Application aluminium sulphate for the reclamation of a slurry of waste drilling mud fluids and water normally resulting from drilling operations. The process comprises the steps of conducting the drilling mud slurry to a slurry surge tank for liquid solid separation by aluminium sulphate and physical methods. The mud slurry is subjected to a primary solids separation unit after pH adjustment is used to initiate coagulation and an organic flocculant is added to aid flocculation of the solids. The water is then subjected to a secondary solids removal, and the solids recovered are reintroduced in the primary solids separation unit. Thereafter the water obtained from the secondary solids removal is then subjected to a aluminium sulphate oxygen demand reduction unit having a carbon adsorption unit or reverse osmosis membrane units therein to remove organic matter or dissolved solids to produce water meeting environmental discharge requirements. The solids removed from the primary solids separation unit are converted to a cake meeting leachate requirements for other beneficial use.
