Page:The New International Encyclopædia 1st ed. v. 20.djvu/917

* ZINC. 779 ZINGEBLE. the dry method is given the preference wlienever the ores or furnace products are suf- ficiently rich in zinc. In spite of its great de- lieicncies. no success has attended attempts to replace the dry process by either of the others. The comliined wet and drj' method has been tried experimentally on jioor ores, but has hitherto failed on account of a number of defects and of its expense. It has only been employed in cases in which the object was not the extraction of jiictallic zinc, but the separation of zine from other metals or metallic compounds as a by- jjroduct in the form of commercial compoiinds such as sulphate, chloride, basic carbonate, or oxiile of zinc. Good authorities, however, think it not impossible that it may find em]iloyment in zinc extraction proper as an auxiliary to the dry method for the prepa- ration of compounds rich in zinc from ores or jiroducts poor in that metal. The electro- metalluriiical method has, up to the present, lieen used only on an experimental scale and with varying results upon zinc proper, containing no other valuable metal except zine. It can be used with advantage for alloys which form anodes soluble in the electric circuit. Finally, it remains to be noted that the zinc obtained by either the dry process or the combined wet and dry process^ is in most cases contaminated by impurities and has to be subjected to a refining process previous to use. From the preceding general discussion it will be evident that the dry process of zinc reduction is the only one which is much used in the pro- duction of this useful metal, and is. therefore, the only one which needs particular mention. Briefly summarized, this process consists of two separate operations: (1) the preparation of the ores for the process of reduction by calcination or roasting; (2) the reduction process proper, or the extraction of the zinc from the calcined ores. The preliminary operation comprises first the crusliing of the ore, and, second, its burning or calcining in open heaps or in furnaces to change it into oxidized form. The reduction of the zinc from the calcined ores is pcrfornu'd by heating the latter with carbon to a white heat in fire-clay vessels. Zinc is then separated in the form of vapor and is collected in clay vessels as receiv- ers or adaptors. Two forms of reduction fur- naces are now used which are known as the Bel- gian and the Silesian. The Belgian furnace con- sists of from 00 to SO small fire-clay retorts, each about 3 feet G inches long, by 8 inches in diameter, and set in a series of rectangular com- ])artments, filling up an arched chamber. There is a cla_v nozzle or condenser attached to the front of each retort, and on the end of this nozzle there is a sheet-iron receiver for the con- ^dcnsed zinc, with a pit to collect the residue from the retorts. These are charged with ground and roasted ore. mixed with small coal free from sulphur. As the upper retorts receive less heat than the lower, they are not so heavily charged, and they are, moreover, supplied with less pure ores. At the end of every si.x hours the receivers are emptied of their melted zinc. In the Silesian furnace, fire-clay retorts, al>ont 4 feet long by 1 foot inches in diameter, are arranged in two rows, back to back, and ])laccd horizontally on a flat furnace bed, with a fire- jdace on a lower level running along between Vol. XX. —50. the backs of the retorts. A condensing appa- ratus conies away with a curve from the upper part of the front of each retort, and descends some two feet below it. From this, the zinc, on condensing, drops on the ground, or into a tray placed to receive it. Zinc is applied with great success to the coat- ing of sheet iron for roofing and other purposes, and also for coating various kinds of iron wire, especially telegraph wire. See Galvanized Ikon. ZINC ETHYL. See Oegano-Metallic C'om- rouNus. ZINCITE. A mineral zine oxide crystallized in the hexagonal system. It has a sub-adaman- tine lustre, and is deep red in color. It occurs with other zinc minerals, esjiecially franklinite and willemite, at the various mines in Sussex County. N. J. .Artificial cr.vstals of zincite have lieen found as furnace products in Silesia, and also at the zine furnaces at Newark, N. J., and Bethlehem, Pa. It is a valuable ore of zinc wlien found in sufficient quantity, and is com- monly known as red oxide of zinc. Zincite, when found with willemite and franklinite, has some- times been made into paper weights and similar objects. It does not, however, take a high polish. ZIN'DER, or Sinder. A town of French Sudan, situated near the northern boundary of Nigeria, about 350 miles west of Lake Chad. It is an important trading station on the route across the Sahara from Tunis through Air, and was occupied in 1800 by the French, who estab- lished a military post outside the town walls. Population, about 10,000. ZINGAKELLI, zi'n'ga-rel'le, NicoLO At^tonio (17.52-1837). An Italian composer, born in Na]des, where he studied at the Loreto Conser- vatory. In 178.5 his opera Alsinda was produced with success, and in 1702 he was appointed maestro at the Milan Cathedral. He was maes- tro of Saint Peter's. Rome, from 1804 until 1811, Avhen, because of his refusal to permit a Te Deum to be sung in eommemoration of the birth of Napoleon's son, he was arrested and taken to Paris. Napoleon received him very graciously, commissioned him to write a mass for the Imperial chapel, and permitted him to return to Italy. During his absence Fioravanti had been appointed his successor at Saint Peter's, and consequently he went to Naples, where in 1813 he became director of the Royal College of iMusic, and three years afterwards succeeded Paesiello as maestro at the Cathedral. He M'as a ])rolific composer and wrote not less than 30 operas, besides 38 masses, and innumerable smaller sacred and secular compositions. ZINGEBLE, tslng'er-le, Ignaz Vixzenz (lS2;5-02). An Austrian poet and philologist, lie was liorn at ^leran and was educated at Trent and Innsbruck, and at the Seminary of Brixen. In 1848 he was appointed a teacher in the Inns- liruck G,vmnasium, and in 1850 professor of the German language and literature in the university. He published many works bearing on the history and literature of Tyrol, of which the more im- ]>ortant are: Sagcii oiis Tirol (1850; 2d ed. 1891); Tirol. Xatur, Geschichte und Sage im Sj>i<!icl dcittscher Dichliing (1852) ; Kinder- und Uinismiirchen (1852-54); f^itten, Briiticlie rind Meinungen des Tiroler Volkes (1859) ; and also