WATER-IN-OIL EMULSION CONTAINING FINELY-DIVIDED COAL

摘要

Pulverized coal is slurried with water then oil or if desired oil and pulverized alkalis preferably lime or limestone is added and the mixture subjected to sonic vibrations with an energy density of at least 11.625 watts per cm2. Liquid suspension is produced and any excess water or oil separates out as a separate phase. Normally excess oil is used and the excess oil phase can be recycled. The resulting dispersion is utilized and burned in a furnace. A clean flame is produced which has the characteristics of an oil flame and not a powdered coal flame. The addition of lime is optional as its purpose is to reduce sulfur dioxide in burning where the coal contains sulfur. If there is no sulfur or so little as to meet environmental standards the addition of lime may be omitted. The amount of lime is preferably at least about twice stoichiometric based on the sulfur content of the coal. Up to 80% of sulfur dioxide produced on burning can react with the lime and the calcium sulfate produced removed by conventional particle separators.