Alucyc

The aim of the Alucyc project is to develop a new process to recover metallic aluminium from aluminium dross. Comparing with available state-of-the art technologies, the yield of metallic aluminium is increased from 95% to 99%. Alucyc technology is waste-free, cryolite and the remaining aluminium oxide could be used in melting of primary aluminium as additives. Alucyc project is funded under FP7. Duration of the project was 01.12.2011 – 31.03.2014. Alucyc technology is protected by patents WO2009076969A1 and EP2231889A1.

Background

The production of one metric ton of aluminium from ore (bauxite) requires about 17000 kWh of electricity while the same amount of recycled aluminium consumes approximately 750 kWh. Therefore, the recovery of aluminium from, aluminium dross requires only 5% of energy related to that which is needed to produce the aluminium from ore[1]. During aluminium melting the dross is generated, resulting typically 25 kg of dross per metric ton of molten aluminium (3 wt%)[2]. That means 0.9 million tons of dross per year is generated. The generated dross contains 30-70% (in average 50%) metallic aluminium. Today the best technologies in dross processing make possible to get a recovery up-to 94%.
The existing dross processing technology suggests using salts (NaCl, KCl) in amount of 600 kg per 1 MT of dross that have serious environmental threat. For economic reasons, it is desirable to recover in usable form as much as possible of the free metal that is carried from the furnace into the dross. However, separation of metal is difficult, because the metal is dispersed as fine particles that are surrounded by a matrix of non-metallic components of the dross. Further, the free metallic aluminium in the more or less porous dross is highly susceptible to oxidation, especially at elevated temperatures[3]. To overcome these limitations and achieve higher yield of metallic aluminium the Alucyc project was launched.

Members of the consortium

The Alucyc consortium includes 6 partners from 4 different countries. They include 3 SME-s and 3 research institutions, RTD-s

SME partners

  • Coordinator Metallurg Engineering from Estonia
  • Barida Makina ve Sanayi Ticaret Limited Şti from Turkey
  • Sistemas y Control del Mediterráneo s.l. from Spain

RTD partners

  • Eesti Innovatsiooni Instituut from Estonia
  • The Chancellor, Masters and Scholars of the University of Cambridge from United Kingdom
  • Fundacion Tecnalia Research & Innovation from Spain

Scientific and technical objectives

The goal is to develop a full recovery technology for aluminium dross that enables:

  • Processing of aluminium dross with cryolite (Na3AlF6) on an electro slag furnace without salt addition that creates a metallic aluminium yield at least 99% instead of 95% in current SOA technologies;
  • Processing use electro slag melting with non-consumable electrode where:
    • Aluminium will deposit to the bottom of crucible due to the higher density;
    • Usage of DC instead of AC that is common in state-of-the-art (SOA) electro slag melting technologies with a non-consumable electrode

(ESMNC) process enabling the separation of metallic aluminium from oxides due to different charge states of aluminium.

  • More efficient melting process due to:
    • rotating of molten mass due to rotating magnetic field, generated by “right hand rule”
    • selective heating due to different resistance of aluminium and oxide fractions
    • processing is available in dross with aluminium content >15% instead of 35% in SOA technologies;
    • process results are only metallic aluminium and salt cake mixture that could be reused.

The main innovations

  • technology transfer from super alloys recovery to aluminium dross recovery;
  • re-usage of process waste as additives for primary aluminium processing.

Advantages over state of the art

  • Energy savings
  • Environmental savings
  • Aluminium processing industry saves 4.875 (TWh) of electricity each year per Alucyc unit installed with dross processing capability of 300 KT/year,
  • Based on the market figures for the 10 years post-project, the cumulative estimated energy saving is 131 625 TWh. This is the equivalent of a continual 3 GW generator, the same as a medium power station.
  • Aluminium industry will save € 345 Million by recovery of additional aluminium dross instead of salt cake landfill.
  • Additional yield 22.5 thousand tons of metallic aluminium that enables additional production for € 32 million in total;
  • 7 tons less of CO2 emission and saving of electric energy 16 250 kWh/t for production of 1 ton aluminium from aluminium dross comparing with production of aluminium from primary source.

Results

The Alucyc project has 4 main results:

  • Process model for complete recycling of primary aluminium dross;
  • Power control unit of hydraulic system
  • Control unit software
  • Integrated Alucyc solution, realized in pre-production prototype.

The project is successfully finished and the tests in industrial size furnace will take place during May 2014.

See also

aluminium dross recycling

External sources

http://www.alucyc.eu
http://cordis.europa.eu/programme/acronym/FP7-SME_en.html
http://cordis.europa.eu/projects/rcn/101127_en.html

References

  • 1. J. Mukhopadhyay, Y.V. Ramana, Upendra Singh. Extraction of Value Added Products from Aluminium Dross Material to Achieve Zero Waste. Light Metals 2004 Edited by A.T. Tabereaux. The Minerals, Metals & Materials Society, (2004)
  • 2. Kassabji F., Weber J. C. Aluminium dross processing in a rotary plasma furnace. (2003)
  • 3. McLeod et al. Recovery of metal from dross. U.S. Patent 3676105 (1971)