Sorry for the delay in responding to this one but yesterday morning we had a sever storm blow though here (80 mph winds) that blew out our electric power (no computer) & today was spent cleaning up the storm damage.
Anyway – I see most of best minds in refining (those I have learned “so much” from) have already posted replies – lots of technical info to help understand what’s going on in the process.
I still consider my self a beginner at refining with so much yet to learn so I hope my post here doesn’t sound like a student trying to be smarter then my teachers & as much as the technical info is good to know for understanding the process of working with AgCL – in practice the process is simple & I have figured out a few things to even make it easy.
Whether doing AgCL or cementing end product of course depends on how clean or how dirty your starting material is (concerning base metals) if you start with a dirty source (like contact points) you are going to get drag down whether going with AgCL or cementing. What I like about AgCL is that I seem to get a cleaner end product.
Based on XRF read out I have had my cement come back as low as around 95 but my worst AgCL has been around 97 (from contact points) On the other hand the best cement I have had (from sterling) has been 98.5 with AgCL coming in at 99.95
As a “hobby” refiner doing batches of 20 oz to 40 oz – this is what I like about going with AgCL instead of cementing - I can achieve 999 in less time & with less hassle.
Once you have your Ag nitrate – if your starting material was a clean source like sterling there is no reason why you should not have 999 powders ready for drying after 4 – 6 hrs. If your starting material was dirty like contact points 3 days once you have your Ag nitrate. Day 1 – drop Ag CL wash – convert – wash – dry over night, --- Day 2 – weigh – re-dissolve to nitrate. --- Day 3 same as day 1 with 99 plus Ag in the end. --- On say a 40 oz batch with cementing & running a 1 or 2 liter cell off a computer power supply it would take 5 to 7 days with much time spent watching the cell to keep the crystals knocked down to prevent shorting the cell.
The 2 reasons most people avoid going with AgCL is first the concern of not getting complete conversion due to the cottage cheese clumping nature of AgCL & concern that the NaOH wont get to all the AgCL in the middle of the clumps to complete the conversion. And the clumping is made even worse if you use hot water wash’s to wash out water soluble CL’s like Lead CL etc.
The second is washing out the NaOH. Its nasty stuff & can take a LOT of water washing to really get it out. (I have had to do as much as 5 or 6 washing to really get it out) --- But there is a solution to both of these problems.
First “cold” water along with a kitchen egg beater “whip” will brake most of the clumps down to much finer particles & smaller clumps. – Then “before” adding your NaOH – take your corn syrup – dilute it about 50/50 with warm water (I always use D-water) so it’s still syrupy but flows nice & add it to your AgCL & whip the living day lights out of it with your kitchen whip. The vast majority of your AgCL will brake down to very fine particles with only some very small clumps. More of a milky slurry. (note - you should have your AgCL in plenty of water when you ad the corn syrup)
Now you can ad your NaOH while stirring vigorously (I use 98.5% NaOH dry form & I ad it dry) & your end result should be a nice gray fine divided silver cement.
Now to get the NaOH out --- ad small amounts of HCL stirring it till you get a ph of 7 or 6.5 (keep it just slightly alkaline) & you should now only have to wash it 2 or 3 times before its ready to go to drying.
There is no reason to not get 995 to 999 silver in short order with the AgCL method – the only delay being maybe to give it a couple days to settle if you need to re-dissolve & run a second time.
Trace amounts of Pd = DMG --- if there are more then trace amounts of PGMs – then its cement & silver cell.
Kurt
Anyway – I see most of best minds in refining (those I have learned “so much” from) have already posted replies – lots of technical info to help understand what’s going on in the process.
I still consider my self a beginner at refining with so much yet to learn so I hope my post here doesn’t sound like a student trying to be smarter then my teachers & as much as the technical info is good to know for understanding the process of working with AgCL – in practice the process is simple & I have figured out a few things to even make it easy.
Whether doing AgCL or cementing end product of course depends on how clean or how dirty your starting material is (concerning base metals) if you start with a dirty source (like contact points) you are going to get drag down whether going with AgCL or cementing. What I like about AgCL is that I seem to get a cleaner end product.
Based on XRF read out I have had my cement come back as low as around 95 but my worst AgCL has been around 97 (from contact points) On the other hand the best cement I have had (from sterling) has been 98.5 with AgCL coming in at 99.95
As a “hobby” refiner doing batches of 20 oz to 40 oz – this is what I like about going with AgCL instead of cementing - I can achieve 999 in less time & with less hassle.
Once you have your Ag nitrate – if your starting material was a clean source like sterling there is no reason why you should not have 999 powders ready for drying after 4 – 6 hrs. If your starting material was dirty like contact points 3 days once you have your Ag nitrate. Day 1 – drop Ag CL wash – convert – wash – dry over night, --- Day 2 – weigh – re-dissolve to nitrate. --- Day 3 same as day 1 with 99 plus Ag in the end. --- On say a 40 oz batch with cementing & running a 1 or 2 liter cell off a computer power supply it would take 5 to 7 days with much time spent watching the cell to keep the crystals knocked down to prevent shorting the cell.
The 2 reasons most people avoid going with AgCL is first the concern of not getting complete conversion due to the cottage cheese clumping nature of AgCL & concern that the NaOH wont get to all the AgCL in the middle of the clumps to complete the conversion. And the clumping is made even worse if you use hot water wash’s to wash out water soluble CL’s like Lead CL etc.
The second is washing out the NaOH. Its nasty stuff & can take a LOT of water washing to really get it out. (I have had to do as much as 5 or 6 washing to really get it out) --- But there is a solution to both of these problems.
First “cold” water along with a kitchen egg beater “whip” will brake most of the clumps down to much finer particles & smaller clumps. – Then “before” adding your NaOH – take your corn syrup – dilute it about 50/50 with warm water (I always use D-water) so it’s still syrupy but flows nice & add it to your AgCL & whip the living day lights out of it with your kitchen whip. The vast majority of your AgCL will brake down to very fine particles with only some very small clumps. More of a milky slurry. (note - you should have your AgCL in plenty of water when you ad the corn syrup)
Now you can ad your NaOH while stirring vigorously (I use 98.5% NaOH dry form & I ad it dry) & your end result should be a nice gray fine divided silver cement.
Now to get the NaOH out --- ad small amounts of HCL stirring it till you get a ph of 7 or 6.5 (keep it just slightly alkaline) & you should now only have to wash it 2 or 3 times before its ready to go to drying.
There is no reason to not get 995 to 999 silver in short order with the AgCL method – the only delay being maybe to give it a couple days to settle if you need to re-dissolve & run a second time.
Trace amounts of Pd = DMG --- if there are more then trace amounts of PGMs – then its cement & silver cell.
Kurt
