Which one of the following is not a calcination reaction?

• A

  $\mathrm{ZnCO}_3 \stackrel{\Delta}{\longrightarrow} \mathrm{ZnO}+\mathrm{CO}_2$
• B

  $\mathrm{Fe}_2 \mathrm{O}_3 \cdot x \mathrm{H}_2 \mathrm{O} \stackrel{\Delta}{\longrightarrow} \mathrm{Fe}_2 \mathrm{O}_3+x \mathrm{H}_2 \mathrm{O}$
• C

  $\mathrm{CaCO}_3 \cdot \mathrm{MgCO}_3 \stackrel{\Delta}{\longrightarrow} \mathrm{CaO}+\mathrm{MgO}+2 \mathrm{CO}_2$
• Correct answer
  D

  $\mathrm{CaCO}_3 \cdot 2 \mathrm{HCl} \stackrel{\Delta}{\longrightarrow} \mathrm{CaCl}_2+\mathrm{H}_2 \mathrm{O}+\mathrm{CO}_2$

Hence, the correct answer is option: 'D'.