Amalgamation of Mercury-Contaminated Waste using ADA Process, Colorado Minerals Research Institute

Site Name:

Los Alamos National Laboratory


New Mexico and Ohio

Period of



Field demonstration

Amalgamation using the ADA Process
- Process consists of combining liquid mercury with a proprietary sulfur mixture in a pug mill to stabilize the elemental mercury
- The pug mill was a dual shaft mixer 0.9 m long with a 0.1 m2 cross section, and held 0.06 m3 of material; the mixing blades were 14 cm long and overlapped; mixing speed was 50 rpm
- Mixing was concluded when the reaction exotherm subsided and free elemental mercury analysis indicated that more than 99% of the mercury had reacted
- Air above the pug mill was swept to remove mercury vapors and filtered through a HEPA filter and a sulfur-impregnated carbon filter to capture mercury
- Processing was conducted at ambient conditions

Cleanup Authority:
Not identified

Technology Vendor:
ADA Technologies
Englewood, CO
Thomas B. Conley
Oak Ridge National Laboratory
Telephone: (423) 574-6792
Fax: (423) 574-7241

William Owca
DOE Idaho Operations Office
Telephone: (208) 526-1983
Fax: (208) 526-5964

Heavy metals
- Mercury

Waste Source:
Nuclear processing operations at U.S. DOE Los Alamos National Laboratory and Fernald Facilities

Type/Quantity of Media Treated:
Liquid mercury
- 112 kg of mercury from LANL and 20 kg from Fernald
- No radioactivity was detected in either waste stream
- The waste from Fernald contained significant amounts of water

Purpose/Significance of Application:
Demonstrate amalgamation of elemental mercury

Regulatory Requirements/Cleanup Goals:
- Envirocare of Utah Waste Acceptance Criteria
- RCRA TCLP limit for mercury - 0.20 mg/L

- Wastes were processed in 5 batches (4 from LANL and 1 from Fernald) of 20 to 33 kg/batch
- The amount of free mercury was reduced from 99.87 to 99.98% per batch
- TCLP mercury was less than 0.1 mg/L in each batch, with a mercury waste loading of 57%
- Product from the amalgamation process was found to meet the Envirocare Waste Acceptance Criteria
- Mercury vapor concentrations above the pug mill were below the TLV of 50 µg/m3

Cost Factors:
- Projected costs for full-scale amalgamation using the ADA Process were $300/kg for more than 1,500 kg, assuming waste is elemental mercury, and does not include disposal costs of the treated waste

ADA Technologies conducted a demonstration of a proprietary amalgamation technology on wastes containing elemental mercury from Los Alamos and Fernald. The ADA process consists of combining liquid mercury with a proprietary sulfur mixture in a pug mill, and is conducted at ambient conditions.

Results showed that the process reduced the free mercury by 99.87 to 99.98%, and that the product met the Envirocare Waste Acceptance Criteria and passed the RCRA TCLP criteria for mercury. Projected costs for use of the technology were $300/kg and costs for treating smaller amounts of wastes, such as at a specific site, were projected to be prohibitive. The report discusses the possibility of a national procurement contract to lower the cost of the technology on a unit mass basis.