Without reagents there would be no flotation, and without flotation the mining industry, as we know it today, would not exist. Reagents in mineral processing are therefore an inseparable part of the flotation process. Many books, articles and patents exist on development of reagents, reagent chemistry and reagent application. In spite of all this, researchers and those who work on the development of reagent schemes for the treatment of new ores or improvement in existing operations still rely heavily and almost exclusively on the advise of chemical companies and their technical services to select specific collectors or depressants for the plant. Unfortunately, the reagent schemes do not consist of only collectors and frothers. Pulp chemistry in an operating plant is a complex system involving the interaction of all additives, including collectors, depressants, activators, pH regulators, frothers and, most of all, soluble components of the ore and altered mineral surfaces.

In 1992, R. D. Crozier advocated that those who work on reagent scheme development must understand surface chemistry. This may be true for those dedicated to fundamental research using pure minerals, but not for those who are involved in applied research. Surface chemistry has been and will remain an important part of the flotation process, but even if we understand the surface chemistry of pure minerals, the same minerals in natural settings can be vastly different. What does this means in terms of reagent scheme development and development of new reagents? It means that we have to learn how to interpret...