Sheffield's 2019 bankable feasibility study update shows Thunderbird to be a technically low risk, modest capital expenditure project that will generate strong cash margins from significant levels of production over a mine-life spanning several decades.

Thunderbird's zircon products and ilmenite are suitable for manufacturing titanium dioxide pigment or smelting into chloride slag.

Sheffield was intent on developing the project on its own, with the help of a $95 million NAIF loan approved in 2018.

However, a lack of funding options led the company to turn to Chinese steel giant Yansteel in January, with Yansteel providing $130.1 million in project equity funding in exchange for a 50% stake of company Kimberley Mineral Sands.

Yansteel has started construction of a 500,000 tonne per annum integrated titanium dioxide processing facility and titanium slag smelter that will feed on the low temperature roast ilmenite offtake from stage 1 of the project.

Sheffield executive chairman Bruce Griffin said NAIF's continued support of the world class Thunderbird mineral sands project was extremely pleasing.

"We look forward to concluding the Thunderbird definitive feasibility study and project financing activities ahead of an expected 2022 final investment decision," he said.