Methods of decontaminating mercury-containing soils
US5516968A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 7, 1995 |
| Grant date | May 14, 1996 |
| Priority date | — |
| Expiry date | Jun 7, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Soil including sand and clays contaminated with elemental mercury are decontaminated by forming slurries with anhydrous liquid ammonia. An ammoniacal liquid, such as anhydrous liquid ammonia facilitates decontamination by breaking up soil into fine slurries for releasing droplets of mercury metal. The high density of the mercury metal permits precipitation with larger soil particles and for recovery from soil particulates. Contaminated soils having mixed wastes comprising metallic mercury with organic compounds like PCBs are decontaminated first by slurring with anhydrous liquid ammonia to release droplets of mercury for coalescing and recovery. Solvated electrons are formed in the slurry in-situ by treating the slurry with an alkali metal or alkaline earth metal to reduce or degrade toxic organic compounds to more environmentally benign substances. Mixed waste comprising elemental mercury and nuclear waste, such as radionuclides like plutonium and uranium in the fines of soil and clay can also be concentrated to yield residual soil products which are sufficiently free of contaminants to allow reclamation. Economics are improved over aqueous systems since ammonia can be recovered a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.