Examination of phosphate ores bioleaching from Lisina deposit

Abstract

Phosphorus solubilization from insoluble phosphate ores by acidophilic autotrophs and heterotrophs is a research of significant interest, because of potential use of these ores as fertilizers, which are economically and ecologically more acceptable than industrial phosphate fertilizers. The object of this paper was to examine the possibility of phosphorus leaching from phosphate ore from Lisina deposit (Bosilegrad), by bacterially generated sulfuric acid, in laboratory conditions. The experiments were carried out with bacterium Acidithiobacillus (At.) ferrooxidans, which is isolated and selected from the copper sulphide mine in Bor. The main goal of the experiment was to confirm if it is possible to use phosphate ore in combination with examined bacterial culture, as a natural fertilizer. Results obtained show that phosphorus has been leached up to 24,5 % in suspension with At. ferrooxidans, and in the same time, degree of leaching in control suspension (without At. frrooxidans) was up to 7,2 %. Influence of At. ferrooxidans on phosphorus solubilization has been confirmed, so the future perspective of our investigations should be directed to examination of microbiological leaching of apatite mixtures with sulphide substrates, and their potential use in quality improvement of alkaline soils.

Postupci rastvaranja fosfora iz nerastvornih fosfatnih ruda pomoću acidofilnih autotrofa i heterotrofa spadaju u veoma bitna istraživanja, zbog moguće primene ovih ruda kao đubriva, čija je upotreba ekonomski i ekološki prihvatljivija od industrijskih fosfatnih đubriva. Predmet ovog rada je bio da se ispita mogućnost rastvaranja fosfora iz fosfatne rude sa ležišta Lisina (Bosilegrad), u laboratorijskim uslovima, dejstvom sumporne kiseline generisane pomoću bakterijske kulture Acidithiobacillus (At.) ferrooxidans, izolovane i selekcionisane sa jalovišta površinskog kopa rudnika bakra u Boru. Cilj eksperimenta je da se utvrdi da li je moguće rudu sa navedenog ležišta u kombinaciji sa ispitivanom bakterijskom kulturom koristiti kao prirodno đubrivo. Dobijeni rezultati pokazuju da se tokom eksperimenta rastvara fosfor iz ispitivane rude pod uticajem At. ferrooxidans i da je stepen rastvaranja 24,5 %, dok je rastvaranje fosfora u kontrolnoj suspenziji (bez At. ferrooxidans) iznosilo 7,2 %. Uticaj At. ferrooxidans na rastvaranje fosfora je potvrđen, tako da dalja istraživanja treba usmeriti na ispitivanja mikrobiološkog luženja mešavina apatita sa sulfidnim supstratima, zbog eventualne primene vezane za poboljšanje kvaliteta alkalnih zemljišta.