Thursday, October 09, 2008 Waste from mining firm ‘safe’
A MINING firm’s waste material that has spilled into the Sapangdaku River in Toledo City is not harmful, the Mines and Geosciences Bureau (MGB) 7 assured.
MGB 7 Director Roger de Dios gave this assurance yesterday in a meeting with Gov. Gwendolyn Garcia, Toledo City Mayor Arlene Zambo, barangay and Carmen Copper Corp. (CCC) officials.
CCC vice president and resident manager Rodrigo Cal echoed de Dios’ statement in a tour that the company organized for media practitioners.
“The tailings are not toxic…There is no chemical used that causes any harmful side effects in the entire process,” explained Cal, adding that since the entire copper mining process was done mechanically and did not use any harmful chemicals, the tailings would not end up as toxic residue.
The MGB 7 earlier ordered the suspension of the operations of CCC’s emergency tailings pond (ETP).
But during the meeting yesterday, de Dios said the waste “is not harmful” and that the pH level of these materials falls within the standards of the Department of Environment and Natural Resources.
Despite the assurance, Garcia directed CCC officials to closely monitor their main pipe, which reportedly malfunctions from time to time.
During yesterday’s tour, Cal said the ETP has now been secured and no more leakage would occur.
“The outflow has already been sealed, so zero discharge na,” said Cal.
He also assured that the mine tailings did not have any high concentrations of heavy metals.
“That’s a common misconception that the tailings have high metal contents where in fact the metals are extracted to form the concentrate,” Cal said.
In the entire process of extracting copper, all that would be left would be the residual mine tailings without any metals.
In extracting copper, Cal explained that they would initially mine for ore. The ore would be extracted from either the mine’s open pits and underground pits. Once enough ore has been extracted, the ore would undergo primary crushing to reduce the ore’s size into six-inch rocks.
The smaller ores would then be forced through a secondary and tertiary grinder to decrease the ore’s size to one-half inch or less.
Once half an inch in size, the ore would undergo another round of grinding until the ore is as fine as sand.
“Once it is sand-size, the ore will be processed in water. The system will create bubbles that would allow the copper to cling to the bubbles and all that does not cling to the bubbles and floats is the tailing,” explained Cal.
The copper that clings to the bubbles will be collected and that would be the copper concentrate. The copper concentrate is made up of 28.5 percent copper.
Aside from the copper concentrate, the CCC also produces magnetite concentrate and pyrite concentrate. The magnetite concentrate is made up of 60 to 65 percent iron while the pyrite concentrate is made of 42 percent sulfur.
Cal predicts that there would still be enough ore reserves in their mines that would last them for the next 25 years. (GMD/EPB)
