Hey guys. I've been reading Hoke's book and using the search function like crazy on this forum. I am having an issue with nitric acid elimination. I completely dissolve my gold in AR (note: I am using a 4:1 hcl to nitric ratio and I am careful not to add too much) and filter it many times. Then I evaporate it over a day or more until it is about one third of its previous volume. At this point it's a thin syrup and it has a noticeable difference in the viscosity from before. I add some sulfamic acid and get absolutely no reaction. So this leads me to believe that I have evaporated away all of my nitric acid and only have gold and base metal chlorides. After this is add ice to the syrup until I at least double the liquids volume. It gets so cold that ice forms on the outside of my beaker. I let this ice melt for about ten minutes with occasional stirring. Then I get my smb and start adding it while some ice is still left on top of the liquid. It usually takes me half an hour to add all the needed smb because I do not want to add too much at a time and have excess SO2 gas suspending my gold particles in the solution. While I am doing this I am constantly doing stannous chloride test until I am getting absolutely no gold content in the solution. I let the gold settle overnight and come back the next morning and I have bubbling from the settled gold redissolving and a stannous test reveals that I have gold chloride in the solution. I am completely lost on how any nitric acid could have been left in this solution. I have used urea before but I quit using that because of the possible dangers involved (and it's messy), I have recently started using the sulfamic acid but after I have evaporated the solution it isn't reacting. I am already waiting on this gold for over two days and I am still running into issues. Why is it redissolving? How long should a refining session take? (These are diamond removals in small lots so there is no quartering) How can I eliminate nitric acid the quickest way possible? I appreciate any help, I am sitting on valuables longer than I want to be and I've looked at Hoke's book and this forum and I don't know what I am doing wrong. If anybody has any advice or at least suggestions of what to search or where to look I would greatly appreciate it.