Subclass : COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM (metal hydrides C01B 6/00 ; salts of oxyacids of halogens C01B 11/00 ; peroxides, salts of peroxyacids C01B 15/00 ; sulfides or polysulfides C01B 17/22 ; thiosulfates, dithionites, polythionates C01B 17/64 ; compounds containing selenium or tellurium C01B 19/00 ; binary compounds of nitrogen with metals C01B 21/06 ; azides C01B 21/08 ; metal amides C01B 21/092 ; nitrites C01B 21/5 ; phosphides C01B 25/08 ; salts of oxyacids of phosphorus C01B 25/16 ; carbides C01B 31/3 ; compounds containing silicon C01B 33/00 ; compounds containing boron C01B 35/00 ; cyanides C01C 3/08 ; salts of cyanic acid C01C 3/14 ; salts of cyanamide C01C 3/16 ; thiocyanates C01C 3/2 ; fermentation or enzyme-using processes for the preparation of elements or inorganic compounds except carbon dioxide C12P 3/00 ; obtaining metal compounds from mixtures, e.g. ores, which are intermediate compounds in a metallurgical process for obtaining a free metal C22B ; production of non-metallic elements or inorganic compounds by electrolysis or electrophoresis C25B )