Ferrous and non-ferrous smelting processes produce different slags. However, slags can contain metal sulfides and elemental metals. The lead containing the gold is separated by cupellation, the metal rich slags are re-smelted. Mills' main research was carried out on metals and alloys, slags and refractories. Basic refractories are used in areas where slags and atmosphere are basic. He also uses the monikers Sycophant Slags and Indigo Kidz. Common crystalline constituents of blast-furnace slags are merwinite and melilite. These types of gasifiers do not suffer from corrosive slags. It is made of reavertine, flint and iron slags. For example, Hauptmann performed lead isotope analysis on slags from Faynan, Jordan. The Fat Slags is a British comic strip appearing in the alternative British comic "Viz". It also occurs in slags and cement. "Fat Slags" received near unanimously negative reviews and was panned by critics. Deayton had a cameo role as a hotel receptionist in the 2004 Fat Slags film. One analysis gives 0.10% in the slags for 0.18% in the iron itself.