AR Shelf Life

[rusty]

I've had some milled cats soaking in AR for the past 3 or 4 months at ambient temperature now I would like to hit it with heat to assure I reclaim all the PGM's present in the leach.

Can I freshen up the AR by adding fresh HCL - suggestions.

 

[goldenchild]

I dont think the HCL would be what needs to be replenished. HCL can sit in extreme conditions over long periods of time and still work. The nitric is what you will probably need to replenish. Was the AR ever in direct sunlight? If so you will almost definately need to replenish nitric. Also the life of AR is short to begin with. A few weeks maybe. Working on metals, a few hours and it should be spent.