GB645225A - Improvements in or relating to the stabilization of hydrogen peroxide - Google Patents

Abstract

A hydrogen peroxide solution of at least 50 per cent strength by weight is stabilized by adjusting the pH of the solution to a value not more than 1 pH unit above and 2 pH units below the "neutrality pH," i.e. the pH corresponding to the "neutrality point" or inflection point (P) in a graph obtained by plotting the pH against the amount of titrating agent when an aqueous hydrogen peroxide solution is titrated with a standard acid and another portion of the solution with a standard alkali, the pH being measured with a glass electrode system after adding each small portion of <PICT:0645225/III/1> titrating agent. Water-soluble tin compounds, such as stannates of potassium and lithium, but preferably sodium stannate trihydrate, in amount equivalent to 36 to 288 milligrams of sodium stannate/litre of hydrogen peroxide solution, may be added as stabilizers to the adjusted peroxide solution. The stabilization procedure of the present invention may be combined with other processes for treating hydrogen peroxide such as those involving the use of nitrates as corrosion inhibitors, as described in Specification 460,208, and after conventional purification treatments such as distillation, filtration and precipitation. Specification 409,361 also is referred to.