Showing papers on "Calcium oxide published in 1971"

Equilibria in the silicothermic reduction of calcined dolomite

Abstract: When a mixture of calcium oxide and silicon is heated to above 1000°C a liquid Ca-Si alloy is formed. When magnesium metal is produced by reacting calcined dolomite with silicon, the alloy still forms and is the effective reducing agent for magnesium oxide. In this investigation the thermodynamic data on the Ca-Si alloys have been related to the magnesiumproducing reaction, the calcium pressures over mixtures CaO + Si were measured using a Knudsen cell, and the magnesiumand calcium pressures over the mixtures CaO + MgO + Si were measured using the transportation method. The magnesium content of the equilibrium alloy was determined isopiestically and the identity of the silicate was established. The results constitute a complete and consistent definition of the equilibria in the magnesium production reaction, and have also yielded an improved value of thefree energy of formation of calcium orthosilicate.

Reducing deposits and smoke from jet fuels

Abstract: Smoke and ash deposit formation in commercial and military jet engines and power plants is minimized by inclusion in the fuel of an additive comprising oil-soluble salts of a transition metal, such as manganese or iron, and an alkaline earth metal. A preferred additive comprises methylcyclopentadienyl manganese tricarbonyl and calcium alkylphenol sulfide in amounts to provide a manganese/calcium weight ratio about 5/1. The calcium salt may be in an alkaline form derived by over-basing with calcium oxide and carbon dioxide.

Medicament and method of increasing the calcium content of the blood

Abstract: A DERIVATIVE OF DIPROPYLACETIC ACID HAVING THE FORMULA: ((C3H7-)2-CH-COO-)2-CA WHICH WHEN MIXED WITH A PHARMACEUTICALLY ACCEPTABLE CARRIER MEDIUM IS ADMINISTERED TO HUMANS AND ANIMALS TO INCREASE THE CALCIUM CONTENT OF THE BLOOD, IS PREPARED BY STIRRING AND HEATING TO LESS THAN 10*C, A MIXTURE OF WATER AND CALCIUM OXIDE, ADDING DIPROPYLACETIC ACID, KEEPING THE MIXTURE FOR SEVERAL HOURS BELOW 100* C., FILTEING CONCENTRATING THE FILTRATE, TREATING THE FILTRATE WITH ACETONE, REMOVING THE ACETONE AND DRYING THE RESIDUE.

Single crystal beryllium oxide growth from calcium oxide-beryllium oxide melts

Abstract: A process for growing large single crystals substantially free of surface inclusions within several days is disclosed. This process involves the concept of promoting further growth on seed crystals from a melt composition of suitable oxides which will form a eutectic. Growth occurs as the crystal seed is rotated and pulled slowly from the melt composition. The temperature decrease of said melt is such that the temperature can be defined by the liquidus curve of the melt composition phase diagram. Growing single crystal beryllium oxide at a temperature of about 1,980* C from a melt composition having 56 weight percent beryllium oxide and 44 weight percent calcium oxide is an example of this process.

Catalytic activity and selectivity of evacuated calcium oxide for isomerization of but-1-ene

Abstract: Calcium oxide treated in air, does not catalyse the isomerization of but-1-ene even at 200°, but calcium oxide treated in vacuo catalyses the isomerization at 30°, selectively forming cis-but-2-ene.

Electroslag refining flux compositions and process for making same

Abstract: An improved electroslag refining (ESR) flux composition and process for making same are shown. The instant ESR flux compositions are made from particulate batch materials providing at least alumina, a fluoride and alkaline earth metal oxide, including calcium oxide, by the process described to yield a product exhibiting a substantially uniform fusion characteristic and to be substantially free of contamination from outside sources. The improvement in process comprises subjecting a substantially homogeneous mixture of batch materials, advantageously pelletized, to heat reaction at a temperature short of their complete fusion and in the range of about 1,900*2,400* F, generally most suitably until the free calcium oxide in the resulting product is below about 1 1/2 %.

