Stabilization and Solidification of Mercury
Following the adoption of the Minamata Convention on Mercury, it is expected that the demand for mercury will decrease in the coming years, and that there will be a surplus of mercury in the marketplace. Consequently, finding a long-term solution for safely storing mercury will play an increasingly pivotal role in mercury management.
Mercury has the unique characteristic of being the only metal that is liquid at room temperature and is highly volatile. In addition, when mercury comes into contact with water, it quickly reacts and leaching of 10μg/ℓ of mercury occurs, which goes over the Uniform National Effluent Standards in Japan *1. Given these hazardous characteristics, it is crucial that countries seek proper long-term solutions for storing mercury in order to suppress the amount of mercury that is dispersed into the environment.
We, at Nomura Kohsan, have already established a safe and reliable way to produce mercury sulfide (HgS) using the mechanochemical reaction. This stabilized mercury compound is our long-term mercury storage solution.
Stabilization of mercury as HgS occurs by mixing the collected metal mercury with sulfur and by enhancing the activity and reaction of the particles through the provision of mechanical energy such as impact, shear and friction.
However, as HgS on its own exists in powder form, it would easily permeate the environment. Therefore, using resin and cement, we solidify the HgS powder to eliminate this problem.
Although Japan has strict analysis methods for mercury management, we have conducted our tests for mercury stabilization technology using these methods. For several years now, we have been conducting research and tests to hone our technology.
As the demand for mercury decreases in the future, it would be inevitable for countries to think of long-term storage solutions for mercury once it comes to the end of its lifecycle. We believe that Nomura Kohsan’s mercury stabilization technology would be one solution to a long-standing issue.
*1 The National Effluent Standards for mercury in Japan is 5μg/ℓ