A method for controlled exothermic reduction of a metal chloride of one or more of base metals Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd, and Mo, with an Al reducing agent, the method comprising: • contacting said one or more metal chlorides, a control powder and an Al reducing agent corresponding to between 80wt% and 5000wt% of the amount required to reduce all the reducible precursor chemicals to their elemental base metal state, all in a fine particulate form, at temperatures between 160oC and 600 oC in a reduction stage in which at least 50% of the chlorine of the starting base metal chloride is removed, and a purification stage at temperatures above the sublimation/evaporation temperatures of the base metal chlorides and below a maximum temperature T max to form a metal or metal alloy product in a powder form and a by-product including aluminium chloride; and wherein the purification stage serves to purify the powder product and complete the reduction reaction leading to formation of a solid powder product and gaseous by-products; and • separating the by-products from the metal alloy powder product; • wherein the control powder includes one or more of Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb Cu, Pt, W, Pd, and Mo being final or intermediate reaction products based on the one or more base metals, or an alloy or compound thereof, and acts to control exothermic heat release from the reduction reaction and to thereby keep reaction temperatures to less than T max; • wherein T max is between 400oC and 1100oC, and below the melting temperature of the base metal or metal alloy product; and • wherein the reaction is controlled such that heat generated by the reaction does not increase the reaction temperature by more than 600oC. • contacting said one or more metal chlorides, a control powder and an Al reducing agent corresponding to between 80wt% and 5000wt% of the amount required to reduce all the reducible precursor chemicals to their elemental base metal state, all in a fine particulate form, at temperatures between 160oC and 600 oC in a reduction stage in which at least 50% of the chlorine of the starting base metal chloride is removed, and a purification stage at temperatures above the sublimation/evaporation temperatures of the base metal chlorides and below a maximum temperature T max to form a metal or metal alloy product in a powder form and a by-product including aluminium chloride; and wherein the purification stage serves to purify the powder product and complete the reduction reaction leading to formation of a solid powder product and gaseous by-products; and • separating the by-products from the metal alloy powder product; • wherein the control powder includes one or more of Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb Cu, Pt, W, Pd, and Mo being final or intermediate reaction products based on the one or more base metals, or an alloy or compound thereof, and acts to control exothermic heat release from the reduction reaction and to thereby keep reaction temperatures to less than T max; • wherein T max is between 400oC and 1100oC, and below the melting temperature of the base metal or metal alloy product; and • wherein the reaction is controlled such that heat generated by the reaction does not increase the reaction temperature by more than 600oC.