造纸白泥处理处置方法研究及改进
任书魁
中国轻工业长沙工程有限公司 长沙市 410114
摘要:造纸污泥按来源来分可分为生物污泥、碱回收白泥和脱墨污泥。其中碱回收白泥来源于碱回收车间白泥回收工段,是苛化反应的产物,属沉淀碳酸钙,主要产生于利用纸浆造纸的造纸厂。白污泥主要成分为碳酸钙,由于其具有高含水率,高黏度,易流变性和低渗透系数等特性,在工程实践中时常发生污泥处理构筑物或污泥料仓堵塞,排泥不畅等现象,为污泥处理厂日程运行管理带来诸多困扰。同时大量处理后的造纸白泥如何处置也已成为摆在世界各国面前的重要难题之一。本文基于对制浆造纸白污泥处理处置过程中的难点进行分析,结合工程实践,对工业园区如何科学合理的处理处置造纸白泥提供思路和指导。
关键词:污泥处理;造纸白泥;碳酸钙;污泥脱水;机械加速澄清池;
Study and improvement on the treatment of white Sludge in Papermaking
REN Shu-kui
(China Light Industry Changsha Engineering Co. Ltd., Changsha 410114, China)
Abstract: Papermaking sludge can be divided into biological sludge, alkali recovery white sludge and deinking sludge according to its source. The alkali recovered white mud comes from the white mud recovery section of the alkali recovery workshop. It is the product of causticization reaction and belongs to precipitated calcium carbonate. It is mainly produced in paper mills that use paper pulp. The main component of white sludge is calcium carbonate. Due to its high moisture content, high viscosity, easy fluidity and low permeability, sludge treatment structures or sludge silos are often blocked and sludge discharge is not smooth in engineering practice, which brings many troubles to the schedule operation management of sludge treatment plant. At the same time, how to dispose of a large number of treated papermaking white mud has become one of the important problems in front of countries all over the world. Based on the analysis of the difficulties in the treatment and disposal of pulp and paper white sludge, combined with engineering practice, this paper provides ideas and guidance on how to scientifically and reasonably treat and dispose paper white sludge in the industrial park.
Key words: Sludge treatment; Papermaking white mud; calcium carbonate; Sludge dewatering; Mechanical accelerated clarifier;
引言
目前,我国产纸量占世界总量的一半以上,造纸工业碱回收过程中产生的造纸白泥是一种有毒的工业废弃物,每生产1吨纸浆就会产生约0.5吨造纸白泥。因此亟需研究合理的处理方法来减少造纸白泥带来的环境污染问题。白泥主成分中碳酸钙占80%-90%,其他的组分为少量微量元素,其具有高含水率,高黏度,易流变性和低渗透系数等特性,在处理过程中容易板结,堵塞污泥处理构筑物,为污泥处理厂日程运行管理带来诸多困扰。同时大量白泥如何合理处置,实现其"三化"(无害化,减量化,资源化)已经成为摆在世界各国面前的重要难题之一。