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17 THE CIVIL ENGINEER AND ARCHITECT’S JOURNAL. THE NEW MODE OF PRODUCING WROUGHT OR MAL LEABLE IRON DIRECT FROM THE ORE. Patented by Mr. William N. Clay. Fig. 1.—LONGITUDINAL SECTION OF BALLING AND PILING FURNACE, WITH RETORTS. The retorts are covered with a layer of sand. Fig. 2.—PLAN. Furnace, Retorts, Chimney. 0 5 10 15 20feet. Fig. 3 TRANSVERSE SECTION OF RETORTS AND 1HORIZONTAL FLUES. The 0 are small apertures to allow a portion of the flame to pass over the top of the retorts. The retorts may be in creased or diminished, as the waste heat is greater or less. REMARKS BY THE PATENTEE. Iron is popularly divided into two descriptions, cast and wrought. Cast, or pig iron, is principally a combination of the metal with carbon, which it absorbs from the coke or charcoal of the blast fur nace. Wrought iron has been hitherto produced by freeing cast iron from the carbon, &c., with which it is combined: the nearer it ap proaches to a state of purity, the better wrought or malleable iron will it be. The richer ores of iron contain the metal combined with oxygen; if that oxygen were separated, the metal would be in its malleable state as wrought iron. And yet, the advance of science has left this great branch of our national prosperity so far behind, as to suffer the manufacturer still to continue the practice of impregnating the iron with carbon in the first instance, which carbon must afterwards be separated, by tedious and expensive processes, to produce wrought iron of good quality. But there are other evils in the common mode. It is necessary for the manufacturer to have a sort of glass floating on the molten iron at the bottom of his furnace, to prevent the oxydation of the recently produced metal by the blast. This glass is formed from the earths with which the ores of iron are mixed, and limestone to flux those earths: so that, ores of a very superior quality cannot be used by themselves, but only in part, to enrich such poor ores as have more earths combined with them than are necessary for their own fusion. Thus it is, that the Hematites, and other rich ores, found abundantly in Lancashire, Cumberland, Cornwall, &e., reach no higher a marketable value at the place of their production than the common earthy ores of the coal districts, although they contain twice as much iron, and that iron of a very superior quality. Again, English iron is, from its mode'of reduction, almost certain to be injured to a greater or less extent by combination with sulphur; the earthy ores, which form nine-tenths of those generally used, are impregnated with that deleterious mineral to a great extent; the coals from which the coke is formed are likewise more or less sul phurous; and this gives the high estimation and value to charcoal iron, or such as has been reduced in the several processes by the agency of wood instead of coal. It is the object of the patent taken out by Mr. William Clay, to produce wrought iron of best quality, direct from the rich ores No. 1.—January, 1839.—Vol. II. hitherto so little used from the causes beforenamed, by a process simple, rapid, and economical. To make wrought non of such quality, for instance, as chain cables are made from, five several operations are necessary, besides the preliminary one of making the coke for the blast furnace, namely— 1. Roasting the ore. 2. Smelting in the blast furnace.* 3. Refining. 4. Puddling, balling, hammering, and rolling. 5. Cutting up, piling, and rolling. All these processes requiring a separate application of heat. It is stated in the article on iron, the 106th number of the “ Library of Useful Knowledge,” a work written with great clearness, and an intimate knowledge of the subject, that 8 tons 17cwt. 3qrs. 31bs. of coals are required for the production of one ton of finished bar iron; doubtless, the introduction of the hot blast has reduced the consump tion of fuel in the smelting operation considerably, and the adoption of anthracite coal may decrease it still further, it seems, however, yet doubtful, whether the best bar iron can be produced from “ hot blast pigat all events, very small proportions of that description are as yet used in the fabrication of iron of superior quality. On the patent plan, the operations are reduced to three; namely— 1. Reducing, or preparing the ore in retorts, or other close vessels. 2. Balling, hammering, and rolling. 3. Cutting, piling, and rolling. The first of these processes is accomplished by the otherwise waste heat of the two latter, so that only two separate applications of heat are required; and the second operation on this plan com mences with the iron in as forward a state as the fourth of the old mode, whereby the cost of fuel and labour, and the enormous outlay of capital in land, blast furnaces, and machinery required to bring iron on the old mode to the third, stage, are all avoided. It is now necessary to state how this is to be accomplished. Referring to the plan, it will be seen that between a r verberatory furnace of the common construction employed in “puddling,” “ball ing,” or “piling” iron, and the chimney, a range of retorts are placed, which are heated on their exterior by the otherwise waste heat of the furnace.t Into these retorts are thrown 100 parts of Ulverstone, or other rich ore, and 20 parts of coke dust, ground charcoal, anthracite, or other carbonaceous matter, well mixed together. The retort is clo-ed, and the vapours generated escape as gas. In the course *t>f from thirty to forty-eight hours, as the heat is greater or less, the carbon will carry off the oxygen, and leave the iron in a metallic state. It has then to be taken to the balling furnace, where it welds up, like scrap iron, and in fifteen minutes is ready for the hammer; thence it undergoes the customary process of rolling. It is then cut up, piled, and rolled, and the operation terminates with the production of bar iron of superior and extraordinary quality. The fourth operation of the old process, “ puddling,” takes from one and a half to two hours to perform: the second operation of the pa tent, only fifteen minutes ; consequently, the consumption of fuel will be much less than if refined iron were used. It would be idle to compare the simplicity and economy of the first stage of the patent process, with the cost of the three stages required to make the iron stone into refined iron on the old mode, when we find by referring to page 28 of the work alluded to, that of the 8.889 tons of coal consumed in the whole process, 6.989 tons are used up to the refining, so that the 1.9 tons required for the subsequent operations, may be calculated on as more than sufficient for the patent plan—to which nny be added (if the furnaces themselves do not supply sufficient cinders), the one-fifth part of the weight of the ore used, to mix therewith, as carbonaceous matter. An objection may be made by an iron master that the mode is not wholesale enough—that the retorts contain only hundred weights, while his mighty tower furnaces hold tons. If the question were the production of pig, or cast iron, there might be some weight in this; but the superiority of the patent mode refers more particularly to the production of wrought iron ; and here, the largest maker in the king dom must await the laborious and tedious operation of the puddlcr— him he can only supply with a few hundred pounds of iron every two hours; so that, the retorts have only to furnish the same quantity, to keep up with the puddling furnace of the present system ; if necessary, it might be shown that a balling furnace, on this plan, will produce considerably more than a puddling furnace on the old one. * In this operation, the expenses of limestone and breaking it have also to be incurred. + To show what this waste heat is, it is only necessary to state, that the chimneys of these furnaces in % the iron districts are compelled to fee lined with fire-bricks to the top. &