Other

28.24 - Lead oxides; red lead and orange lead. 2824.10 - Lead monoxide (litharge, massicot) 2824.90 - Other A massicot (PbO). Lead or cerussite (lead roduces rst unmelted lead oxide or massicot, when the temperature asses the blood-red or reddlsh pow er or scales. The applied more particularly to the latter. extraction of silver from argentiferous lead. (manufacture of lead and crystal glass), in the matches, colours, driers, etc. $ (2) Trilead tetraoxide Lead saline oxide, red lead, miniurn) (approximate formula Pb3O4 . Obtained from unme ted lead monoxide (massicot). A toxic, orange-red owder spec1 ic avity 8 to 9). The term orange lead is applied either to a very ure same 0x1 e, more Bghly ooloured and less dense than the common variety, or to lea oxides still containing lead carbonate from the cerussite used in their preparation. Red lead is used for extending other colours (Saturn red), for anti-rust paints or mastics and for colourin is employed in the manufacture of crysta sealing-wax. It is also used as a the monoxide, because it gives a fusible glass and optical glass even refractive index. glass of remarkable brilliance \ g p. .A 2 f (3) Lead dioxide @uce oxide, plumbic anhydride) (PbOz). Prepared by treating the lead sdine oxide with nimc acid or by electrolysing lead nitrate. A brown powder, insoluble in water, capable of igniting organic matter on contact. It is an oxidising agent used in pyrotechnics; also for manufacturing matches or accumulator plates, and as a mordant in the textile industry. This arnphoteric oxide gives the plumbates of heading 28.41. 28.25- H d r d n e and hydroxylamine and their inorganic salts; other inorganic bases; ot er metal oxides, hydroxides and peroxides. r, 2825.10 - Hydrazine and hydroxylamine and their inorganic salts 2825.20 2825.30 2825.40 2825.50 2825.60 2825.70 2825.80 2825.90 - Lithium oxide and hydsoxide - Vanadium oxides and hydroxides - Nickel oxides and hydroxides - Copper oxides and hydroxides - Germanium oxides and zirconium dioxide - Molybdenum oxides and hydroxides - Antimony oxides - Other This heading covers : (A) Hydrazine and hydroxylamine and their inorganic salts. (B) The metal oxides, hydroxides and peroxides of this Chapter not included in preceding headings. The most important products are : (1) Hydrazine and its inorganic salts. Hydrazine (NH2.NH2),a basic product prepared by the oxidation of ammonia with sodium hypochlorite. Also exists as the hydrate (NH2.NH2.H20). Colourless, lachrymatory liquid which fumes in the air. A powerful reducing agent, used in the manufacture of a priming explosive or in chemical synthesis. Inorganic salts of hydrazine, obtained by reaction with mineral acids, are also classified here. The most important is hydrazine sul hate, colourless crystals which are slightly soluble in cold water and decompose vio entl when heated; this sulphate is used as a reagent in analysis, and in metallurgy go separate polonium fiom tellurium). P Organic derivatives of hydrazine are excluded (heading 29.28). (2) Hydroxylamine and its inorganic salts. is a basic product obtained by hydrolysis of Hydrox lamine (NH20 nitromet iane; colourless, eliquescent crystals, very soluble in water, melting at 33 "C,decomposing violently at 130 OC. ? Inorganic salts of hydroylamine, obtained by reaction with mineral acids, also fall in this heading. The most lrnportant are hydroxyarnmoniurn chloride, sulphates and nitrate, white or colourless crystals soluble in water. They are used as reducing agents in organic synthesis, as anti-oxidants for fatty acids, in the bleaching, dyeing or printing of textiles, and as reagents, etc. Organic derivatives of hydroxylamine are excluded (heading 29.28). (3) (4) z Lithium oxide and hydroxide. The oxide (LizO) and its h droxide (LiOH) are obtained fiom lithium nitrate. They are white owders, solu le in water, used in photography and for the preparation of lithium sa ts. Vanadium oxides and hydroxides. The most important vanadium oxide is divanadium pentaoxide (vanadium anhydride) (V205),obtained from the natural vanadates, vanadinite (heahng 26.15) and carnotite (heading 