Abstract: A process for preparing calcium silicate articles having a bulk density of 0.3 to 0.9 g/cm.sup.3 including the steps of mixing a major portion of calcium silicate and minor portions of anhydrous calcium aluminosilicate or its analogue, a reinforcing fiber and a polymer binder in water to give an aqueous slurry, molding the slurry into a desired for, and drying the molded slurry at 100.degree.-180.degree. C.

Abstract: A durable structure can be easily and safely demolished by using a demolition-facilitating agent comprising, as an effective principal component 50% to 100% by weight of quick lime particles having an apparent density of 2.0 or more, a weight per unit volume of 1.0 kg/l or more, a particle size of 15 mm or less, and an average particle size of 0.1 mm or more, and optionally, additional solid particles, for example, sand particles, which are inert to water, rigid, porous inorganic grains, for example, hydrated zeolite grains, or a water-absorbing organic material, for example, acrylonitrile-grafted starch in a manner such that the demolition-facilitating agent in the dry state is fed into holes formed in a durable structure to be demolished and then water is fed into the holes to allow the quick lime particles to react with water and thus expand, to demolish the durable structure.

Abstract: A process for producing a low water-absorbing artificial lightweight aggregate, which comprises:granulating a starting powdery material containing coal ash, having such a particle size distribution that a residue on a 297 .mu.m standard wire sieve is not more than 1 wt. %, and 1 to 20 parts by weight of a hydraulic material per 100 parts by weight of said coal ash in the presence of water;curing the resulting granules for a period of not shorter than 20 hours; orheat-treating the resulting granules at a temperature of not higher than 700.degree. C. for a period of not shorter than 30 minutes; and,calcining the granules at a temperature of 1,000.degree. to 1,500.degree. C.

Abstract: A process for the preparation of micro inorganic foamed granules chracterized in that amorphous particles having particle size of not greater than 150 .mu.m recovered from particles of an amorphous residue produced by partial oxidation of coal is heated by introducing the same into a flame or gas at a high temperature, whereby foaming the amorphous particles.

Abstract: An novel solution for anodic oxidation of magnesium or magnesium alloy is prepared by dissolving silicate, carboxylate and alkali hydroxide in water. The anodic oxidation coating formed on the surface of magnesium or its alloy using the anodizing solution has a superior combination of properties, especially with respect to corrosion resistance, abrasion resistance and ornamental properties, as compared to any prior art anodic oxidation coating. The solution may further contains one or more compounds selected from the group consisting of borate, fluoride and phosphate, in addition to the foregoing essential components in order to obtain a further improvement.

Abstract: The specification discloses a novel calcium silicate water-treating agent exhibiting a superior ability to remove various kinds of phosphorus compounds or other environmental pollutants contained in wastewater, the calcium silicate water treating agent comprising a burned product which is prepared by burning a mixture containing as main constituents calcium compound, thermally decomposable to calcium oxide (CaO), and SiO.sub.2 -containing compound at a temperature of 1300.degree. to 1600.degree. C., the molar ratio of CaO/SiO.sub.2 of the resultant burned product being in the range of 1.5 to 5.0, preferably 2.0 to 4.0. In this water treating agent, SiO.sub.2 component may be partially replaced by Al.sub.2 O.sub.3 and/or Fe.sub.2 O.sub.3. A further water treating agent is prepared by heating the hydrate of the burned product prepared above at a temperature of 50.degree. to 700.degree. C.

Abstract: A hydraulic material composition comprising cement and 0.01 to 2.0% by weight, as zinc oxide based on the cement, of a zinc-containing compound, such as zinc oxide having an average particle diameter of at least 20 micrometers. It does not corrode a steel material even when molded with the use of sand or sea water containing steel-corroding components such as chlorides.

