cheers for that. so if I understand this right the carbon was...

cheers for that.

so if I understand this right the carbon was robbing/absorbing the gold from the cyanide or acted in refractory manner - right?

Found some reading materials and they mention kerosene can be used to reduce the effects of preg-robbing. It seems ALK did not realise what was going on until it was too late.
And that is not good - if this is the case it points to lack of checks and balances.

Lessons learned hard way... about 4.5Koz hard way.

I sent them an email asking few questions to better understand what took place and if they have taken any steps to mitigate such risks. I also mentioned to explore an option to buy a Lab is such Lab exists for metal recovery plant. The one at CSR was not an expensive set up and if something similar can do the job the ALK should be getting one. Carbon content tests took about 5 min to perform and can be done every hour or two.. depending how much material is being pushed through the plant.
They are ramping up production and if they make another similar mistake it may cost us 5-6Koz or even more by the time they realise what is going on.