The extraction of tin (Sn) from primary tin ore deposits using wet chlorination

Abstract More than half of the world’s tin production is from secondary ore deposits. However, along with its depletion, PT Timah Tbk has explored and mined the primary deposits in Belitung, one that is expected to become tin’s new source. Tin was found liberated as cassiterite in the secondary deposits, while in the primary, it was associated with other minerals requiring more complex processing. Therefore, a suitable technology is needed to extract the tin from the primary ore deposits. This research aims to observe the extraction of tin from primary deposits (oxide and skarn ores) using HCl wet chlorination, observed at different temperature (60 – 90°C), HCl concentrations (10 – 50 % excess of stoichiometric amount), leaching time (60 – 300 minutes), and with or without the addition of oxidant (hydrogen peroxide, H2O2). The research found that the highest percentage of tin extraction from oxide and skarn ores was 92.32% and 97.28%, respectively. Both results were achieved at the same optimum condition: temperature of 60°C, 50% excess of HCl, 240 minutes of leaching time, and at two-fold excess of the stoichiometric amount of H2O2. It was concluded that oxidative wet chlorination could be used to recover tin from its primary ore deposits.

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The Study Of Conversion Cpo To Polyol (Polyalcohol)

REAKTOR ◽

10.14710/reaktor.11.1.8-13 ◽

2017 ◽

Vol 11 (1) ◽

pp. 8

Author(s):

F. S. Budi ◽

Z. Abidin

Keyword(s):

Hydrogen Peroxide ◽

Fatty Acid ◽

Optimum Condition ◽

Formic Acid ◽

The Other ◽

Hydroxyl Number ◽

Main Component

Indonesia is the second big CPO producer after Malaysia. The CPO production of Indonesia gradually increases and reaches 8.2 million tones. About two third of it is used to meet the domestic will receive little income. Therefore, it must be converted into the other product, which has the high value. The main component of it is glyceride composed of glycerol and fatty acid. The glyceride can be converted into polyol (polyalcohol) which is the material in manufacturing polyurethane, cosmetic, lubricant etc. the process of converting of CPO into polyol is called the hydroxylation. This research aim to study the hydroxylation process of CPO into polyol and to optimize the variable which really affect the hydroxyl number of product. Based on the experiment, the optimum condition of hydroxylation of CPO with the hydrogen peroxide (H2O2) and the formic acid (HCOOH) into polyol is got as follows: temperature 50 0C, composition of reactan 40% and time 2 hours. The polyol produced has the hydroxyl number 148.Keywords : CPO, hydroxylation, polyol

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The X-Ray Analysis of Uranium Ores for Iron Sulfide Minerals

Advances in X-ray Analysis ◽

10.1154/s0376030800009617 ◽

1981 ◽

Vol 25 ◽

pp. 113-115

Author(s):

A. J. Durbetaki ◽

R. H. Carlson ◽

T. F. Quail

Keyword(s):

Hydrogen Peroxide ◽

Iron Sulfide ◽

Sulfide Minerals ◽

Ore Deposits ◽

X Ray Diffraction ◽

X Ray ◽

Iron Sulfide Minerals ◽

Xrd Method

Hydrogen peroxide is used to extract uranium by the in situ leaching of sandstone ore deposits containing uraninite (UO2). Since FeS2 minerals, marcasite and pyrite, also occur in these deposits and they consume hydrogen peroxide in their oxidation, it is important to determine their concentration.A quantitative X-ray diffraction (XRD) method was therefore developed in order to monitor the concentration of marcasite and pyrite in sandstone ores.

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Hydrogen Peroxide Sensitivity of Catechol-2,3-Dioxygenase: a Cautionary Note on Use ofxylE Reporter Fusions under Aerobic Conditions

Applied and Environmental Microbiology ◽

10.1128/aem.66.9.4119-4123.2000 ◽

2000 ◽

Vol 66 (9) ◽

pp. 4119-4123 ◽

Cited By ~ 18

Author(s):

Daniel J. Hassett ◽

Urs A. Ochsner ◽

Stephanie L. Groce ◽

Kislay Parvatiyar ◽

Ju-Fang Ma ◽

...

