Method of regenerating mercury adsorption means

• US 5,460,643 A
• Filed: 01/26/1994
• Issued: 10/24/1995
• Est. Priority Date: 01/27/1993
• Status: Expired due to Fees

• Current Assignee: Degussa AG (Rag-Stiftung)
• Original Assignee: Degussa AG (Rag-Stiftung)
• Inventors: Hasenpusch, Wolfgang, Wetterich, Harald
• Primary Examiner(s): SPITZER, ROBERT H
• Application Number:
  US08/186,517
• Time in Patent Office: 636 Days
• Field of Search: 95/110, 95/134, 423/210, 502/27, 502/56
• US Class Current: 95/134
• CPC Class Codes: B01J 20/103 comprising silica
• CPC Class Codes: B01J 20/3204 Inorganic carriers, supports or substrates
• CPC Class Codes: B01J 20/3236 containing metal, other than zeolites, e.g. oxides, hydroxides, sulphides or salts
• CPC Class Codes: B01J 20/3433 of sorbents or filter aids other than those covered by B01J20/3408 - B01J20/3425
• CPC Class Codes: B01J 20/3475 in the liquid phase
• CPC Class Codes: B01J 20/3483 by thermal treatment not covered by groups B01J20/3441 - B01J20/3475, e.g. by heating or cooling

Abstract

Ceramic particles impregnated with silver nitrate for adsorbing mercury from waste gases can be regenerated and reused if the mercury is distilled off at 600° to 900° C. and the ceramic particles are subsequently impregnated with nitric acid.

Claims

1. A method for regenerating ceramic particles impregnated with silver nitrate used for the removal of mercury from waste gases, comprising heating ceramic particles containing adsorbed mercury to 600°

to 900°

C. in order to distill and remove the mercury from said particles prior to treatment with nitric acid, recovering the ceramic particles and subsequently impregnating said particles which are free of mercury with nitric acid.

2. The method according to claim 1 further comprising drying said particles.

3. The method according to claim 1, wherein the particles are heated to 850°

to 900°

C.

4. The method according to claim 1 further comprising adding hydrogen peroxide to the nitric acid.

5. The method according to claim 1 wherein said ceramic particle are selected from the group consisting of silica gels, silica and zeolites.

6. The method according to claim 1 further comprising cooling said particle after heating to 600°

to 900°

C.