AN′TIMONY

(-te-mŭn-e). Syn. Metal′lic antimony *, Reg′ulus of a. †; Antimo′′nium , A. metal′licum , Stib′ium , Metal′lum antimo′′nii †, A. reg′ulus †, ., L.; Antimoine , Fr.; Antimon , Spie glanz , Spie glas , Spie glanzmetall , Ger.; Antimonio , It., Sp. The term formerly applied to the native sulphide or greyish-black semi-crystalline ore of antimony; but now solely appropriated to the pure metal. Sources. Metallic antimony, in combination with silver and iron ( NATIVE ANTIMONY ), with sulphur ( GREY SULPHIDE OF A. ), or with nickel ( NICKEL IF′EROUS SULPHIDE OF A. ) is found in Bohemia, Hungary, Germany, Sweden, France, England, Borneo, and America; and oxidised, combined with oxide of iron, . ( ANTIMO′′NIAL , O′CHRE , RED ANTIMONY , WHITE A. [68] ), forming ores, either small in quantity or of little value, in various parts of the world. Of these the only one in sufficient abundance for smelting is the common sulphide known as ‘grey antimony’ or ‘stibnite.’ [68] White A. occurs in considerable quantities in Borneo, and is used after roasting as a white pigment for iron and other surfaces. IMG:596405606043057898_i178.png: a , b , Grate and fire-place. c , Bridge. d , Air-channel. e , Concave space for ore, resting on a solid bed f , formed of sand and clay. g , Door for introducing the ore, and abstracting residuary slag. h , Pipe to convey away the liquid metal. i , Chimney. Prep. Native antimony is freed from impurities by fusion. The sulphide, after being melted from the gangue, is commonly oxidised by exposure on the concave hearth of a reverberatory furnace, and is then reduced to the metallic state by fusion in crucibles with coal-dust, crude tartar, or some other deoxidising agent. To free the product from iron, it is generally fused, or re-fused, with a little antimonic oxide; and when the ore contains arsenic, iron, or its oxide, and an alkaline carbonate or sulphate, are used in the same way. It is seldom prepared on the small scale. The following formulæ are in use, or are recommended:— 1. On the SMALL SCALE :— a. From tersulphide of antimony, in coarse powder, 2 parts; iron filings, 1 part; fused together in a covered crucible, at a heat gradually raised to dull redne . b. From the teroxide or the oxy chloride of antimony, fused together, as before, with twice its weight of crude tartar. c. (Ph. Castr. Ru. 1840.) Sulphide of antimony, 16 parts; cream of tartar, 6 parts; both in powder; throw the mixture, in small quantities at a time, into a ve el (an earthen crucible) heated to redne ; when the reaction is over (having closely covered the ve el), fuse the ma , and after a quarter of an hour pour it out, and separate the metal from the slag. d. From sulphide of antimony, 8 parts; crude tartar, 6 parts; nitre, 3 parts; as last. e. (Wöhler.) Sulphide of antimony, 10 parts; nitre, 12 parts; dry carbonate of soda, 15 parts; deflagrate together; powder the resulting ma , and wash it thoroughly with boiling water; lastly, smelt the dried residuum with black flux. All the preceding are nearly pure; the impurity, if any, being traces of copper, lead, or iron. f. (Berzelius.) From metallic antimony, in fine powder, 2 parts; teroxide of antimony, 1 part; fused together. The product will be pure provided the antimony employed is free from lead. g. (Muspratt.) From antimony, 9 parts; peroxide of manganese, 1 part; fused together; the resulting metal being re-fused with 1-10th of its weight of carbonate of soda. 2. On the LARGE SCALE —commercial:— a. See above (before 1 a .). b. From sulphide of antimony, 100 parts; iron (in very small scraps), 40 parts; dry crude sulphate of soda, 10 parts; powdered charcoal, 2 1 ⁄ 2 parts; fused together.— Prod. 60 to 65 parts of antimony, besides the scoriæ or ash, which is also valuable. c. (Berthier.) Sulphide of antimony, 100 parts; hammerschlag (rough oxide or iron from the shingling or rolling mills), 60 parts; crude carbonate or sulphate of soda, 45 to 50 parts; charcoal powder, 10 parts; as last.