(Replacement of cyanide agent)


There are a number of features and operational advantages EarthGold offers when compared to a cyanide reagent which while at a comparable cost to a cyanide reagent offers strong safety advantages:

  • Environmentally-friendly product – lower toxicity
  • Safer product – Labeled within an ordinary goods item; non-burning, non-explosive, non-oxidizing, zero radioactivity and is less toxic.
  • Wide applicability – it can be used for leaching gold and silver from various kinds of gold and silver ores by heap leaching, pond leaching and carbon leaching processes.
  • Higher leaching rate
  • Faster recovery
  • Easy to use– It can replace sodium cyanide in gold and silver leaching processes without changing existing technical processes used for sodium cyanide.



  • Lower cost for transportation, storage, operation and tailing water disposal than sodium cyanide, price to site is similar to cyanide.
  • Faster recovery
  • Reduction of your mine’s environment protection cost


Application scope:
Gold and silver oxide ore, primary gold ore, high-sulphur and high-arsenic gold ore, cyanided slag, gold concentrate, pyrite cinder and anode mud.

Product ingredients:
Sodium oxide, nitrogen, ammonium, calcium, iron, carbon, etc.

Product form:
In solid granular or powdery form; soluble in water; best when being fully dissolved into clear water.

Application method:
The application methods of heap spraying, pond leaching and carbon leaching are the same as that when using sodium cyanide.

During the procedure, the pregnant solution and the barren solution can be reused. It would be better to use activated carbon for pregnant solution adsorption in gold & silver extraction. Environment temperature over 10℃ would be better for the gold & silver leaching process. This method is compatible with the cyanide process.

Before adding the ore pulp for gold and silver leaching, the gold & silver leaching reagent shall be fully stirred to complete dissolution stage with alkaline water at normal temperature.

Basicity adjustment:
The PH value keeps at 10~12 generally when being adjusted with lime (CaO) or caustic soda (NaOH), while 11±1 when being adjusted with backwater after the heap spraying or tank leaching of the raw ore.

The dose of the reagent is generally 0.1‰~0.9‰ of the ore volume (100~900 gram of reagent/ 1 ton of ore), which may change with the property, grade and pH value of the ore. The practical dosage can be calculated based on the mass concentration of the reagent. In general, its consumption is at similar rate of sodium cyanide

Dosing method:
Use the reagent directly when fully dissolved in water under room temperature. Generally, the water turbidity and concurrent stirring can accelerate dissolution. Spraying the gold extraction reagent makes it dissolve in the tank (barren solute tank) or place it directly into the tank for dissolution. For heap spraying, the processes of dosing and spraying can be conducted simultaneously

Reagent concentration:
Since the composition and pH value may vary with different ores, the gold and silver reagent will be calculated proportionally and as per the optimum concentration calculated, based on the actual ore volume and the ore sample test result. The reagent concentration can be tested as per the method provided by our company.