Thermal Purification of Graphite

EFB Technology for Graphite Purification

One of the reasons why the demand in high quality graphite has shown steady growth is the booming development of chemical power sources, wherein this material is utilized for anodes. In experts’ opinion, the current production dynamics of electric vehicles, electronic and energy storage devices can result in shortages of such strategic material in the near future. Therefore, sustainable mining, processing, application and recycling of high-quality graphite are the top priority for the most developed countries.

Along with such existing technologies of graphite purification to battery grade as acid and chlorine treatment, the high-temperature electrothermal fluidized bed processing (EFB), developed by Thermal and Material Engineering Center (TMEC), deserves special consideration. The technology allows treating carbon powder at temperatures up to 3000°C in continuous mode. It resolves purification and graphitization tasks consuming only electric power with possible integration of renewables. The last one can potentially result in the synthesis of high-quality almost «green» graphite with a low environmental footprint.

It should be noticed, that the EFB technology, except Li-batteries purpose, allows to resolve much wider tasks due to significant changes in lattice structure of carbon during treatment. Its potential includes capability of nuclear grade graphite production or graphitization of carbon black. As multiple studies by TMEC have shown, EFB operating parameters such as temperature and treatment duration dramatically influence performance of the technology like purification or graphitization level.

Thermally purified graphite

Graphite, an important material for many industries, is deemed a strategic mineral in EU, US and China. Therefore, development of technologies relevant to enhancing its properties is of great interest.

For many years, the TMEC’s engineers have been successfully working on the development of the thermal treatment process applied for the wide variety of carbon materials such as natural and synthetic graphite, carbon black and biomass derived carbon with the view to commercialising the state-of-the-art Chlorine- and Acid-free clean technology.

TMEC purified carbon materials can be applied in variety of industries such as:

  • Electrodes for Aluminum production

  • Carburizers for steelmaking industry

  • Diamonds

  • Crucibles for ultra-pure metals

  • Additives to protective paints and coating

  • Fire retardant insulation, gaskets and sealing

  • Electric batteries

  • Nuclear Energy.

Graphite Purification - Process Flow-Chart

To meet the demands of the global market, industries and environment regulations, our cutting edge solutions based on the electro-thermal fluidized bed concept allow materials treatment in continuous modes under inert gaseous atmosphere at temperatures up to 3000°C, improving the product purity, crystallinity and conductivity.

With carbon content of 99.0% to 99.995%, the final product of the TMEC technology has a set of unique properties and competitive market price. It is applicable on industrial scale in different technologies related to energy, space and military programs as well as for medical and environmental purposes.

Graphite Purification in a Lab

The major advantages of EFB purification of are:

  • High purity level (99.95-99.995%)

  • Uniform quality (due to intensive mixing)

  • Customized kind of material (graphite, coke, carbon black, etc.)

  • Continuous mode

  • High productivity - up to 1 tph

  • Cl- and HF / H2SO4-free process

  • Enhanced crystallinity and conductivity

  • Low energy consumption rate

  • Applicability of Renewables

  • Feasibility on an industrial scale.

EFB pilot of 10 kg/h

TMEC continuous its work on the improvement and development of the EFB technology, testing various carbon materials under simulated conditions. For this purpose, a 5 kW laboratory resistive furnace was developed. While processing carbon samples weighing up to 30 g, the reactor simulates the operating conditions that arise during fast heating to 3000°C in a fluidized bed under an inert gas atmosphere. A typical multistage purification cycle in laboratory conditions included the heating of the material for 0.5-1 min and holding it at a constant temperature for 3–30 min.

The laboratory study of the thermal purification of natural graphite from world's deposits was carried out. The composition of the processed samples was determined by elemental analysis using a spectrometer and by measuring the ash after combustion of the samples.

TMEC is the only world company which offers such a technology with customized productivity of 50…1000 kg/h at affordable low price.