Abstract: The content of fluoride ions in aqueous solutions of calcium chloride is reduced by contacting with activated alumina. The contacting can be accomplished either as a batch slurry process or a continuous process using a fixed bed. The adsorption rate of fluoride ions by the activated alumina is increased by pre-treating the alumina with either an aqueous acid or a sulfate solution. Spent alumina can be regenerated by washing with dilute caustic.

Abstract: Significant amounts of soluble fluoride, known to create problems in processes requiring high quality grade calcium chloride, are removed from calcium chloride solution using hydroxyapatite as a removal mechanism. Under acidic conditions, calcium chloride solution is purified to about less than 10 ppm fluoride, significantly, to less than 1 ppm fluoride. At least 0.1 weight percent hydroxyapatite and concentrated hydrochloric acid are added to calcium chloride solution and slurried to remove fluoride and create a highly purified calcium chloride solution, substantially free of fluoride.

Abstract: A method is provided for the efficient, low cost removal of acetol from a phenol stream. The method results in removal of substantially all of the acetol from the phenol stream without the formation of substantial amounts of additional methylbenzofuran. The method also avoids the use of expensive reagents and capital intensive distillation equipment.