Coal ashes used for treating various media and facilities for using same

• US 6,015,498 A
• Filed: 11/10/1997
• Issued: 01/18/2000
• Est. Priority Date: 05/19/1995
• Status: Expired due to Fees

• Current Assignee: Raymond M. Gleizes, Terrils & Co.
• Original Assignee: Raymond M. Gleizes, Terrils & Co.
• Inventors: Gleizes, Raymond M.
• Primary Examiner(s): CINTINS, IVARS C
• Application Number:
  US08/930,109
• Time in Patent Office: 799 Days
• Field of Search: 210/688, 210/691, 210/747, 210/770, 210/787, 210/143, 210/219, 210/153, 210/251, 210/241, 210/194, 134/7, 425/62
• US Class Current: 210/688
• CPC Class Codes: B01D 15/00 Separating processes involving the treatment of liquids with solid sorbents using liquid sorbents B01D11/00; ion exchange processes or materials, sorbent materials in general B01J, e.g. sorbents for chromatography B01J20/281; for investigating or analysing materials G01N30/00; Apparatus therefor
• CPC Class Codes: B01J 20/00 Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
• CPC Class Codes: B01J 2220/4887 Residues, wastes, e.g. garbage, municipal or industrial sludges, compost, animal manure; fly-ashes
• CPC Class Codes: B09B 1/00 Dumping solid waste
• CPC Class Codes: C02F 1/00 Treatment of water, waste water, or sewage C02F3/00 - C02F9/00 take precedence

Abstract

Ashes are used when they have the particle size of fly-ash, i.e., when they have just been produced by a combustion process. They can be used, inter alia, for dehydrating and/or stabilizing sewerage plant sludge or sludge from surface treatment plants, for detoxifying liquid, semi-liquid or solid media contaminated by heavy metals and the like, and for removing pollutants from hydrocarbon-containing liquid or semi-liquid media.

Claims

1. Process for the treatment of a liquid or semiliquid medium, which comprises:

contacting the medium to be treated with from 0.2 to 2% by weight, relative to the volume of the medium to be treated, of coal fly ash produced by burning in a boiler with a circulating fluidized bed, at a temperature of about 850°

C., said ash having a particle size such that at least 80% by weight passes through a screen having a mesh opening of 80 μ

m.

2. Process according to claim 1, wherein the medium contains a toxic constituent selected from the group consisting of heavy metals, polycyclic aromatic hydrocarbons, and mixtures thereof.

3. Process according to claim 1, further comprising after treatment of the medium with said ash, centrifuging the treated medium to separately recover the liquid of the treated medium and the ash, said ash being mixed with solid matter which was suspended in the medium.

4. Process according to claim 1, wherein the medium to be treated and the ash are contacted for a period of between ten minutes and an hour.

5. Process according to claim 1, wherein the medium to be treated and the ash are contacted for a period of about half an hour.

6. Process according to claim 1, wherein the medium treated comprises sludge from purification stations or sludge produced by surface treatment workshops, and said sludge is dehydrated or stabilized by contact with the ash.

7. Process for the detoxification of soils contaminated with heavy metals, which comprises:

mixing the contaminated soils with coal fly ash in an amount sufficient to detoxify the soils, said ash being produced by burning in a boiler with a circulating fluidized bed, at a temperature of about 850°

C., said ash having a particle size such that at least 80% by weight passes through a screen having a mesh opening of 80 μ

m.

8. Plant for the treatment of liquid or semiliquid media, which comprises:

a stirring vessel having an outlet;

first adjustable flow-rate means fluidly connected to a source of coal fly ash for feeding coal fly ash to said stirring vessel, said ash produced by burning in a boiler with a circulating fluidized bed at a temperature of about 850°

C., said ash having a particle size such that at least 80% by weight passes through a screen having a mesh opening of 80 μ

m;

second adjustable flow-rate means for feeding the liquid or semiliquid medium to said stirring vessel;

a centrifugal separator having an inlet fluidly connected to the outlet of said stirring vessel, a discharge conduit for separated liquid, and a discharge outlet for ash removal; and

closed circuit recirculation means operatively associated with said stirring vessel for maintaining uninterrupted circulation in said stirring vessel when the plant is in a standby state.

9. Mobile plant for the treatment of liquid or semiliquid media, which comprises:

means for storing coal fly ash produced by burning in a boiler with a circulating fluidized bed at a temperature of about 850°

C., said ash having a particle size such that at least 80% by weight passes through a screen having a mesh opening of 80 μ

m;

means for supplying ash;

means for feeding liquid or semiliquid medium to be treated;

a blender structured and arranged to be fed by the supplying means and the feeding means;

a centrifugal separator fluidly connected to the blender and having a first outlet for removing separated liquid of the treated medium, and a second outlet for removing separated ash;

means for automatically controlling the supplying, feeding, blending, centrifuging and removal operations;

an electricity generating unit for supplying said plant with electrical energy; and

wherein the plant is mounted on a trailer.

10. Plant according to claim 9, further comprising a device for molding ash blocks fed by the second outlet.