How to make high-purity haloisite nano tube powder

摘要

In order to remove quartz (SiO_2) impurities from kaolin and to separate particles and obtain high purity halloysite nano tube (HNT) particles, first, a suspension of kaolin fine grains is prepared, a mixture was strongly stirred with a homogenizer to separate into acicular particles, and an excessive amount of a dispersant is added to remove aggregated sediment. After adding polyvalent metal cation salt such as Ca to a supernatant, an anionic polyelectrolyte coagulant is added and the quartz coagulates and precipitates in two stages with slight stirring. The HNT particles can be first separated and dispersed from a peptization slip of raw material kaolin, and aggregating agents of SiO_2 can be precipitated and removed to separate highly-pure HNT particles.