摘要
运用半连续反应装置对山西吴家坪煤和四川华荧山煤中铅在亚临界水萃取过程中的脱除率和挥发性进行了研究.着重考察了反应温度、压力对铅脱除率和挥发性的影响;同时应用浮沉实验和逐级化学提取考察了原煤及残渣中铅的赋存形态.研究结果表明:在亚临界水条件下,2种煤中铅都不易挥发;随着温度升高,2种煤中铅的脱除率和挥发性都有所增加,当温度从320℃增加到380℃时,吴家坪和华荧山两煤中铅的脱除率分别从4.9%和7.1%增加到24.6%和10.9%;当温度升高到410℃时,华荧山煤中铅的脱除率增加为13.7%;在相同温度下,亚临界水处理过程中铅的挥发性要高于热解过程中铅的;随着压力的增大,2种煤中铅的脱除率和挥发性无明显变化;华荧山和吴家坪煤中的铅都主要以不溶态存在,分别为46%和54%,同时也以碳酸盐结合态、硫酸盐和单硫化物结合态及二硫化物和部分有机质结合态存在,亚临界水萃取过程中,2种煤中以上述形态赋存的铅都有所减少并转化为新的含铅不溶稳定态.
Removal and volatility of lead in WJP coal and HYS coal during sub-critical water treatment in a semi-continuous reactor were studied. The effects of temperature and pressure on the volatility of lead were examined; and sequential chemical extraction and float-sink experiments also were conducted in order to determine the occurrence mode of lead in the coal samples and the residuals. The results show that during sub-critical water treatment, it is difficult for lead to release from the two Chinese coals, and with increasing of temperature, the removal and volatility in the two coals are also increasing. At 320℃ the removal of lead from WJP and HYS coal is 4.9% and 7. 1%; and when the temperature increases to 380℃, it is 24. 6% and 10. 9%, respectively. When the temperature is 410℃, the removal of lead from HYS coal increases to 13.7%. At same temperature the volatility of lead from coal by sub-critical extraction is higher than that by pyrolysis. Extraction pressure just has no obvious effect on the removal and volatility of lead in the two Chinese coals. Lead in HYS and WJP coals mainly exists in the insoluble forms which content is 4 6 % and 54 % , respectively ; and it is also associated with carbonates , mono - sulfide and sulfates, disulfide and some organic matters. During sub-critical water extraction, lead in these forms all decreases and turns into new stable forms.
出处
《中国矿业大学学报》
EI
CAS
CSCD
北大核心
2006年第1期29-34,共6页
Journal of China University of Mining & Technology
基金
国家自然科学基金重大研究计划项目(90210001)
国家自然科学重点基金项目(90410017)
关键词
亚临界水
煤
铅
挥发性
sub-critical water
coal
lead
volatility
