1046 results about "Alkaline earth oxides" patented technology

The process comprises the reduction of niobium and/or tantalum oxides by means of alkaline earth metals and/or rare earth metals, wherein the first reduction stage is carried out as far as an average composition corresponding to (Nb, Ta)Ox where x=0.5 to 1.5 and before the second stage the reduction product from the first stage is freed from alkaline earth oxides and/or rare earth metal oxides which are formed (and optionally from excess alkaline earth metal and/or rare earth metal) by washing with mineral acids.

A catalyst for treating the exhaust gas from internal combustion engines is provided, wherein the catalyst contains two catalytically active layers supported on a support. The first catalytically active layer contains a platinum group metal in close contact with all of the constituents of the first catalytically active layer, wherein the constituents of the first catalytically active layer include particulate aluminum oxide; particulate oxygen storage material, such as cerium oxide, cerium/zirconium and zirconium/cerium mixed oxides, and alkaline earth metal oxides. The second catalytically active layer, which is in direct contact with the exhaust gas, contains particulate aluminum oxide and at least one particulate oxygen storage material, such as cerium oxide, cerium/zirconium and zirconium/cerium mixed oxides. Rhodium is supported on part of the aluminum oxides in the second catalytically active layer or on the particulate oxygen storage material in the second catalytically active layer. By providing the platinum group metal in close contact with all of the constituents of the first catalytically active layer, improved conversion efficiency of the impurities in the exhaust gas can be achieved.

An aqueous, viscoelastic fluid gelled with a viscoelastic surfactant (VES) is stabilized and improved with an effective amount of an alkali earth metal oxide and/or alkali earth metal hydroxide. These fluids are more stable and have reduced or no tendency to precipitate, particularly at elevated temperatures. The additives may also increase viscosity to the point where less VES is required to maintain a given viscosity. These stabilized, enhanced, aqueous viscoelastic fluids may be used as treatment fluids for subterranean hydrocarbon formations, such as in hydraulic fracturing.

Alkaline earth alumino-silicate glass compositions with improved chemical and mechanical durability and pharmaceutical packages comprising the same are disclosed herein. In one embodiment a glass composition may include from about 65 mol. % to about 75 mol. % SiO₂; from about 6 mol. % to about 12.5 mol. % Al₂O₃; and from about 5 mol. % to about 12 mol. % alkali oxide. The alkali oxide may include Na₂O and K₂O. The K₂O may be present in an amount less than or equal to 0.5 mol. %. The glass composition may also include from about 8.0 mol. % to about 15 mol. % of at least one alkaline earth oxide. The glass composition is susceptible to strengthening by ion-exchange thereby facilitating chemically strengthening the glass to improve the mechanical durability.

A composition of a rapidly disintegrating buccal dosage form containing a drug, at least one non-effervescent base such as an alkali metal or alkaline earth metal oxide or hydroxide, and a disintegrant. The base regulates the pH gradient to deliver the drug to the buccal, sublingual or oral mucosal membranes at a desired rate of absorption. The composition is micronized for uniform distribution, and the drug is converted from ionized form to unionized form, without the use of an effervescent agent.

A process for preparing ethylene and propylene from the hydrocarbon mixture containing C4 (or C5) olefine includes such steps as contacting the zeolite contained catalyst in fixed-bed reactor, reacting at 350-500 deg.C and 1-10 /hr of space speed under 0.6-1.0 MPa to obtain the mixture of ethylene and propylene, and cooling separating. Said catalyst contains Al2O3 or SiO2, high-Si zeolite and modifier.

A glass article may formed from a glass composition that may include from about 70 mol. % to about 78 mol. % SiO₂, from about 3 mol. % to about 13 mol. % alkaline earth oxide, X mol. % Al₂O₃, and Y mol. % alkali oxide. The alkali oxide may include Na₂O in an amount greater than or equal to about 9 mol. % and less than or equal to about 15 mol. %. The ratio of Y:X may be greater than 1. The glass article may be free of boron and compounds of boron. The glass article may have a compressive stress layer with a compressive stress greater than or equal to about 250 MPa and depth of layer greater than or equal to about 25 μm. The glass article may have at least a type HGA2 hydrolytic resistance according to the ISO 720 standard.

