basic process

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A method of steel production that uses a furnace lined with a basic refractory material.

from the GNU version of the Collaborative International Dictionary of English.

• (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.