scholarly journals Processing of Waste Copper Converter Slag Using Organic Acids for Extraction of Copper, Nickel, and Cobalt

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 290 ◽  
Author(s):  
Pratima Meshram ◽  
Uday Prakash ◽  
Lalit Bhagat ◽  
Abhilash ◽  
Hongbo Zhao ◽  
...  
Keyword(s):  
Citric Acid ◽  
Organic Acids ◽  
Converter Slag ◽  
Pulp Density ◽  
Hydrometallurgical Process ◽  
X Ray ◽  
Pourbaix Diagrams ◽  
Leaching Experiments ◽  
Environmentally Sound ◽  
Optimum Recovery

An innovative, economical, and environmentally sound hydrometallurgical process has been proposed for recovering Cu, Ni, and Co from copper-rich converter slag by organic acids. In the leaching experiments, the effects of organic acid concentrations, pulp density, temperature, and time were investigated. Optimum recovery of 99.1% Cu, 89.2% Ni, 94% Co, and 99.2% Fe was achieved in 9–10 h at 308 K (35 °C) temperature and 15% pulp density with 2 N citric acid using <45 µm particles. Pourbaix diagrams of metal-water-citrate systems were supplemented to examine solubility of ligands at the desired conditions. Furthermore, the leaching mechanism was based on the SEM-EDS (energy-dispersive X-ray spectroscopy) and XRD characterization as well as the leaching results obtained.

Bioleaching of a High Iron Content Kaolin by Aspergillus niger: The Effects of Organic Acids Biosynthesis

2007 ◽  
Vol 20-21 ◽  
pp. 111-114
Author(s):  
Mohammad Pazouki ◽  
M.R. Hosseini ◽  
M. Ranjbar ◽  
F. Ghavipanjeh
Keyword(s):  
Citric Acid ◽  
Aspergillus Niger ◽  
Oxalic Acid ◽  
Organic Acids ◽  
Iron Removal ◽  
Pulp Density ◽  
High Iron Content ◽  
Pistachio Shell ◽  
Strain Type ◽  
Different Strains

In this work, bioleaching of iron from a kaolin sample was carried out using two different strains of Aspergillus niger, and the effects of strain type, pulp density, and addition time of clay on the iron removal were investigated using a full factorial design. It is concluded that strain type has the most significant effect on the iron removal. Also, the highest removal extent was 42.8% that was achieved by using the strain isolated from pistachio shell at the pulp density of 20 g/l, when the clay was added at the beginning of the experiments. The results showed that for the experiments in which the clay was added in the first day of cultivation, the average organic acids concentration (citric acid: 5.6 g/l, and oxalic acid: 4.54 g/l) were higher in comparison to those experiments in which the clay was added in the third day (citric acid: 5.25 g/l, and oxalic acid: 2.87).

scholarly journals Leaching and solvent extraction purification of zinc from Mehdiabad complex oxide ore

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Faraz Soltani ◽  
Hossna Darabi ◽  
Reza Aram ◽  
Mahdi Ghadiri
Keyword(s):  
Solvent Extraction ◽  
Environmental Pollution ◽  
Central Composite Design ◽  
Complex Oxide ◽  
Hydrometallurgical Process ◽  
Purification Process ◽  
Optimum Conditions ◽  
Leaching Experiments ◽  
Central Composite ◽  
Sulphuric Acid Concentration

AbstractAn integrated hydrometallurgical process was used for the zinc leaching and purification from a zinc ore containing 9.75 wt% zinc. The zinc minerals in the ore were hemimorphite, willemite, and calcophanite. Main gangue minerals were quartz, goethite, hematite, and calcite. Central composite design (CCD) method was used to design leaching experiments and the optimum conditions were found as follows: 30% of solid fraction, 22.05% sulphuric acid concentration, and the leaching temperature of 45 °C. The PLS containing 35.07 g/L zinc, 3.16 g/L iron, and 4.58 g/L manganese impurities was produced. A special purification process including Fe precipitation and Zn solvent extraction was implemented. The results showed that after precipitation of iron, Zn extraction of 88.5% was obtained with the 2 stages extraction system composed of 30 vol% D2EHPA as extractant. The overall Zn recovery from the ore was 71.44%. Therefore, an appropriate solution containing 16.6 g/L Zn, 0.05 g/L Fe, and 0.11 g/L Mn was prepared for the electro-winning unit without using the roasting and calcination steps (conventional method), which result in environmental pollution.

scholarly journals Enhanced Electrokinetic Remediation for the Removal of Heavy Metals from Contaminated Soils

2021 ◽  
Vol 11 (4) ◽  
pp. 1799
Author(s):  
Claudio Cameselle ◽  
Susana Gouveia ◽  
Adrian Cabo
Keyword(s):  
Heavy Metals ◽  
Citric Acid ◽  
Organic Acids ◽  
Contaminated Soils ◽  
Electrokinetic Remediation ◽  
Deionized Water ◽  
Soil Specimen ◽  
Removal Of Heavy Metals ◽  
Ph Conditions ◽  
Neutral Metal

