The Collaborative International Dictionary of English v.0.48:

Basic process \Ba"sic proc"ess\ (Iron Metal.)
   A Bessemer or open-hearth steel-making process in which a
   lining that is basic, or not siliceous, is used, and
   additions of basic material are made to the molten charge
   during treatment. Opposed to acid process, above. Called
   also Thomas process.
   [Webster 1913 Suppl.]