Tungsten West Plans to Restart Hemerdon Mine for 2021

The Hemerdon tin-tungsten mine in Plymouth, UK is known as one of the largest tungsten deposits in the Western world. The mine faced a challenging past with its previous owner, Australian specialty metals miner Wolf Minerals, reopening in 2015 but being mothballed in 2018 after failing to reach expected recovery rates. Tungsten West acquired the mine for less than 3 million pounds (3.7 million US dollars) in November 2019, and is further studying ore bodies and processing technology to create an economically viable supply chain. Argus recently conducted a telephone interview with Max Denning, CEO of the company.

Hemerdon is currently receiving care and maintenance. A few employees keep their distance and no employees are infected with the novel coronavirus. They have completed initial test work and are currently conducting a feasibility study, which is expected to be completed this year or the first quarter of 2021. The feasibility study has completed further financing and the reconstruction time is 6 months.

Hemerdon Tungsten Mine image

The historical data of the mine was not fit for purpose. The old processing plant did not account for certain nuances of the ore, the most obvious is the fragility of the ore, so there was not enough recovery rate in its three-year operation. In addition, the plant's lack of stability and capacity expansion led to excessive downtime. After six months of technical investigation and detailed study of the characteristics of the ore, we found that the mineral is tungsten iron ore. Therefore, the company has designed a new processing route.

First, the company will implement x-ray transmission ore sorting, a pre-concentration technique that scans the density of each rock and removes barren materials. The ore body is massive and contains coarse iron sphalerite crystals, which makes it the best choice for ore sorting. The additional ore sorting step will significantly reduce downstream processing costs, and feed into the concentrator plant, leading to a much cleaner and higher-grade ore.

They also plan to introduce wet high-strength magnetic separation next to the existing fine-grain gravity circuit because iron sphalerite is quasi-magnetic. This means it concentrates via magnetic separation. Upgrade works on the dense media separator [DMS] circuit was completed during Wolf's era and with a few further required modifications, the DMS will operate well as the main method of concentration for the coarse circuit.

Wolfe Minerals has invested more than 200 million pounds in the Hemerdon mine. Part of the ongoing improvement work has already been spent. Overall, the restart costs including rebuild, modifications, and working capital are expected to be between 30 million and 40 million pounds.

Shortly after the Hemerdon project entered bankruptcy management in August 2019, the APT inventory (about one-third of APT consumption) in the now-defunct Fanya Metal Exchange had an impact on the market, causing prices to fall sharply.

Tungsten concentrate buyers need to secure supply. Outside of China, tungsten concentrate is a rare commodity. China also has a ban on the export of concentrates. and as there are few producers of tungsten concentrates in the rest of the world, there is a gap to fill. Tungsten West is in talks with a multitude of potential buyers on offtake agreements. With the Hemerdon mine, it would be one of the biggest producers of tungsten concentrate outside China at a time when there may be a certain level of increased scrutiny over supply chains.

 

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