Abstract: A process for reforming the fly ash, including the heating step that heats a raw fly ash powder containing the unburned carbon at a temperature of 780 to 1000° C. to decrease the amount of the unburned carbon contained in the raw fly ash powder; the classifying step that introduces the heat-treated fly ash containing the unburned carbon in decreased amounts obtained through the heating step into a classifying apparatus in the state of being heated at a high temperature so as to separate the fly ash into a coarse powder and a fine powder; the fine powder recovering step that recovers the fine powder of the heat-treated fly ash obtained through the classifying step by using a dust-collecting apparatus; and the milling step that mills the coarse powder of the heat-treated fly ash obtained through the classifying step until a 45 ?m sieve residue becomes not more than 34% by mass, and then recovers the milled powder.

Abstract: A method of recovering the fly ash, including the firing step in which the raw fly ash powder containing the unburned carbon is fired to remove the unburned carbon by burning, characterized by further including the step of measuring the content of unburned carbon in the raw fly ash powder; and the sieve-classifying step of obtaining a fine fly ash powder which is the component under the sieve and has a decreased content of unburned carbon as a result of sieve-classifying the raw fly ash powder; wherein the perforation size of the sieve used in the sieve-classifying step is set depending upon the content of unburned carbon in the raw fly ash powder, the sieve having a small perforation size being used when the content of unburned carbon is large and the sieve having a large perforation size being used when the content of unburned carbon is small; and the fine fly ash powder which is the component under the sieve is recovered through the firing step.

Abstract: A process for reforming the fly ash by heating a raw fly ash powder that contains the unburned carbon and thereby decreasing the content of the unburned carbon, characterized in that (a) as means for heating the raw fly ash powder, use is made of a heating unit that heats the raw fly ash powder by passing it through a heated medium-fluidized bed, (b) a high-temperature gas stream is passed through the heating unit to form the heated medium-fluidized bed and to fluidize and convey the raw fly ash powder that is thrown into the medium-fluidized bed, (c) the flow rate of the high-temperature gas stream is so set that the raw fly ash powder thrown into the heating unit is all heated in the medium-fluidized bed and is taken out from a take-out port provided at an upper part of the heating unit but that the particulate medium forming the medium-fluidized bed is not discharged from the take-out port, (d) the fly ash powder after heated and discharged from the take-out port of the heating unit is introduced into an a

Abstract: A process for reforming the fly ash, including the heating step that heats a raw fly ash powder containing the unburned carbon at a temperature of 780 to 1000° C.

Abstract: A process for producing a modified fly ash comprising the steps of providing, as a raw material, the raw fly ash discharged from a pulverized coal combustion boiler; classifying the raw fly ash into a crude powder and a fine powder; removing the unburned carbon contained in the crude powder by heating the crude powder at a temperature in a range of 500 to 1000° C.; and mixing together the crude powder from which the unburned carbon has been removed and the fine powder to obtain a modified fly ash.

Abstract: A process for reforming the fly ash, including the heating step that heats a raw fly ash powder containing the unburned carbon at a temperature of 780 to 1000° C. to decrease the amount of the unburned carbon contained in the raw fly ash powder; the classifying step that introduces the heat-treated fly ash containing the unburned carbon in decreased amounts obtained through the heating step into a classifying apparatus in the state of being heated at a high temperature so as to separate the fly ash into a coarse powder and a fine powder; the fine powder recovering step that recovers the fine powder of the heat-treated fly ash obtained through the classifying step by using a dust-collecting apparatus; and the milling step that mills the coarse powder of the heat-treated fly ash obtained through the classifying step until a 45 ?m sieve residue becomes not more than 34% by mass, and then recovers the milled powder.

Abstract: A process for producing a modified fly ash comprising the steps of providing, as a raw material, the raw fly ash discharged from a pulverized coal combustion boiler; classifying the raw fly ash into a crude powder and a fine powder; removing the unburned carbon contained in the crude powder by heating the crude powder at a temperature in a range of 500 to 1000° C.; and mixing together the crude powder from which the unburned carbon has been removed and the fine powder to obtain a modified fly ash.

Abstract: A sieve with a mesh opening of 75 to 20 ?m is provided. A raw fly ash powder is separated into a component remaining on the sieve and a component passing through the sieve by classification using the sieve. A fine fly ash powder, which is the component passing through the sieve, is used as a cement admixture. A coarse fly ash powder, which is the component remaining on the sieve, is used for production of cement clinker.