GOLD EXTRACTION METHOD FROM SLUDGE ANTHROPOGENIC DEPOSITION Russian patent published in 2008 - IPC C22B11/00 

FIELD: metallurgy, mining.

SUBSTANCE: method includes preparation of dry mix from sludge depositions with addition of bleaching powder, preparation of suspension by addition to mixture sulphuric acid solution and further gold sorption by sorbent of vegetable type. At that preparation of dry mix is implemented by blending of sludge depositions in the form of fractions of size less than 0.05 mm with bleaching powder in ratio 100:5. Suspension preparation is implemented by addition into dry mix 10% solution of sulphuric acid in volume of 250 ml and by blending in mixing device during four hours. Then it is implemented sorption by introduction into received suspension serpent of vegetable type, minced till size in limit less than 0.5 and more than 0.2 mm after thermal treatment at 200°C during one hour, and by additional blending during 20 minutes. After sorption it is implemented mixture wash by water on screen with size of cells less than 0.5 and more than 0.2 mm, drying and assay melting.

EFFECT: extraction of fine, superfine and collaurin gold from clay-sludge depositions, which can't be extracted by traditional gravity method.

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