Morphological properties of peroxidic pulp from hemp bonfire

Abstract The bonfire (Cannabis sativa) was delignified with the reaction mixture “acetic acid - hydrogen peroxide - sulfuric acid catalyst - water” at a sulfuric acid concentration of 0.45%, a liquid module of 6, and a temperature of 85 °C. The effect of cooking conditions (hydrogen peroxide concentration and process duration) and mass grinding up to 34 … 36 °SR on the morphological properties of technical cellulose fibers - length, width, degree of inhomogeneity (polydispersity) - has been studied. Hemp fibers are inferior in length to those of spruce wood and wheat straw, but more uniform. The widths of hemp and wood fibers are almost the same. Due to its high strength characteristics, peroxide cellulose from bonfire is suitable for use in composition with other fibrous semi-finished products in the production of mass types of paper and cardboard products.

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The paper-forming properties of hemp fire peroxide cellulose in combination with wood sulphate cellulose

Journal of Physics Conference Series ◽

10.1088/1742-6596/2094/5/052043 ◽

2021 ◽

Vol 2094 (5) ◽

pp. 052043

Author(s):

R A Marchenko ◽

R Z Pen ◽

I L Shapiro ◽

Y A Ambrosovich

Keyword(s):

Hydrogen Peroxide ◽

Sulfuric Acid ◽

Cannabis Sativa ◽

Sulfuric Acid Concentration ◽

Acid Catalyst ◽

Strength Properties ◽

Mixed Composition ◽

Deciduous Wood ◽

Sulfuric Acid Catalyst ◽

Hardwood Pulp

Abstract Hemp fire (Cannabis sativa) was delignified with the reaction mix “acetic acid - hydrogen peroxide - sulfuric acid catalyst - water” under sulfuric acid concentration of 0.45%, liquid module of 6, and temperature of 85 ° C. The cellulose was ground to 34 … 36°SHR and mixed in different ratios in compliance with the simplex-centroid experimental design with bleached sulfate softwood and hardwood pulp. The influence of the mixed composition formulations on the main strength properties of paper castings has been studied. It has been concluded that technical cellulose obtained from hemp fire applying this method, can be used for paper products manufacturing in combination with sulphate cellulose from coniferous and deciduous wood.

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Effective Recovery Process of Copper from Waste Printed Circuit Boards Utilizing Recycling of Leachate

JOM ◽

10.1007/s11837-020-04510-z ◽

2020 ◽

Author(s):

Joona Rajahalme ◽

Siiri Perämäki ◽

Roshan Budhathoki ◽

Ari Väisänen

Keyword(s):

Hydrogen Peroxide ◽

Sulfuric Acid ◽

Printed Circuit Boards ◽

Sulfuric Acid Concentration ◽

Recovery Process ◽

Copper Recovery ◽

Circuit Boards ◽

Printed Circuit ◽

Waste Printed Circuit Boards ◽

Acid Consumption

AbstractThis study presents an optimized leaching and electrowinning process for the recovery of copper from waste printed circuit boards including studies of chemical consumption and recirculation of leachate. Optimization of leaching was performed using response surface methodology in diluted sulfuric acid and hydrogen peroxide media. Optimum leaching conditions for copper were found by using 3.6 mol L−1 sulfuric acid, 6 vol.% hydrogen peroxide, pulp density of 75 g L−1 with 186 min leaching time at 20°C resulting in complete leaching of copper followed by over 92% recovery and purity of 99.9% in the electrowinning. Study of chemical consumption showed total decomposition of hydrogen peroxide during leaching, while changes in sulfuric acid concentration were minor. During recirculation of the leachate with up to 5 cycles, copper recovery and product purity remained at high levels while acid consumption was reduced by 60%.

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Kinetics of Chalcopyrite Leaching by Hydrogen Peroxide in Sulfuric Acid

Metals ◽

10.3390/met9111173 ◽

2019 ◽

Vol 9 (11) ◽

pp. 1173 ◽

Cited By ~ 6

Author(s):

Sokić ◽

Marković ◽

Stanković ◽

Kamberović ◽

Štrbac ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Particle Size ◽

Sulfuric Acid ◽

Sulfuric Acid Concentration ◽

Dissolution Kinetics ◽

Poor Quality ◽

Characterization Methods ◽

Quantitative Light Microscopy ◽

Chalcopyrite Concentrate ◽

Pyrometallurgical Processing

In ores, chalcopyrite is usually associated with other sulfide minerals, such as sphalerite, galena, and pyrite, in a dispersed form, with complex mineralogical structures. Concentrates obtained by flotation of such ores are unsuitable for pyrometallurgical processing owing to their poor quality and low metal recovery. This paper presents the leaching of chalcopyrite concentrate from the location “Rudnik, Serbia”. The samples from the flotation plant were treated with hydrogen peroxide in sulfuric acid. The influences of temperature, particle size, stirring speed, as well as the concentrations of hydrogen peroxide and sulfuric acid were followed and discussed. Hence, the main objective was to optimize the relevant conditions and to determine the reaction kinetics. It was remarked that the increase in temperature, hydrogen peroxide content, and sulfuric acid concentration, as well as the decrease in particle size and stirring speed, contribute to the dissolution of chalcopyrite. The dissolution kinetics follow a model controlled by diffusion, and the lixiviant diffusion controls the rate of reaction through the sulfur layer. Finally, the main characterization methods used to corroborate the obtained results were X-ray diffraction (XRD) as well as qualitative and quantitative light microscopy of the chalcopyrite concentrate samples and the leach residue.

