$34
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I A T E E R I N G C H E M I S T R Y .
pressure. The iron or steel objects become coated with a carbon and iron compound possessing a blue color when the objects are removed from the furnace; when cool, a thin coating of linseed oil is applied, changing the color to a deep black. The coating is said to resemble t h a t produced by the Bower-Barff process in appearance, and t o have a hardness of about 9. A Pittsburgh manufacturing firm has for some time been making a special study of slow-corroding steel for pipe, and is reported to have succeeded in developing a soft steel having a n exceptionally high degree of uniformity. This is said t o have, been further improved by a patented process of hot forging, known as spellerzzing, which is applied to the metal in the course of manufacture, and which renders the surface more uniformly dense and less liable t o become pitted. It is claimed t h a t this steel will give good service in cases where no protective coating can be applied. To protect pipe from moisture, the same company has developed a coating to be applied t o pipe ranging from 3 to 18‘/* inches in diameter. The Coslettizing process, said t o produce a black, rust-proof finish on iron, consists in boiling the article in a solution of I ounce of iron filings and 4 ounces of phosphoric acid in I gallan of water. LOHMANNIZING. The protection of iron and steel is a t present effected by means of three dnc coating processes: the old “hot galvanizing” process, the “cold galvanizing” process (electrolytic zinc plating), a n d the “sherardizing” process (see Met. Chem. Ind., 6, 189; IO, 253). The process of “Lohmannizing,” invented by H. J. Lohmann, differs from these in that i t is not restricted to the application of ziqc coatings, b u t may, it is claimed, be used for coatings of zinc, lead, and tin in varying preparations t o suit the requirements of each case. The process of Lohmannizing begins, as usually, with pickling the iron and steel articles in a bath of sulphuric acid. Then the article is dipped into the Lohmann bath, which, being “composed of a n acid and a n amalgamated salt, further cleanses the pores and cavities, and deposits metallic salt upon the entire surface, penetrating into the most minute pores and cavities.” The patent specification states that the Lohmann bath is a solution of hydrochloric acid, mercuric chloride, and ammonium chloride. Next follows drying and then immersion in the molten protective alloy which is at a temperature of 950 t o IOOOOF. “An amalgam or chemical union is thus formed between the amalgamating salt and the protective alloy.” The temperature of the immersed article rises in contact with the molten alloy, and, when i t reaches a temperature of 5ooo, volatilization of the mercury occurs. Since the mercury passes from the surface of the alloy, the complete surface is said to be left free and open for the protective alloy to fill its pores and cavities, there being freedom from oxidizing influences. As i t is said t h a t it is possible to obtain a perfcctly satisfactory lead plating by the Lohmann process, it would seem that the process would be of value in the production of lead-lined apparatus.
THE INFLUENCE OF ADDITIONS TO BRONZE. Bronze composed of copper and up to zo per cent. of tin is usually specified for monumental work. It has been found, however, t h a t the shrinkage of these pure copper-tin bronzes is considerable, and since it militates against the precise jointing of large bronze works of art cast in several pieces, undesirable experiences have been the result. Von Miller [Metalluvgie, 9, 63 ( I ~ I Z ) ]aftersexperimenting , on a bronze composed of gz per cent. of copper and 8 per cent. of tin, has come to the following conclusions: Shrinkage can be appreciably diminished only by the addition of about I O per cent. of zinc in the presence of tin. Cobalt, aluminium, silicon, iron, and nickel ’
May, 1912
