Small Scale Mining in Papua New Guinea

 

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Small Scale Mining in Papua New Guinea (PNG)

Small-scale mining in Papua New Guinea was practiced for more than a century when the first ever gold discovery was done in the Sudest Island in in the Milne Bay Province in 1888. The small-scale mining operation then extended to other neighbouring islands of Missima and Woodlark and further to the other parts of Papua New Guinea.

It is also known that about 100 years ago there were also miners mining on the Yodda and Gira fields in Oro Province and 10 years later at Lakekamu in Gulf Province in 1920s. These discoveries led to the development of major mining operations in Papua new Guinea.

Gold is still actively produced in Bulolo Wau area as well as other areas in PNG today.

The early miners were able to open up the Highlands in the 1930's and located gold at Kainantu, Kuta and Porgera. Others discovered the Sepik areas and found gold at Maprik and Amanab. The early miners also mined at Kupai on Bougainville near the closed Panguna Mine.

Gold remains an integral part of the cash economy in areas where gold has been traditionally mined. The local landowners are testing their own land and finding new gold anomalies throughout PNG.

There are more than 50,000 to 60,000 small scale gold miners working at various alluvial gold districts throughout he country using various mining methods.

The most commonly known basic mining methods are sluicing and panning. The miners sometimes use water pump and other motor powered machines in their operation to either go semi-mechanised or fully mechanised.

Abandoned Trommel at Tuguba River Mine Site in Tamo, East Sepik Province

Mechanized Mining Equipment Parked at an alluvial mine site at Tuguba River, Tamo in the East Sepik Province

Note:
The this article is an extract from a publication by Department of Mining Papua New Guinea,2001.

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Description of Gold

Gold is a soft yellow metal which is much heavier than a normal stone of the same size. It is non-corrosive, non-magnetic. However, gold is very good conductor of heat and electricity and it does not change its state or color even when exposed to the nature for millions of years.

Gold is valuable and can be a substitute for money in trade. Gold is like money and it is used as a financial instrument and is readily traded throughout the world. It has a well-publicized price. Gold is mined and recovered by utilizing different mining and processing techniques. 

It can be mined by locals using small scale mining methods for alluvial or mined from hard rock gold deposits using highly mechanized operations or from placer deposits using simple or semi mechanized alluvial mining techniques.

Some minerals can be misleading. i.e. pyrite will look similar to gold but you need to know very well the properties of gold in terms of shape patterns and appearance. Pyrite is actually a fools gold.  First timers need to be very careful if you are buying gold from alluvial gold miners. There are other various techniques which you can use to identify and be sure that what you see is for sure gold. Stay in tune or subscribe for updates on the next article(s)

Photo Courtesy of Gem Rock Auction

Reference:

Small Scale Gold Mining in Papua New Guinea, Department of Mining Papua New Guinea 2001.

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Environmental Impacts of Artisanal and Small Scale Gold Mining in Papua New Guinea

Mechanize Small Scale Mining

Artisanal and small scale gold mining (ASSM) offers lucrative employment opportunities to the locals of most developing countries. The major drawback of ASSM is its impacts on the environment as a result of improper mining and processing techniques. Exposed and disturbed lands are usually subject to soil erosion and avalanches of debris in active ASSM areas. Mercury is commonly used to concentrate gold, and if not handled properly causes pollution of life supporting river systems.

Small scale gold miners in many developing countries rely primarily on deposits containing free gold and may be classified as shallow/deep alluvial or lode type. The mining method used in artisan small scale gold mining employ very basic technology. Shallow alluvial deposits are commonly found in valleys and streams at depths not more than two meters. Deep alluvial deposits are found along major riverbanks and older river courses, and usually at depths exceeding six metres along the banks of rivers. The lode type of gold deposits is usually composed of partially weathered gold bearing reefs, which are either outcrops or near surface deposits. In Papua New Guinea, active artisanal mining are commonly found abandoned mining areas like Panguna and Missima and also near operating mines like Porgera, Eddie Creek in Wau Bulolo, Morobe Province. Not only that but also other parts of the Provinces also have active small scale miners. Other provinces include but not limited to: East Sepik, Sandaun, Enga, Western, Eastern Highlands, Jiwaka, Madang, Western Highlands, Oro, Milne Bay,Morobe.

