Method for making sulfated polyaluminum chloride (PACS) or polyaluminum chloride (PAC) and PACs or PAC made by same

A method for making aqueous sulfated polyaluminum chloride, the method comprising:

• adding a first solution comprising an amount of a sulfate-containing aluminum compound to a reaction vessel;
• adding a second solution, simultaneously with the first solution, comprising an amount of a base to the reaction vessel;
• mixing the first solution and the second solution in the reaction vessel to produce a mixture as the first solution and the second solution are added to the reaction vessel until a pH between 4.5 and 10 of the mixture is attained;
• once the pH of the mixture is attained between 4.5 and 10, maintaining the pH of the mixture between 4.5 and 10 during the mixing to produce an aluminum hydroxide precipitate dispersed in a liquid;
• allowing the aluminum hydroxide precipitate in the mixture to settle and creating a supernatant liquid;
• removing an amount of the supernatant liquid from the mixture to form a slurry;
• mixing the slurry;
• and
• adding a third solution comprising a polyaluminum chloride solution having about 10% to about 18% alumina and a basicity of about 20% to about 45%, an aluminum chloride solution, and/or a hydrochloric acid solution to the slurry to dissolve the aluminum hydroxide precipitate to form the aqueous sulfated polyaluminum chloride.