Título

NICKEL RECOVERY BY CARBOTHERMIC REDUCTION FROM SLUDGE GENERATED DURING NICKEL PRODUCTION

NICKEL RECOVERY BY CARBOTHERMIC REDUCTION FROM SLUDGE GENERATED DURING NICKEL PRODUCTION

Autoria

Neira, John Bernardo Vilca; Santos, Dener Martins dos; Mourão, Marcelo Breda; Takano, Cyro

DOI

10.5151/5463-5463-0028

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Resumo

During nickel extraction from ores by Caron process a large amount of sludges is generated. These sludges still contain an average of 0.54%Ni mainly as silicate, 0.07%Co and total iron of around 30%. This work intends to recover the contained Ni and Co from them. A composite pellets was produced with petroleum coke and using CMC (carboxi-metil-cellulose) as binder. The reduction behavior was determined by weight loss at temperatures of 1423, 1473, 1523 and 1573 K and times at each temperature of 2, 5, 15,30 and 45 minutes. The reduced pellets were analyzed by Electron Microscopy and XDS. The metallic phase of Fe-Ni presented a composition varying from 1 up to 2.2%Ni, with residual Cu and Co . The reaction fraction was around 80%. At this range of temperatures the reaction fraction was very sensitive to temperature variations. For 45 minutes the reaction fraction was 50% at 1423 K and 80% at 1573 K. It was identified 2 steps for reduction reaction. The first step up to around 10 minutes is very fast and the second step after 10 minutes is slow. The apparent activation energies determined were 86 kJ/mol and 135 kJ/mol, respectively.

 

During nickel extraction from ores by Caron process a large amount of sludges is generated. These sludges still contain an average of 0.54%Ni mainly as silicate, 0.07%Co and total iron of around 30%. This work intends to recover the contained Ni and Co from them. A composite pellets was produced with petroleum coke and using CMC (carboxi-metil-cellulose) as binder. The reduction behavior was determined by weight loss at temperatures of 1423, 1473, 1523 and 1573 K and times at each temperature of 2, 5, 15,30 and 45 minutes. The reduced pellets were analyzed by Electron Microscopy and XDS. The metallic phase of Fe-Ni presented a composition varying from 1 up to 2.2%Ni, with residual Cu and Co . The reaction fraction was around 80%. At this range of temperatures the reaction fraction was very sensitive to temperature variations. For 45 minutes the reaction fraction was 50% at 1423 K and 80% at 1573 K. It was identified 2 steps for reduction reaction. The first step up to around 10 minutes is very fast and the second step after 10 minutes is slow. The apparent activation energies determined were 86 kJ/mol and 135 kJ/mol, respectively.

Palavras-chave

Slugs; Nickel; Carbothermic reduction.

Slugs; Nickel; Carbothermic reduction.