摘要:
It is the object of the invention to provide a cement admixture, and a cement composition that can impart good enough rustproofness to reinforcing bars in hardened cement concrete, and can have resistance to penetration of chloride ions entering from the outside, prevent the hardened cement concrete from getting porous due to reduced leaching of Ca ions and have a self-recovery capability.The invention provides a cement admixture characterized by containing a calcium ferroaluminate compound comprising a CaO—Al2O3—Fe2O3 system, and having a Fe2O3 content of 0.5 to 15% by mass and a CaO.2Al2O3 structure with a CaO/Al2O3 molar ratio ranging from 0.15 to 0.7. It is preferable that the fineness is 2,000 to 7,000 cm2/g as represented in terms of the Blaine's specific surface area value; the potentially hydraulic substance and/or pozzolan substance (pozzolan substance or the like) is also used; the pozzolan substance or the like contains one or two or more selected from the group consisting of finely pulverized, quenched, granulated blast-furnace slag, fly ash, silica fume, metakaolin, incinerated pulp sludge ash, incinerated sewage sludge ash, and waste glass powder; and the blending proportion of the calcium ferroaluminate compound to the pozzolan substance or the like ranges from 10/1 to 1/10 by mass. The invention also provides a cement composition containing cement and the cement admixture.
摘要翻译:本发明的目的是提供一种水泥混合物和一种能够赋予硬化水泥混凝土中的钢筋足够好的防锈性的水泥组合物,并且可以具有抵抗从外部进入的氯离子的渗透性,防止硬化的水泥混凝土 由于Ca离子的浸出减少而变得多孔,并且具有自恢复能力。 本发明提供一种水泥外加剂,其特征在于含有CaO-Al 2 O 3 -Fe 2 O 3体系的铁铝钙钙化合物,Fe 2 O 3含量为0.5〜15质量%,CaO / Al 2 O 3的CaO / Al 2 O 3结构为0.15 至0.7。 如Blaine的比表面积值所示,细度优选为2,000〜7000cm 2 / g; 还使用潜在的水力物质和/或火山灰物质(火山灰物质等); 火山灰物质等含有选自微粉碎,碾磨,造粒的高炉渣,飞灰,硅灰,偏高岭土,焚烧纸浆泥灰,焚烧污泥,灰渣和废玻璃中的一种或两种以上 粉末; 铁铝钙钙化合物与火山灰物质等的混合比例为10/1〜1/10质量%。 本发明还提供一种含有水泥和水泥外加剂的水泥组合物。
摘要:
Procedure for obtaining calcium aluminate from the dry waste generated in the treatment, for recovery of metallic Al and salts, of the saline dross produced in the metallurgy of secondary aluminium and calcium oxide and/or CaO precursor. The procedure may produce briquettes or pellets of precursors of calcium aluminate through cold sintering or premolten calcium aluminate through hot sintering.
摘要:
The present invention relates to a method for producing an oxide containing a conductive mayenite type compound and having an electron concentration of 1×1018/cm3 or more, from a raw material which is a combination of a calcium compound and an aluminum compound or is a compound containing calcium and aluminum, each having a molar ratio of calcium oxide and aluminum oxide ranging from 9:10 to 14:5 in terms of the oxides, the method including the steps of: heating and holding the raw material at 900 to 1,300° C. to produce a calcined powder containing at least one oxide selected from the group consisting of a calcium aluminate, calcium oxide and aluminum oxide; and heating and holding the calcined powder at 1,200° C. to less than 1,415° C. under a reduction atmosphere in an inert gas atmosphere or a vacuum atmosphere each having an oxygen partial pressure of 1,000 Pa or less.
摘要:
The invention relates to materials which are stable at high temperatures and which have high specific surfaces. Said materials are produced by heating them to a temperature in a matrix above the later temperature at which they are used, e.g. aluminum oxide or zirconium oxide. The temperature of the specific surfaces thereof, after relatively long tempering, is 1100° C. or 1000° C., even above 50 m2/g or 10 m2/g. Carrier catalysts can be also be produced according to said method.
