Stabilization process of metallic mercury by sulphur
- AREVA CL BU, Gif-sur-Yvette (France)
The technical field of this subject can be described as the treatment of mercury based wastes in order to stock or eliminate them. Toxic mercury vapours prevent from directly stocking or incinerating the wastes. Therefore, some processes have already been implemented to reduce the mercury mobility. Those immobilization processes are created to avoid mercury release in the atmosphere by volatilization or in the soil by leaching. Among the 3 current processes: encapsulation, amalgamation and stabilization, we took an interest on the last one. Stabilization can be defined as an immobilization due to a combination between a molecule and motionless particles to reduce the release of dangerous elements in the atmosphere or the biosphere. The most common technique of metallic mercury stabilization found in readings is the sulphur amalgamation technique. It consists in the chemical reaction: Hg + S → HgS. A mercury sulphide is then produced and is very insoluble in the water. A 386 deg. C heating transforms it in red sulphide. The obtained mixture can be easily and safely stored in a waste storage. In this context, solid sulphur is added in wide excess compared to the liquid mercury to cause the reaction: Hg(l) + S(s) → HgS(s) with a molar ratio between 1/6.5 and 1/19. The main drawback of this technique is the generation of an important waste quantity: a mixture of HgS and sulphur. Moreover there's no guarantee about the absence of mercury vapours. Therefore there's a real need to improve the ratio and the safety of the reaction, which is the purpose of this study. The volume of the created product is greatly reduced in this case and authorizes significant savings on storage costs. The other experimental parameters discussed in this study are temperature, volume, flask type and mixing speed. (authors)
- Research Organization:
- American Society of Mechanical Engineers - ASME, Nuclear Engineering Division, Environmental Engineering Division, Two Park Avenue, New York, NY 10016-5990 (United States)
- OSTI ID:
- 22535177
- Resource Relation:
- Conference: ICEM2013 - ASME 2013: 15. International Conference on Environmental Remediation and Radioactive Waste Management, Brussels (Belgium), 8-12 Sep 2013; Other Information: Country of input: France; 0 refs
- Country of Publication:
- United States
- Language:
- English
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