Sigma makes first 'green tailings' sale

29th May 2023 By: Mariaan Webb - Creamer Media Senior Deputy Editor Online

Sigma makes first 'green tailings' sale

Nasdaq- and TSX-V-listed Sigma Lithium has received payment on its first shipment under its offtake to sell ‘green tailings’ to Yahua International Investment and Development to be upcycled into battery grade lithium concentrate for use in electric vehicle (EV) battery production.  

Green tailings are high-purity, zero chemicals, about 1.3% lithium oxide ultra-fine tailings generated by the Sigma’s Greentech lithium processing plant as a by-product at its Grota do Cirilo project in Brazil.

Grota do Cirilo is focusing on ‘green lithium’, which is a high purity 5.5% battery grade sustainable lithium produced by the Greentech plant.

The company early this month signed a three-year offtake for 300 000 t/y of green tailings. Concurrently, it entered into a spot sale agreement with Yahua for 15 000 t/y of green lithium.

Sigma’s zero tailings strategy ensures that lithium material is neither wasted nor consigned to environmentally hazardous tailings dams.

"Achieving Zero Tailings marks a major milestone for Sigma Lithium and for the battery materials industry, demonstrating that lithium battery materials can be produced in harmony with the environment and without hazardous tailings dams," said Sigma Lithium CEO and co-chairperson Ana Cabral-Gardner.

"Our zero tailings strategy enables Sigma Lithium to lead the way in the inception of a sustainable global supply chain for the next generation of EVs built in line with the ethos of the consumer to meet the accelerated global demand for lithium."

"Reaching zero tailings is a result of our consistent investments in clean technologies over the last five years to deliver on our commitment to achieve a green process flowsheet for lithium materials. The successful operation of our Greentech plant, which uses 100% renewable energy, 100% recycled water and 100% dry-stacked tailings, is a testament to this commitment and a model of environmental sustainability." 

Sigma began trucking green lithium and green tailings last month for stockpiling in warehouses at Vitoria port in preparation for its first shipment.