METHOD FOR INTEGRATED PROCESSING OF PERSISTENT GOLD-CONTAINING MATERIAL Russian patent published in 2004 - IPC

FIELD: precious metals technology and hydrometallurgy. SUBSTANCE: invention relates to hydrometallurgical opening of persistent gold-containing material utilizing energetic effects and microorganisms. Method comprises (i) pretreating moistened raw material with electromagnetic pulses with electric field component intensity amplitude exceeding electric strength of material and pulse front duration lesser than spark discharge formation time in air gap equal to thickness of material layer and (ii) leaching pretreated raw material. Pretreatment and leaching of pretreated raw material are accomplished using acidic leaching solution containing mixture of autotrophic thion bacteria Acidithiobacillus thiooxidans, Acidithiobacillus ferrooxidans, and Leptospirillum ferrooxidans. Leaching is carried out at solids-to-liquid ratio between 1:3 and 1:10 at stirring under natural or forced aeration conditions and pretreatment is conducted at solids- to-liquid ratio between 5: 1 and 10:1 using 3-5% of the total amount of leaching solution. EFFECT: intensified sulfide oxidation and disintegration process. 6 cl