Concentrated aqueous bromine solutions and their preparation

A concentrated liquid biocide composition is produced by a continuous process. The process comprises continuously feeding into mixing apparatus (i) bromine chloride and (ii) an aqueous solution of alkali metal salt of sulfamic acid. These are proportioned to produce an aqueous product having an active bromine content of at least 100,000 ppm (wt/wt), and an atom ratio of nitrogen to active bromine from (i) and (ii) greater than 0.93:1. The desired product which is thus continuously formed, is withdrawn from the mixing apparatus at a rate sufficient to enable the continuous feeding to be maintained. Thus, the withdrawal of the product can be continuous or intermittent, depending upon the type of mixing apparatus being used. In various embodiments of the invention, the bromine chloride is continuously produced from separate feed streams of bromine and chlorine by maintaining such streams under automatic feed rate control whereby the streams are continuously proportioned to come together to form bromine chloride.