Monday, 16 December 2019
Introduction to Mineral Processing- Questions and Answers
S
1.
Write
down the main objective and technological summary of mineral processing on
mining industries.
The main objective of mineral processing in
mining industries is to separate the gangue minerals from the valuable or
target minerals or the desired minerals. The desired or valuable minerals are
fixed within the ore. The target minerals are to be liberated from the ore and
gangue minerals are disposed of.
The summary of the mineral processing
technology is in the following sequence:
·
Rock drill & blasting of Ore
·
Crushing &
Grinding (Liberation)
·
Sieving &
Classification
·
Separation, Extraction,
Concentration
·
Concentrate &
Metallurgical Treatment
The crushing and grinding technology is
very important in securing resources because without crushing or grinding you
cannot go further. Crushing and grinding are the only primary actions for
further downstream processing. After crushing and grinding you can look for
other alternatives of screening and separation and further downstream
processing techniques that suites the recovery of target mineral.
For example, you can’t recover in-situ or ROM
gold by leaching if there is no fracture to expose gold surface interaction
with cyanide solution. You cannot
proceed with flotation if you have not crushed and ground the materials to
expose the surface of mineral particles
3. It is required to process a low grade ore
in which the primary mineral is chalcopyrite associated pyrite. Suggest a
process flowsheet, a reagent scheme and a set of operating conditions that may
optimize the recovery of copper while minimizing the recovery of pyrite. Explain
the reason that led to your decisions.
Froth Flotation process is best for
recovering Chalcopyrite. Both Chalcopyrite and pyrite are in pregnant solution
at lower pH value. In order for us to separate Chalcopyrite from pyrite, we
need to regulate the pH value in the flotation. This can be done by introducing
lime and alkaline reagents into floatation thank so that the pH is increased
above 6. The pyrite will then precipitate at pH above 6 and the chalcopyrite floats
as bubble which is separated from pyrite.
Describe with your idea.
The development of processing technology would be a
challenge to recover very low grade ore which is regarded as waste materials or
tailings. It is assume that the tailings at least contain some valuable
minerals but are hardly recoverable using the metal recovery techniques. It is
normally allowed to pass through as tailings into the tailings dams or discharged into the river or on to the seafloor.
Some researchers have come up with proposals to recover low
grade ore with a concept of near zero
waste through bio-leaching processing techniques but it will be a challenge
whether such technology will truly help to recover very low grade ore mixed
with silts and fine particles of rocks and soil.
Tuesday, 8 October 2019
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.
Note:
The this article is an extract from a publication by Department of Mining Papua New Guinea,2001.
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.
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Abandoned Trommel at Tuguba River Mine Site in Tamo, East Sepik Province |
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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.
Sunday, 29 September 2019
Tailings Dam Construction in Papua New Guinea a Challenge
September 29, 2019Mine Management, Mine Waste Management, Mining Engineering, Slope Stability Analysis
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Tailings dam constructions in Papua New Guinea (PNG) are faced with natural factors such as high altitude with high rainfall (2000-5000mm), active seismic zone and other geotechnical structural factors which pose threat to the stability of tailings
dam and potential failure. As such, the
PNG government has allowed mining companies to discharge tailings into the river
systems over the last 30 to 40 years which pollutes the riverine and ecology within the vicinity of the mine
impacted communities downstream. However,
the PNG Government intend to discourage riverine tailings disposal and
encourage tailings dam construction in PNG.
The current tailings dams in PNG include Hidden Valley Tailings Storage Facility(TSF) and K92 Mine Tailings Dam.
The Porgera Gold Mine discharges its tailings into the Strickland River in the Enga Province. The Ok Tedi Copper and Gold Mine at the Mt.Fubilan, Tabubil in the Western Province discharges its tailings into the Ok Tedi River System.
The Lihir Gold Mine in the Luise Caldera of New Ireland Province places its tailings onto the deep sea floor (DSTP).
The Ramu Nickel and Cobalt Mine at Kurumbukari in the Madang Province also practice the deep sea tailings placement (DSTP).
The Wafi Golpu project is an advanced project with the Special Mining Lease Application lodged with the Mineral Resources Authority and is under technical appraisal by government at its engaged independent consultants. This project proposed for a DSTP.
The Frider River Project proposed for an Integrated Storage Facility which will contain waste rock and tailings at the same time. The dam will also but used as hydro-dam to generate electricity.
The government of Papua New Guinea will never or might not allow riverine tailings discharge for all future mines in the country. It would be either by practice of building of Tailings Storage Facilities of place them one deep seafloor.