26.12). It may be either amorphous or crystalline, in lumps or in powder. Colour ranges fiom yellow to reddish-brown; it turns red when exposed to heat and is almost insoluble in water. Used for pr arin vanadium salts, certain inks, and as a catalyst (manufacture of sulphuric acz, phtialic anhydride or synthetic ethanol). There are several hydroxides, constituting acids, fiom which the various vanadates of heading 28.41 are derived. (5) Nickel oxides and hydroxides. (a) Nickelous oxide (NiO) is obtained b thoroughly calcining the nitrate or the carbonate. A greenish-grey powder, t e density and shade of which vary with the method of preparation. It is used in the enamel industry, in the glass industry as colouring matter and in organic synthesis as a catalyst. It is a basic oxide. g (b) Nickelic oxide (sesquioxide) (Niz03). A black powder used as colouring matter in the enamel industry and for the manufacture of alkaline accumulator grid plates. Lq (c) Nickelous hydroxide (Ni 0 2). A fine een powder used in electroplating, as a constituent of plates in a line accumu ators and in the manufacture of nickel catalysts. ?= The heading excludes : (a) Natural nickeI oxide (bunsenite) (heading 25.30). (b) Im ure nickel oxides, e-g., nickel oxide sinters, nickel oxide in granular form (" green niciel oxide '7 (heading 75.01). (6) Copper oxides and hydroxides. (a) Cuprous oxide red cop er oxide) (CuzO). Obtained from copper acetate or sul hate; a crysta line re powder, insoluble in water. Used for colouring glass re (glass for signals), manufacturing antifouling paints or synthetic precious stones (artificial emeralds), and as a fungicide in agriculture. B B (b) Cu ric oxide (black copper oxide) (CuO). Prepared car onate or by oxidising the metal. Black powder or sheen, insoluble in water. Pigment used in the enamel, ceramic industries and in the reparation of paints. AIso electric batteries and as an oxi$sing agent or catalyst in organic chemistry. % (c) Cop er hydroxides. The most common of these is cupric hydroxide (Cu OH)a). Blue solid which, alone or mixed, constitutes a pigment (Bremen blue . It is also used in the manufacture of pigments e.g., Peligot blue, permanent in artificial light) and of the ammoniaci solution known as " Schweitzer's reagent ", a solvent in the cupramrnonium process of rayon manufacture. f Natural cu rous oxide (cuprite) and natural cupric oxide (tenorite) are excluded (herding 2&03). (7) Germanium oxides. The most important germanium oxide is the dioxide (GeOz) obtained in the metallurgy of the metal fiom natural copper germqo-sulphide ermanite (heading 26.17), or by hydrolysing the chloride. It is a white powder, i?igbtly so uble in water. It is used for pre aring germanium metal (for transistors, etc.), in medicine and in the manufacture o special glass. (8) P Molybdenum oxides and hydroxides. The most irn ortant molybdenum oxide is the trioxide (Moo3), obtained from the natural suphide, rnolybdenite (heading 26.13). It is a white crystalline product which turns ellow on heating; practically insoluble in water. Used as a catalyst in organic syn esis (manufacture of phthalic anhydride). f X There are also blue oxides which are still used as such or in mixture (in the latter case, they fall in Chapter 32) by artists, under the names of molybdenum blue and mineral indigo. Hydroxides include molybdic acid (H2Mo04),a white or yellowish powder, slightly soluble in water, used in the ceramic industry (glazes) or as a catalyst. The molybdates of heading 28.41 are derived from these hydrox~des. Natural molybdenum oxide (molybdenum ochre, molybdite) is excluded (heading 25.30). (9) Antimony oxides. (a) Trioxide or antimonous anhydride (Sb203).Obtained by oxidising the metal or fiom the natural sulphide (stibnite). Whitepowder or needle-shaped c stals; ractically insoluble in water. The term " anhmony white " is used in re erence goth to the ure oxide of this heading, and to a mixture of that oxide with zinc oxide, whic is classified in Chapter 32. Antimony trioxide is used in paints, as an opacifier in the enamel industry (enamelling of iron) and pottery industry