DAVAO CITY—The outcome of a government-initiated gold processing method in the mining industry is churning out a promising future for mineral extraction among small-scale operators: No more mercury and cyanide scare to blight people’s lives, the river systems and the environment as a whole.
Eight years after the project “Integrated Gold-copper Mineral Processing Pilot Plant in the Regions” was field-tested in October 2015 in Nabunturan, Davao de Oro, the Department of Science and Technology (DOST) reported increased earnings for small-scale miners and the absence of severe environmental pollution associated with small-scale mining in the past.
“The latest performance of the facility has shown that it can increase the earnings of small-scale miners up to 86.5 percent, with opportunities for further improvement,” the DOST told the BusinessMirror.
With non-pollutive efficiency to extract gold from the ore and lesser risk of an environmental damage, the new processing method may likely ease the negative impression against small-scale mining and a future gold rush, and offer a better income outlook for people seeking their fortune from small-scale mining operations.
Critical assistance
DOST Region XI Director Anthony Sales said small-scale mining operations continue to thrive alongside corporate mining operations, which are mostly found in mineral-rich Davao de Oro province, formerly called Compostela Valley.
He said the small-scale mining operations still needed critical assistance to avoid polluting the environment because of their reliance on the poisonous mercury and cyanide to extract gold. “The problem with small-scale mining operations is that these are unregulated or non-regulated. And they cause pollution to the environment, aside from also endangering [the miners’] health,” Sales added.
This, he added, is one reason the DOST is embarking on a program called Community-led Non-Cyanide Non-Mercury Mining Technology. The initiative was pilot-tested in Davao de Oro.
Focus on small-scale miners
THE unresolved plight of small-scale miners and the persistent challenge in mass transportation systems are on the spotlight in this year’s regional scientific meeting in Mindanao, one of three legs of meetings before the annual national gathering of scientists, researchers and academicians in Manila.
Experts from the Department of Mining of the University of the Philippines-Diliman said the initiative would apply the new ore processing method “since this technology extracts double amount of gold than the usual method.”
“This also extracts copper from the same ores in a single process,” the provincial information office said, quoting UP experts.
New processing
THE Integrated Gold-Copper Mineral Processing Pilot Plant (IGCMPPP) facility in Nabunturan houses a new technology called CLINN-GEM (Community-Led Integrated Non-Cyanide Non-Mercury Gold Extraction Method), which was developed by UP-Diliman and funded by the DOST-Philippine Council for Industry, Energy, and Emerging Technology Research and Development (PCIEERD).
The technology uses various processes, including gravity concentration, flotation and leaching, in addition to the typical crushing and grinding processes.
“The gravity concentration process uses a gravity concentrator and shaking table to recover free gold, which is not associated with other minerals, by taking advantage of the differences in densities between minerals and metals,” the DOST said.
In contrast, the flotation process utilizes flotation cells to recover gold associated with sulfide minerals by altering their surface properties with the help of flotation reagents such as frothers, collectors and pH adjusters, which increase its hydrophobicity.
This produces a gold concentrate that is fed into the next process, which is leaching. Chlorination leaching is used to recover the gold from the concentrate through the dissolution and eventual precipitation of gold particles.
“Finally, these particles are refined in a furnace to obtain the highest possible purity of gold,” it added.
The IGCMPPP facility is composed of six sets of mineral processing packages and 10 laboratory services, all of which are already enrolled in the Provincial Local Revenue Code of Davao de Oro. The team that manages the facility is currently addressing risks and opportunities, including but not limited to increasing inventory buffer of supplies and equipment, adding technical personnel, and other measures to ensure consistent quality of service for the public, the DOST said.
Remaining lab
THE Davao de Oro province wanted the pilot testing of the processing plant to produce positive results “to help small-scale mining communities through the new technologically innovative and pro-environment mineral processing and extractive methods.”
“This is a safer method on gold-processing for it uses no harmful chemicals like mercury and cyanide,” it said.
