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Pulping paper-making process with zero discharge of sewage water

A technology for pulping and papermaking with zero discharge, applied in pulp beating/refining method, papermaking, textiles and papermaking, etc., can solve the problems of high operating cost and large investment, reduce investment, simplify concentration process, and improve water drainage. performance effect

Inactive Publication Date: 2008-12-03
CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problems of huge investment and high operating costs in the existing alkali recovery technology, and to provide an alkaline zero residual alkali cooking pulping technology, and the obtained pulping black liquor can be used for the production of organic fertilizers or for other purposes , zero discharge after sewage treatment, so that the pulping process not only has no sewage discharge, but also because the black liquor is used to produce organic fertilizers, the black liquor treatment has produced economic and social benefits. The present invention is not limited by papermaking raw materials and scale , especially suitable for my country's unique non-wood fiber pulping and papermaking

Method used

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  • Pulping paper-making process with zero discharge of sewage water
  • Pulping paper-making process with zero discharge of sewage water
  • Pulping paper-making process with zero discharge of sewage water

Examples

Experimental program
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Effect test

Embodiment 1

[0035] Using reed as raw material for pulping, add 10m of black liquor with 8mg / l residual alkali at room temperature to 2000kg of crushed and dedusted reed 3 Carry out presoaking, and drain after presoaking for 2 hours. When the moisture content of the raw material is 65% to 75%, put the raw material into the reaction pot and heat it with steam for low-temperature cooking. The temperature is controlled at 100°C to 120°C. When the pH value of the inner liquid is about 7, stop the reaction, use a twin-screw rubbing pulper to separate the material, extract black liquor, add alkali and catalyst, the concentration is 20% sodium hydroxide and 600L of catalyst solution, of which the catalyst The mass dosage is 3%, of which urea is 0.2%, and ammonium sulfite is 2.8%. The treated raw materials for pulping are added into the cooking pot for cooking. The cooking pressure is 0.3-0.4Mpa, the cooking time is 3 hours, and the slurry concentration is controlled at 20-25%. After cooking, the...

Embodiment 2

[0037] Using cotton stalks as raw material for pulping, add 10m of black liquor with 12mg / l residual alkali at room temperature to 2000kg of broken and dedusted cotton stalks 3 Carry out presoaking, and drain after presoaking for 2 hours. When the moisture content of the raw materials is 65% to 75%, put the raw materials into the reaction pot and heat them with steam for normal pressure cooking. The temperature is controlled at 100°C to 120°C. When the pH value of the liquid in the pot is about 7, stop the reaction, use a twin-screw rubbing squeezer to separate the material, extract black liquor, add alkali and catalyst, the concentration is 20% sodium hydroxide and 700L of catalyst solution, of which The mass dosage of catalyst is 3.5%, wherein urea is 0.2%, ammonium sulfite is 2.8%, and potassium sulfate is 0.5%. The treated raw materials for pulping are added into the cooking pot for cooking. The cooking pressure is 0.3-0.6Mpa, the cooking time is 3 hours, and the slurry c...

Embodiment 3

[0039] Using rice straw as raw material for pulping, add 10m of black liquor with normal temperature residual alkali of 10mg / l to 2000kg of crushed and dedusted rice straw 3 Carry out presoaking, and drain after presoaking for 2 hours. When the moisture content of the raw materials is 65% to 75%, put the raw materials into the reaction pot and heat them with steam for normal pressure cooking. The temperature is controlled at 100°C to 120°C. When the pH value of the liquid in the pot is about 7, stop the reaction, use a twin-screw rubbing squeezer to separate the material, extract black liquor, add alkali and catalyst, the concentration is 20% calcium hydroxide and 1000L of catalyst solution, of which The mass dosage of catalyst is 4.5%, wherein urea is 0.3%, ammonium sulfite is 3.7%, and potassium sulfate is 0.5%. The treated raw materials for pulping are added into the cooking pot for cooking. The cooking pressure is 0.2-0.4Mpa, the cooking time is 2 hours, and the slurry co...

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Abstract

A pulp and paper preparation method with zero-emission of sewage comprises the steps as follows: (1) stewing for the first time: mixing materials for preparing the pulp with a thin black liquid obtained from stewing of the second time, pre-soaking the mixture, dewatering and then stewing at a low temperature; milling and devillicating the materials after stewing for the first time by adopting a double screw pulp milling and pressing machine, extracting a thick black liquid, concentrating and drying the thick black liquid, selling the same as a commodity, adding alkali and a catalyst, intensively mixing with the materials for making the pulp to obtain a material (B); (2) stewing for the second time: stewing the material (B) at a high temperature through steam; pressing the stewed material and extracting the thin black liquid by adopting at least two double screw extruders or filter presses connected in series; using the thin black liquid in stewing for the first time for pre-soaking the materials; (3) washing the pulp and treating the water for washing the pulp: grinding the pulp material through stewing for the second time in a high consistency pulping machine; washing the pulp; the water for washing pulp is reutilized for washing the pulp after anaerobic treatment, aeration treatment, and materialized and flocculation treatment; and (4) preparing paper and treating white water: purifying thick pulp, fine-grinding by adopting a double disc refiner, using the ground thick pulp for preparing paper, and reutilizing the paper-preparing white water after treatment.

Description

technical field [0001] The invention belongs to the technical field of pulping and papermaking, and in particular relates to a technology for making the pulping and papermaking process without sewage discharge. Background technique [0002] After alkaline pulping, a large amount of fiber and non-fiber raw materials and most of the alkaline substances are dissolved in the cooking liquid to become black liquor, which is the largest pollution source in the paper industry, and the pollution load can reach 90% of the total pollution load. At present, large-scale papermaking enterprises at home and abroad mostly use traditional alkali recovery technology to treat black liquor. This technology is more effective in reducing environmental pollution caused by the paper industry. However, the one-time investment of traditional alkali recovery technology is huge, and it generally takes The investment is tens of millions of yuan, and the daily operating costs are quite high. Therefore, ma...

Claims

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Application Information

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IPC IPC(8): D21C3/26D21C11/00D21C7/00D21D1/00D21C9/02D21C9/18D21C3/02C02F9/14C02F1/24C02F3/30
Inventor 晏永祥
Owner CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY
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