Page 211 - 《精细化工》2021年第8期
P. 211
第 38 卷第 8 期 精 细 化 工 Vol.38, No.8
202 1 年 8 月 FINE CHEMICALS Aug. 2021
建筑用化学品
复合硅酸盐水泥对含氟污泥的固化处理
*
汤文文,林子增
(南京林业大学 土木工程学院,江苏 南京 210037)
摘要:采用复合硅酸盐水泥对含氟污泥进行固化处理并制取了不同污泥掺量的水泥标准试块,考察了含氟污泥
掺量对试块抗压强度、氟离子浸出量、物相转变和晶体形态的影响。结果表明,含氟污泥掺量(质量分数)为
10%时,试块强度高,氟离子浸出量低。10%含氟污泥掺量试块 28 d 抗压强度达到 22.2 MPa,满足一般垫层、
基础、地坪及受力不大的结构强度要求;10%含氟污泥掺量试块在地下水和酸雨作用下的氟离子浸出量分别为
0.16 和 0.39 mg/L,远小于危险废物 100 mg/L 的标准限值,安全性较高;机理研究表明,含氟污泥的加入加快
了水泥中铝酸三钙(C 3 A)的水化速度,增加了早期钙矾石(AFt)生成量,提高了试块早期强度。
关键词:含氟污泥;水泥固化;抗压强度;浸出毒性;机理;建筑用化学品
中图分类号:TQ124.3;TQ177.6+2 文献标识码:A 文章编号:1003-5214 (2021) 08-1705-06
Solidification treatment of fluorine-containing sludge
by composite Portland cement
*
TANG Wenwen, LIN Zizeng
(College of Civil Engineering, Nanjing Forestry University, Nanjing 210037, Jiangsu, China)
Abstract: Composite Portland cement was used to solidify fluorine-containing sludge and to prepare
cement standard test blocks with different sludge content. The effects of fluorine-containing sludge content
on the compressive strength, fluorine ion leaching amount, phase transformation and crystal morphology of
test blocks were investigated. The results showed that when the fluorine-containing sludge content (mass
fraction) was 10%, the prepared test block had the highest strength and low amount of fluorine ion leaching.
The compressive strength of the test block after maintenance 28 d reached 22.2 MPa, which met the
strength requirements of general cushion, foundation, floor and structure with little stress. The fluoride ion
leaching amount of the test block with 10% fluorine-containing sludge under the action of groundwater and
acid rain was 0.16 and 0.39 mg/L, respectively, far less than the standard limit of 100 mg/L of hazardous
waste, indicating had high safety. Mechanism study indicated that the addition of fluorine-containing sludge
accelerated the hydration rate of tricalciumaluminate (C 3A) in cement, increased the formation amount of
ettringite (AFt) in the early stage, and improved the early strength of the test block.
Key words: fluorine-containing sludge; cement solidification; compressive strength; leaching toxicity;
mechanism; building chemicals
[2]
20 世纪以来,中国氟化工行业迅速发展,形成 万吨增加到 2017 年的 4.5 万吨 。含氟污泥含有大
了以氟烷烃、含氟聚合物、无机氟化物及含氟精细 量的 CaF 2 ,氟化钙具有低毒性,若处置不当,则氟
化学品为代表的四大类氟化工产品体系。上述氟化 离子易通过雨水淋溶、地表径流等方式污染地表水、
[1]
工行业每年产生大量的含氟污泥 。官方数据表明, 土壤和地下水环境,对农作物的生长、土壤中微生
仅中国台湾地区,含氟污泥产量就由 2006 年的 1.6 物产生毒害作用。如果进入人体,则会造成牙齿生
收稿日期:2021-04-30; 定用日期:2021-07-26; DOI: 10.13550/j.jxhg.20210450
基金项目:国家自然科学基金(51608272)
作者简介:汤文文(1995—),男,硕士生,E-mail:1164938292@qq.com。联系人:林子增(1982—),男,副教授,E-mail:linzizeng@
njfu.edu.cn。