Method of manufacturing fine powders of metal sulfide

The process of producing the sulfide of chromium or aluminum which comprises the steps of:

• placing a chromium or aluminum chloride or bromide occluded mass in the shape of a porous hollow cylinder which does not contain carbon, moisture, hydroxyl ions or oxidizing agent in a closed heating chamber;
• heating said mass to at least the fusing point of said chromium or aluminum chloride or bromide;
• vaporizing the chromium or aluminum chloride or bromide produced thereby in a stream of a dried gaseous mixture supplied to said chamber at a low temperature, said low temperature being lower than the temperature at the point where the chromium or aluminum chloride or bromide occluded body is heated and lower than the fusing point of said bromide or chloride, and said gaseous mixture consisting of an inert gas and hydrogen sulfide gas, and thus directly reacting the vaporized chromium or aluminum chloride or bromide with the hydrogen sulfide component of said dried gaseous mixture whereby the corresponding metal sulfide is produced;
• and quenching and recovering the chromium or aluminum sulfide so produced in the form of a fine dry powder in the presence of the said inert gaseous component of the dried gaseous mixture.