Treating Tailings for Disposal by Agglomeration.
Proc 2nd Int'l Conf on the Abatement of Acidic Drainage Quebec 1991 2:499-515
Mill tailings are commonly disposed by deposition in a tailings pond which dries into a body of fine particles. Old tailings ponds can be a source of dust pollution because the fine particles are easily scoured from the surface by the wind. Weathering of the minerals in the fine tailings may be rapid. If sulfidic components are present, incident precipitation may mobilize the contained metals in the acidic effluent. Disposal of tailings as backfill in mines will prevent dusting, but oxidation and subsequent metal mobilization may still occur. A means of alleviating these problems is to chemically and physically stabilize the tailings by agglomeration, which consists of tumbling the tailings with a binder and moisture to form agglomerates. The use of a chemically basic binder such as portland cement will neutralize acid generated during oxidation. If the proper binder is used, the bonds in the agglomerates will be strong and permanent. Properly agglomerated material is physically and chemically stable and easy to handle. This U.S. Bureau of Mines paper presents data obtained by agglomerating sulfide flotation mill tailings with three concentrations of a binder. Chemical stability of agglomerates was quantified by acid consumption data. Agglomerate physical stability was characterized by wetting tests and resistance to point loading.
Proc. 2nd Int'l Conf. on the Abatement of Acidic Drainage, Quebec, V. 2, 1991, PP. 499-515