 The small scale gold fields are mainly riverine deposits where mining occurs along river banks, terraces and in active river channels. Using poorly constructed sluice boxes, gold bearing material is fed into the inclined sluice boxes. The box is constructed using plywood or flattened roofing iron with wooden/metal ripples. These types of operations are associated with low to very low recovery because of uncontrollable river flow rates, incorrect inclination of the sluice boxes and inappropriate amounts of feed material at any one time. It is extremely difficult to introduce mechanised alluvial mining because of low skills and knowledge, isolation from transport infrastructure and lack of basic infrastructure.

The gold bearing gravels are concentrated by rippled sluice boxes. The fine gold is not commonly trapped in the ripple compartments. The fine particles of sand with gold in it are than poured into the panning dish for further panning. Mercury is placed in into the panning dish to concentrate the fine gold particles. Amalgamation is an efficient mean of extracting gold particles from concentrates after panning or sluicing.

In PNG small scale mining operations, the concentrates from sluicing operations are mixed with mercury in gold dishes or in sluice boxes. Mechanised concentrating equipment like the shaking table and Nelson concentrators are other options that few small scale miners are looking at. 

Health and environmental impacts (Watch Video)

The artisanal and small scale gold mining provides employment at local and national levels, and the sector is an important source for the inflow of foreign exchange into rural communities. However, small scale mining activities are associated with sensitive health and environmental issues.

The process of recovering gold by retorting and heating the amalgam over an open fire is a dangerous practice. The open fire could be in houses or at river banks and thus a whole family could be exposed to poisonous mercury fumes.

Concentrate from sluicing near streams is usually mixed with mercury and a considerable amount of mercury is lost to the streams. Apart from direct inhaling of mercury fumes by miners, aquatic life also feeds on mercury lost into the river, which are then eaten by the locals through the food chain. The Watut and Bulolo Rivers has been subject to prolonged mercury contamination and discharges of hydrocarbon wastes. The Watut people depend on the river for fishing, washing and farming on the river banks.

Some miners in old shafts and adits and they are consequently exposed to the trapped noxious gases such H2S. Locals have been reported that they are buried alive when they burrow through soft oxidized lodes or vein systems.

Some operators locate their sluice boxes in streams, thus polluting the water. Silting and stream discolouration are very common. Farmlands are usually destroyed by mining activities. Locals even uproot big trees along structurally defined thin gold deposits. Sometimes, the narrow gullies are not rehabilitated and are left to be taken care of by nature.

Exposed and disturbed lands are subject to soil creep widening the flow channels, and debris avalanches are common along rivers at the active mining areas. The loss of fertile land due to small scale mining puts socio-economic pressure on the local society. Old gravel pits are usually abandoned without reafforestation. Pits filled with stagnant water are common.

Education and training

Small-scale mining technology in most developing countries is simple and attracts many unskilled people. The desire for economic and social survival has attracted many people to the industry. The law expects the licensed small-scale miner to mine using effective and efficient methods, and observe good mining practices, health and safety and protect the environment.

The Small Scale Mining Branch of PNG Mineral Resources Authority (Formerly Department of Mining) in Wau, Morobe Provine has created education and training materials for the miners. The Department has produced seven booklets and DVDs on

• Simple Gold Mining;

• Basic Mining Practice;

• Advanced Mining practice;

• Handling of Mercury;

• Occupational Health and Safety;

• Environmental Issues; and

• Economics of Mining.

The major focus of the training resources is to ensure that small scale operations are safe, environmentally friendly and economically viable.

Small-scale mining operations in most developing countries have serious negative environmental impacts. One of the major factors is the implementation of the associated mining Acts  which are lacking.

Donor agencies like the World Bank, European Union and Japanese International Cooperation Agency (JICA) have in recent times shown keen interest in the negative and positive impacts of the PNG’s ASSM sector. AusAid and the World Bank have sponsored the building of the ASSM sector capability in PNG through legislative framework and training and awareness on the use of mercury.

Note: This article is a reproduction of a learning material with inclusion of up to date information.

Reference

[1] Ail, K. K. (2005. Kwoe River Alluvial Gold Deposit Evaluation and Development Plan, PNG University of Technology, Lae.

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