The action of various lime soap dispersants

The course of the lime soap-dispersing action of various surfactants has been examined by use of a titrimetric method. Two types of dispersants can be distinguished. With the addition of a surfactant of the first type, the concentration of the dispersed fatty acid increases gradually. If a surfactant of the second type is used, a definite increase of the fatty acid concentration first occurs after the addition of considerable amounts of the dispersant. Ethylene oxide adducts and sodium triethylene glycol monolauryl ether sulfate behave like dispersants of the first type whereas sodium dodecylbenzenesulphonate and sodium lauryl sulfate belong to those of the second type. The dispersing action of both types of surfactants is discussed.     

Experiments with flame guncreting of basic refractories

Conclusions A laboratory installation for flame guncreting was designed, built, and tested. A method was developed for flame guncreting of basic refractories. The guncreted layer obtained as a result of flame guncreting is formally bonded with the refractory, and in its density and structure, is significantly better than it.Translated from Ogneupory, No.2, pp.54–57, February, 1967.     

Properties of aluminophosphate concretes containing various types of orthophosphoric acid

Conclusions The type of orthophosphoric acid has the maximum influence on the properties of corundum concretes, a lower influence on high-alumina concretes, and practically no influence on quartz-clay concretes. It is desirable to use wet-process orthophosphoric acid for refractory concretes. The excellent properties of concretes in the system A1₂O₃-SiO₂ based on this acid which is also cheaper enabled us to recommend it for preparing refractory concretes.The advantage of using H₃PO₄ of various types for corundum concretes is determined by the requirements placed on them in actual working conditions.Translated from Ogneupory, No.6, pp. 58–61, June, 1970.     

Coordination polymers of Zn(II) and N,N'-bis (carboxymethyl) dithiooxamide

Summary Coordination polymers were synthesized using N,N'-Bis (carboxymethyl) dithiooxamide (NN' CMDTO) and Zinc(II) salts. The complexes were characterized by elemental analyses, IR spectral studies, TGA and viscosity measurements. In the proposed structures the ligand was supposed to be coordinated to metal through sulphur and oxygen.     

Basic-Composition Mixture for the Consumable Lining of Intermediate Ladles

Thermomechanical and chemical-ceramic properties of the PTMS basic-composition mixture for the consumable refractory lining of intermediate ladles in service at the Kombinat Magnezit Joint-Stock Co. are considered and some details of the fabrication technique are discussed. Results for the mixture tested for performance at various metallurgical plants are given. Advantages of the mixture for practical application, its microstructural characteristics in pre- and post-service conditions, and the wear behavior are discussed.     

Explosive compaction of amorphous Cu−Sn powder prepared by the method of mechanical alloying

Novosibirsk. Translated from Fizika Goreniya i Vzryva, Vol. 25, No. 2, pp. 125–129, March–April, 1989.     

The effect of fillers on strength of cement mortars

The effect of three fillers (ground limestone, dolomite and basalt) on the strength of cement mortars was studied on 1:2.75 mixes having a w/c ratio of 0.70. The filler content ranged from 10 to 40% of the cement weight and their fineness (specific surface) from 1,150 to 11,200 sq. cm per g. Results confirmed earlier conclusions that fillers effect on strength is primarily an accelerating effect on the cement hydration. The improvement in strength is essentially the same for all non-pozzolonic fillers increasing with both filler content and fineness. In part, this improvement in strength is attributable to the increase in the density of the mix (i.e. a lower air content) associated with the use of fillers. There is some indirect evidence that monocalcium carboaluminate is formed when the finest limestone filler (10,300 sq. cm per g) is used. This formation, however, apparently does not affect strength.     

Behavior of biliary phospholipids in intestinal lumen during fat digestion in rat

The phospholipids present in the intestinal lumen of rats following ingestion of triglycerides are of biliary origin. They consist of lecithins accompanied by a small proportion of lysolecithins. Their behavior in comparison with the other lipid constituents of the intestinal content was studied by subjecting the latter to gel filtration on an agarose column in the presence of a solution of 6 mM sodium taurocholate in 0.1 M NaCl. Part of the phospholipids is present with the triglycerides and diglycerides in the emulsified phase excluded from the gel where pancreatic lipase and colipase also are found. The remainder is found in optically clear fractions containing fatty acids, monoglycerides, and bile salts. These fractions are eluted at 2.0 column volumes, while mixed fatty acids, monoglycerides, bile salts micelles emerge from the column at 2.4 column volumes in the same chromatographic conditions. This difference in behavior may be explained by the presence of biliary lecithins. This presence could have an important bearing upon the mucosal uptake of the lipolysis products of triglycerides.     

Graft-copolymerization of starch with acrylamide,II. Thermal behaviour of graft copolymers

Thermal behaviour of starch-graft-polyacrylamide (S-g-PAM) copolymers was evaluated. Grafting of polyacrylamide onto starch lowers the initial decomposition temperature. However, the over-all stability as assessed by the shape of thermogravimetric curve and integral procedural decomposition temperature increased with an increase in % graft-on.     

Life of stopper heads in continuous steel casting

Conclusions Chamotte heads with 5, 10 and 15% graphite differ from conventional chamotte by high thermal endurance, thermal conductivity and wear resistance. The increased rigidity of stopper heads with a graphite content of 5 to 15% used in combination with magnesite sleeves enhances the formation of longitudinal cracks.Chamotte specimens fired at 1230° C are endowed with high wear-resistance. They differ from conventional chamotte refractories by higher thermal endurance and provide for good stopper service in reladling killed steel.High-alumina SP-9-type heads made at Chasov-Yar Combine wear less in intermediate ladles and are endowed with greater thermal strength than chamotte heads.The higher quality of the chamotte heads under conditions of Stalino Metallurgical Plant in comparison to that of Krasnoye Sormovo Plant is not only due to the quality of the refractory but also to such factors as the rate and degree of preheating intermediate ladles before filling with metal, careful placement of the stoppers, and use of graphite packing around the teeming head.Despite higher wear SP-12-type chamotte heads made at Chasov-Yar Combine allowed normal teeming of rimmed steel in 50 ton ladles.To ensure a steady service of the stoppers in continuous steel casting the preheating of intermediate ladles of 1300 and the use of precooled stoppers are recommended.