Tanzania has increased the rate of royalty paid on minerals such as gold from 3% to 4% under the Mining Act 2010.
The new law will give governments the right to own a stake in future mining projects and will require mining companies to list on the Dar es Salaam Stock Exchange, according to Reuters.
Under the new law, Tanzania will not issue new gemstone mining licences or change the current agreements for foreign mining companies.
The bill will make comprehensive provision for the prospecting of minerals, for the mining, processing and dealing in minerals, and for the granting, renewal and termination of mineral rights.
Zitto Kabwe, a member of parliament from the opposition Chadema party, said the bill might send a negative signal to investors and might impact foreign direct investment.
Mining stakeholders said they will issue a joint statement on the law.