360 



METALLURGY. (COPPER ALLOYS PROCESSES.) 



the inventor hopes by slight modifications to 

 make it practicable. Specimens of 99.90 per cent. 

 purity were exhibited at Glasgow by Brunner, 

 Mond & Co., which, according to Mr. Swan, were 

 made electrolytic-ally on lines suggested by the 

 Hoeifner process. 



In a process for extracting zinc from waste 

 products patented by C. Kellner, the waste prod- 

 ucts resulting from roasting pyrites are treated 

 with water and snlfuric acid. The bisulfid of zinc 

 so obtained is oxidized by air into the sulfate, 

 which is then mixed with the chlorid of an alkali 

 or alkali earth preferably sodium or calcium 

 chlorid to convert the sulfate into chlorid of 

 /inc. with the formation of an alkali sulfate; and 

 final! v. the chlorid solution is electrolyzed to ob- 

 tain xinc and chlorin. " whether or not the sul- 

 fate be caused to crystallize out of the electrolyte." 

 The sulfate may be crystallized by electrolyzing 

 the liquor until it is sufficiently concentrated, or 

 !v cooling or evaporating. 



"it appears from a consular report on the pro- 

 duction of zinc in the United States, that while 

 th gain in Europe during the past ten years had 

 been just over 27 per cent., the production in the 

 United States had increased 115 per cent. The 

 increase in the American product since 1880 had 

 been 437 per cent. 



Copper. It is proposed by Victor Pizet and 

 Juan Torrico y Meza, of Lima, to establish in Peru 

 an industry for the reduction of copper mattes 

 into bars of pure copper by the Manhes process, 

 or Bessemerization. The fundamental princi- 

 ples of this method are: (1) The production of 

 pure copper instead of rich mattes that always 

 contain from 30 to, 40 per cent, of foreign sub- 

 stances; (2) the reduction of the consumption of 

 coal to such a point that the cost of the whole 

 process is altogether disproportionate to that of 

 the present production of mattes containing from 

 50 to 70 per cent, of copper. 



The improved process of H. J. Martin for manu- 

 facturing copper, yellow metal, and brass con- 

 sists in utilizing the heat resulting from the opera- 

 tion of refining copper for the purpose of carrying 

 out the rolling in the breaking-down and drawing- 

 out stages, thus doing away entirely with any re- 

 heating in the furnaces usually employed for 

 these operations in the existing mode of manufac- 

 ture. The process is applicable to the manufac- 

 tured alloys, such as yellow metal, normal brass, 

 and the like, which require to be rolled hot. Prac- 

 tical advantages in manipulation are claimed for 

 the process. 



Alloys. In a Cantor lecture before the British 

 Society of Arts on the Microscopic Structure of 

 Alloys, Dr. T. Kirke Rose first dealt with the new 

 method of preparing specimens for examination 

 suggested by Mr. Hannover. This method is de- 

 signed to be used instead of the ordinary polishing 

 materials, in the case of very soft or brittle speci- 

 mens. It consists in pouring the molten alloy 

 on a surface of mica, and allowing it to solidify. 

 The smooth surface thus obtained can be exam- 

 ined and photographed under a magnification of 

 850 diameters. The various structures in alloys 

 observed by the microscope and lantern slides of 

 different purely metallic chemical compounds 

 were shown in connection with the lecture, and 

 the different modes of isolating them and prov- 

 ing their existence were indicated. A case was 

 cited in which a compound in an alloy is of tech- 

 nical value, viz.. in the antifriction alloys used 

 for axle and shaft bearings. In all these alloys a 

 hard constituent exists, which takes the weight 

 of the axle, and the crystals of this hard com- 

 , pound are embedded in a soft matrix which 



molds itself to the shape of the axle. The lec- 

 turer referred to the use of the nickel alloys in 

 boiler-tubes, and other cases in which great 

 strength and toughness are required, together 

 with an almost complete absence of expansion or 

 contraction with changing temperatures. 



While alloys containing equal parts of zinc 

 and aluminum or more zinc than aluminum have 

 no specially valuable mechanical properties, the 

 case, according to J. W. Richards, is different 

 when aluminum prevails over zinc. The alloy 2 

 parts of aluminum to one of zinc, or 33-j per cent, 

 of zinc, has a strength according to Durand equal 

 to that of cast iron. It melts at about 425 C., 

 fills the joints of a mold perfectly, does not oxi- 

 dize readily, and takes a fine finish. It is brittle, 

 but resists corrosion well. A tensile strength 

 of 40,000 pounds per square inch can be obtained. 

 Such a casting resembles a high carbon steel, but 

 works well under tools, and does not require 

 lubrication. Its high specific gravity of 3.8 shows 

 that great contraction has taken place in the 

 formation namely, 17 per cent.- and thus sug- 

 gests a cause for its great strength. The alloy 

 3 parts of aluminum to 1 of zinc that is, about 

 25 per cent, of zinc is the one most generally 

 used. It is softer than the alloy with 33J- per 

 cent, of zinc (above), has a tensile strength of 

 35,000 pounds, and is less brittle. Its specific 

 gravity is 3.4, showing a contraction of 14 per 

 cent. With alloys containing less than 25 per 

 cent, of zinc, the strength and hardness decrease 

 quickly. An alloy -with 10 per cent, of zinc and 

 less can be forged, rolled, and drawn. 



Ferro-silicon is referred to by J. W. Swan, 

 president of the Society of Chemical Industry, as 

 one of the alloys now produced on a commercial 

 scale by the electric furnace. At present the de- 

 mand for it is small, and the manufacture is in 

 excess, but it is hoped that there will be in time 

 large use for it in the manufacture of steel to 

 make available the improvement of quality which 

 silicon imparts to the metal when there is not 

 an excess of carbon, and to take advantage of 

 its thermal energy in steel casting. At Meran, in 

 the Tyrol, where ferro-silicon is made at a cost of 

 8 a ton, the raw materials used in making it are 

 scrap-iron, quartz, and coke. The product contains 

 77.5 per cent, of iron and 21.5 per cent, of silicon. 



For the purpose of discovering the nature of 

 the changes that take place during the arrests 

 that occur in the progress of the cooling of sub- 

 stances that have solidified from a molten condi- 

 tion, Messrs. C. T. Heycock and F. H. Neville took 

 a definite alloy of copper and tin, and allowed it 

 to cool after melting. A part of the sample was 

 chilled while still partly fluid, at 740 C., and was 

 found on microscopic examination to contain 

 large primary combs, considerably richer in cop- 

 per than the mother substance. Another portion 

 was chilled at 630 C., or not less than 100 degrees 

 below the point of solidification. It showed no^ 

 difference in composition, but was apparently 

 homogeneous. In another portion, chilled to 500 

 C., crystallization was found to have taken place 

 in the solid solution, with the production of 

 rosettes and bands of a substance rich in tin 

 within a medium rich in copper. 



A mild ferro-chromium made in the electric fur- 

 nace and containing 60 per cent, of chromium, 

 from 39 to 29 per cent, of iron and carbon reduced 

 to 1 per cent., patented in France, is distinguished 

 from ordinary ferro-chromium by being magnetic, 

 tough, not scratching iron, and being capable of 

 being drilled by steel.. 



Processes. By observing the effects of differ- 

 ent natural pressures according to differences of 



