Postby dognose » Sun Aug 01, 2021 1:27 pm
A NEW ALLOY
Birmingham
There has recently been patented in most of the leading countries of the world an invention which, it is alleged, will revolutionize the metal trades. For the last twenty years aluminium has been recognized as the most valuable metal for forming workable alloys, as it readily combines with zinc, tin, copper, and lead, and the varieties of alloys thus obtained are almost innumerable, any degree of hardness or ductility combined with sonorousness and tenacity being possible. Hitherto, however, the metal has been found so difficult of extraction and the process so costly, that it has only been possible to use it in its alloys for the manufacture of jewelry and very small articles, so that it has been comparatively of little commercial importance. The Aluminium Crown Metal Works Company, at Hollywood, near Birmingham, now claim to have invented and perfected a process by which, taking alum as the source, they can produce any quantity of pure alumina, which is afterwards converted into chloride of alumina, from which in turn the metal is extracted by the ordinary process of fusion with sodium. By this process the two impurities of aluminium — iron and silica — are got rid of. The author and patentee of this valuable invention is Mr. James Webster, the founder and principal of the Aluminium Company. The works having been erected within the last five years, the plant is of the most recent date, comprising all the most modern improvements in calcining furnaces and retorts, sheet-rolling and wire-drawing mills, together with the requisite casting, fitting, and other shops. On retiring from business as a metal manufacturer some years ago, Mr. Webster took up his residence at Hollywood, and while nominally engaged in farming pursuits carried on the experiments, which he had commenced as far back as 1851, for the invention of a more expeditious and inexpensive mode of producing aluminium. His experiments were conducted with great secrecy, none but his most intimate friends being admitted to his laboratory. Mr. Webster designed all the different buildings, appliances, and apparatus necessary for carrying on the experiments, upon which he has expended upwards of £30,000, besides £2,000 or £3,000 in procuring patent rights at home and abroad. A French syndicate have just offered over a quarter of a million sterling for the patent for France alone, while companies in the United States are proposing even larger sums to acquire the right of manufacture in the States. Scarcely less eagerness is displayed by the Belgians and Germans to purchase the rights for their respective countries, but the arrangements are not yet completed. The invention has only been perfected about eighteen months, and the firm have but recently begun to place the product on the market ; yet such is the demand that, though they are working day and night, they cannot execute one-twentieth part of the orders that are accumulating on their books. By the ordinary method of precipitation 12 tons of alum and 6 tons of carbonate of potash, soda, or ammonia are required to produce 1 ton of alumina, and the whole process occupies nine months ; whereas, in Mr. Webster's plan, no precipitant is used, and a ton can be manufactured in a week with the existing plant at Hollywood. The cost of producing a ton of alumina by the ordinary methods is upwards of £1,000, while it is less than £100 by Mr. Webster's process. Mr. Webster's process for the manufacture of alumina is to take a given quantity of alum and pitch. Which are first finely ground, then mixed together and placed in a calcining furnace, by which means 38 per cent, of water is driven out, leaving the sulphur, potash, and alumina with oxide of iron. The calcined mixture is then put into vertical retorts, and steam and air are forced through, which leaves a residue of potash and alumina only. This residue is afterwards placed in a vat filled with warm water, which is heated with steam. The potash is thus withdrawn, and the alumina left as a deposit in a very condensed state. The potash liquor is then run off, boiled down, while the alumina precipitate is collected in sacks and dried. It is then ready for making chloride of alumina. The alumina deposit thus obtained contains 84 per cent, of pure alumina, while that which is obtained by the old process of precipitation has only 65 per cent. Mr. Jones, the Wolverhampton borough analyst, certifies that the constituents of Messrs. Webster's alumina deposit are as follows : — Alumina, 84.10; sulphate of zinc, 2.68; silica, 7.40; water, 4.20; alkaline salts, 1.62. It should be explained that the sulphate of zinc is simply the accretion from the zinc vessel into which it is drawn. Thus there is not only a saving of nine-tenths in the cost, but a gain of 19 per cent, of alumina over the method of precipitation. In addition, Messrs. Webster recover the whole of the bye-products, consisting of potash, sulphur — which is utilized for making sulphuric acid — and the aluminate of iron. From these bye-products is made a blue dye, which is sold for 6s. per lb., and is used in the place of indigo for dyeing calico and other material. In order to complete the process, and convert it into aluminium, the chloride of alumina is treated with sodium in order to withdraw the metal. Aluminium is afterwards alloyed with copper, silver, and other metals? It is used for the manufacture of bismuth bronze, aluminium bronze, or any other alloys. The former is especially adapted for marine purposes, for ship-fittings, screw-propellers, or anything opposed to corrosion. This bronze can be rolled down to a gauge as fine as tissue paper, suitable for covering champagne bottles or in the various strengths required for drinking and culinary vessels, dish-covers, knives and forks, spoons, razors, or any articles which are now electro-plated. Beautiful specimens of railway-carriage door-handles, equal in appearance to electro-plated silver and gold articles, are produced at the "Crown" Works, and also by Sheffield firms from this metal, and are being supplied to railway companies. There are also samples of aluminium spoons in imitation of gold-plated articles, these having been manufactured by a leading Sheffield house from Messrs. Webster's alloys. Among the other purposes for which the bismuth bronze is suited is that of the manufacture of bells. Perhaps the most important use of the bismuth bronze, however, is its adaptability for ship fittings, screw-propellers, and other purposes where the metal is subject to saline influences. In respect of the patent bronze for submarine use, Messrs. Webster's prospectus states that this metallic alloy, which is the result of many years' experiments, is the most perfect material for the manufacture of steamship propellers. A quantity of this bronze has just been ordered for the Royal Gun Factory at Woolwich for bearings for heavy machinery, and negotiations are going on with the War Office for large consignments of the metal for the manufacture of artillery. Messrs. Webster & Co. claim that their aluminium bronze metal, which is a combination of aluminium with tin, nickel, and copper, possesses greater power of resistance than the best gun-metal, and is very much lighter. Another very important use to which the aluminium bronze is being applied is that of pen-making, one or two firms in London and Birmingham having already commenced the manufacture. These aluminium pens not only have all the flexibility and temper of steel, but are incapable of corrosion and are equal to gold pens. Messrs. Webster's aluminium is adaptable for the manufacture of rings set with precious stones. Samples of wire made from the bronze have been sent to London and Glasgow for telegraph coils, and they are being used for electric telegraph purposes in some parts of the metropolis. Mr. Webster has also succeeded in uniting aluminium with other metals by a welding or soldering process — a feat which has not hitherto been accomplished.
Source: Birmingham Gazette - December 1882
Trev.