The electrokinetic remediation of an agricultural soil contaminated with heavy metals was studied using organic acids as facilitating agents. The unenhanced electrokinetic treatment using deionized water as processing fluid did not show any significant mobilization and removal of heavy metals due to the low solubilization of metals and precipitation at high pH conditions close to the cathode. EDTA and citric acid 0.1 M were used as facilitating agents to favor the dissolution and transportation of metals. The organic acids were added to the catholyte and penetrated into the soil specimen by electromigration. EDTA formed negatively charged complexes. Citric acid formed neutral metal complexes in the soil pH conditions (pH = 2–4). Citric acid was much more effective in the dissolution and transportation out of the soil specimen of complexed metals. In order to enhance the removal of metals, the concentration of citric acid was increased up to 0.5 M, resulting in the removal of 78.7% of Cd, 78.6% of Co, 72.5% of Cu, 73.3% of Zn, 11.8% of Cr and 9.8% of Pb.

scholarly journals Characterization of Spent Ni-MH Batteries

2012 ◽  
Vol 730-732 ◽  
pp. 569-574
Author(s):  
Marta Cabral ◽  
Fernanda Margarido ◽  
Carlos A. Nogueira
Keyword(s):  
Quantitative Analysis ◽  
Electrode Materials ◽  
Phase Identification ◽  
Recycling Process ◽  
X Ray ◽  
Leaching Experiments ◽  
Plastic Components ◽  
Definition Of ◽  
Physical And Chemical

Spent Ni-MH batteries are not considered too dangerous for the environment, but they have a considerable economical value due to the chemical composition of electrodes which are highly concentrated in metals. The present work aimed at the physical and chemical characterisation of spent cylindrical and thin prismatic Ni-MH batteries, contributing for a better definition of the recycling process of these spent products. The electrode materials correspond to more than 50% of the batteries weight and contain essentially nickel and rare earths (RE), and other secondary elements (Co, Mn, Al). The remaining components are the steel parts from the external case and supporting grids (near 30%) containing Fe and Ni, and the plastic components (<10%). Elemental quantitative analysis showed that the electrodes are highly concentrated in metals. Phase identification by X-ray powder diffraction combined with chemical analysis and leaching experiments allowed advancing the electrode materials composition. The cathode is essentially constituted by 6% metallic Ni, 66% Ni(OH)2, 4.3% Co(OH)2 and the anode consists mainly in 62% RENi5 and 17% of substitutes and/or additives such as Co, Mn and Al.

X-ray crystal analysis of the substrates of aconitase. II. Anhydrous citric acid

1960 ◽  
Vol 13 (5) ◽  
pp. 418-426 ◽  
Author(s):  
C. E. Nordman ◽  
A. S. Weldon ◽  
A. L. Patterson
Keyword(s):  
Citric Acid ◽  
X Ray

Intramolecular versus Intermolecular Hydrogen Bonding of Coordinated Acetate to Organic Acids:  A Neutron, X-ray, and Database Study

2003 ◽  
Vol 3 (5) ◽  
pp. 699-704 ◽  
Author(s):  
Guillaume Vives ◽  
Sax A. Mason ◽  
Paul D. Prince ◽  
Peter C. Junk ◽  
Jonathan W. Steed
Keyword(s):  
Hydrogen Bonding ◽  
Organic Acids ◽  
Intermolecular Hydrogen Bonding ◽  
Database Study ◽  
X Ray

scholarly journals Effect of organic acids fed through drinking water on carcass and internal organs of broiler chickens

2021 ◽  
Vol 41 (1) ◽  
pp. 60-67
Author(s):  
E. K. Ndelekwute ◽  
H. O. Uzegbu ◽  
K. U. Amaefule ◽  
C. O. Okereke ◽  
B. I. Umoh
Keyword(s):  
Drinking Water ◽  
Acetic Acid ◽  
Citric Acid ◽  
Gall Bladder ◽  
Organic Acids ◽  
Formic Acid ◽  
Butyric Acid ◽  
Broiler Chickens ◽  
Internal Organs ◽  
Carcass Yield

A Six week study was carried out to investigate effect of different organic acids (OAs) fed through drinking water on carcass yield and internal organs weight of broiler chickens. The OAs were acetic acid (AA) butyric acid (BA), citric acid (CA) and formic acid (FA). One hundred and fifty (150) day old AborAcre-plus chicks were used. There were five treatments. Treatment 1 which served as control (CON) consumed water with no organic acid, while treatments 2,3, 4 and5 respectively were offered drinking water treated with 0.25% acetic acid (AA), butyric acid (BA), citric acid (CA) and formic acid (FA). Each treatment was replicated three times each having 10 birds arranged in completely randomized design (CRD). Feed and water were offered ad libitum. Results showed that dressed carcass weight and breast weight were improved by all the organic acids. While only AA positively influenced the thigh weight, all the OAs drinking water fed resulted to smaller drumstick compared to the CON. Feeding of AA, BA and FA through drinking water increased (PSO.05) deposition of abdominal fat. Weight of pancreas, small intestine, caecum and large intestine was significantly (P<0.05) higher in CON. The gall bladder was significantly (P<0.05) bigger in all the OA groups. Conclusively, OAs could be fed through the drinking water for improved percentage carcass yield, breast meat and larger gall bladder and invariably bile volume

scholarly journals The Cardioprotective Effects of Citric Acid and L-Malic Acid on Myocardial Ischemia/Reperfusion Injury