Low expansion,multiband transmitting glass

Abstract: GLASS COMPOSITIONS ARE DISCLOSED WHICH HAVE LOW THERMAL EXPANSION CHARACTERISTICS AND EXCELLENT INFRARED AND ULTRAVIOLET OR RADIO FREQUENCY TRANSMITTANCE CHARACTERISTICS. THESE COMPOSITIONS ARE USEFUL IN MANUFACTURING DOMES SUITABLE FOR HOUSING INFRARED AND ULTRAVIOLET OR RADIO FREQUENCY DETECTORS SUCH AS ARE USED IN MISSILE SYSTEMS. THE GLASSES ARE BASICALLY GERMANIUM OXIDE GLASSES INCLUDING SUITABLE AMOUNTS OF ALKALI OXIDES, ZINC OXIDE, CALCIUM OXIDE, ZIRCONIUM OXIDE, ALUMINUM OXIDE AND OTHERS. THE ADDITION OF CERTAIN RARE-EARTH OXIDES, SUCH AS YTTERBIUM OXIDE, GIVE A DESIRABLE INCREASE IN SURFACE HARDNESS.

Slagging in basic steel-making process

Abstract: IN A BASIC STEEL-MAKING PROCESS WHEREIN DOLOMITE IS CHARGED AS A SLAG-FORMING INGREDIENT, THE IMPROVEMENT WHEREIN DOLOMITE, PRIOR TO ITS CHARGING, IS INTIMATELY MIXED WITH IRON OXIDE IN DEFINED PROPORTIONS, AND FORMED INTO SHAPED BODIES. IN ONE PREFERRED EMBODIMENT, THE INTIMATE MIXTURE IS PRE-REACTED, BY HEATING, TO CONVERT THE CALCIUM OXIDE PORTION OF THE MIXTURE INTO DICALCIUM FERRIE WITH OR WITHOUT CONVERSION OF MAGNESIUM OXIDE TO MAGNESIO FERRITE. COMPOSITIONS FOR ADDITION TO A BASIC STEEL-MAKING FURNACE IN THE FORM OF PREFORMED BODIES OR THE STATED FERRITE MIXTURE OF DOLOMITE ANS IRON OXIDE OR THE STATED FERRITE OR FERRITES RESULTING FROM THE AFORESAID PRE-REACTION, ARE ALSO PROVIDED.

Process for preparing olefins

Abstract: Olefins are manufactured by catalytically cracking a hydrocarbon feedstock by contacting said feedstock with steam at a temperature of 650 DEG -900 DEG C in the presence of a catalyst consisting essentially of at least 20 wt. percent of an oxide selected from the group consisting of beryllium oxide, calcium oxide and strontium oxide and the balance is aluminum oxide.

Effect of soil surface area and extractable silica, alumina, and iron on lime stabilization characteristics of illinois soils

Abstract: SEVERAL YEARS AGO, A GROUP OF ABOUT 40 ILLINOIS SOILS WAS COLLECTED BY M.R. THOMPSON OF THE UNIVERSITY OF ILLINOIS. THOMPSON DETERMINED THE LIME REACTIVITY OF THE SOILS AND ALSO SUBJECTED THE SAMPLES TO A NUMBER OF ROUTINE ANALYTICAL PROCEDURES IN AN ATTEMPT TO DETERMINE IF LIME REACTIVITY IS CLOSELY RELATED TO ANY PARTICULAR ENGINEERING, MINERALOGICAL, OR PHYSIOCHEMICAL PROPERTY OF THE SOIL. THE WRITERS SOUGHT TO EXTEND THOMPSON'S ANALYTICAL WORK TO INCLUDE DETERMINATION OF SEVERAL OTHER SOIL PROPERTIES NOT INCLUDED IN THE ORIGINAL WORK. SPECIFIC PROPERTIES INVESTIGATED INCLUDED SOIL SURFACE AREA, AMOUNT OF FINELY DIVIDED IRON PRESENT IN THE SOIL, AND AMOUNT OF SILICA AND ALUMINA ENTERING AN AQUEOUS SOLUTION MAINTAINED AT THE PH LEVEL OF A SATURATED SOLUTION OF LIME IN WATER. WORK WAS DONE BY USING THOMPSON'S ORIGINAL SOIL SAMPLES, AND RESULTS OBTAINED BY THE WRITERS WERE COMPARED WITH HIS DETERMINATION OF LIME REACTIVITY OF THE SOILS. IT WAS FOUND THAT LIME REACTIVITY DOES NOT APPEAR TO BE VERY CLOSELY CORRELATED WITH SOIL SURFACE AREA AND EVEN LESS SO WITH THE AVAILABILITY OF DISSOLVED SILICA OR ALUMINA OR BOTH. HOWEVER, IT WAS FOUND THAT LIME REACTIVITY DOES APPEAR TO BE SIGNIFICANTLY INHIBITED BY THE PRESENCE OF FINELY DIVIDED IRON INTIMATELY DISTRIBUTED THROUGH THE SOIL MASS, A CONDITION THAT IS TYPICAL OF MANY BETTER DRAINED SOILS IN ILLINOIS. /AUTHOR/

