For 10 points, name this industrial process, the first widespread way to make steel.
This technique was developed alongside an analogous, but slower and easier-to-control procedure, named for Siemens and Martin. Sidney Gilchrist Thomas solved the "phosphorus problem" with this procedure by introducing a dolemite lining, which produced phosphate fertilizer as a byproduct. The apparatus central to this technique depends on openings called "Tuyeres," through which oxygen flows into an ovoid container. This process results in the removal of sulfur and excess carbon in order to make an alloy of iron. For 10 points, name this industrial process, the first widespread way to make steel.
This technique was developed alongside an analogous, but slower and easier-to-control procedure, named for Siemens and Martin.
{Bessemer} process [prompt on {steelmaking} or equivalents]