Keyword(s):

Oxidative Stress ◽

Hydrogen Peroxide ◽

Active Site ◽

Gene Fusion ◽

Galactosidase Activity ◽

Cautionary Note ◽

Paramagnetic Resonance ◽

Aerobic Conditions ◽

Electron Paramagnetic ◽

Fold Excess

ABSTRACT Catechol-2,3-dioxygenase (C23O) of Pseudomonas putida, encoded by the xylE gene, was found to be sensitive to hydrogen peroxide (H2O2) when used as a reporter in gene fusion constructs. Exposure of Pseudomonas aeruginosa katA or katA katB mutants harboringkatA- or katB-lacZ (encoding β-galactosidase) or -xylE fusion plasmids to H2O2stimulated β-galactosidase activity, while there was little or no detectable C23O activity in these strains. More than 95% of C23O activity was lost after a 5-min exposure to equimolar H2O2, while a 10,000-fold excess was required for similar inhibition of β-galactosidase. Electron paramagnetic resonance spectra of the nitrosyl complexes of C23O showed that H2O2 nearly stoichiometrically oxidized the essential active-site ferrous ion, thus accounting for the loss of activity. Our results suggest using caution in interpreting data derived from xylE reporter fusions under aerobic conditions, especially where oxidative stress is present or when catalase-deficient strains are used.

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Enzymatic Degradation of Congo Red by Turnip (Brassica rapa) Peroxidase

Zeitschrift für Naturforschung C ◽

10.1515/znc-2012-7-811 ◽

2012 ◽

Vol 67 (7-8) ◽

pp. 429-436 ◽

Cited By ~ 2

Author(s):

Afaf Ahmedi ◽

Mahmoud Abouseoud ◽

Annabelle Couvert ◽

Abdeltif Amrane

Keyword(s):

Hydrogen Peroxide ◽

Brassica Rapa ◽

Congo Red ◽

Enzymatic Degradation ◽

Ph Value ◽

Enzyme Concentration ◽

Operating Conditions ◽

Time Analysis ◽

C 50 ◽

By Products

The enzyme peroxidase is known for its capacity to remove phenolic compounds and aromatic amines from aqueous solutions and also to decolourize textile effluents. This study aims at evaluating the potential of a turnip (Brassica rapa) peroxidase (TP) preparation in the discolouration of textile azo dyes and effluents. An azo dye, Congo Red (CR), was used as a model pollutant for treatment by the enzyme. The effects of various operating conditions like pH value, temperature, initial dye and hydrogen peroxide concentrations, contact time, and enzyme concentration were evaluated. The optimal conditions for maximal colour removal were at pH 2.0, 40 °C, 50 mM hydrogen peroxide, 50 mg/l CR dye, and TP activity of 0.45 U/ml within 10 min of incubation time. Analysis of the by-products from the enzymatic treatment by UV-Vis and IR spectroscopy showed no residual compounds in the aqueous phase and a precipitate of polymeric nature.

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Highly Efficient and Ambient-Temperature Synthesis of Benzimidazoles via Co(III)/Co(II)-Mediated Redox Catalysis

Catalysts ◽

10.3390/catal12010059 ◽

2022 ◽

Vol 12 (1) ◽

pp. 59

Author(s):

Renyuan Zhong ◽

Wulin Xiong ◽

Haoyuan Zhang ◽

Tongtong Zeng ◽

Shanshan Gong ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Ambient Temperature ◽

Efficient Method ◽

Solvent Free ◽

Redox Catalysis ◽

Temperature Synthesis ◽

Fast Green ◽

Stoichiometric Amount ◽

Highly Efficient ◽

Solvent Free Conditions

An efficient method for ambient-temperature synthesis of a variety of 2-substituted and 1,2-disubstituted benzimidazoles from aldehyde and phenylenediamine substrates has been developed by utilizing Co(III)/Co(II)-mediated redox catalysis. The combination of only 1 mol% of Co(acac)2 and stoichiometric amount of hydrogen peroxide provides a fast, green, and mild access to a diversity of benzimidazoles under solvent-free conditions.

