Preparation of CaO-containing carbon pellets from coking coal and calcium oxide:Effects of temperature,pore distribution and carbon structure on compressive strength in pyrolysis furnace

CaO-containing carbon pellets(CCCP)were successfully prepared from well-mixed coking coal(CC)and calcium oxide(CaO)and roasted at different pyrolysis temperatures.The effects of temperature,pore distribution,and carbon structure on the compressive strength of CCCP was investigated in a pyrolysis furnace(350-750℃).The results showed that as the roasting temperature increased,the compressive strength also increased and furthermore,structural defects and imperfections in the carbon crystallites were gradually eliminated to form more organized char structures,thus forming high-ordered CC.Notably,the CCCP preheated at 750℃exhibited the highest compressive strength.A positive relationship between the compressive strength and pore-size homogeneity was established.A linear relationship between the com-pressive strength of the CCCP and the average stack height of CC was observed.Additionally,a four-stage caking mechanism was developed.

焙烧温度与碳结构对钙碳球团抗压强度的影响

电弧法生产电石的过程中,原料应具备一定的强度,保证产物一氧化碳顺利通过。为了提升两步法中钙碳球团的抗压强度,以混合均匀的氧化钙和贫瘦煤为原料,通过嵌样机在压力为8MPa、时长为1min条件下压制直径为15mm、质量为2.5g的钙碳球团,在温度为350-750℃时进行了焙烧,研究了在不同焙烧温度下碳结构对钙碳球团抗压强度的影响。结果表明:当温度为350-<550℃时,煤发生分解和解聚反应,半焦缺陷碳结构相对数量增加,抗压强度随着温度的升高而减小;温度为550-<650℃时,煤固化收缩成半焦,导致抗压强度升高,达到最大值为59.9kPa;温度为650-750℃时,半焦发生缩聚反应,缺陷结构向有序性发展,发生石墨化,导致抗压强度降低。

电石渣制备高强度氧化钙及其含碳球团循环生产电石

电石及乙炔生产过程中产生大量电石渣及细颗粒的兰炭粉,目前尚无大量消纳的利用途径。为了解决煤基电石行业的能源与环境问题,提出利用电石渣制备块状CaO或者与兰炭粉共成型制备CaO含碳球团,用于电石生产的新工艺,该工艺特点在于利用电石渣与兰炭粉为原料,实现工业固废回收利用;同时通过共成型增大原料间的接触面积,改善电石制备反应动力学条件。