Effects of Acidithiobacillus ferrooxidans inoculation density and minerals collection time on the formation of biogenic secondary iron minerals in bioleaching system

The formation of secondary iron minerals often is observed in sludge bioleaching system fa-cilitated by Acidithiobacillus ferrooxidans,which affected the sludge dewaterability and heavy metals leaching.At the critical point of jarosite formation in FeSO4-K2SO4-H2O system inoculated by Acidi-thiobacillus ferrooxidans,a simulative experiment were carried out to study the effects of bacteria den-sity and the resulting minerals collection time on the iron precipitation formation.The results indicated that the amount and type of precipitates formed in the bioleaching system depended,to a certain extent,on the Acidithiobacillus ferrooxidans density and mineral collection time.If the resulting iron mineral wasn’t removed through manual collection in time,monovalent cation(such as K+) existed in reaction solution would facilitate easily the resulting schwertmannite to transform into jarosite.