increase the shrinkage. Tensile strength is increased by cobalt, ‘ nickel and manganese, but is considerably lowered by antimony and zinc. Cutting, boring, chiseling and engraving are rendered, easier by up to z per cent. of antimony and lead, and more‘ dificult by nickel and manganese. The addition of tungsten, nickel, iron, manganese or cobalt raises the melting point. The formation of,a patina is less on bronzes containing zinc and aluminium, but is greater on those containing cobalt, nickel, antimony, iron, silicon, or phosphorus than on a normal coppertin bronze. Patina formation was tested for with a weak soh-‘ tion of ammonium sulphydrate containing sulphur. COPPER FUNGICIDES. Pickering Agric. Sci., 4, 273 ( I ~ I Z ) points ] out t h a t the most effective form of Bordeaux mixture is obtained by adding, lime water to copper sulphate until just short of alkalinity, This b a s k splphate, which possesses. the formula I O CuO.SO, and is known as Woburn Bordeaux, has been shown by di-ect, experiments to be e n t t o 6 times the weight of ordinary Bordeaux. Accor Pickering, the copper in Bordeaux, mixture is r e n d q le by the carbon dioxide, and dissolved copper is invariably present in the drip water collected from trees which have been sprayed. Gimingham and Barker ( J . SOC.Cheni. Ind., 1911,760) have suggested t h a t the solvent of the nrmnally insoluble copper compound is a substance excreted by the fungus itself; but this is denied by Pickering and experiments are described t o prove t h a t t h e copper in Bordeaux mixture is brought into the soluble condition by the action .of air. Pickering shows t h a t the greater the excess of lime] present the longer is the interval before this action commences; t h a t Bordeaux mixture does not dissolve sufficiently t o give a reaction for copper with ferrocyanide, although it does dissolve enough t o react with iron; t h a t an atmosphere of carbon dioxide greatly accelerates action, but until the carbon dioxide actually reaches a certain proportion a reduction of action is noticed; and t h a t action is also increased by the presence of calcium sulphate. It would appear t h a t if fungicidal action were dependent upon a solvent material exuded from the fungus, all basic sulphates and carbonates of copper would be equally efficacious for a given weight of copper present; but, as shown by Pickering, this+is not the case.
u.
THE UTILIZATION OF THE POTASSIUM CONTENT ,OF b * r‘ I’ I f ’ I MINERALS. Aschan [Z. anorg. Chem., 74, jj (1912)l has recently investigated the utilization of the potassium contents of the “Rapakivi” and pegmatite granites. He has found t h a t the potassium present in the feldspar may be rendered soluble in water by fusing the powder with anhydrous calcium chloride or with lime and sodium chloride (see, in this connection, Rhodin, /. SOC.C h e m Ind , 1901,431),and both methods are considered of possible value in rendering the potassium available for agricultural purposes, the former presenting distinct advantages if the calcium chloride is obtainable cheaply. Aschan found t h a t the greater part of the potassium in feldspar may also be rendered soluble, as hydroxide, by heating under pressure with lime and water. He found t h a t treatment with acids was unsuitable.
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PURIFICATION O F WATER BY FORCED OXIDATION. It is reported t h a t at Cardiff, Reading, Tunbridge Wells, and elsewhere in Great Britain, a new system of purifying water is in operation, and the results have, so far, been apparently satisfactory. The “Candy” apparatus consists of a steel cylinder, the lower portion of which contains the filtering media-fine silica grit, sand, and a special oxidizing substance termed “oxidium.” A special correspondent of Metalluvgical and
May
1912
T H E JOURlVAL OF I,VDUSTRIAL A N D E N G I N E E R I N G C H E J 4 I S T R Y .
Chemzcal Engineering ( I O , No. 2 , p. 86) reports t h a t the water to be purified is forced into the cylinder at a pressure of from 5 lbs. to 2 5 lbs. per sq. in., depending upon the character of the mater, and compresses the air in the upper portion thereof, thereby increasing t o a considerable extent the amount of oxygen dissolved in the water; in cases of highly impure water, the air supply may be maintained at the necessary r a t e by the aid of a small force-pump. By this new apparatus it is said t h a t oxidation of the dissolved iron compounds is so rapidly effected that the water leaves the filter practically free from iron. Organic matter also seems to be thoroughly removed. It is said t h a t the cleansing of the filter may be easily conducted by reversing the flow of water, and i t is stated t h a t the quantity of water Tequired for washing does not exceed 0.75 per cent. of the quantity filtered. A filter 8 f t . 3 in. in diameter is said to be capable of dealing with some 9,000 gal. per hour, and the capital cost of the apparatus is reported to be only from $15 to $20 per Working expenses are 1,000 gal. working capacity per day. p u t a t $0.24 per 1,000,ooo gal. for the “Candy” apparatus. THE
“ CHLORIDE ”
WATER PURIFICATION PROCESS.
