TRANSFER OF O-2 FROM AIR TO MINERAL SLURRIES IN A RUSHTON TURBINE AGITATED TANK

G VANWEERT*, D VANDERWERFF, JJ DERKSEN

*Corresponding author for this work

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Oxygen transfer from dispersed air in agitated slurries represents an important unit operation in the minerals processing industry. Gold leaching, iron precipitation and especially bio-oxidation come readily to mind. However, little engineering information is available on the effect of mineral solids on such O-2 transfer. Engineering literature on the subject, i.e. information which relates slurry density and energy input to O-2 transfer, is reviewed and compared to current experimental work. The latter was carried out with minus 50 micron sand/water slurries in a 64 l laboratory tank of standard proportions, equipped with a standard Rushton turbine and variable speed drive with torque meter.

Results confirm an increasing impairment of O-2 transfer with increasing slurry density. The volumetric mass transfer coefficient k(l)a, in a IO vol.% slurry shows a decrease of 30% compared To the k(l)a in water. At 40 vol.% sand this decrease is near 60%, depending somewhat on superficial gas velocities. Power needed for equivalent oxygen transfer increases even more steeply with slurry density. Experimental results are presented and their significance for slurry bio-oxidation discussed.

Original languageEnglish
Pages (from-to)1109-1124
Number of pages16
JournalMineral Engineering
Volume8
Issue number10
Publication statusPublished - Oct 1995
EventMinerals Engineering 95 - ST IVES
Duration: 14 Jun 199516 Jun 1995

Keywords

  • AERATION
  • MINERAL SLURRIES
  • RUSHTON TURBINE
  • BIOOXIDATION
  • OXYGEN-TRANSFER

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