The physico-chemical aspects of hydrothermal decomposition of zircon have been studied. It is found that NaOH is the efficient reagent for decomposition of zircon. Under the optimum conditions, above 99% of zircon can be decomposed. The effects of various reaction conditions such as temperature, concentration of alkali, solid/liquid ratio, particle size, stirring rate on the decomposition rate are investigated in detail, and rational operation conditions for decomposition have also been given in this paper. The results show that the hydrothermal decomposition reaction ZrSiO4+2NaOH=Na2ZrSiO5+H2O is a diffusion-controlled, non-catalytical, solid/liquid reaction. Based on the experimental data a flow diagram of preparation of ultrafine ZrO2 powders from zircon by hydrothermal reaction method has been suggested. Ultrafine ZrO2 powders with d-0.01 μm can be obtained.
|Number of pages||6|
|Publication status||Published - 1992 Aug 1|
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