How #graphitization produces #graphite with Carbolite furnaces, of which the high-temperature regions are made 100% of graphite (including graphite felt insulation and graphite heating elements) and thus must be protected from feedstock outgassing and, of course, filled with argon or vacuum when hot. The thermocouple is withdrawn at 1200° and further temperature control is pyrometer-only. #materials
on 02020-12-20this #paper reports on production of #graphite, normally made by the Acheson Process (heating amorphous carbon at 3000°). They achieved almost complete or complete #graphitization (the paper repeatedly contradicts itself on this point) in 5 minutes by microwave-heating activated charcoal (mesh 100–325, 600–1500 m²/g) to 1000° after ethanol-impregnating it with 6 mmol NiCl₂ (per gram of carbon, mysteriously resulting in 15–35% wt% Ni), which produces a metallic nickel catalyst which can dissolve a little carbon (2.7% at 1327°), which then precipitates as graphite. They did this under argon in a quartz reactor over total processing times of 35–60' to allow 30' to heat up to 1000°. They report that microwaves’ penetration depth into graphite is only a few microns. They report both that the Acheson process takes two weeks and that they achieved full graphitization by heating various feedstocks to 3000° without catalyst for a few minutes. #materials
on 02020-12-20