of soluble pollutant, especially NH and Mn, and also the possible dam break risk because of its huge storage. There seems to be not a mature and stable industrial solution for EMR, though a lot of researches have been done in this area.

Metal mobility and toxicity of reclaimed copper smelting fly ash and smelting slag.

Copper is a nonferrous metal closely connected to humans. Approximately 40% of copper is produced by reclaimed copper smelting (RCS). Reclaimed copper smelting fly ash and smelting slag are generated during the RCS process, posing a serious threat to the ecosystem and environment as they contain many heavy metals, such as Cu and Zn.

Enhanced leaching of manganese from low-grade pyrolusite using ball milling and electric field.

In this study, electric field and ball milling were used to leach Mn from low-grade pyrolusite (LGP). The effects of current density, reaction time, reaction temperature, ball-to-powder weight ratio, and ball milling time on the leaching efficiency of Mn from LGP as well as the leaching mechanism were systematically studied. The results showed that the combined use of electric field and ball milling enhanced the leaching of Mn from LGP.

A new electrochemical method for simultaneous removal of Mnand NH-N in wastewater with Cu plate as cathode.

In this study, a new electrochemical method was used to simultaneously efficient removal of Mn and NH-N in wastewater with Cu plate as cathode. The effects of various reaction parameters on the concentrations of Mn, NH-N and by-products (NO-N and NO-N, free chlorine and residual chlorine), as well as the removal mechanism were investigated. The results showed that the removal efficiencies of Mn and NH-N were 99.

A low cost of phosphate-based binder for Mn and NH-N simultaneous stabilization in electrolytic manganese residue.

Electrolytic manganese residue (EMR) is a solid waste remained in filters after using sulfuric acid to leaching manganese carbonate ore. EMR contains high concentration of soluble manganese (Mn) and ammonia nitrogen (NH-N), which seriously pollutes the environment. In this study, a low cost of phosphate based binder for Mn and NH-N stabilization in EMR by low grade-MgO (LG-MgO) and superphosphate was studied.

Chloride ion inhibition of electrochemical oscillations on the anode of an electrolytic manganese metal cell.

In industrial electrolytic manganese metal process, the energy consumption closely related to the electrolysis of cathode and anode. The effect of Cl concentration on electrochemical oscillation at the anode of the electrolytic manganese metal cell was investigated. The results showed that the electrochemical oscillation at the anode was inhibited by Cl, and the amplitude and frequency of the electrochemical oscillation decreased as the increase of Cl concentration.

An innovative method for manganese (Mn) and ammonia nitrogen (NH-N) stabilization/solidification in electrolytic manganese residue by basic burning raw material.

High concentrations of manganese (Mn) and ammonia nitrogen (NH-N) in electrolytic manganese residue (EMR) have seriously hindered the sustainable development of electrolytic manganese industry. In this study, an innovative basic burning raw material (BRM) was used to stabilize/solidify Mn and NH-N in EMR. The characteristics of EMR and BRM, stabilize mechanism of NH-N and Mn, and leaching test were investigated.

Heavy Metals Removing from Municipal Solid Waste Incineration Fly Ashes by Electric Field-Enhanced Washing.

Municipal solid waste incineration (MSWI) fly ash contains chlorides, heavy metals, and organic pollutants, which requires appropriate disposal to eliminate this risk. In this study, the effects of agents on heavy metals removal from MSWI fly ash by electric field-enhanced washing were systematically studied. The results show that when these fly ashes were washed at a current density of 35 mA/cm, polarity switching frequency of 40 Hz, Ethylenediaminetetraacetic acid (EDTA) dosage of 0.

Sol-gel hydrothermal synthesis of nano crystalline silicotitanate and its strontium and cesium adsorption.

Crystalline silicotitanate (CST) was synthesized via a sol-gel hydrothermal method using NaSiO·9HO and TiCl as silicon and titanium sources. The effects of pH, silicon concentration, hydrothermal temperature, and time on the CST synthesis were studied at a fixed molar ratio of silicon:titanium (0.98:1).

Effect of ionic liquid [MIm]HSO on WPCB metal-enriched scraps refined by slurry electrolysis.

Waste printed circuit boards (WPCBs) are usually dismantled, crushed, and sorted to WPCB metal-enriched scraps, still containing an amount of non-metallic materials. This research used slurry electrolysis to refine these WPCB metal-enriched scraps and to examine if a standard ionic liquid, [MIm]HSO, can replace HSO in the system. The impact of the refinement process on metal migration and transformation is discussed in detail.

Effect of electrolyte reuse on metal recovery from waste CPU slots by slurry electrolysis.

As an indispensable part of printed circuit boards (PCBs), central processing unit (CPU) slots contain a significant amount of precious metals which makes economic sense to recycle these materials. Slurry electrolysis is an attractive approach for electronic waste (e-waste) recycling. In this study, the effect of electrolyte reuse on the recovery of metals (Primarily aluminum, nickel, copper, lead, silver, palladium, platinum and gold), from waste CPU slots by slurry electrolysis is discussed in detail.

An innovative method for synergistic stabilization/solidification of Mn, NH-N, PO and F in electrolytic manganese residue and phosphogypsum.

Electrolytic manganese residue (EMR) contains large quantities of manganese (Mn) and ammonia nitrogen (NH-N). Phosphogypsum (PG) contains plenty of phosphate (PO), fluorine (F) and some heavy metals. Separate storage of EMR and PG could seriously damage the ecological environment.

Fractional removal of manganese and ammonia nitrogen from electrolytic metal manganese residue leachate using carbonate and struvite precipitation.

A comparative investigation of hydroxide precipitation, sulfide precipitation, carbonate precipitation and the struvite formation process for removing manganese and ammonia nitrogen from electrolytic metal manganese residue leachate (EMMRL) was investigated. Chemical equilibrium model-Visual MINTEQ was applied to simulate the chemical reactions and optimize chemical dosages in manganese and ammonia nitrogen removal. Phase transition, morphology, and valence state of the precipitates were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray Photoelectron Spectroscopy (XPS).