12/07/2018 - 10:29

Greenland ticking boxes for rare earths pilot plant

12/07/2018 - 10:29


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Greenland Minerals and Energy is inching closer to commencing building its rare earths pilot plant in Greenland after major Chinese shareholder and technical partner, Shenghe, said it will shortly select the best flotation circuit for the project, clearing the way for pilot plant operations to begin. Greenland has already produced mineral concentrates with grades approaching 25% rare earth oxides.

Greenland ticking boxes for rare earths pilot plant

Greenland Minerals and Energy is well on its way towards the commencement of building operations for its proposed pilot plant at the giant Kvanefjeld project in Greenland, with a decision on the best flotation circuit due very soon.

Major Chinese shareholder and global rare earths technical expert Shenghe, will shortly select a simpler, more efficient flotation circuit to reduce capital and operating costs from two competing options by leading Chinese laboratories.

Initial test work by both technical groups has already produced substantially enhanced mineral concentrate grades approaching 25% rare earth oxides, well above the 14% rare earth oxide concentrate grade used in the Kvanefjeld Feasibility Study.

The increase in concentrate grade along with a reduced mass of solids will reduce the size of the required equipment, which will in turn reduce the capital and operating costs of the processing plant circuit.

Greenland Managing Director Dr John Mair said: “It is fantastic to have two established rare earth specialist groups assisting Shenghe in the optimisation program and final pilot plant specification.”

“Each group has a pedigree in metallurgical work for production assets in China and delivered exceptional initial results for Kvanefjeld. The approach taken will ensure the establishment of the most efficient and cost competitive concentrator circuit.”

The Institute of Multipurpose Utilisation of Mineral Resources – Chinese Academy of Geological Sciences, based in Chengdu in the Sichuan Province of China, was the first institute engaged.

It has developed flotation reagents and methods which have been successfully commercialised at Shenghe’s operating mines in the past.

Its process to upgrade Kvanefjeld ores will also result in the rejection of “gangue elements” such as aluminium, reducing that unwanted material  from 7% in the ore to less than 2% in the mineral concentrate.

This has the handy benefit of lowering acid consumption in the leach process and reducing mass for transport purposes.

Baotou Meng Rong Fine Materials Co Ltd is a privately-owned technology and technical service provision company based in Baotou, Inner Mongolia.

Its range of specialty flotation collectors allows it to customise the chemistry to target specific minerals selectively, reducing the amount of gangue minerals which float and increasing the grade of the resulting concentrates.

According to the company, this approach is ideal for the unique nature of the rare earth elements ore minerals at Kvanefjeld, which will be the first source of large-scale, non-refractory source of rare earth materials.

As part of the selection process, a 5 tonne sample of ore has been prepared and is currently being shipped to Perth, Western Australia.

This ore material is from a bulk sample that was crushed and blended by GTK of Finland in 2014 as part of pilot plant operations for the EURARE program.

The metallurgical performance of this sample is well known as it has been extensively tested. This includes mineralogical liberation studies.

Kvanefjeld has a resource inventory of 1.01 billion tonnes containing 593 million pounds of uranium, 11.14 million tonnes total rare earth oxides and 2.25 million tonnes of zinc.

Notably, it is earmarked to produce an awesome foursome basket of rare earths including “neodymium”, “praseodymium”, “dysprosium” and “terbium”.

The deposits are characterised by thick mineralisation hosted within sub-horizontal lenses that in some instances exceed 200m in true thickness.

Management says that a further key advantage of the Kvanefjeld rare earth ores is the unique mineralisation that can be effectively beneficiated into a low-mass, high-value concentrate before being leached with conventional acidic solutions to achieve particularly high extraction levels of both heavy rare earths and uranium.

There is also significant upside with less than 20% of the prospective area has been evaluated by Greenland with billions of tonnes of host rock still awaiting assessment.


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