Converters

84.54 - Converters, ladles, ingot moulds and casting machines, of a kind used in metallurgy or in metal foundries. 8454.10 - Converters 8454.20 - Ingot moulds and ladles 8454.30 - Casting machines 8454.90 - Parts (A) CONVERTERS These are used for converting or refining metals (e.g., for converting iron into steel, or smelting copper or nickel mattes, galena, etc.) by subjecting the materials, previously melted or brought to a high temperature in a furnace, to a strong current of oxygen; by this action most of the carbon and hssolved elements such as manganese, silicon and phosphorus are oxidised and eliminated in the form of gas or molten slag. The oxidation increases the temperature of the metal further. The most common types of converters are pear-shaped or cylindrical vessels consisting of an outer shell of heavy steel plates with an internal limng of refractory material. The oxy en is brought in either by a lance from above (LD-converters (Linz-Donawitz) or through nozz es in the converter bottom (OBM-converters (Oxygen Bodenblasen e Maxirnilianhiitte)). Combinations of the two exist. Other types include converters with the tuycres incorporated in the sides, rotating cylindrical converters, conical converters (for treating copper matte) with an internal metal grille for supporting the charge. (B)LADLES These are used to receive the molten metal from a furnace and pour it into converters or moulds; they are simple open containers generally lined with refractory material, usually fitted with devices to facilitate tip ing or pourin and in some cases fitted with wheels. They are usually handled mechanically g.g., by cranes?, but the heading also covers foundry- e casting ladles manipulated by hand. Small hand ladles of the type used by tinsmiths, go smiths, etc., are excluded (heading 73.25 or 73.26). P (C) INGOT MOULDS These may be of various shapes, in one iece or two halves, in which the molten metal is provisionally cast into, e.g., ingots, pigs, sla s. ! Other moulds (e.g., for casting articles) are generally classified in heading 84.80. The moulds of this group are of metal, usually iron or steel. Ingot moulds of graphite or other carbon or of ceramic material are, however, excluded (headings 68.15 and 69.03, respectively). @) CASTING MACHINES OF A KIND USED IN METALLURGY OR IN METAL FOUNDRIES This group includes : a (1) Machines (generally incorporatin a conveyor belt or chain) for the successive filling, cooling and em tying of the moul s. These sometimes incorporate devices for shaking or tapping the mou ds to facilitate the even setting of the molten metal. f (2) Machines for casting under pressure. These consist essentially of two adjustable lates to which are fixed the two halves of the mould. The liquid metal fiom a reservoir is orced into the mould, either by the direct action of conipressed air on the free surface of li uid metal in the reservoir, or by the insertion of a piston into a closed reservoir full o the li uid metal. In some cases these machines incorporate cooling devices, to accelerate so idification of the metal, and arrangements for separating the cast article fiom the mould. They are mainly used for casting small non-ferrous metal articles. ? However, the headin does not cover machines for moulding metal powders under pressure, by sintering, (heading 8j.62). (3) Centrifu a1 casting machines in which the molten metal is led into a c lindrical mould rotaun a? high speed; the metal is thrown on to the sides of the mould anlsolldlfies m the formo apipe. B (4) Continuous castin machines. In these, steel is conve ed from the ladle in a distributor which feeds the dif erent casting flow lines. These flow gnes include : F (a) an ingot mould, without bottom, with its cooling devices; (b) outside the ingot mould a system for atomising water in order to cool the cast metal; (c) a group of conveyor rollers allowing the regular extraction of the solidified metal; and (d) a system of cutting-off machines, followed by an evacuation device. The moulds to be used with the machines of this group fall usually in heading 68.15,69.03 or 84.80. PARTS Sub'ect to the general provisions regardin the classification of parts (see the General Exp anatory Note to Section XVI), the h e a k g also covers parts of the machines of this heading. I