Chinese National Engineering Research Center for Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, China; School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China.
School of Environment and Resource, Southwest University of Science and Technology, Mianyang 621010, China.
Waste Manag. 2020 Jul 15;113:62-69. doi: 10.1016/j.wasman.2020.05.045. Epub 2020 Jun 4.
In this paper, the waste fried oil was used to remove the unburned carbon in coal fly ash during flotation process, and found that the waste fried oil could be a novel collector for the removal of carbon from coal fly ash. The results implied that the wetting rate of the fly ash after treated by waste fried oil was decreased, meanwhile the contact angle was increased. A significant decrease in wetting heat was observed, which indicated a weaker interaction between deionized water and fly ash after treatment with waste fried oil. Flotation tests showed that the content of unburned carbon could be reduced effectively through froth flotation when took waste fried oil as collector. FTIR analysis testified that waste fried oil had abundant oxygen-containing groups that could be adsorbed in a carbonaceous matter to achieve hydrophobization. X-ray photoelectron spectroscopy, scanning electron microscope, and energy dispersive analyses showed that the main compositions of flotation concentrate products were unburned carbon, whereas the tailing products consist of aluminum and silicon, which confirmed the superior separation performance when the waste fried oil was used as a collector in coal fly ash flotation. This investigation provides an approach to remove the unburned carbon in coal fly ash based on the principle of "waste control through waste", which can solve the environmental problems brought by large amounts of both coal fly ash and waste fried oils.
本文利用废食用油在浮选过程中去除粉煤灰中的未燃碳，发现废食用油可以作为一种新型的捕收剂用于去除粉煤灰中的碳。结果表明，经过废食用油处理后的粉煤灰的润湿性降低，同时接触角增大。观察到润湿热显著降低，表明经过废食用油处理后，去离子水与粉煤灰之间的相互作用减弱。浮选试验表明，采用废食用油作为捕收剂通过泡沫浮选可以有效降低未燃碳的含量。FTIR 分析证明，废食用油中含有丰富的含氧基团，可吸附在含碳物质上实现疏水化。X 射线光电子能谱、扫描电子显微镜和能谱分析表明，浮选精矿产品的主要成分是未燃碳，而尾矿产品主要由铝和硅组成，这证实了在粉煤灰浮选过程中使用废食用油作为捕收剂时具有优异的分离性能。本研究为基于“废物控制废物”原则去除粉煤灰中的未燃碳提供了一种方法，可以解决大量粉煤灰和废食用油带来的环境问题。
