… articles thereof. Aluminium is obtained principally from bauxite, a crude hydrated alumina (see the Explanatory Note … is designed to convert the bauxite into pure aluminium oxide (alumina). For this purpose the ground ore is calcined and then treated with sodium hydroxide to produce a solution of sodium aluminate; this is …
… furnaces for zone melting and refining of silicon rods, oxidation furnaces for oxidizing the surface of wafers and diffusion furnaces for … to the generation of a particular type of film. (a) Oxidation furnaces , which form a “film” of oxide on the …
… acid, readily giving off chlorine, is a very powerful oxidising and bleaching agent. (1) Sodium hypochlorite … carbonate on calcium hypochlorite, or by treating sodium hydroxide (caustic soda) with chlorine. This salt, very soluble in water, does not exist in the anhydrous state; it is rather unstable and …
… Sub-Chapter XII GLYCOSIDES AND ALKALOIDS, NATURAL OR REPRODUCED BY … in medicine as heart stimulants. The group includes digitoxin , white crystalline powder, odourless, very toxic; digoxin ; and digitonin , a saponin of digitalis, …
… (A) NITRIC ACID Nitric acid (HNO 3 ) is mainly obtained by oxidising ammonia in the presence of a catalyst (platinum, iron, chromium, bismuth or manganese oxides, etc.). Alternatively, nitrogen and oxygen may be … in an electric‑arc furnace and the resulting nitric oxide oxidised. It can also be prepared by the action of …
… OR NOT CALCINED OR MIXED TOGETHER; NATURAL MICACEOUS IRON OXIDES The colours classified here are usually naturally … Verona earth and Cyprus earth (green). Calcination or the mixing together of various earth colours does not affect …
