Abstract: In accordance with the present invention, there is provided a calcium removal method capable of reducing operation cost. A solution L2 containing potassium or/and sodium, and calcium is passed through an ion-exchange resin 35 to separate the solution into a solution containing potassium or/and the sodium, and a solution containing calcium. Operation cost can remarkably be decreased since potassium carbonate is not required to remove calcium as before. Timing for changing a calcium-containing water L3 and a salt water L4 discharged from the ion-exchange resin can be performed based on at least one measurement result selected from the group consisting of: a calcium or chlorine concentration; electrical conductivity; and pH of a fluid which is discharged from said ion-exchange resin. The solution may be a filtrate L1 that is obtained by washing a chlorine bypass dust D generated in a cement burning process, or a leachate W of a final disposal site 50.

Abstract: In accordance with the present invention, there is provided a treat chlorine bypass dust while preventing increases in chemical cost and concentrations of heavy metals in clinker, and ensuring stability in quality of cement. In a chlorine bypass facility 1 extracting a part G of combustion gas, while cooling it, from a kiln exhaust gas passage, which runs from an inlet end of a cement kiln to a bottom cyclone, and recovering a high chlorine concentration chlorine bypass dust D5 from the extracted gas G1, a slurry S containing chlorine bypass dust and SO2 gas or/and CO2 gas are contacted with each other to obtain solid content. The slurry containing chlorine bypass dust and an exhaust gas from the chlorine bypass facility or/and the exhaust gas from the cement kiln can be contacted with each other, and the solid content can be fed to a cement finishing process, which allows cement with low CaO and Ca(OH)2 contents and with stable property such as setting time to be produced.

Abstract: A combustion exhaust gas processing device comprises: a dust collector collecting dust in a cement kiln combustion exhaust gas: a wet dust collector as a catalyst-poisoning-substance stripper removing a catalyst-poisoning substance from a combustion exhaust gas which passed the wet dust collector; and a catalyst device from which NOx, a persistent organic pollutant, etc. in the preheated combustion exhaust gas, are removed. A titanium-vanadium catalyst etc. as an oxide catalyst is used upstream of the catalyst device, and a platinum catalyst etc. as a noble-metal catalyst downstream of the catalyst device. The temperature of the combustion exhaust gas after the catalyst-poisoning substance is removed is increased up to 140° C. or more with the preheaters to prevent decline in denitration efficiency of and the decomposition efficiency of a volatile organic compound.

Abstract: To reduce cost of chemical by reducing quantity of foaming agent used when removing unburned carbon in fly ash with wet floatation and to prevent decrease in activity index of the fly ash. In wet decarburization of fly ash, the solution comprising the steps of: adding water to fly ash to generate slurry; adding hydrophobizing agent and foaming agent to the slurry and agitating them to generate bubbles; and adhering unburned carbon in the fly ash to the bubbles to float them to remove the unburned carbon in the fly ash, when sedimentation component at wet floatation separation is solid-liquid separated and liquid phase obtained by solid-liquid separation is reused for another floatation separation for new fly ash, the quantity of foaming agent added to the slurry is adjusted such that concentration of the foaming agent in liquid phase is in a predetermined range.

Abstract: A method for handling a substance from which a combustible gas volatilizes. A method for handling a substance from which a combustible gas volatilizes, in which, when such substance is handled inside an apparatus with a high degree of hermeticity, air is introduced into the apparatus and the substance is handled in a state in which the volatilized combustible gas is diluted to a concentration at which neither explosion nor fire occurs. With this method for handling a substance from which a combustible gas volatilizes, the combustible gas is diluted with air to a concentration at which neither explosion nor fire occurs, without using inactive gases such as nitrogen or carbon dioxide that have to be produced or purchased. Therefore, a substance from which a combustible gas volatilizes can be inexpensively and safely handled in operations such as mixing and storing.

Abstract: There is provided a method for producing a high-purity metal nitride by simple processes with good yield. Specifically provided is a method for producing a metal nitride including heating a metal hydride under a nitrogen gas or an ammonia gas.

