PRODUCTION OF ZIRCONIUM OXIDE FROM ZIRCONIUM SILICATE


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Doğan Ö., Yavuz M., Çetiner B. N. , Aktaş S.

3rd International Congress on Engineering, Architecture and Design, İstanbul, Türkiye, 4 - 05 Mayıs 2018, ss.433-434

  • Yayın Türü: Bildiri / Özet Bildiri
  • Basıldığı Şehir: İstanbul
  • Basıldığı Ülke: Türkiye
  • Sayfa Sayıları: ss.433-434

Özet

Abstract: Introduction: Found application as furnace linings in iron and steel industry, as casting filters in

several casting techniques, for color setting in paint industry, due to its ionic conductivity in electroceramics,

zirconium oxide is mainly used in the production of hard ceramics in dentistry such as the laminate veneers or

in textile industry as spinning rolls. The demand of zirconium oxide is mostly provided by importers from countries

such as Italy, Australia, Germany, England, Netherlands and Republic of South Africa. The annual zirconium

oxide consumption is about 1800-2000 metric tonnes per year. According to data of Turkish Statistical

Institute in 2015, zirconium silicate cost about 30 million US dollars and zirconium oxide about 59 million US

dollars were imported. Purpose: A sustainable manufacturing technique was aimed to produce the zirconium

oxide which is imported every year with high cost. Scope: Development of a new sustainable refining process

of zirconium oxide from zirconium silicate sand in Turkey. Limitations: In this research, main limitation is

economic constraints and profit/loss analysis, but also environmental concerns in the design of this process.

Utilizing minimum amount of chemicals of affordable prices and distilled water, considering electrical consumption

during processes, also repetition of the process in order to dissolve all the zirconium and at the end of

the process, the neutralization of acidic solutions were procedures applied to meet these limitations. Method:

Firstly, zirconium silicate sand was ground and homogenized. Theoretically, in order to dissolve zirconium

oxide of 250 kg, NaHSO4 about 317 kg is needed. Then for the dissolution process of zirconium silicate

sand, zirconium is subjected to fusion with NaHSO4 at 600 oC. After fusion, obtained mixture is leached by

hot distilled water. At the end of each process, decantation and filtration techniques were used and unreacted

ceramic residue was taken into process again and the same procedures were repeated till a significant amount

of zirconium was found in the solution which was determined by titration. The pH of the solution was about

0. Using caustic solution, pH was arranged to 1, as the solubility product constant of Zr(OH)4 is very low, zirconium

was precipitated as zirconium hydroxide (Zr(OH)4) meanwhile other metals remained in the solution.

Following drying for 24 h at 105 oC, the zirconium hydroxide was thermally decomposed at 500 oC to obtain

zirconium oxide. Zirconium oxide was subsequently ground for the further analysis. The XRF, XRD and

SEM-EDS analyses were carried out. In order to establish the purity of zirconium oxide samples titrations were

performed. It was found that the produced zirconium oxide can successfully be used in various applications

including dentistry. Results: The production of zirconium oxide of more than 99 % of purity was attained. The

XRD results and EDS analysis indicated the mono phase zirconium oxide and zirconium and oxygen peaks,

respectively. Conclusion: The production of zirconium oxide of more than 99 % of purity with feasible budget

comparing to importation was shown possible with the evidence of XRF, XRD and SEM + EDS analysis.


Key Words: Zirconium Silicate, Zirconium Oxide, Hydrometallurgy, Thermal Decomposition

Author note: This work has been financially supported byThe Scientific and Technological Research Council

of Turkey under the programme of TUBITAK 2209