A process for making a mineral oxide concentrate useful as a flocculent, coagulant and/or disinfectant for the treatment of water and wastewater comprises extracting minerals from a natural mineral deposit rich in aluminum, magnesium, potassium and iron; reducing the particle size of the extracted material to a fine particle size, followed by heat treating the resulting mineral-rich material in air to produce a controlled expansion of the material and to oxidize essentially all organic constituents and to evaporate all water, leaving a mass of expanded dried mineral oxide-rich material containing oxides of aluminum, magnesium, potassium and iron. The expanded oxide-rich material is dissolved in a liquid carrier, preferably an alkaline solution, but an acidic solution also can be used, to produce a concentrate in which the mineral oxides are available and useful for said water and wastewater treatment.