Abstract: A process for producing an artificial light-weight aggregate comprising SiO.sub.2, Al.sub.2 O.sub.3, Fe.sub.2 O.sub.3 and at least one oxide selected from the group consisting of MgO and CaO which has an absolute dry specific gravity of not higher than 1.5, a crushing strength of not less than 55 kfg/cm.sup.2 and a 24 hour water-absorption ratio of not greater than 2.4%. The process comprises granulating a raw powder material comprising SiO.sub.2, Al.sub.2 O.sub.3, Fe.sub.2 O.sub.3 and at least one oxide selected from the group consisting of MgO and CaO, in which the total amount of SiO.sub.2 and Al.sub.2 O.sub.3 is from 75 to 92 wt. %, the weight ratio of Al.sub.2 O.sub.3 /SiO.sub.2 is from 0.25 to 0.70, and the total amount of Fe.sub.2 O.sub.3 and MgO and/or CaO is from 6-20 wt. % and containing at least 80% by weight of a coal ash having a Blaine specific surface area of 2,000 to 9,000 cm.sup.2 /g to give granules having an average apparent specific gravity of 1.1 to 1.8 and a crushing strength of 0.

Abstract: A demolition-facilitating agent for durable structures, for example, concrete structures and rocks, comprises (A) 100 parts by weight of a mixture in the form of fine particles, consisting essentially of (1) 90 to 99% by weight of a clinker consisting of (a) 15 to 97% by weight of free CaO crystals, (b) 3 to 85% by weight of free 3CaO SiO.sub.2 crystals and (c) 0 to 10% by weight of an inevitable impurity, the clinker having been produced at a sintering temperature of 1200.degree. C. or more, and (2) 1 to 10% by weight, in terms of gypsum anhydride (CaSO.sub.4), of at least one gypsum compound; and (B) 0.4 to 4 parts by weight of a cement water-reducing agent.

Abstract: An aqueous anodizing solution for anodizing an article of magnesium or magnesium-base alloy which contains, per one liter volume thereof, 20-300 g. of an aluminate, 0.5-8 moles of an alkali hydroxide per one mole of the aluminate, and at least one kind selected from the group consisting of 20-200 g. of a boron compound, 2-50 ml. of a phenol, 2-50 g. of a sulfate, and 5-70 g. of an iodine compound. A process for coloring an article of magnesium or magnesium-base alloy which comprises forming an aluminum oxide-containing layer over a surface of said article and subsequently coloring said layer with an anodized aluminum-coloring dye is also disclosed.

Abstract: A high density magnesia fine powder having an improved sintering property is produced in such a manner that magnesium is vaporized at 700.degree. C. or more in a magnesium-vaporizing refractory tube while an inert gas flows through the magnesium-vaporizing tube; the flow of the vaporized magnesium-containing inert gas is introduced into a magnesium-oxidizing tube; a molecular oxygen-containing gas is introduced into the magnesium-oxidizing tube in a concurrent relationship to the flow of the vaporized magnesium-containing inert gas to provide a reaction mixture, while the temperature of the magnesium-oxidizing region is adjusted to 800.degree. C. to 1600.degree. C. and the partial pressures of the vaporized magnesium and oxygen in the magnesium-oxidizing region are regulated to 0.

Abstract: An expansive cement additive and a cementitious material added therewith, said expansive additive consisting of a pulverized product of clinker containing 15.about.60% by weight of free CaO, 5.about.30% by weight of free CaF.sub.2, 30.about.80% by weight of 11CaO.7Al.sub.2 O.sub.3.CaF.sub.2, and less than 10% by weight of other ingredients or a mixed pulverized product of said clinker and gypsum, in which the weight ratio of CaSO.sub.4 /Al.sub.2 O.sub.3 ranges from 1.0 to 3.5.

Abstract: A calcia clinker having an excellent resistance to slaking and an enhanced modulus of rupture at elevated temperatures is produced by a process comprising the steps of: (1) calcining a lime material at a temperature of 800.degree. to 1300.degree. C. to prepare a calcia; (2) providing an admixture, in the form of fine particles having a specific surface area of 5000 cm.sup.2 /g or more, of the calcia with an additive comprising (A) 0.5 to 3%, in terms of oxide and based on the weight of CaO in the calcia, of at least one inorganic compound of an element selected from the group consisting of titanium, aluminum and silicon and (B) 0.5 to 2.0%, based on the weight of CaO in the calcia, of calcium fluoride; and sintering the above-mentioned compound (A), and; (3) sintering the admixture at a temperature of 1200.degree. to 1650.degree. C.