The invention relates to a jade-type glass-ceramic and a preparation method thereof. The jade-type glass-ceramic contains a main crystal phase and can also contain a secondary crystal phase, wherein the maximum crystallite dimension of the secondary crystal phase is equal to or smaller than visible wavelength, the jade-type glass-ceramic contains the following components in percentage by weight: 45.0-75.0% of SiO2, 1.0-25.0% of Al2O3, 0-20.0% of alkaline earth metal oxide, 3.0-15.0% of alkali metal oxide, 0-4.0% of TiO2, 0-2.5% of ZrO2, 0-8.0% of F and the balance of flux and clarifier. The preparation method of the jade-type glass-ceramic comprises the steps that the main raw materials and the auxiliary materials are mixed uniformly and then are melted at high temperature to form molten glass, then the molten glass is thermally treated after being cooled and molded so as to form an organization structure beneficial to the penetration of the visible light part in molten glass, and after thermal treatment, the glass-ceramic is in a semitransparent neftdegil shape and becomes a jade-type glass-ceramic. The jade-type glass-ceramic has delicate texture, is translucent, can be widely used as a decorative plate, and can also be carved into handicrafts and prepared into tableware and sanitary ware.

The embodiments described herein relate to chemically and mechanically durable glass compositions and glass articles formed from the same. In another embodiment, a glass composition may include from about 70 mol. % to about 80 mol. % SiO₂; from about 3 mol. % to about 13 mol. % alkaline earth oxide; X mol. % Al₂O₃; and Y mol. % alkali oxide. The alkali oxide may include Na₂O in an amount greater than about 8 mol. %. A ratio of Y:X may be greater than 1 and the glass composition may be free of boron and compounds of boron. In some embodiments, the glass composition may also be free of phosphorous and compounds of phosphorous. Glass articles formed from the glass composition may have at least a class S3 acid resistance according to DIN 12116, at least a class A2 base resistance according to ISO 695, and a type HGA1 hydrolytic resistance according to ISO 720.

The invention provides a catalyst for alkane dehydrogenation as well as a continuous reaction regeneration device and method using the catalyst for catalytic dehydrogenation. The catalyst comprises four ingredients, the ingredient A is oxides of one kind of element or several kinds of elements from Ti, Nb, Ta, Mo, W, Re, In or Ga, the ingredient B is one kind or several kinds of materials in MgO, P2O5, ZrO2, Al2O3 or SiO2, the ingredient C is oxides of one kind of material or several kinds of materials from Zn, Cd and Sn, and the ingredient D is one kind of material or a mixture of several kinds of materials from alkali oxides or alkaline earth metal oxides. The catalyst does not contain noble metal such as Pt and the like, does not contain toxic ingredients such as Cr and the like and cannot pollute the environment. The activity of the catalyst is high, the selectivity of olefin generated by alkane dehydrogenation is high, the stability of the catalyst is good, the mechanical intensity is high, the continuous reaction regeneration device is used for alkane dehydrogenation, the reaction and the catalyst regeneration are continuously carried out, the efficiency is high, and the safety is high.

A three-element catalyst for cleaning the tail gas of car features that the cellular cordierite ceramics modified by the RE tailing mixture or transition metal oxide is ued as the first carrier, the internal and external modified alumina coating layers are used as the second carrier, and the noble metal Pt, Rh or Pd is used as its active component.

Nitrogen oxide storage materials and methods of manufacturing nitrogen oxide storage materials are disclosed. The nitrogen oxide storage materials can be used to manufacture catalytic trap disposed in an exhaust passage of an internal combustion engine which is operated periodically between lean and stoichiometric or rich conditions, for abatement of NO_x in an exhaust gas stream which is generated by the engine. In one embodiment, the nitrogen oxide storage material comprises alkaline earth material supported on ceria particles having a crystallite size of between about 10 and 20 nm and the alkaline earth oxide having a crystallite size of between about 20-40 nm.