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Comparative Studies of Hemicelluloses Solubilized during the Treatments of Maize Stems with Peroxymonosulfuric Acid, Peroxyformic Acid, Peracetic Acid, and Hydrogen Peroxide. Part 1. Yield and Chemical Characterization

Holzforschung ◽

10.1515/hf.2000.061 ◽

2000 ◽

Vol 54 (4) ◽

pp. 349-356 ◽

Cited By ~ 7

Author(s):

RunCang Sun ◽

J. Tomkinson ◽

Z. C. Geng ◽

N. J. Wang

Keyword(s):

Hydrogen Peroxide ◽

Cell Wall ◽

Optimum Condition ◽

Peracetic Acid ◽

Chemical Characterization ◽

Alkaline Media ◽

Minimal Amount ◽

Minor Components ◽

Alkaline Peroxide ◽

Peroxyformic Acid

Summary Treatment of the water-extracted maize stems with peroxymonosulfuric acid at 20 °C for 144 h, peroxyformic acid at 80°C for 6 h, peracetic acid at 50°C for 6 h, and 2% hydrogen peroxide at 45°C for 12 h at pH 1.5, 4.4, 9.5, 11.5, 12.0, and 12.6, respectively, solubilized 47.1%, 91.3%, 33.3%, 16.6%, 15.9%, 17.4%, 86.2%, 87.7%, and 91.3% of the original lignin, and hydrolysed or dissolved 12.1%, 99.1%, 4.5%, 2.7%, 3.1%, 3.1%, 63.3%, 64.7%, and 83.0% of the original hemicelluloses, respectively. Substantial lignins and hemicelluloses were degraded or released during the treatment with peroxyformic acid and alkaline peroxide at pH ≥ 11.5, while an insignificant effect on delignification and hemicellulose solubilization was observed by using peroxymonosulfuric acid, peracetic acid, and hydrogen peroxide in acidic, natural, and weak alkaline media. The optimum condition for extraction of hemicelluloses was found to use 2% H2O2 at 45°C for 12 h at pH 11.5–12.0, which yielded 63.3–64.7% of the original hemicelluloses having much lighter color than those obtained by peroxymonosulfuric acid and peracetic acid under conditions used and 2% H2O2 at pH 1.5, 4.4, 9.5, and 12.6. Xylose and arabinose were the major sugar constituents in these hemicellulose preparations, whereas glucose, galactose, mannose, rhamnose, and fucose were present as minor components. The α-ether linkages between lignin and hemicelluloses in the cell wall of maize stems were substantially cleaved during the treatment with 2% H2O2 at pH ≥11.5 as shown by a minimal amount of associated lignin (2.9–3.9%), rich in syringyl units, in the solubilized hemicelluloses.

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Process Optimization for the Production of Ferric Sulfate Coagulant by the Oxidation of Ferrous sulfate with Hydrogen Peroxide

Chemical Product and Process Modeling ◽

10.1515/cppm-2019-0091 ◽

2020 ◽

Vol 15 (3) ◽

Author(s):

Veronica Barbosa Mazza ◽

Luiz Alberto Cesar Teixeira ◽

Ana Rosa Fonseca de Aguiar Martins ◽

Brunno Ferreira dos Santos

Keyword(s):

Hydrogen Peroxide ◽

Ferrous Sulfate ◽

Oxidation Reaction ◽

Reaction Medium ◽

Industrial Process ◽

Oxidation Potential ◽

Ferric Sulfate ◽

Optimum Conditions ◽

Independent Variables ◽

Stoichiometric Amount

AbstractMotivated by the oxidative power of hydrogen peroxide and its environmentally attractive properties, the present study aimed to determine the optimum conditions for the production of ferric sulfate coagulant from ferrous sulfate The independent variables studied were the temperature (7.5–27.5 °C), amount of hydrogen peroxide (100–300 %) of the stoichiometric amount for the oxidation reaction, and dilution of the reaction medium using water (100–300 %) of the stoichiometric amount for the oxidation reaction. For the optimum conditions achieved, it was possible to obtain a conversion of 96.17 % of Fe+2 to Fe+3, using a small hydrogen peroxide excess of 50 %, resulting in a product suitable for use as a coagulant in water treatment. It was found that an oxidation potential (Eh) greater than 0.7 volts corresponded to the conversion of Fe+2 to Fe+3 greater than 90 %, indicating Eh to be useful for reaction control in an industrial process.

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Ti(Phen)(OC2H5)2Cl2: a highly efficient pre-catalyst for selective oxidation of organic sulfides to sulfoxides by hydrogen peroxide

RSC Advances ◽

10.1039/c7ra06883b ◽

2017 ◽

Vol 7 (70) ◽

pp. 44259-44264 ◽

Cited By ~ 6

Author(s):

Rong-Hui Wu ◽

Jing Wu ◽

Ming-Xin Yu ◽

Long-Guan Zhu

Keyword(s):

Hydrogen Peroxide ◽

Selective Oxidation ◽

Room Temperature ◽

Titanium Complex ◽

Stoichiometric Amount ◽

Highly Efficient ◽

Organic Sulfides

A structurally characterized titanium complex [Ti(Phen)(OC2H5)2Cl2] (Phen = 1,10-phenanthroline) is reported as a homogeneous pre-catalyst for the selective oxidation of organic sulfides to sulfoxides with a stoichiometric amount H2O2 in CH3OH at room temperature.

