512 



METALLURGY. (PROCESSES.) 



lead than any of the other alloys experimented 

 with wears 13-50 per cent, slower. 



Deoxidized bronze an alloy resembling phos- 

 phor-bronze somewhat in composition, and also 

 delta metal, in that it contains zinc and iron- 

 is found to have a tensile strength of 150.000 

 pounds per square inch against 70,000 pounds 

 in copper wire, and its sheets a tensile strength 

 of from 30,000 to 50.000 pounds per square inch. 



The action of silicon on copper in silicon-bron/e 

 is similar to that of phosphorus, as a deoxidizer ; 

 while the silica formed is a valuable flux for 

 any metallic oxides remaining unreduced. Wire 

 made from this alloy is said to have the same re- 

 sistance to rupture as phosphor-bronze wire, 

 with a higher degree of electric conductivity, 

 and, though very much lighter than ordinary 

 wires, is of equal strength. The manufacture of 

 silicon-bronze has greatly improved since its in- 

 troduction. The latest kinds, with perhaps less 

 conductivity, have a greater strength, which 

 gives it particular efficiency when subjected to 

 strains caused by accumulations of snow and ice. 



It is claimed for the new alloy of copper, 

 nickel, and manganese, called manganine, that 

 its specific resistance is higher than that of nick- 

 el ine, which has hitherto passed as the least re- 

 sisting metal. Its resistance being affected in 

 only a minute degree by high temperatures, it is 

 adapted for the manufacture of measuring in- 

 struments and electrical apparatus in general, 

 for which as little resistance as possible under 

 different degrees of heat is required. Moreover, 

 while the resistance of other metals is increased 

 by raising the temperature, that of manganine 

 is diminished, 



A new alloy of gold and aluminum, containing 

 78 per cent, of gold, has been discovered by 

 Prof. Roberts-Austen. It is described as the 

 most brilliantly colored alloy yet known. It is 

 bright purple, and by the reflection of light from 

 one surface to another bright ruby tints are ob- 

 tained. Of other alloys of gold and aluminum, 

 1 per cent, of aluminum gives the precious metal 

 a green color, and the very hard and white alloy 

 contains 10 per cent, of gold. 



The following alloys have recently been in- 

 vented: Nickel-aluminum, composed of 20 parts 

 nickel and 8 parts aluminum, used for decora- 

 tive threads; zinc-nickel, composed of 90 parts 

 zinc and 10 parts nickel, used as a pigment ; 

 nickel -hard lead, composed of 100 parts type 

 metal and 5 parts nickel, used for metallic types 

 and for electros; platinide, composed of 00 parts 

 platinum, 35 parts nickel, 2 parts gold, and 3 

 parts iron, used for crucibles and chemical uten- 

 sils ; roseine, composed of 40 parts nickel, 10 

 parts silver, 30 parts aluminum, and 20 parts 

 tin, for jewelers' work; sunbronze, composed of 

 60 parts cobalt, or 40 parts cobalt, 10 parts alu- 

 minum, 40 parts copper, or 30 parts copper ; met- 

 alline, composed of 35 parts cobalt, 25 parts 

 aluminum, 10 parts iron, and 30 parts copper. 



Processes. The Thies process of treating low- 

 grade auriferous sulphides is, in brief, according 

 to the inventor's account, the treatment of dead- 

 roasted auriferous concentrates (pyrite, some- 

 times also chalcopyrite, ag at the Phoenix mine, 

 Cabarrus Co., N. C.),with nascent chlorine, with- 

 out artificial pressure or exhaust, in lead-lined 

 iron cylinders ; the throwing of the mass on a 



sand filter, and the quick filtration and precipi- 

 tation of the gold chloride with fresh and active 

 ferrous sulphate. The gold is precipitated as 

 metallic gold of a reddish-brown color, which, 

 after being allowed to settle, is collected, washed, 

 dried, and melted with soda and borax in graphite 

 pots and cast into bars. The efficiency and econ- 

 omy of the process are such that, in working on 

 a large scale crude ore of the assay value of $4 

 per ton, carrying about one third of its gold free 

 and two thirds in sulphurets, can be profitably 

 treated. 



The method of working the Bernados electric 

 welding process has hitherto been kept secret, 

 but has recently been published. An ordinary 

 lighting low-tension continuous-current dynamo 

 is used, to the terminus of which a battery of ac- 

 cumulators is connected, and into this the cur- 

 rent flows continuously. When the welding cir- 

 cuit is closed the current flows from the dynamo 

 and accumulates through a largo regulating re- 

 sistance. One terminal of the system is con- 

 nected by means of a flexible cable to a carbon 

 pencil fixed in an insulated holder. This is held 

 by the workman. The other terminal is con- 

 nected to the table on which the work lies, or to 

 the work itself. Thus the carbon pencil forms 

 one pole and the work the other pole, and the 

 electric arc is sprung between them. It is pos- 

 sible to obtain an arc for welding purposes six 

 inches in length and having a sectional area of 

 about two square inches. When iron or steel is 

 under treatment, it is usual to make the car- 

 bon the negative pole and the iron or steel the 

 positive pole ; for other metals the poles are 

 sometimes reversed. 



The burning of zinc during melting may be 

 prevented by covering the metal while in a 

 crucible or ladle with a layer of common salt. 

 Combustibility is impaired if a layer of char- 

 coal is kept on top of the zinc, or of any other 

 soft metal which can be melted in a ladle. The 

 coating of oxide forms a protection against oxi- 

 dation only to a certain degree, but the layer of 

 charcoal tends to reduce the oxide again to its me- 

 tallic form. Indeed, it is possible to recover lead, 

 tin, zinc, and antimony from the dross or oxide 

 which gathers in the ladle. It is only necessary to 

 melt the oxide with charcoal, salt, and soda to get 

 it again into useful shape. The dross, salt, char- 

 coal, and soda should be powdered, mixed, and 

 melted. The soda and salt melt into a pasty 

 mass, and the carbon unites with the oxygen of 

 the dross, leaving the metal free. The salt and 

 soda simply act as flux in reducing the oxides. 



A method of recovering acid from waste 

 pickle has long been sought, without any satis- 

 factory result having been obtained. A process 

 devised by Mr. Thomas Turner appears to secure 

 this object in a simple and economical manner. 

 The plant consists of three parts, viz., a special 

 combined roasting and evaporating furnace, 

 adapted for carrying on continuous double dis- 

 tillation ; a series of cooling and condensing 

 pipes ; and a condenser for collecting acid that 

 would otherwise be lost. The waste liquor is 

 allowed to run in a continuous stream into the 

 furnace, and is there decomposed by the com- 

 bined action of heat, air, and steam from the 

 liquor itself into hydrochloric acid and oxide of 

 iron. The latter remains in the furnace and is 



