HARARE, Feb 9 (Reuters) - Zimbabwe's Mimosa platinum mine, ajoint venture between Aquarius and Impala haswarned of possible closure due to a government export taximposed on unrefined platinum, according to an internal companynote.
The southern African country, which has the world's secondlargest deposits of platinum after South Africa, last monthannounced a 15 percent tax on the export of raw platinum.
An internal discussion note circulated among senior managersat Mimosa and seen by Reuters on Monday, showed the companyexpressing reservations over the tax.
"With the company being in a negative cash position, itsshareholders will put the operation into care and maintenance,since continued operation will become unattractive," theone-page document, dated January showed.
"The minute the shareholders understand that the company hashad to pay 15 percent tax, Mimosa will be forced to go onclosure," it added.
Mimosa's executive chairman and managing director did notimmediately respond to emailed questions.
With platinum prices already depressed, the tax would eatinto the profits of companies with platinum assets in thecountry, which include Anglo American Platinum.
Aquarius last year said in its annual report that Mimosa -which produced 110,679 ounce of platinum in its 2014 financialyear - planned a $40 million five-year expansion of the minestarting this year.
That expansion could be scrapped, the document said.
Mining companies have previously argued that the volumesmined in Zimbabwe are not high enough to make construction of amulti-billion-dollar refinery economically viable.
They are also sceptical that the infrastructure and theenergy supply would be adequate to run such plants and point outthat there is excess refining capacity in South Africa. (Reporting by MacDonald Dzirutwe; Editing by James Macharia)