smelting vs vaporization

smelting

noun
  • The process of melting or fusion, especially to extract a metal from its ore. 

vaporization

noun
  • A conversion of a solid or a liquid into a gas. 

  • A destruction of something by turning it into vapor. 

How often have the words smelting and vaporization occurred in a corpus of books? (source: Google Ngram Viewer )