Zirconium tetrachloride production from zircon

Chlorination. Historically, the production of zirconium tetrachloride from zircon sand involved first a reduction to carbide nitride (see above) followed by the very exothermic reaction of the cmshed carbide nitride with chlorine gas in a water-cooled vertical shaft furnace ... 

Zircon is a sihcate of formula ZrSi04 and occurs as the gemstones hyacinth and zirconite. Synthetic gemstones are prepared from zircon and from the oxide Zr02. Zirconium metal is difficult to produce. Its production requires treatment of the tetrachloride ZrC with magnesium metal. Zirconium metal is silvery-gray, ductile, and malleable. 

Preparation of unstabilized zirconia. Zirconia is usually produced from zircon flour. Although the carbochlorination of zircon produces zirconium tetrachloride that can be oxidized to yield zirconia, such a method is only restricted to the production of zirconium metal (see Zirconium and Zirconium alloys). Therefore, to produce zirconia from zircon, the first step is to convert zircon to zirconyl chloride dihydrate. The process starts with the preparation of disodium metazirconate (Na ZrOj) by digesting zircon into molten sodium hydroxide as follows ... 

Zircon silicate is the most important source of hafnium. Ion-exchange and solvent-extraction techniques have supplanted fractional crystallization and distillation as the preferred methods of separating hafnium from zirconium. The metal itself is prepared by magnesium reduction of hafnium tetrachloride (the Kroll process), and by the thermal decomposition of tetraiodide (de Boer-van Arkel process). The annual world production of hafnium metal was about 40 tons at the end of the 1980s (Soloveichik... 

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