WCO Explanatory Notes reproduced for reference. © World Customs Organization. Verify against official WCO publication.
72.02 - Ferro-alloys. - Ferro-manganese : - - Containing by weight more than 2 % of carbon 7202.19 - - Other 7202.1 1 7202.21 7202.29 - Feno-silicon : - - Containing by weight more than 55 % of silicon - - Other 7202.30 - Ferro-silico-manganese - Ferro-chromium : - - Containing by weight more than 4 % of carbon 7202.49 - - Other 7202.50 - Feno-silico-chromium 7202.41 7202.60 - Ferro-nickel - Ferro-molybdenum 7202.80 - Ferro-tungsten and ferro-silico-tungsten - Other : 7202.91 - - Ferro-titanium and ferro-silico-titanium 7202.92 - - Ferro-vanadium 7202.93 - - Ferro-niobium 7202.99 - - Other 7202.70 Ferro-alloys are defined in Note l(c) to this Chapter. Ferro-alloys differ from pig iron in that they contain a smaller proportion of iron which merely acts as a " solvent" for large proportions of a110 elements (e.g., man anese, chromium, tungsten (wolfram), silicon, boron or nickel) and in t at they may contain 2 O o or less of carbon. H B Ferro-alloys are not normally used for rolling, forging or other working, at least not for industrial p oses, even though some are malleable, They are used in the iron or steel industry mainly to ad definite proportions of alloying elements to steel or pig iron in order to obtain special qualities, generally in those cases where the use of the pure elements themselves would be impracticable or uneconomic. Some are also used as de-oxidants, de-sulphurisers or de-nitrating agents or for killing steel, while others are used in welding or for metal deposition. T' r Certain ferro-alloys can be used directly for casting. To fall in the heading, fmo-allo s must be in the form of pigs, blocks, lumps or similar rimary forms, in granules or powder o m s or in forms obtained by continuous casting (e.g., bi ets). B Ferro-silicon is also used, in the form of s hericalgranule ~owdersthe surface of which has been hardened by a special process, as a &nse medium ( pul '3 in gravimetric separation (selective flotation) of metal ores; however, it remains in this hea ing. a The heading also covers products of this type reviousl reduced to granules or powder and means of cement or other binders agglomerated into briquettes, cylinders, thin sla%s, etc., and, in certain cases, with exothermic additives. gy Though some ferro-alloys (e.g., ferro-manganese or ferro-silicon) can be produced in blast furnaces, they are more usually prepared in electric fhmces, or in crucibles by the " thermit " process, etc. The principal varieties are : (8) Ferro-tungsten (ferro-wolfram) and ferro-silico-tungsten (9) Ferro-titanium and ferro-silico-titanium (12) Ferro-silico-magnesium and ferro-silico-calcium. The heading excludes : (a) Chemical products used for the same purposes and in the same way as ferro-alloys, such as molybdenum oxide, calcium molybdate and silicon carbide, and also, if they contain less than 4 % by weight of iron, calcium silicide and manganese silicide (Chapter 28). (b) Ferro-uranium (heading 28.44). (c) Ferro-cerium and other pyrophoric ferrous alloys in all forms (heading 36.06). (d) Products which in some countries are sometimes known as ferro-nickels or ferro-nickel-chromes, and which are malleable and are not normally used as " addition materials " in iron and steel metallurgy (headings 72.18 to 72.29 or Chapter 75).
1.- In this Chapter and, in the case of Notes (d), (e) and (f) throughout the Nomenclature, the following expressions have the meanings hereby assigned to them : (a) Pig iron Iron-carbon alloys not usefully malleable, containing more than 2 % by weight of carbon and which may contain by weight one or more other elements within the following limits : - not more than 10 % of chromium - not more than 6 % of manganese - not more than 3 % of phosphorus - not more than 8 % of silicon - a total of not more than 10 % of other elements. (b) Spiegeleisen Iron-carbon alloys containing by weight more than 6 % but not more than 30 % of manganese and otherwise conforming to the specification at (a) above. (c) Ferro-alloys Alloys in pigs, blocks, lumps or similar primary forms, in forms obtained by continuous casting and also in granular or powder forms, whether or not agglomerated, commonly used as an additive in the manufacture of other alloys or as de-oxidants, de-sulphurising agents or for similar uses in ferrous metallurgy and generally not usefully malleable, containing by weight 4 % or more of the element iron and one or more of the following : - more than 10 % of chromium - more than 30 % of manganese - more than 3 % of phosphorus - more than 8 % of silicon - a total of more than 10 % of other elements, excluding carbon, subject to a maximum content of 10 % in the case of copper.