Improvement of Sintering Properties of Halloysit-Kaolinite Mixture Low Quality Ceramic Raw Material by Mechanical Dispersion and Wet Magnetic Separation


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Durgut E., Çınar M., Terzi M., Kurşun Ünver İ., Yıldırım Y., Boylu F., ...More

17th International Mineral Processing Symposium, İstanbul, Turkey, 15 - 17 December 2022, vol.1, pp.285-290

  • Publication Type: Conference Paper / Full Text
  • Volume: 1
  • City: İstanbul
  • Country: Turkey
  • Page Numbers: pp.285-290
  • Çanakkale Onsekiz Mart University Affiliated: Yes

Abstract

As in all sectors, there should be no disruptions in the supply chains in order to ensure the continuity of the need for quality kaolin group of clay minerals and production safety, which the ceramics industry needs. Therefore, countries turn to domestic raw material resources to meet the raw material needs of their sectors and conduct research for necessary improvements. In this study, in order to improve the sintering properties of a low quality clay ore containing halloysite and kaolinite, it was aimed to obtain a low iron content product by reducing the high iron (3.9%) content of the ore by removing iron and titanium minerals with mechanical dispersion and wet magnetic separation processes to use in ceramic industry.

XRD analysis revealed that the ore contained kaolinite, halloysite, quartz minerals with diamagnetic properties, and goethite gangue mineral with paramagnetic properties. In this context, first of all, the ore was mixed in a pilot scale mixer at a rate of 20% pulp solids by adding 7.5 kg/ton SHMP in aqueous medium, and then wet screened from a 212 µm sieve to remove iron-containing minerals that did not disperse and remained in coarse size fraction. As a result of mechanical dispersion and wet sieving, a product with a size of +212 µm with 26.4% Al2O3 and 9.6% Fe2O3 content of 17.5% was obtained, while at -212 µm size a product with 31.3% Al2O3 and 3.2% Fe2O3 containing a product of 82.5% was obtained.

Then, this sample was subjected to wet magnetic separation at 5750, 7000 and 10540 gauss magnetic field intensities with a wet high intensity magnetic separator. The Al2O3 and Fe2O3 contents of the nonmagnetic products obtained were found to be 31.7% and 2.3%, respectively. Fe2O3 removal efficiencies were 30.2% 31.6% and 31.7% for 5750, 7000 and 10540 gauss, respectively. In addition, shrinkage/water absorption and L-a-b color values ​​in sintering studies with nonmagnetic products were measured as 8.3%/12.7% and 74.0-7.2-12.9 in wall tile conditions and 10.2%/9.4% and 72.2-6.3-11.9 in porcelain conditions.
As a result, it was observed that the mechanical dispersion and wet magnetic separation process provide significant improvements in the color values ​​of the material under wall tile and porcelain sintering conditions.