MGH
Well-known member
Just wondering if anyone else has seen this before, or know what might have caused it. In the end it did not present any difficulty in refining or melting. It was just weird.
I recently refined two different lots side by side. One was a small lot of mixed karat scrap which I inquarted, parted in nitric, and then dissolved in AR and precipitated with SMB twice (1.23 ozt yield). The other was a stone removal lot so I used direct AR digestion, alternating a few times with sodium thiosulfate to remove silver chloride, and then ultimately precipitated twice with SMB as with the other lot (yield 5.82 ozt). These lots were done side by side, same hotplate, same chemicals.
The yields for both lots were as expected. I was initially worried after precipitating the stone removal lot (5.82 ozt) as the volume of the precipitated gold was much less than expected. I carried out the washes and rinses, and then dried the gold, still worried about the volume. The gold powder was not at all spongey. It was dense, and upon stirring a bit, relatively free-flowing. It melted just fine, producing the five bars in the picture below.
The beaker on the left is the 5.82 ozt dense powder. The beaker on the right is the typical sponge I'm used to. Yes, it's a 1.5L beaker vs 1L, but at 5.82 ozt vs 1.23 ozt hopefully it shows the difference in density.
Again, this didn't actually present any trouble or correlate to yield loss. It was just curious.
I recently refined two different lots side by side. One was a small lot of mixed karat scrap which I inquarted, parted in nitric, and then dissolved in AR and precipitated with SMB twice (1.23 ozt yield). The other was a stone removal lot so I used direct AR digestion, alternating a few times with sodium thiosulfate to remove silver chloride, and then ultimately precipitated twice with SMB as with the other lot (yield 5.82 ozt). These lots were done side by side, same hotplate, same chemicals.
The yields for both lots were as expected. I was initially worried after precipitating the stone removal lot (5.82 ozt) as the volume of the precipitated gold was much less than expected. I carried out the washes and rinses, and then dried the gold, still worried about the volume. The gold powder was not at all spongey. It was dense, and upon stirring a bit, relatively free-flowing. It melted just fine, producing the five bars in the picture below.
The beaker on the left is the 5.82 ozt dense powder. The beaker on the right is the typical sponge I'm used to. Yes, it's a 1.5L beaker vs 1L, but at 5.82 ozt vs 1.23 ozt hopefully it shows the difference in density.
Again, this didn't actually present any trouble or correlate to yield loss. It was just curious.
