China is making a smart move; Africa is the largest concentration of cobalt in the world.
"The copper belt in the Democratic Republic of the Congo, Central African Republic and Zambia yields most of the cobalt mined worldwide. The DRC alone accounted for more than 50% of 2016 world production (123,000 tonnes), according to Natural Resources Canada.
In 2005, the copper deposits in the Katanga Province (former Shaba province) of the Democratic Republic of the Congo were the top producer of cobalt with almost 40% world share, reports the British Geological Survey. By 2015, DRC supplied 60% of the world production of 32,000 tons at prices of $20,000 to $26,000 per ton, including artisanal mining which supplied 10 to 25%. The political situation in the Congo influences the price of cobalt significantly.
The Mukondo Mountain project, operated by the Central African Mining and Exploration Company (CAMEC) in Katanga, may be the richest cobalt reserve in the world. It is estimated able to produce about one third of total global production of cobalt in 2008. In July 2009 CAMEC announced a long-term agreement under which CAMEC would deliver its entire annual production of cobalt concentrate from Mukondo Mountain to Zhejiang Galico Cobalt & Nickel Materials of China."
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"Human rights activists had previously alleged, and on February 28, 2017 investigative journalism reported confirmation, that child labor is used in a portion of the worldwide supply of cobalt sourced from African artisanal mines. This revelation prompted cell phone maker Apple Inc., on March 3, 2017, to stop buying the ore from suppliers such as Zhejiang Huayou Cobalt who source from artisanal mines in the Democratic Republic of the Congo, and begin using only suppliers that are verified to meet its workplace standards. In 2017, some exploration companies were planning to survey old silver and cobalt mines in the area of Cobalt, Ontario where significant deposits are believed to lie.
The United States Geological Survey estimates world reserves at 7,100,000 metric tons."