Process for reforming the fly ash and apparatus therefor

Patent metadata

Field	Value
Publication number	US-11407683-B2
Application number	US-201916978578-A
Country	US
Kind code	B2
Filing date	Mar 5, 2019
Priority date	Mar 13, 2018
Publication date	Aug 9, 2022
Grant date	Aug 9, 2022

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 μm sieve residue becomes not more than 34% by mass, and then recovers the milled powder.

First claim

The invention claimed is:

1. A process for reforming a fly ash, including:
a heating step that heats a raw fly ash powder containing an 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;
a classifying step that introduces the heat-treated fly ash containing the unburned carbon in decreased amounts obtained through said heating step into a classifying apparatus while conveying it maintaining a temperature of not lower than 400° C. so that the fly ash is separated into a coarse powder and a fine powder;
a fine powder recovering step that recovers the fine powder of the heat-treated fly ash obtained through said classifying step by using a dust-collecting apparatus; and
a milling step that mills the coarse powder of the heat-treated fly ash obtained through said classifying step until a 45 μm sieve residue becomes not more than 34% by mass, and then recovers a milled powder.

2. The process for reforming the fly ash according to claim 1 , wherein the amount of the unburned carbon is decreased down to less than 3% by mass through said heating step.

3. The process for reforming the fly ash according to claim 2 , wherein heating in said heating step is so executed that 50% by mass is not reached by a content of massive grains that have a maximum diameter of not less than 150 μm contained in the heat-treated fly ash in which the amount of the unburned carbon has been decreased.

4. The process for reforming the fly ash according to claim 1 , wherein a 45 μm sieve residue of the fine powder obtained by the classification is not more than 34% by mass.

5. The process for reforming the fly ash according to claim 1 , wherein the coarse powder of the heat-treated fly ash obtained through said classifying step is milled after having been cooled down to not higher than 200° C.

6. The process for reforming the fly ash according to claim 1 , wherein said fine powder recovered from said dust-collecting apparatus is mixed with the milled powder recovered in said milling step.

7. An apparatus for reforming a fly ash including a heating apparatus capable of heating a raw fly ash powder containing an unburned carbon to a temperature of 780 to 1000° C., a pipe for conveying a heat-treated fly ash obtained by being heated by said heating apparatus maintaining a temperature of not lower than 400° C., a classifying apparatus for classifying the heat-treated fly ash obtained by being heated by said heating apparatus, a dust-collecting apparatus for recovering a fine powder obtained by being classified by said classifying apparatus, a cooling apparatus for cooling a coarse powder obtained by being classified by said classifying apparatus, and a milling apparatus for milling said coarse powder cooled by said cooling apparatus.

8. The apparatus for reforming the fly ash according to claim 7 , wherein said classifying apparatus is a wind power classifying apparatus.

9. The apparatus for reforming the fly ash according to claim 7 , wherein the reforming apparatus further includes a mixing apparatus for mixing said fine powder recovered from said dust-collecting apparatus with said milled powder recovered from said milling apparatus.

Assignees

• Tokuyama Corp

Inventors

• Omura Kohei
• Kakizono Kenichi
• Seki Takuya
• Kawano Takeshi

Classifications

• B09B3/40 Primary

  involving thermal treatment, e.g. evaporation (processes using mineral binders involving a melting or softening step B09B3/29; involving radiation B09B3/50) · CPC title

• C04B7/26 Primary

  from raw materials containing flue dust {, i.e. fly ash (C04B7/243 takes precedence)} · CPC title

• B02C18/0084

  specially adapted for disintegrating garbage, waste or sewage · CPC title

• F23J2700/001

  Ash removal, handling and treatment means · CPC title

• C04B2111/1087

  Carbon free or very low carbon content fly ashes; Fly ashes treated to reduce their carbon content or the effect thereof · CPC title