DOC《响应曲面优化微波干燥铅渣的工艺研究》

响应曲面优化微波干燥铅渣的工艺研究 李健,张利波,彭金辉,刘秉国,周越,郭磊,刘晨辉,王亚健 (昆明理工大学 冶金与能源工程学院,非常规冶金教育部重点实验室,云南省复杂有色金属资源清洁利用国家重点实验室,昆明 650093) 摘要:采用微波加热技术对铅渣进行脱水.

通过响应曲面法中心组合设计分析了干燥温度、干燥时间、物料厚度对脱水率的影响,并建立了相关的数学模型.方差分析表明,二次方数学模型拟合较好,物料厚度、干燥温度对脱水率的影响较干燥时间更为显著.优化工艺参数为干燥温度93 ℃,干燥时间10 min,物料厚度19 mm,相对脱水率达到68.21%,实际值与模型预测值相差0.73个百分点,干燥后铅渣的含水量为8.12%,可以满足后序工艺要求. 关键词:微波干燥;

铅渣;

响应曲面法;

优化 中图分类号:TF812 文献标识码:A 文章编号:1007-7545(2012)12-0000-00 Optimization of Microwave Drying of Lead Slag with Response Surface Methodology LI Jian, ZHANG Li-bo, PENG Jin-hui, LIU Bing-guo, ZHOU Yue, GUO Lei, LIU Chen-hui, WANG Ya-jian (Faculty of Metallurgy and Energy Engineering, Kunming University of Science and Technology;

Key Laboratory of Unconventional Metallurgy, Ministry of Education;

State Key Laboratory Breeding Base of Complex Nonferrous Metal Resources Cleaning Utilization in Yunnan Province, Kunming 650093, China) Abstract:A new technology of microwave heating was applied to dry lead slag. The effects of drying temperature, drying duration and material thickness on the dehydration rate of lead slag were investigated by means of the response surface (RSM) central composite design (CCD), and the mathematical model was established. As can be seen from the ANOV, quadratic of mathematical model is better than others in terms of goodness of fit. The material thickness and temperature are found to exert more significant effects on the dehydration rate than drying duration. The optimum conditions for dying with microwave radiation include temperature of

93 ℃, duration of

10 min and material thickness of

19 mm. The optimum dehydration rate is 67.48% with the relatively error of just 0.73 percentage point. The moisture content after drying is less than 8.12%, which satisfies the technological requirements of following processes. Key words: microwave drying;

lead slag;

response surface methodology(RSM);

optimization 在湿法炼锌过程中,锌灰浸出会产生大量的铅渣,这些铅渣中含有大量的水分,在返回烟化炉处理前必须将一部分水分脱除.目前一般采用回转干燥窑干燥和蒸汽干燥,但回转干燥窑存在着能源大量浪费、干燥时间长、烟气污染、操作环境差等问题[1];

而蒸汽干燥过程[2]的加热不均匀,靠近转筒壁处温度较高的缺点.因此开发新的铅渣干燥工艺具有重要意义.微波作为一种绿色加热技术,具有选择性加热和内部加热特点[3].且干燥过程中温度梯度方向和水分梯度的方向相同,传热和传质方向一致,因此干燥时间大大缩短[4].为防止物质在干燥过程中因温度过高而发生化学变化,本文采用响应曲面优化设计方法,对铅渣进行微波控温干燥,探讨了控温条件下干燥温度、干燥时间和物料厚度对相对脱水率的影响.

1 试验部分 1.1 试验原料和设备 试验原料为锌灰浸出的铅渣,化学成分(湿基,%):Zn 7~

11、Pb 20~

35、Cu 0.5~1.

0、S 14~

14、水分23.09. 干燥设备采用自主研制的箱式微波反应器,频率2