WCO Explanatory Notes reproduced for reference. © World Customs Organization. Verify against official WCO publication.
38.01 - Artificial graphite; colloidal or semi-colloidal graphite; preparations based on graphite or other carbon in the form of pastes, blocks, plates or other semi-manufactures. - Artificial graphite 3801.20 - Colloidal or semi-colloidal graphite 3801.30 - Carbonaceous pastes for electrodes and similar pastes for fiunace linings 3801.90 - Other 380 1.10 :I) Artificial graphite (electro-graphite) is a variety of carbon, usual1 prepared in an electric furnace by heating a mixture of finely gound coke (normal y petroleum coke, but sometimes anthracite coke, retort coke, pitch coke, etc.) and carbonaceous binders (e-g., pitch or tar), to a sufficiently high temperature (2500 to 3200 "C) to ensure its " graphitisation" under the catalytic action of substances present in the mixture (e.g., silica or iron oxide). The mixture is first extruded or moulded under pressure into " green" blocks of s uare or circular cross-section; these blocks may elther be pre-fired (baked) at about '?000 "C and then graphitised, or they may be submitted directly to the graphitisation process. In this way, a product is obtained with an apparent specific gravity of about 1.5 to 1.6 and a homogeneous microc stalline structure which X-ray examination shows to be that of graphite. Chemical ana ysis confirms that the substance is graphite (precipitation of graphitic acid). r In addition to ordinary grades of artificial graphites, the heading includes : (a) Nuclear grade artificial graphite, that is, specially repared artificial graphite which has a boron content of not more than one part per mi ion, and a total thermal neutrons absorption microscopic cross-section of not more than 5 rnillibarns per atom. This grade has a very low ash content (not exceeding 20 parts per million), and is used as a moderator or reflector in nuclear reactors. (b) Im regnated or impervious artificial graphite, that is, artificial graphite which, in or‘!Ier to increase its apparent specific gravity or its impermeability to gases, has first been impregnated in a vacuum with tars or resins or with solutions of sugars or other organic products, and re-fired to graphitise the carbonaceous residues of these additives. may be repeated several times to obtain a higher apparent or high degree of impermeability. Impregnated graphite Artificial graphite of this heading is usually in the form of powder, flakes, blocks, lates, bars, rods, etc. The blocks and plates are used, after cutting and high-finish mac&,n (fine tolerances and appro riate surface finish), to make the brushes or other electrica carbon articles of heading 5.45 or parts of nuclear reactors. Pr The heading also includes scrap, waste and worn-out articles, suitable only for the recovery of artificial graphite. The heading does not cover : (a) Natural graphite (heading 25.04). (b) Retort carbon (or gas carbon), sometimes incorrectly called " artificial graphite " (heading 27.04). (c) Artificial graphite surface-worked, surface-finished, cut to special shapes, lathe-worked, drilled, milled, etc., or transformed into articles. If of a kind used for non-electrical purposes these usually fall in heading 68.15 (e.g., filters, discs, bearings, moulds, acid-resistant bricks, etc.); those of a kind used for electricalpurposes fall in heading 85.45. (d) Refractory goods, fired as ceramics, with a basis of artificial graphite (heading 69.02 or 69.03). (e) Blocks, plates, bars and similar semi-manufactures, of artificial graphite which also contain powders of silver (heading 71.06). (2) Colloidal or semi-colloidal graphite. (a) Colloidal graphite consists of finely divided natural or artificial aphite in colloidal sus ension in water or in other media (e.g., alcohol, mineral oilf to which may be ad ed small quantities of other products such as tannin or ammoma for the p ose of stabilising the suspension. Colloidal graphite is usually semi-liquid, and is used for the manufacture of lubricating preparations or for its high electrical conductivity. aY (b) Semi-colloidal graphite (i.e., graphite in semi-colloidal suspension in water or in other media). Semi-collordal graphite may be used for the preparation of graphited oils or for forming graphited surfaces. This catego covers only graphite in colloidal or semi-colloidal suspension in any media, the graphte eing the basic constituent. (3) Preparations based on graphite or other carbon in the form of pastes, blocks, plates or other semi-manufactures. (a) bb Carbon " blocks, plates, bars and similar semi-manufactures of metallographitic or other grades. These terms cover a group of semi-manufactures such as blocks, plates, etc., of the kind used to make " carbon " brushes for electrical or electrotechn~calmachinery or ap liances, and which are based on carbonaceous materials (alone or compounded with ot er substances). They are generally of the following types : R (i) "Carbons" obtained by the firing, at a temperature (1000 to 1200°C) insuMicient to produce true phitisation ", of mixtures of finely ground coke or lamp black and powdere natural or artificial graphite with carbonaceous binders such as pitches or tars. "P The structure of the products thus obtained is not homogeneous; microscopic examination shows a mixture of grains of graphite with grains of amorphous carbon and, on chemical analysis, the graphitic acid precipitate is weaker than that obtained fi-om artificial graphite. (ii) Metallo-graphitic grade compositions obtained, by a rocess akin to sinterin (agglomeration, mouldin and firing), from mixtures o powdered graphite wi powders of base metals $copper, cadmium or their alloys). Their metal content ranges from 10 to 95 %. ? f (iii) Grades obtained by moulding natural or artificial graphite powder mixed with plastics. The blocks and plates, in articular, as obtained fiom the materials described above are general1 in sizes about 00 x 100 x 35 mm or 150 x 70 x 30 mm. The are mainly used, a er cutting and hip-finishing machining (fine tolerances andYappropriate surface finish) to make the e ectrical brushes of heading 85.45. B i The above-mentioned semi-manufactures, when they contain powdered silver, are classified in heading 71.06. The headin also excludes blocks which have been cut to s ecial shapes, surface-worked, surface finis ed, etc. (generally heading 68.15 or 85.45) and re actory oods, fired as ceramics, based on amorphous carbon or natural graphite (heading 69.01 or 69.037. i iF (b) Carbonaceous pastes for electrodes. These products consist mainly of a mixture of anthracite and coal tar pitch (which acts as a binder). They are usually put up in the form of small blocks, which are inserted in the upper part of a metal container, where they soften when exposed to heat. They are thus moulded inside the container to form an endless electrode for use in the furnaces, which no longer needs to be stopped to chan e worn-out pre-fabricated electrodes. The best known composition of this kind is " oderberg paste ". # Similar pastes are used to make furnace linings which then harden in sitzs. This category also covers raphite in paste form, consisting of a mixture of in the form of articles (most y exceeding 5 micrometres (microns)) with minera olls, and e ually suita le for use for treating the surfaces of heavy machinery or for the manufacture o graphited greases. $aphite
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;