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Arenothiophenes in oil basic sulfoxides synthesis and oxidation receiving sulfoxides from oil

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/939/1/012018 ◽

2021 ◽

Vol 939 (1) ◽

pp. 012018

Author(s):

L Sh Bozorova ◽

M J Qurbanov ◽

O J Pirimov ◽

O Tursunov

Keyword(s):

Hydrogen Peroxide ◽

Sulfuric Acid ◽

Organic Compounds ◽

Chemical Reactions ◽

Acid Catalyst ◽

Composition And Structure

Abstract Some of the sulfide compounds were converted to sulfoxides by the action of a 30% solution of hydrogen peroxide on the acid catalyst of a molecule of bicyclic sulfide organic compounds in the paraffin distillate of the oil. The resulting sulfoxides were treated with 70% sulfuric acid and sulfate compounds of sulfoxides were obtained. In order to confirm the composition and structure of these compounds, chemical reactions of the corresponding sulfoxides on the basis of benzothiophene derivatives were carried out.

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Physical, Chemical, and Crystallographic Characterization of Anodic Coatings on High Strength Aluminum Base Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100093146 ◽

1976 ◽

Vol 34 ◽

pp. 636-637

Author(s):

R. E. Herfert ◽

N. T. McDevitt

Keyword(s):

Sulfuric Acid ◽

Salt Spray ◽

High Strength ◽

Environmental Stability ◽

Anodic Films ◽

Sodium Dichromate ◽

Corrosion Resistant ◽

Aerospace Applications ◽

Bond Strengths ◽

Adhesive Bonded Joints

Durability of adhesive bonded joints in moisture and salt spray environments is essential to USAF aircraft. Structural bonding technology for aerospace applications has depended for many years on the preparation of aluminum surfaces by a sulfuric acid/sodium dichromate (FPL etch) treatment. Recently, specific thin film anodizing techniques, phosphoric acid, and chromic acid anodizing have been developed which not only provide good initial bond strengths but vastly improved environmental durability. These thin anodic films are in contrast to the commonly used thick anodic films such as the sulfuric acid or "hard" sulfuric acid anodic films which are highly corrosion resistant in themselves, but which do not provide good initial bond strengths, particularly in low temperature peel.The objective of this study was to determine the characteristics of anodic films on aluminum alloys that make them corrosion resistant. The chemical composition, physical morphology and structure, and mechanical properties of the thin oxide films were to be defined and correlated with the environmental stability of these surfaces in humidity and salt spray. It is anticipated that anodic film characteristics and corrosion resistance will vary with the anodizing processing conditions.

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REVERE No. 430

Alloy Digest ◽

10.31399/asm.ad.cu0063 ◽

1958 ◽

Vol 7 (5) ◽

Keyword(s):

Corrosion Resistance ◽

Sulfuric Acid ◽

High Temperature ◽

Physical Properties ◽

High Resistance ◽

High Strength ◽

Heat Treating ◽

Aluminum Bronze ◽

Temperature Performance ◽

Excellent Corrosion Resistance

Abstract REVERE No. 430 is an aluminum bronze having high strength, excellent corrosion resistance, and high resistance to sulfuric acid. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-63. Producer or source: Revere Copper and Brass Inc..

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Optimization and characterization of flavonoids extracted from Cannabis sativa fibers

Textile Research Journal ◽

10.1177/00405175211027796 ◽

2021 ◽

pp. 004051752110277

Author(s):

Qilu Cui ◽

Jiawei Li ◽

Chongwen Yu

Keyword(s):

Chemical Structure ◽

Cannabis Sativa ◽

Ethanol Concentration ◽

Extraction Process ◽

Test Results ◽

Hemp Fiber ◽

Hemp Fibers ◽

Structure Surface ◽

Degumming Process

In this paper, the extraction process of flavonoids from hemp fibers was studied. Response surface methodology (RSM) analysis of the extraction parameters indicated that optimized results would be ethanol concentration 76 vol.%, bath ratio 1:50, and reaction time 139 min; therefore, an optimal extraction rate of flavonoids of 0.2275% can be obtained. The chemical structure, surface morphology and element composition of flavonoid extracts were analyzed. The test results indicated that hemp extract contains flavonoids, which can be used to extract flavonoids from hemp fiber, so as to comprehensively develop hemp fiber and reduce the discharge of waste liquid in the traditional degumming process.

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