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Preparation of Paper Mulberry Fibers and Possibility of Cotton/Paper Mulberry Yarns Production

Indian Journal of Materials Science ◽

10.1155/2016/1498967 ◽

2016 ◽

Vol 2016 ◽

pp. 1-6

Author(s):

Manoon Jitjaicham ◽

Boonsri Kusuktham

Keyword(s):

Hydrogen Peroxide ◽

Optimum Condition ◽

Nonionic Surfactant ◽

Sodium Hydroxide ◽

Cotton Fibers ◽

Antifungal Property ◽

Bleaching Process ◽

Inner Bark ◽

Yarn Production

The novelty of yarn production from cotton/paper mulberry fiber blends was reported. The objective of this research was to prepare the paper mulberry fibers and study the possibility of production of yarns from cotton/paper mulberry fibers. For preparation of paper mulberry fibers, the inner bark was first immersed in water for 24 h. Then, the fibers were treated with sodium hydroxide at concentration of 5–10% (w/v) for 1–3 h. After that, the bleaching process was conducted with hydrogen peroxide at concentration of 5–25% (v/v) for different temperature and time. Finally, the fibers were washed with 10% (v/v) of nonionic surfactant at temperature of 90°C for 30 minute to remove the residual gum from the fibers. The results showed that optimum condition for scouring of the paper mulberry fibers was 15% (w/v) sodium hydroxide at 90°C for 2 h. The bleaching process with 15% (v/v) H2O2 at 90°C for 90 minute was suitable. The obtained fibers were blended with the cotton fibers to produce yarns by open-end spinning method. The % elongation and tenacity of the blended yarns increased with the increasing of the paper mulberry ratio. Also, the antifungal property of yarns was improved by the blending of cotton fibers with the paper mulberry fibers.

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Effect of Salinities and Dietary Patterns toward Fullness of Gut and Gut Evacuation Time of the Newly Introduced Penaeus merguiensis Larvae

ILMU KELAUTAN Indonesian Journal of Marine Sciences ◽

10.14710/ik.ijms.26.2.71-78 ◽

2021 ◽

Vol 26 (2) ◽

pp. 71-78

Author(s):

Mostafa Imhmed Ighwerb ◽

Johannes Hutabarat ◽

Ervia Yudiati ◽

Rudhi Pribadi ◽

Widianignsih Widianingsih ◽

...

Keyword(s):

Optimum Condition ◽

Salinity Tolerance ◽

Optimum Growth ◽

Evacuation Time ◽

Digestive Capacity ◽

Live Feed ◽

Gut Evacuation ◽

C 50 ◽

Larvae Culture ◽

Penaeus Merguiensis

The gut capacity of shrimp larvae is minimal, and their digestion is often challenged by the inevitable fact that they tend to develop slowly during the zoea stage. Many studies approved that the digestive capacity of shrimp larvae could be improved by increasing the retention time of food in the intestine. Gut evacuation time and fullness of the gut are crucial parameters in assessing the growth of shrimp larvae, and the diet as well as environmental conditions indeed influence the activity of these parameters. Although many species of shrimps have a wide salinity tolerance, more specific research on salinity and its relation to the type of diet is necessary to find the optimum condition supporting the growth of shrimp larvae. By employing Penaeus merguiensis larvae, this study evaluates the effect of three nominal salinities (28, 32, and 36 ppt) and types of diets (Diet A: 100% live feed; Diet B: 100% FRIPPAK; Diet C: a combination of Diet A and Diet C, 50 % each) toward the fullness of gut and gut evacuation time of the newly introduced Penaeus merguiensis larvae culture. The result showed that the longest gut evacuation time and the highest percentage of gut's fullness were found in all Zoea reared with Diet A at salinity 28 and 32 ppt; Zoea-1 at 28 ppt with Diet A; Zoea-2 at 32 ppt with Diet A; Zoea-3 at 32 ppt with Diet A. Longer gut evacuation time would have an impact on the higher percentage of the fullness of gut. The higher fullness of the gut also indicates that the larvae have the best capacity to produce energy and achieve optimum growth.

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