May,
1912
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 N E E R I N G C H E M I S T R Y .
The defendants claimed t h a t the nuisance was caused b y unskilful management of the farm and t h a t tannery effluents were as capable of bacterial treatment as sewage. A decision was rendered in favor of the defendants, on the ground t h a t the sewage farm was ineffective. A biological treatment of tannery effluents has also been proposed (Eitner, Gerber, 32, 199,213,2 2 7 ) . , Alsop [Chem. Eng., 15, 115 (I~IZ)] has recently reported t h a t the solids of tannery waste may be separated from the liquids by means of precipitating tanks, settling basins or centrifugal separators. He considers t h a t the best plan is t o use continuous centrifugal separators, which give control of the odors, and by means of which the solid; can be placed in receptacles for incineration, for chemical treatment to recover ammonia, greases, etc., or for drying for use as fertilizers. The liquid waste, after the removal of the solids, is, according t o Alsop’s plan, r u n through ozone atomizers in a spray tower, falling on coke filters through which currents of ozonized air are continuously passing. It is said t h a t the effluent resulting from this treatment is entirely unobjectionable from a sanitary standpoint, and t h a t the cost of the treatment will in no case exceed, with all expenses of every kind, IO cents per one thousand gallons of effluent.
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as sand is eliminated from well-washed clays, its addition has a tendency t o weaken a body, and a high temperature of firing which would tend t o strengthen would be disadvantageous from the point of view of the formation of glazed cracks, as the density developed promotes their formation. It is found t h a t the larger the fire-shrinkage is, the smaller the coefficient of expansion, and the greater the sintering the larger the expansion. Additions of lime and feldspar increase t h e strength of the biscuit: t h e effect of the feldspar is attributable t o its fusion, b u t a t that temperature deformation results, although this is not observed when lime is added in amounts u p t o 20 per cent.; lime alone softens a body, and the burning temperature is slightly increased.
THE DECOLORIZATION OF SUGAR JUICE WITH “ EPONITE.” I n 1910,a substitute for animal charcoal in sugar-refining was placed on the market by a Stockerau firm; this decolorizing substance, called “Eponite,” is now being manufactured by two European companies, and is said t o have received favorable consideration by some sugar refiners. Eponite, as marketed, is a fine mealy powder, possessing a dull black color; i t contains about 82 per cent. of carbon and 1.7 per cent. of ash, and secms to be of vegetable origin. Strohmer SCIENTIFIC METHODS IN EARTHENWARE MANUFACTURE. (0esterr.-Ungar. Z. Zukerznd., 39, 687) conducted experiments which showed t h a t i t effected decolorization best o n being heated It has been said that the technology of the lower grades of pottery (common earthenware, Rockingham ware, majolica, with the sugar liquor for ten minutes at 80’ C. with agitation, faience, and stoneware) is comparatively simple; this is un- and that i t had IO times the decolorizingpower of new char of doubtedly correct, viewing the earthenware industry as it exists , fine grain and good quality. H e found that whereas a n ordinary to-day, but it is also true t h a t less advantage has been taken refinery charcoal had no decolorizing action whatever on a 0.25 of scientific methods and research in earthenware manufacture per cent. solution of saccharane, a definite chemical constituent than in other industries. Harkort has recently discussed of caramel (Ehrlich, Bull. Assn. Chim. Sucr. et Dtst., 27, 140), (2. angm. Chem., 24, 2348) the composition of earthenware eponite, under the same conditions, decreased the dark color bodies and its relation t o scientific results; i t is from this con- of the solution by about 40 per cent. Further experiments tribution t h a t the following material is taken. by Strohmer demonstrated that its decdorizing power was not The strength of earthenware is dependent, not as in porcelain affected b y the reaction of the solution; that i t did not absorb o n the fusion of the feldspar, b u t principally upon the close sugar from concentrated solutions when heated for I O minutes packing of the clay particles; i t follows, therefore, t h a t a de- at 80’ C.; and that i t had a deodorizing action on impure sugar termination of strength merely by the “ring” of the articles solutions, a property of some importance when working with leaves out of account such factors as thickness, shape, etc. beet liquors. He also pointed out t h a t the very high decolorThe value of earthenware depends, to a large extent, upon the izing power of eponite would permit of smaller plant than is flawless adhesion of the glaze, and as a defect may not become at present required for passing sugar liquors over charcoal, apparent for a considerable period, a rapid method of testing and t h a t treatment in small tanks with the separation of the is important. Harkort heats the test-pieces in a n electric oven, spent material by small filter-presses would appear feasible. in which t h e temperature is gradually increased, and quenches The experiments made by Prinsen-Geerligs ( Archzef Suzkerznd. them in water from different temperatures. His observations, Neder1.-Ind., 19, 1085), published more recently, indicate t h a t extending €or a year, have demonstrated that test-picces which eponite is hardly suitable for the decolorization of sugar juice will stand higher temperatures withstand ordinary variations in practice. From experiments on the large scale in the refinery, of temperatures longer; and t h a t if no cracks are developed at i t was found by Prinsen-Geerligs t h a t taking the total cost of a certain quenching temperature, a satisfactory deportment decolorizing with animal charcoal as 1.0, t h a t with eponite is towards changes of temperature can be predicted. Seger Apart from 1.7, and with another material, “Blankit,” 2.0. attributed the formation of cracks and the splitting off of a the disadvantage of its comparatively high cost, he concluded glaze t o a difference between the coefficients of expansion of t h a t eponite is unsuitable for use because i t passes t o a greater the body and the glaze. Damaur made measurements on earth- or less extent through all filtering materials, owing to i t s enware bodies and confirmed Seger’s assumption ; he showed very finely divided state. As a result, there appears in the t h a t the coefficient of expansion increased with a n increase in juice or sirup a black turbidity which exerts a detrimental the silica content, but was affected by the temperature of firing, influence on the color of the finished product. if this is raised t o the point of fusion. Harkort finds t h a t silica lowers the expansion in glazes, b u t in sintered bodies the opposite THE PREVENTION OF IRON AND STEEL COROSION. effect is observed, since i t retards the drawing together of the The Bradley process of rust-proofing iron and steel, as described particles of clay substance; and t h a t when the silica is finegrained, the bodies are less liable t o have glaze cracks. By by Brown (see Eng. .lfi%. J., 93, KO.1 1 , 5 3 8 ) , consists in promeans of his quenching process, definite limits have been found ducing a n unoxidizable coating on the surface of the metal. This is effected by heating the iron or steel objects i n a muffle for the ratio of clay substance t o silica in earthenware bodies. furnace heated with coal or coke. After introducing the objects A certain amount of clay substance must be present t o yield an easily workable body, b u t the silica content must be such into the furnace, the doors are sealed with brick t o e x c h d e air, and a j e t of hydrogen is passed into the muffle t o mingle t h a t the coefficient of expansion represents a n applicable value. It is pointed out t h a t while finely ground silica must be added with a stream of kerosene which is forced into the muffle under
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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 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.
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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. ’ p
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
