Evaluation of an Alternative Flocculation System for Manufacture of Fiber-Cement Composites

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• 作者：Carlos Negro ; Elena Fuente ; Luis M. Sá ; nchez ; Á ; ngeles Blanco ; Julio Tijero
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2006
• 出版时间：September 27, 2006
• 年：2006
• 卷：45
• 期：20
• 页码：6672 - 6678
• 全文大小：264K
• 年卷期：v.45,no.20(September 27, 2006)
• ISSN：1520-5045

文摘

Flocculation has been a key issue for fiber cement manufacturing since cellulose or poly(vinyl alcohol) (PVA)fibers are used to replace asbestos. Due to the complexity of flocculation, many fiber cement companies facedifficulties in optimizing it, which leads to unpredicted production problems and lower process efficiency.This paper studies the behavior of a dual system (PFR/PEO) and compares it with two anionic polyacrylamidescommonly used in this industry. The work was carried out using a focused beam reflectance measurement asa sensor to monitor the flocculation process in real time. Results show that the proposed alternative dualsystem induces the formation of larger but less stable flocs than the ones obtained with the anionic polyacrylamides. A flocculation mechanism was proposed for the dual system consisting of the initial adsorptionof the phenol-formaldehyde resin (PFR) onto the particles, which provides junction points for bridge formationby poly(ethylene oxide) (PEO). The flocculation kinetics induced by the dual system is determined by thePFR dosage.