No stopping lithium

Materials World magazine
,
1 Feb 2018

Lithium is the element of the moment, and analysts expect demand to grow more than 20% annually through to 2030. Pertti Lamberg and Chris Broadbent* take a closer look at ambitious plans by Finnish mining company Keliber to produce 9,000 tonnes of lithium carbonate per annum. 

In 2016, global lithium demand was 200,000 tonnes of lithium carbonate equivalent (LCE), and by 2030, this is forecast to be more than two million LCE tonnes annually. This increase is, among other things, driven by requirements to replace conventional internal combustion-powered vehicles with low-emission alternatives and, in particular, the anticipated growth in electric cars. Lithium’s natural properties make it a suitable battery material – it is the lightest of all metals, has the greatest electrochemical potential and provides the largest energy density for weight.

Moreover, it is not a particularly rare element in the Earth’s crust. The average grade is 20-70ppm and it sits in 33rd position on the abundance of elements in the Earth’s crust, meaning it’s slightly less abundant than cobalt, but above lead. Lithium is extracted from two different sources – lithium brines and hard rock mineral deposits. More than half comes from the brines, with the largest producers being Chile, which accounts for 65% of global output and Argentina at 26%. China and the USA are smaller contributors, 7% and 2%, respectively.

Lithium mineral production is dominated by Australia, which accounted for 74% in 2016, with lesser amounts produced in China, 17%, and Zimbabwe, 6%. In Europe, a small quantity of lithium mineral is produced for the glass and ceramic industries, while Portugal hold 2% of global mineral output, followed by Spain.

China leads the way

On the whole, Europe is the second biggest lithium consumer, after China. However, aside from the small Iberian production, the EU has no internal lithium supply – although small processing sites from imported material can be found in some EU countries such as England and Latvia. 

Several lithium battery projects have been announced in Europe and will increase European lithium demand. Based on this, the LG Chem, Poland, Samsung, Hungary, and Northvolt, Sweden, projects will help build a production capacity for 40GWh lithium-ion batteries. 

This figure does not include the Daimler and Terra-E proposals, nor Tesla’s plans for lithium-ion battery production. A capacity of 1GWh lithium-ion batteries per year equals roughly 2,500 LCE t/a, which is enough for 62,500 plug-in hybrid electric vehicles. Therefore, a 40GWh annual production of lithium-ion batteries in Europe will require 100,000 t/a LCE. 

Production and ore reserves for lithium in Europe are small. The table opposite lists current production and advanced projects of lithium in Europe. 

However, there are moves to change this, as demonstrated by projects in Austria, Czech Republic, Serbia and Finland (see more information in the table). Keliber, a Finnish mining company that operates in a sparsely populated area of central Ostrobothnia that is dominated by forests and lake, has one of the most advanced lithium developments and –  at the time of writing – feasibility studies are currently ongoing.

A valuable resource

Finnish mining company Keliber is focusing its resources on producing high-purity lithium carbonate, particularly for the needs of the international lithium battery market. 

The deposits are located in central Ostrobothnia. The local infrastructure is favourable – Kokkola harbour is 55km from the production site, while the nearest international airport is 35km away.
In addition, Kaustinen, which is also part of the Ostrobothnia region, and the surrounding area have been known for spodumene pegmatites since the late 1950s.  

Keliber has a total of 8.065Mt mineral resources, with an average grade of 1.19% Li2O in six different deposits. Intensive exploration has resulted in a 35% increase in the resources since March 2016, while other deposits – Syväjärvi, Rapasaari, Länttä and Outovesi – contain a total of 4.5Mt ore at 1.10% Li2O.  

In addition, Keliber has several exploration permits and claims in the highly prospective Central Ostrobothnian lithium province, spanning more than 500km². 

Lithium ores are hosted by pegmatite veins that vary from 5m to 35m in thickness. The main minerals are spodumene (LiAlSi2O6 – in a typical ore sample the grade is 19 wt%), quartz (SiO2, 30 wt%), albite (NaAlSi3O8, 30 wt%) and K-feldspar (KAlSi3O8, 14%), with the most common accessory being muscovite (KAl3Si3O10(OH,F)2, 5 wt%) and apatite (Ca5(PO4)3(OH,F,Cl), 0.4 wt%). Columbite-tantalite ((Fe, Mn)(Ta,Nb)2O6) is a common trace mineral, but sulphides and other base and heavy metal minerals are virtually absent.

Processing lithium ore

Processing of the ore to the final product, lithium carbonate, includes mineral processing, thermal treatment and hydrometallurgical process. The process has been developed with Outotec, a Finnish technology company, over several years and multiple pilot tests. The key criterion was to minimise the environmental impact.

The process will include optical sorting to remove dark coloured waste rock dilution from the plant feed, and this is followed by grinding, flotation and dewatering. A thermal treatment, at about 1050⁰C, is used for the spodumene concentrate to convert the mine stable alpha spodumene to the soluble beta form. 

In the hydrometallurgical process, beta-spodumene is leached in a soda pressure solution, which is purified, before lithium carbonate is crystallised, dried and packed. In pilot tests, Keliber produced battery-grade lithium carbonate with a purity of up to 99.91%.

What about the byproducts? Waste rock can be used for roads and dams, quartz-feldspar sand is suitable as a finishing filler in cement, while Analcime (Na-zeolite) has the potential to be used in nitrogen capture, fertilisers, water purification and the construction industry.

Resource drilling is now underway and preparation for a final feasibility study and environmental impact assessment programmes are in place. Overall, Keliber plans to produce 9,000 tonnes of lithium carbonate per annum. 

A number of organisations have been involved in the Ostrobothnia project. Mineral processing has been developed and tested with the Geological Survey of Finland, and the EU FAME (Flexible And Mobile Economic Processing Technologies) Horizon 2020 project has played a significant role in geometallurgical studies and in the valorisation of the by-products. Meanwhile, the University of Oulu, Finland, has been involved in studies for process mineralogy and development of higher value products, while the soda pressure leaching process has been refined together with Outotec to allow effective and environmentally sound processing. Tekes – the Finnish Funding Agency for Innovation, has helped with new on-line measurement technologies for lithium and patents related to the chemical processing route.

It is therefore safe to say, the European lithium industry is on course for a sizeable shot in the arm.

*Pertti Lamberg is CEO of Keliber.

Chris Broadbent is Research Director at Wardell Armstrong International and FAME Coordinator.