WCO Explanatory Notes reproduced for reference. © World Customs Organization. Verify against official WCO publication.
38.15 - Reaction initiators, reaction accelerators and catalytic preparations, not elsewhere specified or included. 3 8 15.1 1 3 8 15.12 3815.19 3815.90 - Supported catalysts : - - With nickel or nickel compounds as the active substance - - With precious metal or precious metal compounds as the active substance - - Other - Other e This heading covers reparations which initiate or accelerate certain chemical processes. Products whxch retard t ese processes are not included. These preparations fall broadly into two groups. (a) Those of the first group are, in general, composed either of one or more active substances deposited on a sup ort (known as " supported catalysts ") or of mixtures with a basis of active substances. n the majority of cases, these active substances are certain metals, metallic oxides, other metallic compounds or mixtures thereof. The metals most fre uently used as such or as compounds are cobalt, nickel, palladium, latinum, molyb enum, chromium, copper or zinc. The support, sometimes activate$ gemrally consists of alumina, carbon, silica gel, siliceous fossil meal or ceramic materials. Examples of " supported catalysts " are supported Ziegler or Ziegler-Natta types. f @) Those of the second group are mixtures with a basis of compounds whose nature and ro ortions vary according to the chemical reaction to be catalysed. These preparations ?mgde : (i) " free radical catalysts " (e.g., organic solutions of organic peroxides ox of azo compounds, redox mixtures); (ii) " ionic catalysts " (e.g., alkyllithium); (iii)" catalysts for olycondensation reactions " (e.g., mixtures of calcium acetate with antimony trioxi e). S The preparations of the second group are generally used in the course of manufacture of polymers. This heading does not include : (a) Spent catalysts of a kind used for the extraction of base metals or for the manufacture of chemical compounds of base metals (headin 26.20) and spent catalysts of a land used principally for the recovery of precious metal (heading%.12). (b) Separate chemically defined compounds (Chapter 28 or 29). (c) Catalysts consisting solely of metals or metal alloys in the form of finely divided powder, woven gauze, etc. (Section X W or XV). (d) Prepared rubber accelerators for use in the vulcanisation of rubber (heading 38.12). 38.16- Refractory cements, mortars, concretes and similar compositions, other than products of heading 38.01. This heading covers certain preparations (e.g., for furnace linings) with a basis of such refractory materials as chamotte and dinas earths, crushed or ound corundum, powdered quartzites, chalk-, calcined dolomite, with an added refractory gnder (for example, sodium silicate, magnesium or zinc fluosilicates . Many of the products of this heading also contain non-refractory binders such as hydraulic inding agent.. The heading also covers refract0 compositions with a basis of silica for the manufacture of dental or jewellery moulds by the ost wax process. The heading further covers refractory concretes consisting of mixtures of heat-resistant hydraulic cements (e-g., aluminous cements) and refractory aggre ates, used for the foundation of furnaces, coke ovens, etc., or for patching furnace linings as we as the following : fi (a) Compositions known as refractory 6C plastics ", which are products sold as a dampened mass often consisting of a refractory aggregate, clay and minor additives. (b) Ramming mixes, other than dolomite ramming mixes, which are similar in composition to the products mentioned in (a) above and which, when applied by hand-held pneumatic rammers, form a dense coating or filling. (c) Gunning mixes, which are refractory awegates mixed with hydraulic setting or other binders, applied to furnace linings, sometimes even when these are hot, by special guns which project the mix through a nozzle using compressed air. The heading does not cover : (a) Dolomite ramming mixes (heading 25.18). @) Carbonaceous pastes of heading 38.01. 38.17- Mixed alkylbenzenes and mixed alkylnaphthalenes, other than those of heading 27.07 or 29.02. This headin covers mixed alkylbenzenes and mixed alkylnaphthalenes obtained by alkylation of enzene and naphthalene. They have fair1 long side-chams and are not of the kind mentioned in the second art of the text of heading 2 .07, Mixed alkylbenzenes are used, infer alia, as solvents, and in e manufacture of surface-active agents, lubricants and insulatin oils. Mixed a1 lnaphthalenes are mainly used for the manufacture of alkylnaphthalene sulp onic acids and eir salts. % tg 7' The heading excIudes mixtures of isomers of heading 29.02. Lh -
1.- This Chapter does not cover : (a) Separate chemically defined elements or compounds with the exception of the following : (1) Artificial graphite (heading 38.01); (2) Insecticides, rodenticides, fungicides, herbicides, anti-sprouting products and plant-growth regulators, disinfectants and similar products, put up as described in heading 38.08; (3) Products put up as charges for fire-extinguishers or put up in fire-extinguishing grenades (heading 38.13); (4) Certified reference materials specified in Note 2 below; (5) Products specified in Note 3 (a) or 3 (c) below; (b) Mixtures of chemicals with foodstuffs or other substances with nutritive value, of a kind used in the preparation of human foodstuffs (generally heading 21.06); (c) Products of heading 24.04; (d) Slag, ash and residues (including sludges, other than sewage sludge), containing metals, arsenic or their mixtures and meeting the requirements of Note 3 (a) or 3 (b) to Chapter 26 (heading 26.20); (e) Medicaments (heading 30.03 or 30.04); or (f) Spent catalysts of a kind used for the extraction of base metals or for the manufacture of chemical compounds of base metals (heading 26.20), spent catalysts of a kind used principally for the recovery of precious metal (heading 71.12) or catalysts consisting of metals or metal alloys in the form of, for example, finely divided powder or woven gauze (Section XIV or XV). 2.- (A) For the purpose of heading 38.22, the expression “certified reference materials” means reference materials which are accompanied by a certificate which indicates the values of the certified properties, the methods used to determine these values and the degree of certainty associated with each value and which are suitable for analytical, calibrating or referencing purposes. (B) With the exception of the products of Chapter 28 or 29, for the classification of certified reference materials, heading 38.22 shall take precedence over any other heading in the Nomenclature. 3.- Heading 38.24 includes the following goods which are not to be classified in any other heading of the Nomenclature : (a) Cultured crystals (other than optical elements) weighing not less than 2.5 g each, of magnesium oxide or of the halides of the alkali or alkaline-earth metals; (b) Fusel oil; Dippel's oil; (c) Ink removers put up in packings for retail sale; (d) Stencil correctors, other correcting fluids and correction tapes (other than those of heading 96.12), put up in packings for retail sale; and (e) Ceramic firing testers, fusible (for example, Seger cones). 4.- Throughout the Nomenclature, “municipal waste” means waste of a kind collected from households, hotels, restaurants, hospitals, shops, offices, etc., road and pavement sweepings, as well as construction and demolition waste. Municipal waste generally contains a large variety of materials such as plastics, rubber, wood, paper, textiles, glass, metals, food materials, broken furniture and other damaged or discarded articles. The term “municipal waste”, however, does not cover : (a) Individual materials or articles segregated from the waste, for example wastes of plastics, rubber, wood, paper, textiles, glass or metals, electrical and electronic waste and scrap (including spent batteries) which fall in their appropriate headings of the Nomenclature; (b) Industrial waste;