— Prod. 65 to 70 parts. Prop., . Bluish-white, lustrous, with a lamellar texture, and a crystalline or semi-crystalline fracture, with fern-leaf markings on the surface, when pure (star antimony); extremely brittle (may be powdered); imparts brittlene to its alloys (even 1-1000th part added to gold renders it unfit for the purposes of coinage and the arts); melts at 809-810° Fahr., or just under redne ; fumes, boils, and volatilises at a white heat, and, when suddenly exposed to the air, inflames with conversion into the teroxide, which is deposited in beautiful flowers or crystals; when perfectly pure and fused without contact with air or foreign matter, it bears an intense heat without subliming (Thénard); allowed to cool slowly from a state of perfect fusion, it crystallises in octahedrons or dodecahedrons; tarnishes, but does not rust by exposure to air or moisture at common temperatures; hot hydrochloric acid di olves it, with the formation of TRICHLORIDE OF ANTIMONY ; nitric acid, when concentrated, converts it into ANTIMONIC ACID ; and when dilute, into TRIOXIDE OF ANTIMONY . Sp. gr. 6·7 to 6·8. [69] [69] When perfectly pure, 6715—Ure. Tests. Metallic antimony may be recognised by the above properties; its oxide, salts, ., by the following reactions:—1. Sulphuretted hydrogen gives, with acid solutions, an orange-red precipitate, which is sparingly soluble in ammonia, [70] and insoluble in dilute acids; but readily soluble in pure pota a and alkaline sulphides, and in hot hydrochloric acid with the evolution of sulphuretted hydrogen gas:—2. Sulphydrate of ammonium gives an orange-red precipitate, readily soluble in exce of the precipitant, if this latter contains sulphur in exce ; and the liquor containing the re-di olved precipitate gives a yellow or orange-yellow precipitate on the addition of an acid:—3. Ammonia and pota a, and their carbonates, give (except in solutions of tartar emetic) a bulky white precipitate; that with ammonia and its carbonate being insoluble in exce of the precipitant; that with pota a, readily so; whilst that with carbonate of pota ium is only soluble on the application of heat:—4. A rod of zinc throws down metallic antimony, as a black powder, from all its solutions not containing free nitric acid. If the experiment be made with a few drops of a solution of antimony containing a little free hydrochloric acid, and a small platinum dish or capsule be employed, the part covered by the liquid is soon stained brown or blackish, and the stain is irremovable by cold hydrochloric acid, but may be easily removed by warm nitric acid:—5. By ebullition of the acidulated liquid along with copper gauze, foil, or wire, as noticed under ‘Reinsch’s Test.’[71] The peculiar violet-grey of the deposit is characteristic, and may easily be distinguished from that given by arsenical solutions:—6. Mixed with dilute sulphuric acid and poured on some metallic zinc in a gas-generating flask, provided with a small bent tube (see engr. ), it yields ANTIMONETTED HYDROGEN (Marsh’s test), recognised by burning with a bluish-green flame, and furnishing dense white fumes which adhere readily to any cold substance (as a porcelain plate) held over it; or, if the plate be depre ed upon the flame, a deep black, and almost lustrele spot of metallic antimony; the fumes and spots in both cases being insoluble in water, and in dilute solution of chloride (crude hypochlorite) of soda. On heating the centre of the tube to redne with a spirit lamp, the bluish-green colour of the flame le ens in intensity, and a mirror of metallic antimony, of silvery lustre, forms inside the tube at the ignited part. On pa ing dry sulphuretted hydrogen through the tube, still heated by a spirit lamp, this mirror a umes a reddish-yellow colour, approaching black in its thicker parts; and by exposure to a feeble stream of hydrochloric acid gas, almost immediately, or in a few seconds, disappears, being carried off by the gas, which, if pa ed into a little distilled water, yields a solution of chloride of antimony, which may be further submitted to any of the usual tests. [71] If the substance be in the solid state, it must be reduced to powder and di olved in water; or if insoluble in that menstruum, a solution must be obtained by digestion in either hot hydrochloric or nitro hydrochloric acid, before proceeding to examine it by this method. [70] The like precipitate from a solution of antimonic acid in hydrochloric acid, di olves readily in ammonia, particularly when heated. [71] See Arsenious Acid . IMG:596405606043057898_i179.png: a , Flask containing the suspected fluid, dilute sulphuric acid, and zinc. b , Small tube, at