| 摘要 |
A process for the production of a flocculant from an acidic aqueous liquor containing dissolved salts of aluminium and/or iron such as a waste liquor from the acid activation of a montmorillonite clay mineral comprises contacting the liquor with a basic material such as magnesite capable of reacting with the dissolved salts to precipitate aluminium and/or iron values, separating the precipitate in the form of a cake or slurry from the remaining liquor, treating the cake or slurry with hydrochloric acid to redissolve aluminium and/or iron values, preferably introducing into the digestion liquor metallic aluminium and/or iron, in the case where the solution contains ferrous iron preferably contacting the solution with an oxidising agent to convert iron to the ferric form, and separating suspended solid matter from the resulting solution. The flocculant product, which may comprise a solution of basic poly(aluminium and/or iron) halide, gives a low residual aluminium value when used to treat water. A novel magnesium-containing poly(aluminium/iron) halide product is also provided. |
