Method for compression of aqueous slurry containing solid foreign matter and paper dust, and treatment method of waste gypsum board
AssigneeTokuyama Corporation
InventorsShingo Hiranaka, Kentarou Matsuo
Life of this patent
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Abstract
Aqueous slurry which includes solid foreign matter and paper dust is pressed by means of a screw press, provided with a mesh having openings not less than 1.5 mm and not greater than 3 mm, to separate the aqueous slurry into the solid foreign matter and the paper dust, and liquid component passing through the mesh. Then, the liquid component is sieved by means of a sieve having openings not greater than 1 mm to separate from the liquid component the solid foreign matter and the paper dust.
Claims5
A pressing method of aqueous slurry, including solid foreign matter and paper dust, comprising:
- a pressing step for pressing said aqueous slurry by means of a screw press, provided with a mesh having openings not less than 1.5 mm and not greater than 3 mm, such that said aqueous slurry is partially separated into the solid foreign matter and the paper dust not passing through said mesh, and liquid component passing through said mesh, and
- a sieving step for sieving said liquid component by means of a sieve having openings not greater than 1 mm to further separate the solid foreign matter and the paper dust from the liquid component.
A processing method of waste gypsum boards comprising:
- a deposition step for mixing gypsum hemihydrate and/or anhydrous type III gypsum, derived from waste gypsum boards with an aqueous medium to form a gypsum slurry including paper dust and solid foreign matter and then for depositing gypsum dihydrate particles in the gypsum slurry;
- and
- a solid/liquid separation step for extracting the gypsum dihydrate particles from the gypsum slurry, wherein
- a pressing step for pressing said gypsum slurry by means of a screw press, provided with a mesh having openings not less than 1.5 mm and not greater than 3 mm, such that said gypsum slurry is partially separated into the solid foreign matter and the paper dust not passing through said mesh, and a gypsum slurry passing through said mesh, and
- a sieving step for sieving said gypsum slurry passing through said mesh by means of a sieve having openings not greater than 1 mm to further separate the solid foreign matter and the paper dust as oversized components from the gypsum slurry
- are performed after forming the gypsum slurry and before the solid/liquid separation step.
Dependencies are inferred from the claim text.