By Alex MacDonald

LONDON--African iron-ore explorer Zanaga Iron Ore Co. Ltd. (ZIOC.LN) said on Tuesday that its Congo Brazzaville Zanaga mining project will have enough reserves to produce 30 million tons of iron ore per year, developed over two phases, for a period of 30 years.

The U.K.-listed company, which is developing the Zanaga Iron Ore Project in partnership with commodities trader and miner Glencore PLC (GLEN.LN), said the mine's reserves total 2.07 billion metric tons of ore with 33.9% ferrous content. This stems from 6.9 billion tons of mineral resources with 32% ferrous content grade. The project's first proved ore estimate of 770 million tons alone underpins the first stage of the project, which aims to produce 12 million tons a year of ore for more than 25 years.

Zanaga owns 50% less one share in the Zanaga Iron Ore Project through its joint venture partnership with Glencore.

Zanaga's shares are down 37% since the beginning of the year at 13 pence a share, resulting in a market capitalization of GBP34.9 million or $56.6 million.

Write to Alex MacDonald at alex.macdonald@wsj.com

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