| 摘要: |
| 以城市污泥和磷尾矿为原料，选取4个质量混合比（2∶1、1∶1、1∶2、1∶3），在不同烧结条件下（5个温度、5个时间）制备陶粒，对陶粒的堆积密度、吸水率、盐酸可溶率进行测定并对原料和部分陶粒进行XRD物相分析。研究结果显示：随着污泥添加比增大，陶粒堆积密度降低、盐酸可溶率（2∶1除外）和吸水率升高。污泥∶磷尾矿质量比为2∶1的陶粒，当烧结温度为1000—1100℃时，其堆积密度小，吸水率较高；1100—1200℃时，陶粒盐酸可溶率降低，且显著低于其他比例。污泥含量的增加有助于提高陶粒物相特征峰的强度和丰富度，优化骨架结构。在配料比2∶1、烧结温度1150℃、烧结时间15 min的条件下，制得堆积密度小（434.70 kg∙m−3）的轻质陶粒。 |
| 关键词: 污泥 磷尾矿 陶粒 烧结时间 烧结温度 |
| DOI：10.7515/JEE212003 |
| CSTR： |
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| 基金项目:贵州省基础研究计划项目（黔科合基础[2017]1123）；贵州省普通高等学校青年科技人才成长项目（黔教合KY字[2021]300）；贵州省科技合作计划项目（黔科合LH字[2016]7215号） |
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| Research on sintering conditions and performance of municipal sludge / phosphate tailings ceramsite |
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ZHANG Xiaoya, FENG Lijuan, WANG Ji, CHEN Jiahui, WU Rendi
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School of Geography & Environmental Science, Guizhou Normal University, Guiyang 550025, China
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| Abstract: |
| Background, aim, and scope Sewage sludge and phosphate tailings are byproducts of wastewater treatment and phosphorite exploitation, respectively. Improper disposal of these materials may cause soil, groundwater, and air pollution. Both materials can, however, be reused to make cement, bricks, and ceramsite. The aim of this study was to prepare ceramsite from such sludge and phosphate tailings, and to determine the optimal sintering conditions. Materials and methods Sewage sludge and phosphate tailings were used as raw materials. Chemical components of the materials were examined by X-ray fluorescence spectrometry. The phases of the raw materials and some ceramsites were determined by X-ray diffractometry. Four mixing ratios and five different sintering temperatures and times were tested. Bulk density, water absorption, and hydrochloric acid solubility of the resulting ceramsites were measured. Results The results showed that as the sludge addition ratio in the ceramsite increased, its bulk density and HCl solubility (except for the 2∶1 mass ratio) decreased and water absorption increased. An increase of sludge content improved the strength and richness of ceramsite phase structure. The optimal ceramsite exhibited a bulk density of 434.70 kg·m−3, water absorption of 61.20%, and HCl solubility of 20.44%. Discussion For a sintering time of 15 min and temperature of 1000—1050℃, the sludge/ phosphate tailings ceramsite produced using a mass ratio of 2∶1 had low bulk density, high water absorbance, and low HCl solubility. As the sludge content increased, the proportion of organic matter increased. Decomposition of this organic matter released significant heat at high temperature, which was conducive to an increase of pores in the ceramsite, formation of framework and enamel layers, and enhancement of characteristic peaks. The optimized ceramsite composition had relatively stable chemical properties and could be used as lightweight aggregate or as a filler for sewage treatment. Conclusions The ceramsite produced using a raw materials at a mass ratio of 2∶1 and a sintering time of 15 min at 1150℃ gave optimal properties of low bulk density, high water absorption, and low HCl solubility. Recommendations and perspectives Preparation of ceramsite from sewage sludge and phosphate tailings provides a method for resource utilization of these waste materials. |
| Key words: sludge phosphate tailings ceramsite sintering time sintering temperature |
