Abstract: A method for the production of finely particulate solid chemical products from a molten stock comprises the steps of: (a) feeding the product, as molten stock, to an elongated treatment space, sealed from the ambient; (b) causing the product to flow as a flowable mass within space, while leaving a free portion of said space above the surface of said mass; (c) maintaining in said space an atmosphere that is non-reactive with said product; (d) subjecting said product to a stirring and mixing action by rotary means; (e) concurrently cooling said product as it proceeds along said space, whereby to solidify it; (f) concurrently detaching any product that adheres to surfaces within said space; and (g) discharging the solidified product, in the form of solid particles, from said elongated treatment space.