Introduction to Mineral Processing- Questions and Answers

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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

 

 2.       Describe what kind of technology is important for securing resources (or resource supply), including the reason and your idea.

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.

 4.       What kind of technology development do you think is necessary for the mining and mineral processing, which is expected to become difficult in future?

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.

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Nature of Geothermal Resources- The Earth's Thermal Engine

Nature of geothermal resources are explained by many  researchers from all works of lives. Most of the information provided in this articles is purely educational information and not intended to propose or produce as a research paper. This article was produced as part of published journal research presentation for graduate school of engineering at Kyushu University. Some of the information provided in this article may relate to an original journal or research papers.

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Thyphoon Hagibis Hitting Japan and Many Lives are in Danger 12th October 2019

Typhoon Hagibis is strongly hitting the Tokyo Metropolitan area and Shizuoka Prefecture and many lives and properties in danger and some have already being affected by the most dangerous typhoon. This Typhoon Hagibis has caused catastrophic damage to the people and the properties and infrastructures.

The typhoon has already started and will continue for the next two to three days.

According to the NHK live news, the Japan's Meteorological Agency has issued heavy rain emergency warnings for Tokyo and Shizuoka, Kanagawa, Saitama, Gunma, Yamanashi, Nagano, Ibaraki, Tochigi, Fukushima, Miyagi and Niigata prefectures. It is the highest level of warning in the JMA's five-level warning scale.

Photo taken from Youtube live stream

Live news on latest updates regarding typhoon hagibis refer to the link below;

https://www3.nhk.or.jp/nhkworld/en/live/ 

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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.

today we have 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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Stability Analysis of Tailings Dam - Brief

Stability of Tailings Dam describes the tendency of a dam to resist failure. Failure encompasses both mass movements in which large volumes of rock/soil or dam embankment materials slip and smaller-scale displacements such as minor tension cracks on surface, rock falls etc. All types of rock-slope failures are important as they can have a significant impact on Tailings dam, mines, properties and lives either on the slope or at its base. Instability cause by mass movement of rocks along a plane occurs in four ways: plane failure, wedge failure, toppling failure and circular failure. 

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Tailings Dam Construction in Papua New Guinea a Challenge

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.

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