OXIDATIVE AMMONIA LEACHING OF SPHALERITE CONCENTRATE

Abstract

This paper presents a study of kinetics of leaching of sphalerite concentrate in ammoniasolutions. The effects of ammonia concentration, oxygen partial pressure, reaction temperature andparticle size on the leaching rate were investigated. The shrinking core model was applied to the resultsobtained from these experiments. Reaction on order with respect to PO2 (1-10 atm.) and NH3 concentration(1.05-5.20 M) were 0.22 and 0.63 and the activation energy was determined to be 43.59 kj/mol in thetemperature range of 90-130 °C. In addition, the apparent rate constant is in inverse relationship with themean initial particle radius. The results of this study showed that the leaching of sphalerite was areaction controlled process.

Keywords

• Sphalerite, ammonia, kinetic model, reaction controlled process.

Sfalerit Konsantresinin Oksitleyici Amonyak Liçi

Öz

Bu makalede, sfalerit konsantresinin amonyak çözeltisinde liç kinetiğine ait bir çalışmasunulmuştur. Amonyak konsantrasyonunun, oksijen kısmi basıncının, reaksiyon sıcaklığının ve taneboyutunun liç hızına etkisi araştırılmıştır. Deneylerden elde edilen sonuçlara küçülen partikül modeliuygulanmıştır. Oksijen kısmi basıncına PO2 (1-10 atm) ve NH3 konsantrasyonuna (1.05-5.20 M) görereaksiyon dereceleri sırasıyla 0.22 ve 0.63 olarak bulunmuştur. 90-130 °C aralığında aktivasyonenerjisinin 43.59 kj/mol olduğu belirlenmiştir. Görünür hız sabitinin ortalama başlangıç tane yarıçapı ileters ilişkili olduğu görülmüştür. Bu çalışmadan elde edilen sonuçlar sfalerit liçinin reaksiyon kontrollübir proses olduğunu göstermiştir.

Anahtar Kelimeler

• Sfalerit, amonyak, kinetik model, reaksiyon kontrollü proses.

Kaynakça

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