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Xilan Tang ◽  
Jianxun Liu ◽  
Wei Dong ◽  
Peng Li ◽  
Lei Li ◽  
...  
Keyword(s):  
Citric Acid ◽  
Myocardial Ischemia ◽  
Organic Acids ◽  
Reperfusion Injury ◽  
Malic Acid ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Protective Effects ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion

Organic acids in Chinese herbs, the long-neglected components, have been reported to possess antioxidant, anti-inflammatory, and antiplatelet aggregation activities; thus they may have potentially protective effect on ischemic heart disease. Therefore, this study aims to investigate the protective effects of two organic acids, that is, citric acid and L-malic acid, which are the main components ofFructus Choerospondiatis, on myocardial ischemia/reperfusion injury and the underlying mechanisms. Inin vivorat model of myocardial ischemia/reperfusion injury, we found that treatments with citric acid and L-malic acid significantly reduced myocardial infarct size, serum levels of TNF-α, and platelet aggregation.In vitroexperiments revealed that both citric acid and L-malic acid significantly reduced LDH release, decreased apoptotic rate, downregulated the expression of cleaved caspase-3, and upregulated the expression of phosphorylated Akt in primary neonatal rat cardiomyocytes subjected to hypoxia/reoxygenation injury. These results suggest that both citric acid and L-malic acid have protective effects on myocardial ischemia/reperfusion injury; the underlying mechanism may be related to their anti-inflammatory, antiplatelet aggregation and direct cardiomyocyte protective effects. These results also demonstrate that organic acids, besides flavonoids, may also be the major active ingredient ofFructus Choerospondiatisresponsible for its cardioprotective effects and should be attached great importance in the therapy of ischemic heart disease.

scholarly journals Two-Step Separation of Chitin from Shrimp Shells Using Citric Acid and Deep Eutectic Solvents with the Assistance of Microwave

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 409 ◽  
Author(s):  
Dandan Zhao ◽  
Wen-Can Huang ◽  
Na Guo ◽  
Shuye Zhang ◽  
Changhu Xue ◽  
...  
Keyword(s):  
Citric Acid ◽  
Deep Eutectic Solvents ◽  
Second Step ◽  
X Ray Diffraction ◽  
X Ray ◽  
Shrimp Shells ◽  
Ft Ir ◽  
Scanning Electron ◽  
Ft Ir Spectroscopy

In this research, a two-step extraction approach was developed for chitin preparation from shrimp shells by utilizing citric acids and deep eutectic solvents (DESs), which effectively removed minerals and proteins. In the first step, minerals of shrimp shells were removed by citric acid, and the demineralization efficiency reached more than 98%. In the second step, the removal of protein was carried out using deep eutectic solvents with the assistance of microwave, and the deproteinization efficiency was more than 88%. The results of scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction analysis (XRD), and thermogravimetric analysis (TGA) showed that the quality of DES-prepared chitin was comparable to that of traditional acid/alkali-prepared chitin. These results were realized without utilizing hazardous chemicals, which are detrimental to the environment. This research indicates that a DES-based preparation approach has the potential for application in the recovery of biopolymers from natural resources.

scholarly journals Effect of Solid Forms on Physicochemical Properties of Valnemulin

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 675 ◽  
Author(s):  
Jinbo Ouyang ◽  
Jian Chen ◽  
Limin Zhou ◽  
Fangze Han ◽  
Xin Huang
Keyword(s):  
Organic Acids ◽  
Physicochemical Properties ◽  
Excess Enthalpy ◽  
Vapor Sorption ◽  
Dynamic Vapor Sorption ◽  
Scanning Calorimetry ◽  
Intrinsic Dissolution ◽  
X Ray ◽  
Ft Ir ◽  
Scanning Electron

To improve the physicochemical properties of valnemulin (VLM), different solid forms formed by VLM and organic acids, including tartaric acid (TAR), fumaric acid (FUM), and oxalic acid (OXA), were successfully prepared and characterized by using differential scanning calorimetry (DSC), scanning electron microscope (SEM), X-ray powder diffraction (XRPD), and Fourier-transform infrared spectroscopy (FT-IR). The excess enthalpy Hex between VLM and other organic acids was calculated by COSMOthermX software and was used to evaluate the probability of forming multi-component solids between VLM and organic acids. By thermal analysis, it was confirmed that multi-component solid forms of VLM were thermodynamically more stable than VLM itself. Through dynamic vapor sorption (DVS) experiments, it was found that three multi-component solid forms of VLM had lower hygroscopicity than VLM itself. Furthermore, the intrinsic dissolution rate of VLM and its multi-component forms was determined in one kind of acidic aqueous medium by using UV-vis spectrometry. It was found that the three multi-component solid forms of VLM dissolved faster than VLM itself.

Sign in / Sign up

Export Citation Format

Share Document