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

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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Morphological properties of peroxidic pulp from hemp bonfire

Journal of Physics Conference Series ◽

10.1088/1742-6596/2094/5/052034 ◽

2021 ◽

Vol 2094 (5) ◽

pp. 052034

Author(s):

R Z Pen ◽

I L Shapiro ◽

L V Chendilova ◽

R A Marchenko

Keyword(s):

Hydrogen Peroxide ◽

Sulfuric Acid ◽

Cannabis Sativa ◽

Sulfuric Acid Concentration ◽

Acid Catalyst ◽

High Strength ◽

Morphological Properties ◽

Wood Fibers ◽

Hemp Fibers ◽

Length Width

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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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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