Just wanted to share without creating new thread 
After a long time I decided to process cumulated silver contacts scrap. And revisit the lye/sugar again, this time with even more precautions. No lye in the eye this time
Around 1,25 kg raw material (desoldered AgCd stuff, cut points on brass or bronze, some AgNi stuff, gold plated AgCu...). Dissolved with around 1,5L 65% nitric, diluted to half strength by dH2O of course. Some 30g of tungsten contacts fished out afterwards. Filtration was slow and inefficient due to metastannic acid, but I found that Celite also helps here to contain the stuff and prevent it from passing the filter paper. God bless Celite It saved my ass many many times since I discovered it´s ability to clear cloudy solutions also in refining, not only in winemaking and chemistry
Conversion of AgCl to Ag2O was relatively easy going, but I managed to buy some branded crappy NaOH drain cleaner, which is obviously cut with salt... Worse than tech grade NaOH.... So it took unhealthy excess of lye. I was low on hydroxide and cannot buy original stuff when I needed, so I rushed to the store to get some, and for hefty price I bought some crap
Also, some new things for Ag2O to Ag conversion succesfully tested. This is 5th time in row that I performed lye/sugar on kilo-scale without any runaway or "spitting" reaction, completely controlled. Max for 5L beaker is around 1 kilo of silver. Then it is hard to mix. So I can write this down and add to my book of procedures I guess
We will see. Sitting in the beaker for the night, i´ll finish it in the morning.
After a long time I decided to process cumulated silver contacts scrap. And revisit the lye/sugar again, this time with even more precautions. No lye in the eye this time
Around 1,25 kg raw material (desoldered AgCd stuff, cut points on brass or bronze, some AgNi stuff, gold plated AgCu...). Dissolved with around 1,5L 65% nitric, diluted to half strength by dH2O of course. Some 30g of tungsten contacts fished out afterwards. Filtration was slow and inefficient due to metastannic acid, but I found that Celite also helps here to contain the stuff and prevent it from passing the filter paper. God bless Celite
It saved my ass many many times since I discovered it´s ability to clear cloudy solutions also in refining, not only in winemaking and chemistry Conversion of AgCl to Ag2O was relatively easy going, but I managed to buy some branded crappy NaOH drain cleaner, which is obviously cut with salt... Worse than tech grade NaOH.... So it took unhealthy excess of lye. I was low on hydroxide and cannot buy original stuff when I needed, so I rushed to the store to get some, and for hefty price I bought some crap
Also, some new things for Ag2O to Ag conversion succesfully tested. This is 5th time in row that I performed lye/sugar on kilo-scale without any runaway or "spitting" reaction, completely controlled. Max for 5L beaker is around 1 kilo of silver. Then it is hard to mix. So I can write this down and add to my book of procedures I guess
We will see. Sitting in the beaker for the night, i´ll finish it in the morning.
