through it takes no part in the water requirement application_number US 18851788 A description the invention is an improvement in u s patent application ser no 07 129 618 filed dec 12 1987 for a method of preparing overbased calcium sulfonates to tze chi jao a process for overbasing calcium sulfonates has been discovered based on the use of a mixture of calcium oxide and calcium hydroxide in specified proportion as the source of inorganic calcium the entire charge of water is added before the carbonation in an amount of 15 to 30 mole of the calcium oxide a clear product with a low solid waste is produced it is known to produce overbased sulfonates by means of calcium oxide alone or a mixture of calcium oxide and calcium hydroxide overbased sulfonates produced from calcium oxide calcium hydroxide mixtures are noted for a hazy product with a relatively low level of overbasing the instant invention is distinguished in the recognition that calcium oxide calcium hydroxide ratio is essential to produce a clear low solids content mixture for filtering the use of calcium hydroxide alone is undesirable because it typically produces a high solids content product and demonstrates low sulfonate utilization applicant 39 s ser no 07 129 618 filed dec 7 1987 achieved an improvement in using.