| 摘要 |
PURPOSE:To reduce the severe corrosive action of methanol or ethanol contg. water and a acid on a metal, by specifying the concns. of the water and acid. CONSTITUTION:Methanol or ethanol contg. water and a mineral acid such as hydrochloric acid, hydrofluoric acid, sulfuric acid or nitric acid or a carboxylic acid such as formic acid or acetic acid has severe corrosive action on a metal brought into contact with the methanol or ethanol. The methanol or ethanol is sampled and the concn. Xmol.% of the water and the concn. Ymol.% of the acid are measured. The concns. X, Y are controlled so as to satisfy formula n,Y<=0.003X and X<=60 (where n is the basicity of the acid and corresponds to the normality of an aq. acid soln. having 1mol/l concn.) by adding water or the hydroxide of an alkali metal or an alkaline earth metal, ammonia or the like. The electrical conductivity (Kmho.cm<-1>) and pH of the methanol or ethanol are also controlled so as to satisfy a formula log.K<=25.pH 5.2.
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