Process for the elimination of iron and steelmaking wastes with zinc allowing metals recovering

Profil Titel	Process for the elimination of iron and steelmaking wastes with zinc allowing metals recovering
Referenz	10 ES 28G2 3HZI
Herkunftsland	Spain
Kooperationsart	Angebot
Eintrag/Änderung	2010-07-20 / 2010-12-17
Status	Dieses Profil ist abgelaufen! Falls Sie denoch Interesse haben, kontaktieren Sie uns. (2011-06-30)

Kurzfassung

A Spanish research organisation has developed a procedure for the elimination of the filter dust (FD) with zinc, from steelmaking and foundry production. The procedure is based on the carbothermal reduction of the metal oxides presented in the waste as ZnO, allowing the recycling of metals. The solid fraction of the rubber tyre scrap pyrolisis can be used in the carbothermal reduction instead of coal. Industrial partners for the development of the process at industrial scale plant are sought.

Details

This technology is based in a new design of an electric induction furnace that allow the elimination of filter dust with zinc, from steelmaking and foundry production by a procedure based on two consecutive treatments: (1) a previous calcination of the filter dust with Zinc at a temperature higher than 1000 ºC to remove volatile pollutants, and (2) a carbothermal reduction of the wastes with Zinc by means of carbon at a temperature ranged from 1500 and 1600 ºC, giving rise to:
a)The recycling of non volatile metals.
b)Reduction of ZnO and evaporation of the formed metallic Zinc together with volatile compounds not removed in the calcination step.
c)Production of slag with the rest of components.
Preliminary studies for a plant with an annual treatment capacity of 40,000 tons/year show better results compare to the conventional procedure due to the production of metal and ZnO without halogen compounds, lead and cadmium and with a reduce content of alkaline compounds.
The mains figures in concept of costs of the procedure foe an industrial plant are: 1100/1400 kwh of electrical power; 40 Nm3 of Natural Gas; 200 kg of coal; 200-350 kg of produced metalg; 200 to 350 kg of ZnO; 200 to 300 kg of slag and approximately 100 kg of dust waste.
The process can use the solid fraction of the rubber tyre scrap pyrolisis instead of coal in the carbothermal reduction. It can also make use of the steel cans scrap recovered from MSW, steel wire scraps from rubber tyre or mills scale alloyed from steelmaking shops.

Innovative Aspects:
• A new electric induction furnace that allow melting all non-metallic inorganic material
• The uses of the solid fraction of the rubber tyre scrap pyrolysis instead of coal in the carbothermal reduction.
Advantages over conventional methods:
The proposed procedure allows:
• The treatment of filter dusts with Zn, with or without Ni, at a reasonable cost.
• The use of low value steel scraps for the production of commercial iron melts
• The production of concentrated material with high ZnO content and low impurities content including Pb and Cd.
• The waste treatment plant could be allocated close to steel plants since it does not require high treatment capacities.
• The waste treatment plant could be integrated as a cogeneration plant for the production of electrical powder with distilled oils from the tyre scrap minimising the energy consumption of energy.