Spheroidization of silica powders by radio frequency inductively coupled plasma with Ar–H2 and Ar–N2 as the sheath gases at atmospheric pressure
Spheroidization of silica powders by radio frequency inductively coupled plasma with Ar–H2 and Ar–N2 as the sheath gases at atmospheric pressure
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DOI：
10.1007/s12613-017-1497-z
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发表时间：
2017-09
期刊：
影响因子：
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通讯作者：
Lin Li;G. Ni;Q. Guo;Q. Lin;P. Zhao;Jun-li Cheng
中科院分区：
文献类型：
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作者：
Lin Li;G. Ni;Q. Guo;Q. Lin;P. Zhao;Jun-li Cheng
通过在 36.2 MHz 射频下进行感应耦合热等离子体处理制备无定形球形二氧化硅粉末。研究了氩气（作为鞘气）中氢气和氮气的添加量以及载气流量对硅粉球化率的影响。通过扫描电子显微镜、X射线衍射和激光粒度分析对等离子体处理前后制备的二氧化硅粉末进行了检查。结果表明，等离子处理后二氧化硅颗粒的平均尺寸增大，并且晶体发生向非晶态的转变。采用放电图像处理分析等离子体温度场对球化率的影响。随着鞘气中氢含量的增加，二氧化硅粉的球化率增加。另一方面，随着鞘气中氮含量的增加，硅粉的球化率先增加后减少。而且，随着二氧化硅粉体球化率的增加，无定形含量增加。
Amorphous spherical silica powders were prepared by inductively coupled thermal plasma treatment at a radio frequency of 36.2 MHz. The effects of the added content of hydrogen and nitrogen into argon (serving as the sheath gas), as well as the carrier gas flow rate, on the spheroidization rate of silica powders, were investigated. The prepared silica powders before and after plasma treatment were examined by scanning electron microscopy, X-ray diffraction, and laser granulometric analysis. Results indicated that the average size of the silica particles increased, and the transformation of crystals into the amorphous state occurred after plasma treatment. Discharge image processing was employed to analyze the effect of the plasma temperature field on the spheroidization rate. The spheroidization rate of the silica powder increased with the increase of the hydrogen content in the sheath gas. On the other hand, the spheroidization rate of the silica power first increased and then decreased with the increase of the nitrogen content in the sheath gas. Moreover, the amorphous content increased with the increase of the spheroidization rate of the silica powder.