Quartz impurity is considered as pathogenic and carcinogenic associated mineral in kaolin. It is an important reserach point for mineral dressing spechalists to estabish a new method for purifying the high quality kaolin deposits (i.e. with high purity and very low limits of toxic metals) that contain quartz content and promising in pharmaceutical applications.
Thanks for your interest !
Dear Mahmoud,
A recently published paper illustrate the use of flotation method for removing the quartz impurities from coal-series kaolin.
Maybe it would be of interest to you. The paper link is attached.
Kind Regards,
Masoud Ovissi
Bu, X., Evans, G., Xie, G., Peng, Y., Zhang, Z., Ni, C. and Ge, L., 2017. Removal of fine quartz from coal-series kaolin by flotation. Applied Clay Science, 143, pp.437-444.
http://www.sciencedirect.com/science/article/pii/S0169131717301837
Thanks Dear Masoud !
I see that, by applying these new and valuable kinds of researches, I hope that the high quality kaolin deposits (very low limits of toxic heavy metals) with high quartz impurity contents, could meet the required high purity of the pharmaceutical grade (Quartz < 10 % ). Also, I hope that the strong acid chemicals that used in this processing do not influence the crystallinity and crystal structural properties of kaolinite.
Sincerely !
Mahmoud
Dear Mr. Awad:
If you want to know more about processing of kaolin using dry or wet methods, I would like to refer to the following paper:
DILL, H.G. (2016) Kaolin: soil, rock and ore From the mineral to the magmatic, sedimentary, and metamorphic environments.- Earth Sciences Reviews 161: 16-129.
If you look for high-purity kaolin you should take a keen eye on dioxine in kaolin, this has certainly much higher implications for its use as pharmaceutical grade kaolin. You will find information on this chemical compound in the afore-mentioned study.
With kind regards
H.G.Dill