A sintering aid for a low-temperature cofired medium ceramic material is composed of, by weight, 31%-45% of silicon dioxide, 1%-10% of boron oxide, 5.1%-10% of zinc oxide, 18%-30% of aluminum oxide, 11%-24% of alkaline earth metallic oxide and 5%-15% of oxide with the general formula of R2O3, wherein R refers to at least one of lanthanum, cerium, praseodymium, neodymium, samarium, europium and dysprosium, and the alkaline earth metallic oxide refers to one of magnesium oxide, calcium oxide, barium oxide and strontium oxide. Adding the sintering aid into the low-temperature cofired medium ceramic material enables the prepared low-temperature cofired medium ceramic to have excellent thermal mechanical performance and dielectric performance. In addition, the invention provides the low-temperature cofired medium ceramic material and application thereof and a method for preparing the low-temperature cofired medium ceramic.

The invention refers to a kind of catalyst in organic waster gas purification. It is made up of honeycomb pottery carrier and the paint layer on the carrier, and the precious metal active components. The layer has characters such as stable paint layer, excellent high temperature resistant performance, the efficiency is high. The paint layer is made up of Al2O3, SiO2 and a one kind of or more alkali metal oxide. The paint layer combines with the honeycomb pottery carrier stably.

Adhesive antimicrobial dental compositions and methods for forming and using compositions are disclosed. The compositions are primarily useful as pulp caps and dentin liners. The composition includes an alkyl methacrylate having an oxyphosphorus group, a polymerization initiator and an antimicrobial agent. The antimicrobial agent can be organohalogens, antibiotics, alkali metal hydroxides, alkaline earth metal oxides and alkaline earth metal hydroxides. The compositions have high dentin tensile bond strength, are stable as a single component or package system, can be polymerized in situ, prevent ingress by microorganisms into an area of a tooth treated with the compositions and can be syringe delivered.

The invention belongs to the field of porous ceramic, and provides a mullite ceramic foam filter for casting. The mullite ceramic foam filter for casting comprises the following chemical components: 40-80 wt% of Al2O3, 10-50 wt% of SiO2 and 1-10 wt% of alkali-earth oxide. The mullite ceramic foam filter for casting is in a mutually-communicated mesh porous structure. The preparation method comprises the following steps: using natural alumina containing 40-80 wt% of Al2O3 as the main raw material, adding one or more of silicon dioxide, aluminum oxide, kaolin, bentonite and talcum powder as the auxiliary material, and adding adhesive, dispersant and water to obtain a ceramic slurry; and immersing polyurethane sponge foam into the slurry, removing the excessive slurry, drying, and sintering at high temperature to obtain the mullite ceramic foam filter. The invention has excellent thermal impact resistance and molten metal attack resistance, and can be widely used for filtering, purifying and rectifying aluminum, aluminum alloy, copper, iron or any other molten metal liquid, thereby greatly enhancing the quality and yield of castings.

This invention discloses a deoxidizer of manganese system and its preparation and application. The deoxidizer of this invention is using MnO/Mn3O4 as active constituent. Add alkali metal oxide and aluminium oxide that are active accelerators. This invention provides two preparations, which adopt precurosor compound of Mn3O4 or active Mn3O4 that is produced by calcining precurosor compound of Mn3O4 to mix with alkali metal oxide or hydroxide oxide and aluminium, kneading, forming, open-air drying, at last drying or then producing deoxidizer of this invention by calcining after drying. The deoxidizer of this invention can eliminate 1- 2000ppm oxygen which is in the aethylenum or propylene, at the same time it possesses fairly high mechanical strength.

The invention discloses a process for preparing coal water slurry or the mixture of coal water slurry with alkaline metal and / or alkaline earth oxides or hydroxides by the method of low level coal continuous transformation in subcritical or supercritical water which comprises, conducting continuous high pressure conveying of coal water slurry, charging into reaction system, usting the peculiarity of the hypercritical water to extracting and pyrolising low grade coal, converting it into useful product in gas, liquid and solid forms.