the one end having an almost capillary orifice, where the gas is inflamed. c , Spirit-lamp. d , Support. Estim. Antimony is generally WEIGHED under the form of tersulphide; but sometimes as antimonious anhydride, and—though more seldom—as pure metal:— 1. A solution being obtained as above, if nece ary, it is strongly acidulated with tartaric acid, and the antimony thrown down as a sulphide by a stream of sulphuretted hydrogen. After warming the solution and allowing it to cool, the precipitate ( TERSULPHIDE ) is collected on a filter, dried, and weighed. A small portion digested in strong hydrochloric acid will completely di olve if it be the pure sulphide; in which case the quantity of ANTIMONY sought will be equal to 71 1 ⁄ 2 % (71·5%) of the weight of the sulphide found (very nearly). [72] Should only part of the precipitate be soluble, a known weight of it may be introduced into a flask, and a considerable quantity of fuming nitric acid added, drop by drop, and afterwards, a little hydrochloric acid, the mixture being digested, at a gentle heat, until the reaction is complete, and the whole of the sulphur is di olved. The resulting solution diluted with water, strongly acidulated with tartaric acid, and solution of chloride of barium added as long as it disturbs the liquid, yields a precipitate, of which the weight, after it has been thoroughly washed, dried, and gently ignited, multiplied by 136, gives the quantity of SULPHUR in the sample; and which, deducted from the weight of the sulphide first found, gives the quantity of pure ANTIMONY , as before. [72] Tersulphide of antimony dried at 212° Fahr. still retains traces of water, which is not wholly expelled until the heat reaches 390-392°, when it acquires a black colour and a crystalline appearance. 2. The quantity of PURE ANTIMONY in commercial samples may be determined by treating them (in powder) with nitric acid, which oxidises the antimony and leaves it in an insoluble state, whilst it di olves the other metals. The resulting oxide is collected on a filter, washed, dried, ignited in an open porcelain crucible, and weighed—its weight multiplied by ·7898 gives the quantity of pure metal sought. 3. Di olve a known weight of the sample in hydrochloric acid, immerse a blade of pure metallic tin in the solution, and keep the liquor acidulous, and in a state of gentle ebullition by the heat of a sand bath, when the whole of the ANTIMONY will be precipitated under the form of a black powder, and may be collected, washed, dried, and weighed. This is particularly adapted to alloys of antimony and tin. See Tests (above) and Pur. (below). Pur. The antimony of commerce generally contains a little arsenic, with variable quantities of iron, lead, sulphur, and tin. These impurities may be thus detected:— 1. (Arsenic.) By fusing the sample, in powder, mixed with about an equal weight of tartrate or bitartrate of pota ium, in a covered crucible, for 2 or 3 hours, and placing the resulting button, which is an alloy of antimony and pota ium, in a ‘Marsh’s apparatus’ along with a little water, when the disengagement of hydrogen gas will commence, and may be tested in the usual manner. See Arsenic . 2. (Iron.) Di olve the powdered sample in nitro hydrochloric acid, dilute the solution with a large quantity of cold water, filter, and pa a current of sulphuretted hydrogen through the filtrate as long as it produces a precipitate; again filter, boil the filtered liquor for a few minutes to drive off the sulphuretted hydrogen, and then test it with ferrocyanide of pota ium, which will give a blue precipitate if iron be present; or supersaturate the last filtrate with ammonia, and then add hydrosulphydrate of ammonium, when, under like conditions, a black precipitate will be formed. 3. (Lead.) Digest the powdered sample in hot nitric acid, which will di olve out the LEAD but leave the antimony behind. The whitish powdery residuum may be washed, dried, ignited, and weighed, as above; the clear decanted liquor may now be mixed with the first washings, evaporated to dryne , the residuum re-di olved in water, and the solution submitted to reagents (see Lead ). If lead is found to be present, a solution of sulphate of sodium may be added until it ceases to disturb the liquid, and the resulting precipitate (sulphate of lead) washed, dried, and gently ignited (alone) in a porcelain crucible; the weight of the ignited residuum furnishes a number which, multiplied by ·683, gives the weight of the LEAD sought. 