Brazilian mining giant Vale's board of directors has approved a $10.2 billion investment budget for 2015, down 30.9% on the year, the company said Tuesday.

Within that total, $6.4 billion is slated for project execution, with the remaining $3.8 billion to sustain existing operations, Vale said in a statement.

Vale in the third quarter said it expected its 2014 spending to be $13.8 billion, comprised of $9.3 billion for project execution and $4.5 billion for sustaining existing operations. The company also estimated a $900 million investment for research and development.

"This is the fourth consecutive year in which Vale reduces its capital expenditures, maintaining capital discipline and focusing only on world class projects," it said.

Iron ore projects are responsible for 71% of Vale's project execution budget, it said.

The main projects are the expansion of integrated iron ore operations in northern Brazil's Carajas. This work would receive $3.7 billion investments in both mine S11D operations and logistic railway-port expansion CLN S11D. Vale would also spend $659 million to complete the Itabirites projects in southeastern Minas Gerais state, targeting "the partial replacement of capacity, increasing production and quality improvement in the iron ore production from the Southern and Southeastern Systems."

Vale's Carajas S11D is set to produce 90 million mt/year by 2016, while the Itabirites system, including Conceicao Itabiritos II, Vargem Grande Itabiritos and Caue Itabiritos projects, are set to reach production of 53 million mt/year in the second half of 2015, it said.

Logistic project CLN S11D is expected to reach a final 230 million mt/year capacity by 2018, the company said.

Vale's operating budget for 2015, it said, will "fundamentally provide funding" for operations, mainly equipment replacement; building and expanding waste dumps and tailings dams; health and safety; and corporate social responsibility.