ספיחת פחמן פעיל

Typically, gold is not directly recovered. Instead, ore is crushed to release gold, which then reacts with סודיום ציאניד in a process called cyanidation. The process is characterized by the following chemical reaction:After the metal complex (NaAu(CN)2) is formed, פחמן פעיל will adsorb the קומפלקס ציאניד זהב from the gold bearing stream (pregnant liquor).

4 Au + 8(NaCN) + O₂ + H₂O = 4 NaAu(CN)₂ + 4 NaOH

The diagram above depicts gold ADSORPTION on activated carbon’s graphitic plates. Gold alone is not soluble, and will not be readily adsorbed by activated carbon until it is cyanidated, forming a gold-ציאניד coordination complex called dicyanoaurate. It is this gold-cyanide complex that is attracted to the tremendous surface area available on activated carbon, allowing for a variety of recovery techniques.