摘要
本研究采用DSC和热膨胀仪对两种石英砂的原砂和焙烧砂在加热过程中的相变和热膨胀进行了分析。结果发现,石英砂加热过程中,分别在574℃和790℃附近出现了两个吸热峰,高纯度石英砂焙烧后进行加热时只在569℃出现一个吸热峰。石英砂在加热时相变吸收的热量大于冷却时相变放出的热量,焙烧石英砂相变时需要更多的能量。石英砂的膨胀率随温度的升高而增加,焙烧石英砂的膨胀率明显低于新砂。
During heating, phase transformation and expansibility of the new quartz sands and the calcined Quartz sands from two places were determined by DSC and thermodilatometry. It is found that there exist two endothermic peak at 574℃ and 790℃ differently in the DSC curve of the quartz sand during heating. To the calcined high purity quartz sands, there is only a endothermic peak at 569℃ in the DSC curve. The endothermic energy of the sands being heated during phase transformation is more than the exothermic energy being cooled, and the calcined sands need more energy than the new sands during phase transformation. The expansion ratio of the sands increases with temperature, and the expansion ratio of the calcined sands is lower than that of the new sands apparently.
出处
《铸造》
CAS
CSCD
北大核心
2006年第9期961-964,共4页
Foundry
基金
山东自然科学基金资助项目(y2003f03)。
关键词
石英砂
焙烧砂
相变
膨胀
quartz sands
calcined sands
phase transformation
expansion