The technology was also tested in Benguet, Bicol and the Caraga Region. However, only the Davao de Oro facility has remained operational. “This could be attributed to our different implementation strategy, which involves the active participation of the Provincial Local Government of Davao de Oro (PLGU-DdO) led by Gov. Dorothy Montejo-Gonzaga,” the DOST said.
PLGU-DdO has been supporting the project since 2018 through the Green Mining Program implemented by its Provincial Environment and Natural Resources Office. The IGCMPPP is managed jointly by DOST XI and PLGU-DdO, “and both agencies have invested in designating a full-time workforce that reports to the facility,” the DOST added.
Corporate help
THE facility has not been totally adopted yet by any of the small-scale mining operations existing in Davao de Oro. However, one positive note is that “starting this year, the IGCMPPP has secured the support of Apex Mining Co. Inc. through the initiative of Governor Gonzaga,” the DOST said.
The support would be in the form of laboratory supplies to enhance and expand the services of the IGCMPPP laboratory, and immersion and training of small-scale miners: to encourage them and build their capacity in adopting the green mining technology.
Despite the improved outlook—earnings of small-scale miners to rise by up to 86.5 percent—the DOST cautioned, “This level of performance cannot be guaranteed for all types of ores mined in Davao de Oro.” To address this issue, the IGCMPPP Laboratory will be equipped with P9.65 million worth of equipment, including an X-ray diffractometer and X-ray fluorescence spectrometer, through the DOST OneLab for TED project.
“These two pieces of equipment will be used to thoroughly characterize the ores to be processed in the facility and ensure their profitability,” the DOST said.
The IGCMPPP is also involved in researching other green mining strategies and currently has an active collaboration with Mapua Malayan College of Mindanao through a DOST-PCIEERD-funded project entitled “Innovative technology for refractory gold extraction using deep eutectic solvent (DES) and hypochlorite solution.”
Issue of concern
ORGANIZERS of the Mindanao Regional Scientific Meeting in April at the Acacia Hotel here identified the small-scale mining as Minahang Bayan, and topped the issues of concern in the region. It has been logged as one of the top five pressing issues in the country that could be addressed through the application of science and technology.
Small-scale mining became a national concern in the 1990s amid the gold rush in the Diwalwal mountain mining village in Davao de Oro, formerly Compostela Valley, which gathered as many as 100,000 gold hunters and fortune seekers.
The massive influx of people turned the village, 25 kilometers upland from the town of Monkayo, into a ticking time bomb of lawlessness in shantytowns, with violence frequenting the crisscrossing tunnels. Reports of mine tunnel collapse were regular fare. Meanwhile, in the lowlands, farmers and residents complained of rivers poisoned by mercury and cyanide.
Mercury contamination of the rivers was also detected as far as the Davao del Norte portion of the Davao Gulf, 70 kilometers south of Monkayo. This was further aggravated by the operation of crude rock ore processing plants, called ball mills and cyanide plants, outside the población of Tagum. A University of the Philippines study on the extent of mercury contamination has found the underground waters unfit for drinking.
The Mines and Geosciences Bureau (MGB) said 13 Minahang Bayan currently operate in the Davao Region and 15 others have filed their petition to be declared as such. Aside from these Minahang Bayan, the MGB granted small-scale mining contracts to six operations.
A Minahang Bayan is the government intervention into the unregulated, often destructive, operations of small-scale miners.
Some Minahang Bayan independently operating as small-scale miners could be seen around corporate mines, mostly in Davao de Oro and Davao Oriental. The MGB said there are 18 operations granted with the Mineral Production Sharing Agreement, and one with Financial or Technical Assistance Agreement, 51 applications for exploration permits, eight with exploration permits already and three others granted with mineral processing permit.
“Our objective is to balance the effect to the economy and the benefits that we get for sustaining society as well as the environment,” Sales said.
Sales said the DOST will continue to explore ways to alleviate the plight of small-scale miners through this technology.
“I believe this is one way of democratizing science and technology and bringing the technology closer to the people, and to address the pressing problem of the mining industry,” Sales said.
Image credits: ILO / Minette Rimando (Creative Commons BY-NC-ND), Celeste Llaneta, UP MPRO (up.edu.ph/a-better-kind-of-alchemy)
