Abstract text

A method of preparing a potassium monopersulfate composition is presented, wherein the potassium monopersulfate composition has the formula (KHSO₅)_x(KHSO₄)_y(K₂ SO₄)_z, where x+y+z=1 and x=0.46-0.64, y=0.15-0.37, and z=0.15-0.37, said potassium monopersulfate composition having an active oxygen content greater than or equal to 4.9 wt. % and K₂S₂O₈ at a concentration of <0.5 wt. % of the potassium monopersulfate composition. The method includes reacting an H₂O₂ solution containing at least 70 wt. % H₂O₂ with a H₂SO₄ solution at a substoichiometric ratio of the H₂SO₄ to H₂O₂ to generate a weak Caro's acid solution, then combining the weak Caro's acid solution with oleum to produce a rich Caro's acid solution. The rich Caro's acid solution may be combined with an alkali potassium compound to produce the potassium monopersulfate composition. During the process, the temperature is maintained at below 30 ° C.