Aug.,
1912
T H E J O C R N A L OF I S D U S T R I . 4 L AiYD E-YGI-\-EERISG “GRANACIT.”
“Granacit” is described by H. Fischer in Ze&chr$t j ~ i aiiger waiidte Chernie, 2 5 , No. 26, 1327. It is a grayish blue, finely grained, very hard and weather durable true granite, of regular crystalline structure. It has a strength of compression of 2,000 kg./sq. cm. and a density of 2 . 7 . Only traces of water are present and the content of pyrite is small; quartz, feldspar and muscovite are t h e main components. “Granacit” is acted upon by acids only in a dilute and cold condition, while in a concentrated state and hot there is no action, and i t is not affected by prolonged subjection to superheated steam. It is used as a special acid-resisting stone, and in the form of towers and columns for distillation, rectification, condensation, absorption, washing and reaction purposes. “ Granacit ” pressure and vacuum vessels are also on the market. It is especially appropriate as a material for towers for sulphite lye, vessels for acetic acid for white lead factories, phosphoric acid tubes, and in the alkali industry. “Granacit” differs from other granites in t h a t i t does not become decomposed when treated with acids. “Granacit” apparatus is being manufactured by a Dresden, Germany, firm.
THE D E S T R U C T I V E ACTION O F ACIDS ON C O N C R E T E . Neumann (Toizind. Ztg., 36, 601) records cases in which concrete drains have become damaged, sometimes soon after construction. In every case the destructive action was traced to the presence of acid in the water which had access to the drains, either internally or externally. I n one case the swampy soil surrounding the drain contained iron pyrites, and the water became charged with sulphuric acid; in other instances the atmosphere inside the drains became laden with hydrogen sulphide, which underwent slow oxidation to sulphur and sulphuric acid. Sulphuric acid was the most frequent and most powerful destroyer of underground concrete, but such acids as hydrochloric, oleic and acetic, and also carbon dioxide, were found to be almost as harmful. Neumann attributes the destructive action of acids to: ( I ) The formation of certain calcium and aluminum compounds, accompanied by a large increase in volume; and ( 2 ) the formation of soluble compounds (particularly calcium bicarbonate) which go into solution and cause collapse. H e gives as remedies: adequate ventilation inside the drains; the use of non-porous clinker poor in lime as a basis for t h e concrete; and a covering for the exposed surfaces of tar, tar-felt or asphalt. “JRONIZING,” O R “FERROZINCING.” Pure iron, as is well known, is not subject to corrosion to nearly the same extent as steel, and articles made of good w o u g h t iron also suffer less from atmospheric influences than steel. The more impure wrought iron is, the more it appro:tches steel in t h e matter of corrosion, and is therefore more in need of protection than pure iron. I n view of these facts, states Engineeriiig (93, 679), Sherard Cowper-Coles has brought out a new process, which he terms “ironizing ” or “ ferrozincing,” as a means of protecting iron and steel from corrosion; this process gives a more permanent protection than zinc coating. The process consists in first coating the iron or steel m-ith pure iron by a special electrolytic method. Pure iron is slightly electropositive to the underlying iron or steel. A zinc, nickel or brass coating is then applied to the pure iron surface, and forms, i t is claimed, a more durable coating than zinc applied directlqto a wrought-iron or steel surface, since the electrochemical action which is set up when once the zinc is penetrated is reduced. A N E W P R O C E S S F O R ELECTRO-ZINCING. The Eqzgineeriiig Reziew’ ( 2 5 , 50j) reports t h a t Quentin Marino has devised a method of depositing metals on earthenware and
CHElIISTRY.
621
glass by rendering t h e surface of the article t o be coated conductive by “ a chemical reaction” which does not involve the application of heat, with the result t h a t the deposited metal is in direct and adhesive contact with the china or glass. The process, as well as the deposition of metals onto iron and steel, consists of combining a reducing agent with the depositing solution, so t h a t all traces of oxide films, etc., are concurrently removed n i t h the deposition of the required metal. I t is said t h a t a sound adherent metallic coating may also be produced upon wood and paper; the wood is rendered water and weather proof, while the metallized paper may be employed in making metallic joints. By the process of hIarino, i t is claimed t h a t I to 2 grams of zinc per ampere hour a t a pressure of z volts may he deposited upon iron or steel.
TE X T I L O S E Paper (8, IS) states t h a t a factory has been erected a t Fleissen for the manufacture of “textilose,” a substitute for jute. “Textilose” was invented by Emil Claviez, who manufactured i t a s a substitute for jute and cotton in his spinning and weaving establishment a t Adrof, Germany. The invention consists of a material, capable of being spun, made of wood-pulp, cellulose or the like, with which is combined a fleece or nap of textile fibers, such as cotton, ~ ~ o olinen, l, jute, or the waste obtained from a carding machine. Claviez claimed that this substance was adapted to all spinning purposes as \vel1 as for ihe n a n u facture of paper. Uniting the pulp n-ith IO to 20 per cent. of fleece is effected during the production of the paper on the papermaking machine, preferably a t the beginning of the wire cloth, because in this manner the most intimate union is obtained. “Textilose” yarn may be used in the manufacture of bags, linen, carpets, and upholstery fabrics, and may he bleached, dyed and figured. I
THE B L E A C H I N G OF LINEN. I n a paper presented before the Manchester Literary and Philosophical Society on April 23, 1912, on the action of bleaching agents on the coloring matter of linen, I
