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.