4. (Sulphur.) The solution in nitro hydrochloric acid, when tested with either nitrate or chloride of barium, gives a white precipitate of sulphate of barium, insoluble in both water and acids, which when dried, ignited, and weighed, and the weight multiplied by ·136, gives the quantity of SULPHUR as before. In this case, as with the sulphides (see above ), free sulphur maybe removed by digesting and washing the powdered sample in bisulphide of carbon, previous to its solution in the acid, by which the violence of the subsequent reaction will be le ened. 5. (Tin.) Two samples of equal weight are taken; the one is tested for ANTIMONY , as described above; the other is di olved in a mixture of equal parts of hydrochloric and nitro hydrochloric acid, and a blade of zinc immersed in the solution (see above ); the mixed precipitate of tin and antimony which forms is collected on a weighed filter, washed, dried, and weighed. The weight of antimony in the first sample subtracted from that now obtained, leaves a remainder which indicates the quantity of TIN in the original sample. Phys. eff., . Nearly all the salts and preparations of antimony are emetic and cathartic, and in large doses poisonous—occasioning vomiting, profuse alvine dejections, acute colic, and inflammation of the stomach and bowels, often serious, though rarely resulting in death. Tartar emetic and BUTTER OF ANTIMONY are those from which accidents have principally occurred.— Ant., . Copious vomiting, if it has not already occurred, should be promoted, and the recently prepared hydrated sulphide of iron administered in considerable doses, followed or accompanied by mucilaginous drinks and diuretics. If much prostration follows, wine and stimulants may be had recourse to. In the absence of hydrated sulphide of iron, a solution of tannin, or decoction of galls; cinchona, or oak bark, or even powdered cinchona, mixed with tepid water, may be administered. Uses. In the arts , antimony enters into the composition of several useful alloys, as TYPE-METAL , PEWTER , BRITANNIA-METAL , MUSIC-PLATE METAL , . It is added to the alloy for concave mirrors, to give them a finer texture; to bell metal, to render it more sonorous; and to various other metals to increase their hardne and fusibility; for the latter purpose it is employed in the casting of cannon balls. Concluding Remarks. In ‘roasting’ or oxidising the native sulphide of antimony on the bed of the reverberatory furnace, as in the common method before referred to, care must be taken to regulate and gradually raise the heat, which, until towards the end of the proce , need not be extreme, and then only should it approach dull redne . Without this precaution much of the undecomposed sulphide will be lost by volatilisation. During the whole time the ‘charge’ should also be well stirred with an iron spatula, to ensure the constant exposure of every part of it to the atmosphere. The proce is complete when the whole ma a umes a greyish-white appearance. Earthen crucibles are commonly employed for the subsequent reduction, and after being charged and covered over with ground charcoal, are heated in a reverberatory furnace. The product is the crude metallic antimony of commerce. It is generally REFINED by smelting it with about 1-8th of its weight of the refined sulphide, and about 1-4th of its weight of carbonate or sulphate of soda; but if there be much iron present, more of the sulphide—even 1-4th—may be required; for unle there be sufficient sulphur to combine with the whole of the iron, the arsenic will not be oxidised, but remain as a contamination. When cold, the metal is carefully separated from the slag, and is frequently re-fused with a little fresh carbonate of soda (1 to 1 1 ⁄ 2 part); after which it is cast into pigs, lumps, or ingots. The crude metal, thus treated, commonly yields 94% of REFINED METAL of tolerable purity. Should lead have been present in the sulphide or ore, it remains after a second, or even a third fusion, although proportionately reduced in quantity; and it can only be completely separated in the humid way. It is, therefore, always desirable to select an ore free from lead.