Preparation
HfCl4 is produced by several procedures:
- The reaction of carbon tetrachloride and hafnium oxide at above 450 °C;
- Chlorination of a mixture of HfO2 and carbon above 600 °C;
- Chlorination of hafnium carbide above 250 °C.
Hafnium(IV) chloride is prepared by heating a mixture of HfO2 and carbon in a stream of chlorine or sulfur monochloride under hot temperatures as shown in the equation below.
- HfO2 + 2Cl2 + C → HfCl4 + CO2
HfCl4 could also be prepared by reacting Hf(OH)4 with HCl and then boiling the reactants until crystals are formed. Since Hf mineral ores contain Zr compounds as well, some ZrCl4 is also formed in the process of synthesizing HfCl4 therefore the product has to be purified in order to obtain pure HfCl4.
Read more about this topic: Hafnium(IV) Chloride
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