本文探讨了微波加热在工业锡粉熔化中的应用。对离心雾化法制备的金属锡粉的形貌和粒径进行了表征。锡粉颗粒均匀且呈球形,90%的颗粒粒径为38～75μm。通过介电性能测试,研究了锡粉的微波吸收特性。微波的穿透作用对锡粉具有良好的整体...本文探讨了微波加热在工业锡粉熔化中的应用。对离心雾化法制备的金属锡粉的形貌和粒径进行了表征。锡粉颗粒均匀且呈球形,90%的颗粒粒径为38～75μm。通过介电性能测试,研究了锡粉的微波吸收特性。微波的穿透作用对锡粉具有良好的整体加热性能。温度高于150℃时,微波加热锡粉的主要机制是电导损耗。设计开发了20 k W微波熔炼锡合金装备,并将其应用于产业化。该装备的加热速率与常规方法相比能提高10倍以上,缩短了熔炼工艺。研究结果表明,微波加热加快了升温速率,缩短了熔炼时间,锡回收率为97.79%,渣量仅为1.65%,其他损失低于0.56%;单位能耗仅为0.17 k W·h·kg^(–1),远低于传统方法所需要的能量。因此微波冶炼提高了加热效率,降低了能耗。展开更多
The relationship between the improvement of sludge dewaterability and variation of organic matters has been studied in the process of sludge pre-conditioning with modified cinder, especially for extracellular polymeri...The relationship between the improvement of sludge dewaterability and variation of organic matters has been studied in the process of sludge pre-conditioning with modified cinder, especially for extracellular polymeric substances （EPS） in the sludge. During the conditioning process, the decreases of total organic carbon （TOC） and soluble chemical oxygen demand （SCOD） were obviously in the supernatant especially for the acid modified cinder （ACMC）, which could be attributed to the processes of adsorption and sweeping. The reduction of polysaccharide and protein in supernatant indicated that ACMC might adsorb EPS so that the tightly bound EPS （TB-EPS） decreased in sludge. In the case of ACMC addition with 24 g·L^-1, SRF of the sludge decreased from 7.85 × 10^12 m·kg^-1 to 2.06× 10^12 m·kg^-1, and the filter cake moisture decreased from 85% to 60%. The reconstruction of ＂floc mass＂ was confirmed as the main sludge conditioning mechanism. ACMC promoted the dewatering performance through the charge neutralization and adsorption bridging with the negative EPS, and provided firm and dense structure for sludge floc as skeleton builder. The passages for water quick transmitting were built to avoid collapsing during the high-pressure process.展开更多
基金This work was supported by the National Key Research and Development Program （2016YFA0204300） the National Natural Science Foundation of China （21390200, 31440024） and the Tech- nology Support Program of Gansu Provincial S＆T Department, China （1304FKCE106）.
文摘本文探讨了微波加热在工业锡粉熔化中的应用。对离心雾化法制备的金属锡粉的形貌和粒径进行了表征。锡粉颗粒均匀且呈球形,90%的颗粒粒径为38～75μm。通过介电性能测试,研究了锡粉的微波吸收特性。微波的穿透作用对锡粉具有良好的整体加热性能。温度高于150℃时,微波加热锡粉的主要机制是电导损耗。设计开发了20 k W微波熔炼锡合金装备,并将其应用于产业化。该装备的加热速率与常规方法相比能提高10倍以上,缩短了熔炼工艺。研究结果表明,微波加热加快了升温速率,缩短了熔炼时间,锡回收率为97.79%,渣量仅为1.65%,其他损失低于0.56%;单位能耗仅为0.17 k W·h·kg^(–1),远低于传统方法所需要的能量。因此微波冶炼提高了加热效率,降低了能耗。
基金Acknowledgements Support for this research is provided by the National Science ＆ Technology Pillar Program of China （No. 212BAC05B02）, the National Natural Science Foundation of China （Nos. 5117834 and 5378141）, Program for New Century Excellent Talents in University, Ministry of Education of China （Grant No. NCET-13-0180）, State Key Laboratory of Pollution Control and Resource Reuse Foundation （Grant No. PCRRF13003）, Postdoctoral Science-Research Developmental Foundation of Heilongjiang Province （Grant No. LBH-Q12107）, and the National Engineer Research Center of Urban Water Resources.
文摘The relationship between the improvement of sludge dewaterability and variation of organic matters has been studied in the process of sludge pre-conditioning with modified cinder, especially for extracellular polymeric substances （EPS） in the sludge. During the conditioning process, the decreases of total organic carbon （TOC） and soluble chemical oxygen demand （SCOD） were obviously in the supernatant especially for the acid modified cinder （ACMC）, which could be attributed to the processes of adsorption and sweeping. The reduction of polysaccharide and protein in supernatant indicated that ACMC might adsorb EPS so that the tightly bound EPS （TB-EPS） decreased in sludge. In the case of ACMC addition with 24 g·L^-1, SRF of the sludge decreased from 7.85 × 10^12 m·kg^-1 to 2.06× 10^12 m·kg^-1, and the filter cake moisture decreased from 85% to 60%. The reconstruction of ＂floc mass＂ was confirmed as the main sludge conditioning mechanism. ACMC promoted the dewatering performance through the charge neutralization and adsorption bridging with the negative EPS, and provided firm and dense structure for sludge floc as skeleton builder. The passages for water quick transmitting were built to avoid collapsing during the high-pressure process.
