He is a mining billionaire from a council estate in Swansea and now Gren Thomas wants to reopen the last tin mine to close in Cornwall.

Septuagenarian Dr Thomas has had a 50 year career in mining, which began as a coal miner in the Clydach Merthyr.

And in his latest project, through the Canadian company which he chairs, Strongbow Exploration, he is looking reopen the former South Crofty tin mine, funded by raising millions and supported by a planned flotation on London's Alternative Investment Market (AIM).

South Crofty has been shut for nearly 20 years after a collapse in tin prices in the 1980s. However, with a lack of tin supply globally, it has seen prices recover significant in recent years, which Strongbow is keen to exploit.

The company acquired the disused mine in 2016 and is aiming to restart production in 2021.

Tin is now mostly used as a lead free solder in electronics, as well as in chemical production.

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And start-up company Cornish Lithium has also bought the rights to the water in Strongbow’s mine and hopes to build a processing plant to extract it.

Lithium is a key ingredient in batteries and is becoming far more sought after, with demand expected to triple in the next decade to meet the needs of the mobile phone and car industries.

High levels of lithium were identified in the water in Cornish mines in the 19th century, but there has been no market for the mineral until recently.

The development of South Crofty is Strongbow's primary focus and the project is estimated to require it raising £25m over the next 18 months to progress to a production decision.

Its chief executive Richard Williams said: "Strongbow has achieved a great deal since acquiring the South Crofty project in July 2016, and its planned admission to AIM, which is the next step in the company's strategy, is a very exciting development.

"The company continues to advance South Crofty to a production decision, with a plan to re-commence production in 2021. The project has all necessary permits in place, and, as a former producing mine, offers great potential at a relatively low risk.

"The global demand for tin, especially in consumer electronics, combined with current tin price forecasts, underpins Strongbow's strategy

"I would like to take this opportunity to thank our existing shareholders for providing us with the support to reach this milestone."

Gren Thomas

Born in 1941 at Clase in Swansea, Mr Thomas , 77, moved to Canada after graduating from University College, Cardiff, in 1964, finding his fortune prospecting the vast untapped potential of the unforgiving Canadian terrain.

In the early 1990s his flagship company Aber Resources, named after Abertawe, made discoveries that led to the development of the Diavik Diamond Mine in Northwest Canada which now produces about 7 million carats of diamonds annually.

Although Mr Thomas now lives in Canada, he has remained a faithful Welshman - making frequent visits to Welsh rugby internationals and even building a replica of Morriston’s Red Lion pub in his current home country, which his great-grandmother used to run.

In a recent interview he said: "I believe much of my success is attributable to my early life experiences and education in Wales and in the Swansea Valley area in particular.

“I’ve lived in Canada nearly 50 years but have visited Swansea at least once a year and hope to continue doing so.”

His daughter Eira is also a leading figure in the diamond industry having in 2003 founded Stornoway Diamond Corporation.

Earlier this year she took over as chief executive of Lucara Diamond Corp.