The cash proceeds will be used to conclude the excavation and lining of the production and service shafts, alongside the installation of essential surface infrastructure.
The completion of both shafts is scheduled during 2016, while the associated works program will extend into the 2017, the company said.
BHP Billiton chief executive officer Andrew Mackenzie said that the annual investment at Jansen of approximately $800m would form an important part of the group’s capital and exploration budget, which will decline to approximately $16bn this year.
"Continued development of the shafts reflects our confidence in the quality of our
5.3 billion tonne measured resource and the compelling long term fundamentals of the potash industry," added Mackenzie.
"Investment at Jansen is creating a valuable asset and we will continue to pursue a development path that maximises returns for shareholders. In time, this may include the introduction of one or more partners, consistent with our approach for other major operations."
BHP Billiton has also increased the in-situ mineral resource tonnage estimate for Jansen, which includes the additional acquired freehold mineral rights, advanced data analysis and improved estimation methods and the inclusion of additional inferred resource within the granted mining lease.
