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Effect of Heat-Dispersing on Status of Sticky Substances and Stickies Control by Adding Fixing Agent

Author: YuHaiLong
Tutor: GaoYang
School: Shandong Institute of Light Industry
Course: Pulp and Paper Engineering
Keywords: Goo mimics Heat dispersion Tiny stickies Dissolved and colloidal substances Given agent
CLC: TS74
Type: Master's thesis
Year: 2011
Downloads: 47
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Abstract

Waste paper as one of the important sources of raw fiber pulp and paper, you can save the wood fiber raw materials, reduce environmental impact and reduce energy consumption. Therefore, the waste paper reuse technology has been developing rapidly, and is now 100% de-inked pulp newsprint. However, the waste paper recycling process stickies increasingly serious problem, especially papermaking improvement in the level of the water closed loop, exacerbated stickies production hazards. Huatai Group's large modern deinking pulp and newsprint production line as the object of study, in-depth study of thermal dispersion processing conditions stickies dispersion effect. Meanwhile, in the production lines of the three key positions administered fixing agent, its stickies control. By building different components constitute the sticky substance mimics to study the mechanism of deposition of stickies. The heat distributed processing conditions different, for the the subsequent pulp stickies shape has a great impact, directly related to the removal of the effect of viscous substances after flotation. In this study, changing the processing temperature, chainring clearance, and into the plasma concentration of stickies pulp dispersing, also detected after the flotation process for the removal of stickies. The results show that: the thermal dispersion treatment to be effectively dispersed, the micro-stickies and the content of colloidal and dissolved substances so that the size stickies and tiny stickies increase. Improve the processing temperature, reducing the chainring clearance and increase into the plasma concentration will promote large stickies and tiny stickies dispersed in. Large stickies can be reduced by about 92% at a temperature of 100 ° C, chainring gap of 0.3 mm into the plasma concentration of 30%, fine stickies can be reduced by about 81%. Large stickies dispersed into small component size, promote stickies subsequent flotation process effectively remove tiny stickies removal rate of 25% -26%, fine stickies the removal rate of 68% -70%. Studied by changing the heat treatment temperature of the dispersion system, the the toothed disc space and into the slurry concentration, the content of dissolved substances, colloidal material and suspended solids in Deinked Pulp and its changes discussed in the subsequent post-flotation process for these the ingredients removal effect. The results show that, to improve the processing temperature, reducing the toothed disc space, or to increase the concentration of the slurry into DCS content in the slurry after the heat dispersion treatment can make a significant increase in constituting the DCS of the DS and CS content increased accordingly. Temperature of 100 ° C chainring gap of 0.3 mm into the plasma concentration of 30%, compared with the content of each component in the slurry before entering the disperser, DCS increased by 13.6% -16.8%, DS increased 5.7% -5.9%, CS 60.7% -65.3%. However, after the heat dispersion although as much of the amount of increase in CS, but the slurry in the main constituent of the DCS is still DS. The suspended solids content of the slurry water phase after heat dispersion increased significantly, reaching 21.7% -26.0%. After the flotation process can effectively remove the SS, the removal rate of 45.2% -46.7% CS removal rate of only 6.1% -6.8%, the flotation process is difficult to remove the DS. Sampling of the slurry to the three parts of the waste paper deinking line section of the object, two stickies stickies control agent is. Shield method to detect the deposition amount of the adhesive substance by detecting DCS content, and the filtrate turbidity, the cationic charge demand and the Zeta potential of the surface of the fiber, the evaluation administered stickies fixed the agent after jiangshui system wet end chemistry characteristics the control stickies pathway. The research results show that the two fixed agents can effectively control the viscous substances in the waste paper deinking pulp significantly reduce the amount of stickies deposition of aluminum foil detected, and reduce the DCS content and turbidity of the filtrate, and the positive charge demand. Which, given the agent Hybrid 7655 than the effect of the agent Hybrid 8185 as well. DIP slurry storage tower at plasmacytoid application agent stickies deposition decreased even more sharply. Administered after the fixing agent, the physical strength of the sheet will be affected to a certain extent. Constructed by the relevant component of the viscous pollutants mimics, to study changes in the physical and chemical properties of viscous substances under different conditions, as well as its stability and deposition behavior. The results show that: the elevated temperature, the lower the pH, and can reduce the viscosity of the viscous dispersion of pollutants, and the corresponding increase of the deposition amount of the viscous substance. The presence of metal ions cause goo instability, the the compound prices of Al3 low concentration that is easy to cause flocculation of goo. Ca2 calcium soap is formed with the resin component in the sticky substance, thereby deposition, the presence of the pulp fibers can reduce the deposition of calcium soaps. The cationic polymer join result in instability of viscous substances and important cause of deposition, polyethylene imine (PEI), the amount of the charge when near the goo can completely instability, and maximum deposition amount of . While the addition of a small amount of cationic polyacrylamide (CPAM), you can make goo instability caused by the deposition. The added excess polyethyleneimine able regain stability, goo goo deposition was reduced. The presence of excess cationic polyacrylamide, not so goo regain stability, polyethylene imine and cationic polyacrylamide goo can be adsorbed on the fiber leaving sticky substance deposited amount to reduce the fiber exists. Inorganic mineral filler can be adsorbed on the goo deposition with less amount of goo. Therefore, the addition of the fillers can slow down the deposition of viscous substances.

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