azes), in the manufacture of glass with a low coefficient of expansion (lamp g ass), and for producing synthetic precious or semi-precious stones (artificial rubies, topazes, garnets). It gives the antimonites of heading 28.41. ?' R (Y1 (b) Pentaoxide or antimonic anh dride (Sb2O5).Obtained by oxidising the metal or calcining the nitrate. A ye low powder, also used as an opacifier in the enamel industry. Gives the antimonates of heading 28.41. (c) Tetraoxide (Sb204).White powder obtained by heating the pentaoxide. The heading excludes ores, i.e., natural antimony trioxides (senarrnontite and valentinite) and natural tetraoxide (cervantite) (heading 26.17). (10) Beryllium oxide and hydroxide. (a) Oxide (BeO). Prepared from beryllium nitrate or sulphate. White powder, insoluble in water; can be crystallised. Used for making beryllium salts, synthetic precious or semi-precious stones and as a catalyst. (b) Hydroxide (Be(OH)2).White powder resembling alumina in appearance. (1 1) Calcium oxide, hydroxide and peroxide. This heading covers only the oxide (CaO) and the h droxide (Ca(OH)$, in the pure state (i.e., containin practically no clay, iron oxi e, manganese oxide, etc.), such as the product o tained by calcining precipitated calcium carbonate. dY % The heading also covers fused lime obtained by fusing ordinary quicklime in an electric furnace. This product has a high degree of purity (ap roximately 98 % calcium oxide); it is c stdline and generally colourless. It 1s usex in articular, for refractory linings for x maces, in the manufacture of crucibles and or addition to concrete, in small pieces, to increase its resistance to wear. P Calcium peroxide (CaOz) is a white or yellowish powder, hydrated (usually with 8 HzO), sparingly soluble in water. Used as a bactericide and as a detergent, in medicine and in the preparation of cosmetics. Quicklime calcium oxide) and slaked lime (caIcium hydroxide) are excluded (heading 25. 2). (12) Manganese hydroxides. (a) Manganous hydroxide (Mn(OH)2).A whitish powder, insoluble in water. (b) Manganic hydroxide (Mn(OH)3). Derived fiom manganic oxyde (Mn203).A brown powder used for preparing colours (manganese brown) and manganese linoleate. (c) Manganese saline hydroxide. Derived from the saline oxyde Mn304. The heading excludes natural hydrated manganese oxide (natural rnanganic hydroxide) which is an ore of heading 26.02 and non-hydrated manganese oxides (13) Zirconium dioxide (zirconia) (ZrOz),not to be confused with zircon (heading 26.15 or 71.03), which is a crystallised natural zirconium silicate. The artificial oxide is obtained from the above-mentioned ore or fiom zirconium salts. It is a refractory whitish powder with a melting point of about 2,600 O C . Zirconia is used as a refractory product resistant to the action of chemical agents, a pigment and ceramic opacifier (zirconium white), a . abrasive, a constituent of glass and a catalyst. Natural zirconium oxide or baddeleyite is an ore of heading 26.15. (14) Cadmium oxide and hydroxide. (a) Oxide (CdO). Powder of a more or less brownish-yellow colour according to the calcination temperature durin the pre aration from the carbonate or the hydroxide. Used in the ceramic in ustry an as a catalyst. d a (b) Hydroxide (Cd(OH)2).White powder. (15) Tin oxides and hydroxides. (a) Stannous oxide (brown oxide) (SnO). Insoluble in water. It may be grey or black crystals, or olive-brown powder with bluish, reddish or greenish glints, according to the process of preparation. This oxide is amphoteric and gives the stannites of heading 28.41. It is used in organic synthesis as a reducing agent or catalyst. also insoluble in water, is a white oxide is used in the powder, white (tin white) or grey (tin ceramic or glass industries as an opacifier, whereas the gre powder is used for polishing metal, mirrors, etc., and also for obtaining vitnfia le compounds. This oxide is sometimes known as "putty owder", but this term also covers mixtures of this oxide with lead oxide, w 'ch fall in heading 38.24. @) Stannic oxide (stannic anhydride, K g, Stannic oxide is amphoteric and gives the stannates of heading 28.41. a (c) Stannic acid or stannic hydroxide (Sn OH)4). Obtained by the action of an alkali hydroxide on a stannic salt. white powder which turns into meta-stannic acid. (d) Meta-stannic acid. Obtained from stannic acid; a powder, insoluble in water. Used as an opacifylng colour in ceramics and an abrasive in the glass industry. These stannic acids give the stannates of heading 28.41. This heading does not include : (a) Natural tin oxide (cassiterite), an ore (heading 26.09). (b) Tin dross, a mixture of tin oxide and tin obtained during the melting of the metal (heading 26.20). (16) Tungsten oxides and hydroxides. The most im ortant tungsten oxide is tungstic oxide (tungstic anhydride, tungsten trioxide) obtained in the metallurgy of this metal by treating the natural tungstates (wolfiamite or scheelite) (heading 26.1 1). It is a lemon-yellow, crystalline roduct which turns orange on heating and is insoluble in water. Used for preparing tl? e tungsten for electric bulb filaments and in ceramic paints. (wB~), There are several hydroxides, including tungstic acid (H2W04)(yellow hydrate), which gives the normal tungstates of heading 28.41. Natural tungsten oxide (tungsten ochre, tungstite) is excluded (heading 25.30). (17) Bismuth oxides and hydroxides. (a) Dibismuth trioxide (Bi203).Prepared fiom bismuth nitrate or carbonate. Pale yellow powder, insoluble in water and turning red when heated. Used in the glass or ceramic industries. (b) Dibismuth pentaoxide (red oxide) (Bi205).Brownish-red powder. (c) Bismuth hydroxide (Bi(OHJ3). Natural bismuth ochre, which mainly consists of the trioxides, is excluded (heading 26.17). This heading does not include mercury oxides (heading 28.52). Sub-chapter V SALTS AND PEROXYSALTS, OF INORGANIC ACIDS AND METALS GENERAL Metal salts are obtained by replacing the hydro en element in an acid by a metal or by the ammonium ion (NH4'). In the liquid state or in so ution, they are electrolytes giving a metal (or a metal ion) at the cathode. S In neutral salts all the hydro en atoms are replaced by the metal, but acid salts still contain art of the hydrogen replaceable y metal; basic salts contain a greater uantity of basic oxide t is necessary to neutralise the acid (e.g., basic sulphate of cadmium ( dS04.CdO)). % L Sub-chapter V covers metal salts of the acids classified in sub-chapter I1 (acids derived from non-metals) or in sub-chapter IV (acid-function metal hydroxides). Double or complex salts. Certain double or complex salts are specifically referred to in headin s 28.26 to 28.41; for exam le, fluorosilicates, fluoroborates and other corn lex fluorine salts beadin 28.26), alums (hea$ng 28.33 , corn lex cyanides (heading 28.37). 1 s regards double or cornp ex salts not so specified, see e Exp anatory Note to heading 28.42. d f This sub-chapter excludes, infer alia : (a) Salts of Chapter 25 (e.g., sodium chloride). @) Salts constituting ores or other products of Chapter 26. (c) Compounds of precious metals (heading 28.43), of radioactive elements (headin 28-44), of rareearth metals, of yttrium or of scandium or of mixtures of these metals (heading 28. 6), or of mercury (heading 28.52). B (d) Phosphides, carbides, hydrides, nitrides, azides, silicides and borides (headings 28.48 to 28.50) and ferrophosphorus (Section XV). (e) Salts of Chapter 31. ents, colours, opacifiers, enamels and other preparations included in Chapter 32. This suKhapter covers unmixed metal salts (exce t luminophores), suitable for direct use as pigments; when m e d either to ether or with other pro&cts to form pigments, such salts fall in Chapter 32. Lumiwphoreg mke& not, fall in heading 32.06. (f) Pi (g) Disinfectants, insecticides, fungicides, weed killers, etc., of heading 38.08. (h) Fluxes and other auxiliary preparations for soldering, etc. (heading 38.10). (ij) Cultured c stals (other than optical elements) wei hing not less than 2.5 g each, of the halides of the alkali or agaline-earth metals (heading 38.24); w%en they are in the form of optical elements they are classified in heading 90.01. (k) Precious or semi-precious stones, natural or synthetic (headings 71.02 to 71.05). -