Zimbabwe is keen to attract capital to its mining sector after the ousting last year of former president Robert Mugabe after almost four decades in power and is pushing lithium as a major draw for investors.

"We believe we have the potential to actually account for 20 percent of global demand when all known lithium resources are being exploited," Winston Chitando told a mining investment conference in the capital, Harare.

Zimbabwe is a top 10 of lithium producer but currently produces only a fraction of the worldwide total. It aims to supply 10 percent of the world's lithium in four years.

Prices for lithium have more than doubled in the past two years on forecasts for massive demand from the electric vehicle industry. That has sparked work on a flurry of new mines and expansion plans for existing ones.

PLATINUM PENALTY

Zimbabwean Vice President Constantino Chiwenga told the conference Zimbabwe will impose a 15 percent penalty tax from Jan 1, 2019, on exports of platinum producers who do not build refining facilities in the southern African country.

The tax has been mooted since 2013 and been delayed a number of times to provide producers with time to comply.

His presentation showed that the tax would eventually fall to 5 percent without giving a specific timeframe, while companies could also qualify for a lower tax depending on how much product they were refining domestically.

Zimbabwe has some of the world's largest platinum reserves but is keen to industrialise an economy that is still largely reliant on primary commodity production focused on agriculture and mineral extraction.

Platinum producers in Zimbabwe include Zimplats, a unit of South Africa's Impala Platinum, Anglo American Platinum and Sibanye-Stillwater.

Amplats in December said it was nearing completion of a platinum group metal smelter at its Unki mine in Zimbabwe.

Implats said last year that "neither the smelter nor the export levy is affordable" and could result in the closure of its Mimosa mine.