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

Methods for making a sulfated polyaluminum chloride (PACS) flocculating agent solution, which may be aqueous, include neutralizing an aqueous sulfate-containing aluminum compound with an aqueous base to produce an aluminum hydroxide precipitate dispersed in a liquid, settling the aluminum hydroxide precipitate to create a supernatant liquid, removing an amount of the supernatant liquid to leave a remainder that contributes a selected concentration of sulfate to the PACS, and bringing the precipitate back into solution thereby forming the PACS flocculating agent. Also, methods for making a polyaluminum chloride (PAC) flocculating agent solution are disclosed that include neutralizing an aqueous chloride-containing aluminum compound with an aqueous base to produce an aluminum hydroxide precipitate dispersed in a liquid, settling the aluminum hydroxide precipitate to create a supernatant liquid, optionally, removing an amount of the supernatant liquid, and bringing the precipitate back into solution thereby forming the PAC flocculating agent.