Zinc oxide coated urea

Abstract: Urea particles uniformly coated with zinc oxide having excellent adherence and uniformity of the zinc oxide coating are obtained by using a zinc oxide composition characterized by having a purity of 90 to 99% zinc oxide and a uniform particle size of at least 90% smaller than 12 microns and at least 95% smaller than 37 microns. Outstanding coatings are obtained if the zinc oxide composition additionally contains traces of carbon, iron oxide, magnesium oxide, or calcium oxide. High zinc-content coatings of excellent uniformity and adherence may be obtained with these coating compositions.

Marble like glass material and method of producing the same

Abstract: A MARBLE-LIKE GLASS MATERIAL COMPRISES MORE THAN 90% CALCIUM OXIDE, ALUMINUM OXIDE AND SILICON DIOXIDE, THE MATERIAL INCLUDING 15-40% CAO, 3-35% AL2O3 AND 4075% SIO2.

Method of treating slag

Abstract: A METHOD OF TREATING STEEL FURNACE SLAG IN ORDER TO CONVERT UNRECTED CALCIUM OXIDE AND CALCIUM HYDROXIDE INTO A FORM WHICH WILL NOT CAUSE EITHER VOLUMETRIC EX- PANSION OR LEACHING. WET CRUSHED SLAG IS BROUGH INTO CONTACT WITH CARBONATE IONS. THE WATER HYDRATES THE CALCIUM OXIDE TO FORM CALCIUM HYDROXIDE, AND THE CALCIUM AND CARBONATE IONS COMBINE TO FORM CALCIUM CARBONATE.

A lime refractory for high temperature use

Abstract: Lime refractory fabrication and properties for high temperature applications, describing production of calcium oxide grain by sintering process from commercial calcium hydroxide

Control of the impurity content of zinc sulphate solutions

Abstract: A process for controlling the build-up of undesirable ions in an electrolytic zinc plant circuit, comprises a step in which solution from said circuit is treated with a neutralising agent selected from the group consisting of limestone, calcium carbonate, zinc oxide, calcined zinc sulphide, calcined zinc sulphide concentrate, ammonia, ammonium hydroxide, dolomite, lime, calcium oxide, and calcium hydroxide, at a temperature in the range 65 DEG C to the boiling point of the solution at atmospheric pressure, so as to precipitate substantially the whole zinc content thereof in a form in which the content of said undesirable ions is substantially lowered; and a step in which the zinc values contained in the precipitated zinc compounds are returned to the said zinc plant circuit. The undesirable ions are selected from the group consisting of C1 , NO3 , NO2 , NH4 , C104 , C103 , and the ions of the elements Mn, Mg, Cd, Co, Ni, Na, K, Cr, V, Se, Te, Sn, As, Sb, In, and Fe.

Glass color filter for use under daylight color fluorescent light

Abstract: A GLASS COLOR FILTER SUITABLE FOR USE IN COLOR PHOTOGRAPHY UNDER DAYLIGHT COLOR FLUORESCENT LIGHT IS PREPARED FROM A GLASS COMPOSITION COMPRISING 100 PARTS OF BASE GLASS COMPOSED OF, BY WEIGHT, 50-70% SILICIC ACID ANHYDRIDE, 817% LEAD OXIDE, 13-23% OF EITHER ONE OR BOTH OF SODIUM OXIDE AND POTASSIUM OXIDE, 3-12% OF EITHER ONE OR BOTH OF CALCIUM OXIDE AND MAGNESIUM OXIDE. AND 0.2-0.5% ARSENIC OXIDE, AND A COLORING AGENT COMPOSED OF, BY WEIGHT, 2.0-4.0% CERIUM OXIDE, 2.5-5.0% TITANIUM OXIDE, 0.001-0.02 NICKEL OXIDE, 0.8-2.2% MANGANESE DIOXIDE, AND 0.3-2.5% NEODYMIUM OXIDE.

