Monday, February 05, 2007
Mining processors re-using mercury
MINING processors have employed a system called "mercury retort," which facilitates the reuse of the mercury instead of throwing it after use.
Retort facilities heat Mercury at 600 degree Fahrenheit or above forcing it into a vapor phase.
The vapor is pulled on vacuum through distillation coils and cooled to liquefy, then filtered to purify.
Mercury retort generally means mercury is removed from soil and other waste material using a retort or other thermal process.
In mining for gold, mercury is poured in the panned slosh with gold dust as mercury amalgamates the gold.
In the 1980s up until the retort process was introduced, the liquid metal that now contains gold is burned with a blowtorch until it disappears into a vapor, leaving the gold intact.
The vapor is not contained and is allowed to float up into the air, into the miner's body, and everywhere.
The retort system just turns the mercury around and around, from its liquid form to vapor to liquid to vapor over and over again.
Department of Environment and Natural Resources (DENR)-Southern Mindanao Director Ricardo Calderon said this is a recent development now employed by Diwalwal miners to minimize the discharge of hazardous waste down Naboc River that is being rehabilitated by the Mining and Environment Task Group of the Task Force Diwalwal, which DENR is a part of.
In 2006, the task group has conducted analysis of water samples assessed with mercury, chromium and total suspended particulates from Naboc River Irrigation System sourced from Naboc River.
The laboratory results registered that mercury content in the water has exceeded maximum limit by 350 percent while chromium is well within the set limits.
As with the toxic mercury, total suspended particulates also exceeded the standard limit set at 320mg per liter as it has reached 346mg per liter.
Inhalation of the mercury particles may cause the slowing down of the exchange of oxygen and carbon dioxide in the blood causing shortness of breath, straining the heart because it must work harder to compensate for oxygen loss.
The Task Force has also conducted monitoring of establishments, cooperatives, and processing plants to ensure they comply with Republic Act 6969 that requires the proper management and disposal of hazardous substances.
Calderon said the internal security task group has still made numerous arrests of miners who attempt to illegally transport mining chemicals as well as those who use the chemicals indiscriminately. (GLP)
For more Philippine news, visit Sun.Star Manila. For Bisaya stories from Davao. Click here. (February 5, 2007 issue)
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