Born in Cornwall, John Walker began his mining career at 18 with English China Clays, accumulating over 35 years of industry experience, holding P&L responsibility in 15 countries throughout Europe, Asia, and North America. From 1995 to 2008, he was part of the leadership team overseeing Lee Moor operations in Devon. During this period, he also managed a mining facility in France (2003–2008), extracting tin, tantalum, niobium, and kaolin.

In 2009, he relocated to the USA, where he took on leadership roles overseeing mining operations across North Carolina, South Carolina, Georgia, Tennessee, Kentucky, and Mississippi. His work involved exporting substantial quantities of minerals to Mexico, Indonesia, India, and Taiwan.

In 2011, he co-founded The Quartz Corp, a joint venture specializing in high-purity quartz, a critical mineral primarily supplied to China, Japan, and Europe for use in solar, semiconductor, and fibre optic cable industries. This company now has 25% global market share and is conservatively worth 1B$.

More recently, he has played a key role in shaping the World’s critical mineral strategy, particularly focusing on lithium and other essential minerals and metals. His contributions include advisory roles on major projects in the UK, USA, Argentina, Bosnia, Finland, Mozambique and Australia, participation in industry-led workshops, key speaker presentations at conferences, development of large industrial projects and all-party mining discussion panels chaired by Baroness Northover in the House of Lords