(ShareCast News) - Kennedy Ventures, an AIM-listed investment company, has announced that its investee company African Tantalum (Aftan) has successfully completed its testing programme of its plant upgrade.The company's stake in Aftan gives it an interest in the Tantalite Valley Mine (TVM), a Namibian based operation which produces tantalite concentrate. The plant upgrade at the Homestead Project is ramping up to full capacity and commercial rate of production is expected from next week. The firm expects to achieve a higher target rate of 15,000 tonnes per month.Aftan continues to assess the potential of the lepidolite lithium deposit as well as the occurrence of lithium in other pegmatite bodies.General Manager of TVM Renier Swiegers said: "I am very pleased that the progress of the plant upgrade and the testing has gone according to plan. I look forward to the mine resuming full production imminently and recommencing tantalite shipments in the second half of this month."Giles Clarke, Chairman of Kennedy Ventures, said: "The upgrade is part of the overall strategy to maximise production and, upon commercial production, we hope that Aftan will quickly reach a cash generative position."The share price rose 1.37% to 3.09p at 1143 BST on Monday.