05/03/2025
‘Experienced’ small-scale CIP operators usually inquire how to calculate the results of the silver nitrate titration of cyanide. If you bought the standard silver nitrate solution from us, we provide 2 sets of standards: the high standard which is used for “linang” and other high grade materials but can also be used for tailings provided the volume of sample is greater than 10 ml, and the low standard for “lugaba” and tailings materials. Most, if not all, prefer to use the high standard.
So the calculations will be:
For the high standard: (using 10 ml filtered sample solution)
Ppm Sodium cyanide = Volume of silver nitrate used x 1000/2
= Volume of silver nitrate used x 500
For the low standard: 10 ml sample
Ppm Sodium Cyanide = Volume of silver nitrate used x 100
Ppm = parts per million = milligrams per liter. It is the preferred unit for the concentration of sodium cyanide in the CIP circuit rather than the percentage because we are dealing with minute quantities.
To make it simpler (using the high standard and 10 ml filtered sample);
For tailings and regular ore: typical target* sodium cyanide concentration will be 300 to 500 ppm
Your reading (volume of silver nitrate) should be 0.6 to 1.0 ml
For “linang” and high grade ore: typical target sodium cyanide concentration will be 600 to 1000 ppm
Your reading (volume of silver nitrate) should be 1.2 to 2.0 ml
*Typical target concentration is the usual dosage employed by most CIP plants but if you have access to metallurgical testing so much the better. A metallurgical test will determine all the process parameters for a given type of ore or tailings.
Let us improve our small-scale process by monitoring our cyanide concentration in our plant. With this, excess usage of cyanide is avoided hence unnecessary expense on cyanide and ill-effects on our rivers and environment will be minimized. Let us be responsible operators.
