Research On The Acid-drench Processing Of Tourmaline Powder

Tourmaline can possess of natural permanent polarity and form electric field around its particles, which make it has some functional properties such as thermoelectricity, piezoelectricity, radiate far-infrared ray, release anionic etc. as a newly environmental mineral, tourmaline is widely applied in many fields, it creates great social and economical value. Tourmalines from different zones have various shapes, structures and components, which would affect its performance.This article utilizes the chemistry analysis, EMPA, ICP, XRD, FTIR, DTA, TG analysis methods to carry on the test to mineralogy characteristic of tourmaline from JiangXi Ganzhou mine. and contrast to XinJiang Aletai Dravite, to summarize the different characters between Schorl and Dravite. Additionally, based on the experiment of dipping tourmaline in acid liquid, analyzing the changes of crystal chemical characters on tourmaline, which would do further help to its application.The essence differences between Schorl and Dravite are the content and occupation of Mg and Fe, which decide their own crystal cell parameters, infrared absorb spectrums, discompose temperature etc. characters.According to series of experiment, conduct the best way of get rid of Fe in tourmaline by acid liquid, dip tourmaline powder in 38% hydrochloric acid, and keep filtrating until the liquid's color doesn't change. The smaller of the powder make better reaction, besides, high temperature and whipping can also improve the efficiency.The acid liquid can't destroy the structure of tourmaline, which merely reduce the Fe-impurity in the interspaces. Iron in the structure is stable that can't be removed by acid. The hydrochloric acid is electrolytical that provide H⁺ make the water ionization. The O^2- make Fe³⁺ deoxidize Fe²⁺. After acid dipping, tourmaline's character changes somehow, which influence the powder's performance. Because of the reduction and changes of iron, the surface activity of tourmaline weakened and the zeta potential reduced, which means the uniformity of tourmaline powder has been weakened. However, acid liquid could make tourmaline powder looks whiter and releases more anionic.