高岭土矿物中的杂质除石英、云母外,还存有微量的有色矿物(铁、钛的氧化物)。这些杂质几乎均为325目(44微米)以上的粗粒,用机械分级机或湿法旋流器较易除去。另外,为了除去粘附在高岭土颗粒上的氢氧化铁等,可施以化学漂白法。对于除钛,最近研制出了一种叫做 Ultraflotation process 的新浮选法。市售精制高岭土中具代表性的佐治亚州高 In addition to the impurities in kaolin minerals quartz, mica, there are still trace amounts of colored minerals (iron, titanium oxide). Almost all of these impurities are coarse particles of 325 mesh (44 microns) or more, which are easily removed by mechanical classifiers or wet cyclones. In addition, chemical bleaching may be applied to remove iron hydroxide adhering to the kaolin particles. In addition to titanium, recently developed a new flotation method called the Ultraflotation process. Highly representative of the state of the art commercially available kaolin