Abstract: To effectively utilize coal ash while reducing mercury concentration in cement kiln exhaust gas. Coal ash is received from a thermal power plant or the like; the received coal ash is separated into ash and unburned carbon; the separated ash is utilized in a cement manufacturing facility as a cement raw material; and the separated unburned carbon is utilized in the cement manufacturing facility in accordance with mercury concentration in gas exhausted from a cement kiln of the cement manufacturing facility. In case that the mercury concentration in the gas exhausted from the cement kiln of the cement manufacturing facility is high, in the coal ash, unburned carbon with high mercury content can be treated in facilities other than the cement manufacturing facility without feeding the unburned carbon to the cement manufacturing facility, or the quantity of such unburned carbon fed to the cement manufacturing facility can be adjusted.

Abstract: A centrifugal air classifier, in which a relation between an area S1 of a side surface of a cylinder or a truncated cone circumscribed about the rotor blades, an axis of the cylinder or a truncated cone being the rotor rotational shaft, and a calculation average value D of a diameter of a circle orthogonal to the rotor rotational shaft and circumscribed about the rotor blades is S1/D2=0.9 to 1.6, and with the S1, a relation between a cross sectional area S2 of inflow of the air for classification and the D is S2/D2=0.8 to 1.4.

Abstract: An apparatus and a method for adding wet ash to cement which make it possible to fed wet ash to a cement mill without generating cost for drying the wet ash and new setting space at the neighboring area of the entrance portion of the cement mill. The apparatus comprises a dewaterer for dewatering wet ash, a mixer 7 for mixing the wet ash with one of materials that are mixed with clinker and ground together, and a feeder 11 for feeding the mixture to a cement mill 14. After dewatered, the wet ash with predetermined quantity is mixed with the one of the materials that are mixed with clinker and ground together and fed to the mill. The water content of the wet ash after dewatered is adjusted to 20 mass percent or below, preferably to 15 mass percent or below. A centrifugal separator can be used as the dewaterer, and a pug mill may be used as the mixer. Modified ash (fly ash slurry) from fly ash decarbonization facilities can effectively be used as the wet ash by feeding it to the cement mill.

Abstract: Provided is a piezoelectric element including: an electrode portion including a piezoelectric layer and an electrode layer that are laminated; and a non-electrode portion that is in contact with the electrode portion and includes a piezoelectric layer without an electrode layer, in which the non-electrode portion includes a region having a density smaller than a density of the piezoelectric layer of the electrode portion.

Abstract: There is provided a method for efficiently producing a high-purity alkali metal nitride or alkaline earth metal nitride by simple processes. Specifically provided is a method for producing an alkali metal nitride, an alkaline earth metal nitride, or a composite thereof, the method including thermally decomposing one or more alkali metal amides or alkaline earth metal amides.

Abstract: It is aimed at providing a heavy concrete, which does not require addition of a thickener such as methyl cellulose, which is less in segregation between a heavy aggregate and a cement paste, and which is high in flowability and excellent in construction ability. The present invention provides a heavy concrete comprising, at least, a cement, a heavy aggregate, and water, mixed with one another, characterized in that the heavy fine aggregate includes hot scarves brought about in a scarfing process of a steel slab surface. The present invention further provides the above-described heavy concrete characterized in that the heavy fine aggregate includes fine aggregate particles passing through a sieve having a nominal size of 0.15 mm, in an amount of 10% to 20% in mass percentage, and the heavy fine aggregate includes spherical particles each having a distortion irregularity of 3.

Abstract: A cement additive contains industrial waste and has the effect of inhibiting formation of monosulfate in a hardened cementitious material. The cement additive contains specifically calcium carbonate, gypsum and coal ash and/or blast-furnace slag powder. This enables efficient use of industrial waste, allows inhibiting monosulfate formation in the hardened cementitious material, and allows producing a hardened cementitious material having good durability (sulfate resistance).

Abstract: The invention has an object to provide a heavyweight fine aggregate and a heavyweight aggregate for a stiff heavyweight concrete having a slump of 0 to 3 cm, in which segregation from the cement paste is unlikely to occur, and to provide a stiff heavyweight concrete having a slump of 0 to 3 cm, using the heavyweight fine aggregate and heavyweight aggregate. The heavyweight fine aggregate comprises no less than 20 wt % of aggregate having a particle size smaller than 0.15 mm, and no less than 20 wt % of aggregate having a particle size from 2.5 mm to less than 5 mm. The above feature allows effectively inhibiting segregation between the aggregate and cement paste when blending the aggregate into the heavyweight concrete, and allows effectively increasing the filling rate in boxes when blending the aggregate into the heavyweight concrete for box filling.

