Heap leaching: several technical points-2

Spraying:
Agglomerated granules should not be washed and the PH value should be adjusted by washing. The PH value should be adjusted during granulation. It is absolutely impossible to pre-spray the ore. After washing the ore, it will form mud and agglomerate. After the agglomerate is sludged, it means that it will not be granulated. The consequences are serious.

Sodium Cyanide Concentration During Spraying:
As the ore is complex and the weather is cold, the sodium cyanide concentration can be increased appropriately during initial spraying, which can be controlled at 0.1% to 0.08%. Once the liquid gold has been concentrated, the sodium cyanide concentration can be adjusted at any time to adjust the concentration of precious liquid gold. After the time, it can be reduced to 0.08% to 0.06%, and later to 0.04% to 0.02%.
Spraying Cycle:
At most, spraying should be conducted for 7 to 8 hours a day, but it shouldn't exceed 10 hours (although the amount should be reduced). Generally, spray 1 and stop 1 or spray 1 and stop 2. During the day, due to the high temperature, gold is easily leached, so you can spray 1 and stop 1. In the evening, due to the cold weather, if it is not freezing, you can spray for 30 minutes and stop for 1 hour, or spray 1 and stop 2, or do not spray at night. The spraying time should not be too long, so that the ore heap can absorb oxygen when it is not sprayed. If the spraying time is long and the number of times is large, the volume of the solution will definitely increase, so that the concentration of the precious liquid will be reduced and the sodium cyanide will be wasted. The volume of the precious liquid affects the adsorption capacity of the gold-loaded carbon.

Spraying Intensity:
Depending on how long the spraying takes and how much liquid is sprayed, the intensity of the spraying will vary. It is generally recommended to control the spraying intensity at 6-20L/m2.h (6-20L/m2×hour). The yard area, the amount of spraying liquid, and the time of day can be calculated to find the amount of water per square meter per hour. If the spray intensity is large, the volume of the precious liquid will increase, and the gold concentration will be diluted, which will affect the adsorption capacity of activated carbon (generally, the adsorption capacity of activated carbon is 8-10 kg/t). , the adsorption capacity is reduced and the adsorption time is prolonged, which also affects the workload and cost of desorption and electrolysis, and also increases the capacity of the precious liquid pool. The most important thing is to reduce the concentration of gold and prolong the spraying time, so the spraying amount cannot be too large. Large, the spray cycle can not be too much every day.