A Plant for the Treatment of Iron Pyrites - Industrial & Engineering

Publication Date: August 1913. ACS Legacy Archive. Note: In lieu of an abstract, this is the article's first page. Click to increase image size Free f...
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T H E J O U R N A L OF I N D U S T R I A L A N D EA’GIi\’EERI!\-G

at, a pressure of 950 lbs. Formerly this was led through a +inch main direct t o the carbon buildings and the power necessary for driving the scrapers, etc., was obtained from a steam boiler and engine. The management, however, conceived the idea of utilizing the initial pressure of the gas by passing it through the cylinders of the steam engine, the latter serving in the capacity of a reducing valve, and a t the same time, doing away with the use of steam. AccordCarbon Buiid~ngs Safety Yalve ingly, the piping was arranged as shown in the sketch, 4 ~ 23 , ~ ~ a n-inch branch being taken off the 4-inch gas main and led through a regulating valve t o the engine. The exhaust is led into a discharge tank, a spreader being provided a t the end of the exhaust pipe. From the discharge tank the gas passes through a 3-inch main t o a clapper check valve, which works s i m u l t a neously with each chug of the exhaust and allows the gas t o feed into the carbon buildings with constant regularity. By using gas in place of steam in this manner, the engine is said t o respond quicker and more uniformly. Also, i t not only provides free power, but reduces the labor by one man.

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A PLANT FOR THE TREATMENT OF IRON PYRITES The Iron Trade Reciew, June 12, 1913, describes the plant under construction a t Roanoke, Va., by the Pyrites Co., Ltd., for the treatment of iron pyrites to render it suitable for blastfurnace use. The company building the plant is associated with the interests controlling the Rio Tinto mines in Spain, which ship pyrites to this country in large quantities, mainly t o manufacturers of sulfuric acid. After the ore has been used by these manufacturers, the residue is to be collected a t the Norfolk plant, where the copper will be removed and the material sintered for the reclamation of the iron. The sintering is to be carried out in a unit of the Dwight and Lloyd type of 150-ton size. As the pyrites ore contains 60 per cent or over of iron, and the sintered product will run about 0 . 0 2 per cent of phosphorus, it is thought t h a t this material will be attractive t o blast furnaces in the Virginia and Southern districts. It is planned t o enlarge the plant if it proves t o be successful commercially. THE DEPOSITION OF NICKEL The depositing of nickel in thick layers has been a difficult problem to solve, because of the tendency of this metal to raise up and peal off. I n fact, the layer of nickel exercises considerable pressure on the conductor t h a t i t covers and has a tendency t o detach the metal already deposited. The cause of this exfoliation is, according t o the Chemical News, 107,294, probably the hydrogen which is discharged at the cathode a t the same time as the nickel is deposited. I n the presence of much hydrogen, the metal forms a pulverulent deposit; if the gas is less abundant, the nickel becomes saturated with it, loses its suppleness, and peels off. It is well known that nickel in thick layers presents decided advantages over certain other metals; among other applica-

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tions. it would, in particular. permit of the manufacture of printing cliches which would be practically everlasting. Recently Hollard has endeavored to obviate the objectionable hydrogen, by conducting the electrolysis with a complex combination which gives out hydrogen with difficulty. He has employed nickel fluoborate, which gives excellent results for a n intensity of current of I ampere for electrodes 14 X 18 cm. a t a distance of about 4 cm. in a solution possessing a density of about I .OS. This bath is said t o deposit the nickel directly on cast-iron and on aluminum.

TUNGSTEN FILAMENT LAMPS An editorial discussion of the recent report on tests of tungsten filament lamps made by the British Engineering Standards Committee appears in the London Electriaan for June 6, 1913. The lamps tested were those on the market some eighteen months ago and showed great improvements over the older lamps but left much to be desired with respect t o rating. The objects of the tests were to obtain data as to the degree of uniformity in the individual lamps composing batches of metallic filament lamps of given nominal ratings, and also t o obtain data as t o the behavior of metallic filament lamps on life tests, with a view to ascertaining the value of the watts per candle-power on life tests which correspond to a given candle-power drop after 1000 hours. The lamps were assumed to have been manufactured to conform to the values of watts and candlepower which were advertised in the respective makers’ catalogs for the rating in question. From the target diagrams and tables i t appears t h a t “individual lamps on the market at that time, with the exception of those of one maker, vary considerably from their normal ratings, while even t h a t maker whose lamps do not so vary cannot flatter himself exceedingly, as the lamps in question were supplied to a government department, a type of consumer t h a t is, as is well known, extremely rigorous with its lamp-testing, so t h a t these particular lamps can hardly be considered a n ordinary works product. As regards the results of the candle-power tests, only 40 per cent of the batches tested came within the percentage limits laid down by the carbonlamp specification and the same percentage within the makers’ suggested limits. On the wattage basis the percentages complying with the two specifications were 48 and 79, respectively.” The percentage limit described in the British standard specifications for carbon lamps is 5 1 2 % per cent for candle-power and 1 8 per cent for watts. Life tests were conducted on a basis of I 2 watts per c.p.-that is, the voltage was found a t which each lamp consumed I 2 watts per c.p. and the lamp was then run at this voltage for 1000 hours or until it broke. Lamps with a life of several thousand hours are exceptional. “Moreover, the percentage of lamps which do not exist even for 1000 hours is higher than would be believed, especially in the case of high-voltage lamps. The candle-power throughout, however, seems t o remain sufficiently constant t o be satisfactory, and this statement applies equally t o both high-voltage and low-voltage lamps.” THE PLATlNUM MARKET During June, 1913, business was rather quiet, although steady, and prices remained firm a t $45 t o $46 for refined platinum, and $49 t o $52 per ounce for hard metal. It was reported from Russia in the end of June t h a t there was no material change in the market; prices equivalent t o $36.66 a t Ekaterinberg and $37 04 at St. Petersburg were quoted for crude metal, 83 per cent platinum, per ounce. Small quantities only were offered by the starateli, and these were quickly taken up by speculators; it was said t h a t a n advance in price was expected. A t this time, several companies were being organized to lease tracts of platinumiferous gravels, and to operate, on a good scale, with modern appliances.