High gold prices since the early 1980s have resulted in a dramatic rise in gold production. These lure miners into the Small-Scale Gold Mining (SSGM) sector in regions where suitable gold deposits are still available.
The easiest and less expensive methods used are cyanidation and amalgamation. They are, however, generate a legacy of extensive degradation and deplorable social conditions, both during and after activities have ceased. The environmental impacts associated with small-scale gold mining are of major concern to the region’s policy makers as well as in national. Some of these problems include:
- Mercury and cyanide pollution
- Disposal of tailings and effluents into rivers
- Contamination from improperly constructed tailings impoundments
- River damage in alluvial areas
- Erosion damage and deforestation
- Landscape destruction
- Socio-economic consequences
Collectively, small-scale gold mining tends to do more environmental damage than mining carried out by larger and more modern companies. A lack of awareness – particularly of the less visible or long-term consequences of their actions – combined with lack of information about affordable methods to reduce impacts and a lack of obvious incentives to change, all contribute to the problem. The reasoning behind this is that miners tend to focus more on their immediate concerns (quick revenue) rather than on the impacts of their actions.
This proposed alternative technology follows the cleaner technology, reduces the exposure of small-scale miners to toxic substances such as cyanide and mercury which causes health problems, minimizes cyanide and mercury waste in the environment, furnish information on the feasibility of recovering gold using non-conventional techniques, and direct smelting recovers unliberated gold that amalgamation cannot recover.
The present proposal is designed to examine the gold processing technologies currently being used by miners in the CARAGA and South Cotabato Region, and identify some alternative mercury- and cyanide-free techniques that can be adopted in CARAGA and South Cotabato Region.
This proposed project aims to develop and assess the technical feasibility of an alternative technology for cyanidation and amalgamation of gold ore deposits from small-scale mining in CARAGA and South Cotabato Region.
Specific project aims are as follows:
- To evaluate the current practices of small-scale gold mining in certain parts of CARAGA and South Cotabato Region.
- To characterize the ore material used by small-scale gold miners in certain parts of CARAGA and South Cotabato Region.
- To assess the technical feasibility of iodide-iodine leaching for small-scale mining.
- To assess the technical feasibility of chloride-hypochlorite leaching for small-scale mining.
- To assess the technical feasibility of direct smelting using borax for small-scale gold mining.
Prof. Ephraim Ibarra
Master in Metallurgical Engineering, University of the Philippines
Engr. Gevelyn B. Itao
Master of Engineering, MSU-IIT