摘要:
A technique to synthesize complex oxide ceramic powders which offers advantages of both the coprecipitation and sol-gel routes while doing away with the disadvantages is disclosed. Namely, the ability to achieve chemical homogeneity and crystallite size on the namometer length scale at a nonprohibitive cost is provided by the disclosed method. In one embodiment of the invention, a method for the synthesis of a mixed metal oxide powder is provided including (a) combining a liquid absorbent resin with at least one solution selected from the group consisting of solutions containing at least one organo-metallic compound and solutions containing at least one metallic salt compound, such that at least two metals are present in the liquid absorbent resin after the combining is completed; (b) after the combining, allowing the liquid absorbent resin to swell and gel and thereby form a swollen gel; (c) preparing a precursor material by changing at least one of the pH and temperature of the swollen gel; (d) pyrolyzing the precursor material to form a pyrolyzed precursor material; and (e) calcining the pyrolyzed precursor material to form a mixed metal oxide powder.
摘要:
Alkoxylation products are prepared by reacting compounds having active hydrogen atoms with C.sub.2 -C.sub.4 -alkylene oxides in the presence of a mixed hydroxide built up of polycations and modified with additives and having the general formula I or II �M(II).sub.1-x M(III).sub.x (OH).sub.2 !A.sub.x/n .multidot.m L(I) �LiAl.sub.2 (OH).sub.6 !A.sub.1/n .multidot.m L (II) where M(II) is at least one divalent metal ion, M(III) is at least one trivalent metal ion, A is at least one inorganic anion and L is an organic solvent or water, n is the valence of the inorganic anion A or in the case of a plurality of anions A is their mean valence and x can assume a value of from 0.1 to 0.5 and m can assume a value of from 0 to 10, as alkoxylation catalyst, wherein the mixed hydroxide contains additives.
摘要:
An object of the present invention is to provide an alumina-magnesia oxide which can be fine pulverulent bodies by pulverizing. In the alumina-magnesia oxide of the present invention includes: 70-73 WT % of alumina component, which is converted into alumina (Al.sub.2 O.sub.3); and 27-30 WT % of magnesia component, which is converted into magnesia (MgO). The alumina-magnesia oxide is formed into a pulverulent body, which is a hollow grain having loosed bulk density of 0.15 g/cm.sup.3 or less and average grain diameter of 10 .mu.m or more.
摘要翻译:本发明的目的是提供氧化铝 - 氧化镁,其可以通过粉碎而成为细粉碎体。 在本发明的氧化铝 - 氧化镁中,包括70-73WW%的氧化铝组分,其转化为氧化铝(Al 2 O 3); 和27-30%WT的氧化镁组分,其转化为氧化镁(MgO)。 氧化铝 - 氧化镁形成为粉状体,其是松散体积密度为0.15g / cm 3以下,平均粒径为10μm以上的中空粒子。
摘要:
A method for making a synthetic meixnerite which, when activated, has a high B.E.T. surface area, typically about 290 m.sup.2 /g or greater. The method comprises activating hydrotalcite, then cooling and hydrating such activated material in a carbon dioxide-free environment. Such hydration can produce a material that absorbs more than 100% of its weight in water. Following hydration, this material is activated a second time in a virtually carbon dioxide-free environment.
摘要:
An improved process for the production of alkaline earth, aluminum-containing spinel compositions, preferably magnesium, aluminum-containing spinel compositions and preferably further comprising at least one additional metal component, comprises combining at least one alkaline earth metal component; at least one solid organic material acting to alter at least one property of the spinel composition and being capable of being at least partially combusted during the calcination step described hereinafter, and at least one aluminum component at selected pH conditions to form a precipitate and calcining the precipitate to form a spinel composition. The product spinel composition, prepared in the presence of a solid organic material and preferably with included additional metal components, is particularly suited for use to reduce the amount of sulfur oxides emitted from a catalyst regeneration zone, e.g., a catalytic cracking unit regeneration zone.
摘要:
An improved process for the production of alkaline earth, aluminum-containing spinel compositions, preferably magnesium, aluminum-containing spinel compositions and preferably further comprising at least one additional metal component, comprises adding a basic aqueous solution containing at least one aluminum component to an aqueous solution containing at least one alkaline earth metal component to form a precipitate at defined pH conditions and calcining the precipitate to form a spinel composition. The product spinel composition, preferably with included additional metal components, is particularly suited for use to reduce the amount of sulfur oxides emitted from a catalyst regeneration zone, e.g., a catalytic cracking unit regeneration zone.