Mozambique's President Daniel Chapo has signed a new law requiring 15% state ownership in all mining ventures and local processing of minerals, tightening control over its resources as demand for battery materials grows.

Mozambique is the world's third-largest graphite producer, a key material used in batteries for electric vehicles and energy storage.

The mining law, approved by Parliament in May, aims to strengthen Mozambique's "management of strategic resources in defence of the national interest," according to a government notice dated June 3.

"The state, through the National Mining Company (ENM), shall have a minimum, free‑carried and non‑dilutable participation of 15% in all mining projects, at any stage of the value chain," reads part of the new law seen by Reuters on Thursday.

One of the largest graphite deposits in the world

It was not immediately clear whether the new rules would apply to existing mines, which are mostly covered by long-term agreements.

The move places Mozambique among a growing number of African countries, including top continental lithium producer Zimbabwe and the Democratic Republic of Congo, the world's leading cobalt producer and major global copper supplier, which are tightening control over raw exports for greater economic benefit from their resources.

Mozambique has one of the largest graphite deposits in the world at Syrah Resources' Balama operations in the north of the country. According to the US Geological Survey, China and Madagascar are the top two producers.

The world's largest ruby mine, Montepuez, owned by Gemfields, is also located in northern Mozambique and the country also has significant coal assets previously owned by Rio Tinto and Brazil's Vale.

The new regulations prohibit the export of unprocessed or semi‑processed mineral products, except where they are covered by a specific ministerial authorisation, based on approved plans to eventually process locally.