Differential flotation of sulfide ores for recovering refractory gold

• Main Authors: Leppinen, Jaakko, Moilanen, Jari
• Format: Patent
• Language: English
• Published: 12.04.2018
• Subjects: DIFFERENTIAL SEDIMENTATION; FLOTATION; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLIDMATERIALS OR FLUIDS; PERFORMING OPERATIONS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS; SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATICTABLES OR JIGS; TRANSPORTING

Provided herein is a process for recovery of gold from gold-containing raw materials comprising refractory gold-containing minerals, in particular gold-containing refractory sulfidic minerals, comprising (a) obtaining gold-containing raw material comprising refractory gold-containing sulfidic minerals comprising first type of refractory sulfidic mineral having high gold content and second type of sulfidic mineral having low gold content; (b) forming a mineral pulp comprising first type of refractory sulfidic mineral particles having high gold content and second type of sulfidic mineral particles having low gold content by suspending ground gold-containing material in water and optionally further milling the material; (c) conditioning the mineral pulp by addition of a surface modifying chemical for modifying the surface of the first type of refractory sulfidic mineral particles having high content thus making the said particles non-floatable to obtain a conditioned pulp; (d) subjecting the conditioned pulp to a froth flotation process to separate first type of refractory sulfidic mineral particles having high gold content from the second type of sulfidic mineral particles having low gold content; (e) recovering the non-floatable first type of refractory sulfidic mineral particles having high cold content as flotation tailings; (f) pressure oxidizing (POX) the flotation tailings recovered in step (e) to obtain a discharge slurry comprising liberated gold; and (g) recovering gold from the discharge slurry obtained in step (f).