Editing Bessemer process (section)

==="Basic" vs. acidic Bessemer process===
{{further|Gilchrist–Thomas process}}
Industrial chemist [[Sidney Gilchrist Thomas]] tackled the problem of phosphorus in iron, which resulted in the production of low grade steel. Believing that he had discovered a solution, he contacted his cousin, [[Percy Gilchrist]], who was a chemist at the [[Blaenavon Ironworks]]. The manager there, Edward Martin, offered Thomas test equipment and helped him draw up a patent issued in May 1878. Thomas's invention consisted of using [[Dolomite (rock)|dolomite]] or [[limestone]] linings for the Bessemer converter rather than clay, and it became known as the 'basic' Bessemer rather than the 'acid' Bessemer process. An additional advantage was that the processes formed more slag in the converter, and this could be recovered and used profitably as fertilizer.<ref>{{Cite web|url=http://www.visitblaenavon.co.uk/en/WorldHeritageSite/TheBlaenavonStory/BlaenavonandtheGilchrist-ThomasProcess.aspx|archiveurl=https://web.archive.org/web/20131212031458/http://www.visitblaenavon.co.uk/en/WorldHeritageSite/TheBlaenavonStory/BlaenavonandtheGilchrist-ThomasProcess.aspx|url-status=dead|title=Blaenavon World Heritage Site: Blaenavon and the 'Gilchrist-Thomas' Process|archivedate=12 December 2013|website=www.visitblaenavon.co.uk}}</ref>