According to a patented process described by W. B. Bull (Mun. Eng., 42, 151)), salt brine is electrolyzed in suitable cells; the resulting sodium hydroxide solution is concentrated and either sold or employed as a softening agent in the water supply; the chlorine gas produced is conducted into water, and the resulting chlorine water is passed upwards through a conical receptacle containing iron refuse, passing off therefrom as a ferric chloride solution, which is used in the same way as alum solution for the purification of water. Ferric chloride is said by Bull to replace alum a t a fraction of the cost of the latter, and to be a n improvement on the “iron and lime” process of purification. THE SERPEK PROCESS OF NITROGEN FIXATION. The Serpek process consists in heating bauxite with coal at a temperature of 1 7 0 0 ~to 18ooO C. It is said t h a t 15 to 18per cent. of nitrogen is absorbed as aluminum nitride. Treatment of the nitrogen-carrying bauxite with sodium hydroxide liberates ammonia, and i t is claimed that the profit from the ammonia reduces the cost of a!umina.
385
WOOD PRESERVING. At the Eighth Annual Convention of the Wood Preservers’ A&.ociation, held in Chicago, H. F. Weiss pointed out the possibilities of conditioning wood with chemicals to change the appearance of a ivood, such as beech to silverwood, and yellow birch to resemble black walnut, and stated that this process may have commerchl value when the experimental stages are concluded. H. von Schrenk stated, in the course of a paper, that the heavier the oil the longer the life obtained; but pointed out that specifications calling for a density in creosote oil of 1.10 or more were impossible of attainment, for the heaviest oils known rarely exceed 1.082, and to make an oil with a specific gravity of 1 . 1 0 or more means that coal-tar pitch, etc., has to be added t o creosote. I t may be noted t h a t the reason usually given for demanding a high density oil has been t h a t such a n oil would make the blocks more or less waterproof; but von Schrenk failed to find any marked evidence for this claim.
A NEW FILTERING MATERIAL FOR ALKALINE LIQUIDS. I n a recent patent (German Patent 241,710), the claim is for the use of “carbon-stones’’ as filtering material for acid and alkaline liquids. “Carbon-stones,” which have been hitherto employed only for lining blast-furnaces, are prepared by grinding coke of low ash content, mixing i t with about 20 per cent. of tar, compressing the mass in moulds, and then heating with exclusion of air. It is said t h a t they can be used for the filtration of boiling concentrated solutions of potassium or sodium hydroxides. PUMPS. A t one time pumps for only low pressure were manufactured, but the development of large chemical industries has rendered necessary extensive improvements in pump manufacturing industry, so t h a t now there are pumps capable of handling corrosive acid and alkaline solutions, sewage and paper pulp,
DIASTAFOR I N T H E TEXTILE INDUSTRY. Recent investigation has shown that diastase contains two enzymes capable of attacking starch. In 1906, Fraenkel and Hamburg separated, by dialysis, an enzyme which both liquefied and saccharified starch from one which only liquefied it, and Quite recently, ‘ further proved that diastase is not an albumin. Hamburg [see /. SOC.Dyers a d Col., 28, 7-14 (1912)] has recommended “Diastafor” for use in textile industries as a uniform product. He has found that, for sizing yarns, farina converted by diastase easily penetrates the fiber, and for heavy sizes, the weighting material penetrates with it. In silk dyeing, increased strength and elasticity is given to the material. Harnburg states that “Diastafor” may be extensively used before bleaching operations for the removal of the sizing, the subsequent boiling operations in alkalies being in this way considerably shortened ; this ensures greater preservation of the fiber and imparts a fuller handle to the goods. “Diastafor” is also used for degumming, since a t low temperatqres the color is not affected; for discharging when a half-blcach is required, or prior fo mercerizing; and for the production of uniform finishes. “Diastaforstarch” finishes are said to pcnetrate the fiber evenly and to prevent ‘the color from being saddened, thus producing very satisfactory results with regard to_brightness, weight, handle, etc., of the goods.
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aUCTION P L A N 0F:A
NEWSTEA3f
PUMP
and withstanding very high pressures. We have, moreover, reciprocating and centrifugal pumping machinery of various designs, elevator pumps, fire service pumps, geared pumps,