Basic oxygen process using a sodium hydroxide reaction product flux

Abstract: In the manufacture of steel wherein sodium hydroxide is employed as an additive in such manufacture, the improvement of using a reaction product of sodium hydroxide and a calcium oxide source material as the source of sodium hydroxide. A particular instance is the use of this reaction product as an additive to a calcium oxide based flux.

Some properties of rice hull ash

Abstract: A VISUAL INSPECTION OF SOME TEST AREAS OF LIME STABILIZED RICE HULL ASH SUGGESTED THAT THE MATERIAL CONTAINED A LARGE PERCENTAGE OF ORGANIC MATTER, AND THE TEST AREAS APPEARED TO BE EXTREMELY RESILIENT. SAMPLES OF THE STABILIZED MATERIAL WERE OBTAINED FOR DETERMINATION OF THE ORGANIC CONTENT, AND TESTS WERE CARRIED OUT TO DETERMINE THE EASE WITH WHICH THE RICE HULL COULD BE FULLY BURNT. THIS REPORT DESCRIBES FURTHER TESTS ON A TRIAL EMBANKMENT CONTAINING A NUMBER OF EXPERIMENTAL SECTIONS OF RICE HULL ASH. SAMPLES WERE OBTAINED AND THE MOISTURE CONTENT, LOSS ON IGNITION AND LIME CONTENT WERE MEASURED FOR EACH SAMPLE. THE SPECIFIC GRAVITY OF THE ASH WAS DETERMINED, AND COMPACTION AND STATIC LOADING TESTS WERE CARRIED OUT. MENTION IS MADE OF THE USE OF RICE HULL ASH AS A STABILIZER, LIGHT WEIGHT FILL, AND FILTERING MATERIAL. /TRRL/

Burma soils: a study of the effects of lime and cement on paddy and laterite material

Abstract: LABORATORY TESTS WERE PERFORMED ON SAMPLES OF PADDY AND LATERITE SOILS OBTAINED FROM THE PROPOSED RIGHT-OF-WAY OF THE RANGOON-MANDALAY HIGHWAY, BURMA. THESE TESTS WERE CONDUCTED TO DETERMINE THE BASIC ENGINEERING PROPERTIES OF THE SOILS AND TO EVALUATE THE FEASIBILITY OF STABILIZING THESE SOILS WITH LIME AND CEMENT. THE ADDITION OF LIME HAD LITTLE BENEFICIAL EFFECT ON EITHER SOIL, DUE TO THE NON- REACTIVE NATURE OF THE SOILS AND THE POOR STABILIZING QUALITY OF LIME AVAILABLE IN BURMA. SPECIAL TESTS USING AMERICAN LIME INDICATED A STRENGTH INCREASE OF ABOUT 300% OVER THE NATURAL SOIL STRENGTH, COMPARED TO AN INCREASE OF LESS THAN 100% WITH BURMA LIME. ADDITION OF CEMENT, ON THE ORDER OF 6% BY DRY WEIGHT OF SOIL, EFFECTIVELY STABILIZES BOTH SOILS. UNCONFINED COMPRESSIVE STRENGTHS OF BOTH ARE INCREASED ON THE ORDER OF 300%. /AUTHOR/

Frit 釉에 關한 硏究 (第1報) : 無鉛 Frit 乳白釉의 製造

Abstract: This investigation covered several systematic field of compositions of leadless, opaque, fritted glazes. In the present study, the influence of additions of calcium oxide, barium oxide, strontium oxide, and zinc oxide to the frit was studied. All glaze ingredients except the kaolin were incorporated in the frits. Leadless glaze of low zinc oxide content were obtained which possessed gloss and opacity on wall tile. The whitest and most opaque glazes were obtained with the use of calcium oxide and zinc oxide.

Some properties of plasma fused calcium oxide

Abstract: It was shown to be possible to obtain fused calcium oxide by plasma fusion The fused calcium oxide is characterized by a dense structure and an increased resistance in moist atmospheres

Production and properties of sintered ceramics based on high-purity calcium oxide

Abstract: A study was made of the pressing and sinterability of calcium oxide of enhanced purity as a function of the choice of the starting material: CaCO3 or Ca(OH)2, and the conditions of their thermal processing.