Abstract: In an electrostatic separator or a magnetic separator, prior to electrically charging or magnetization of particles in order to carry out separation of mixed powder of particles having different properties from each other, classification is performed by a classifier so that the content of fine powder having a spherical equivalent diameter of 10 ?m or smaller is 15 mass % or less. After the classification, prior to electrostatic separation or magnetic separation, an operation of dispersing the mixed powder of particles may be carried out.

Abstract: In accordance with the present invention, there is provided an apparatus for fuelizing inflammable waste capable of efficiently fuelizing inflammable waste while reducing facility and operation costs of the overall system and maintaining stable operation, and so on. More particularly, the apparatus 1 for fuelizing inflammable waste comprises: a primary crusher 4 for crushing an inflammable waste W containing as principal component at least one selected from a group comprising plastics, sponges, fibers, rubbers and wood materials; a foreign matter removing device 7 for removing foreign matters F contained in the crushed objects W1; a secondary crusher 9 for secondarily crushing the crushed objects W3 from which foreign matters I, M are removed; and an injecting device 11 for injecting the secondarily crushed objects W4 generated by the secondary crusher 9 into a burner 10, and so on.

Abstract: A cement kiln chlorine/sulfur bypass system wherein the equipment cost is suppressed and the sulfur included in a combustion gas bled from a cement kiln is separated and effectively utilized. The cement kiln chlorine/sulfur bypass system comprises an air bleed means for bleeding a kiln exhaust gas passage, which runs from the end of the cement kiln to a bottom cyclone, of a part of the combustion gas, a separating means for separating dust in the gas bled by the air bleed means into coarse particles and fine particles, and a wet dust collector for collecting dust from the gas containing the fine particles separated by the separating means. The separating means is preferably a classifier in which the cut size is changeable. The wet dust collector is preferably a mixing scrubber.

Abstract: When fly ash is added to a cement kiln to materialize it after being desalinated by washing, scale is prevented from growing in a dissolution reaction apparatus depositing calcium-containing compounds dissolved in slurry, and the fly ash is effectively used as a cement material. A dissolution reaction apparatus according to the invention comprises: a dissolution tub 3 for dissolving powder material, a wet dust collector 5 for collecting powder material and mist while reacting slurry S in the dissolution tub 3 with gas G and returning the collected powder material and mist to the dissolution tub 3. A second wet dust collector 7 can be provided for collecting powder material and the like accompanying to the gas G discharged from the wet dust collector 5, and both the wet dust collectors 5, 7 can be vertical type and mounted independently with each other on the dissolution tub 3.

Abstract: A cement kiln from which its brick lining has been removed, or a rotary dryer for cement production is used as a fermentation treatment apparatus 202 for converting waste matter into compost. The waste matter to be subjected to the fermentation treatment includes city waste contained in garbage bags, and its fermentation treatment is carried out by introducing the waste matter directly into the aforesaid cement kiln or the aforesaid rotary dryer for cement production without tearing the aforesaid garbage bags.

Abstract: It is aimed at inexpensively providing a heavy aggregate comprising particles having particle diameters and densities suitable as a fine aggregate of a heavy concrete, heavy mortar, or the like, and there are provided: (i) a heavy aggregate comprising particles including, as a main constituent component, at least one of FeO, Fe2O3, and metal iron, characterized in that spherical particles are included in an amount of 20% or more in the whole of particles, and particles passing through a sieve having a nominal size of 0.15 mm are included in an amount of 10% to 20% in mass percentage in the whole of particles; and (ii) the above-described heavy aggregate characterized in that the heavy aggregate is obtained by mutually mixing at least two or more kinds selected from: mill scales brought about in a rolling process of steelmaking; coarse particle components sievedly caught at a particle diameter of 50 ?m from steelmaking converter dusts; and pig iron particles separated from blast furnace granulated slags.