It looks like nothing I have seen before.I'll try posting a pic with it on cotton or a paper filter, but usually I have a problem with it running everywhere and it's hard to see. the bit of precipitate is the piece of salt not fully dissolved in hcl when I added stannous. the gray is what the orange precipitated salt in the pics turned into upon heating. upon further heating this was my end result...
The yellow salt should be fluffy and light.
Upon heating it should be completely dry and starts by giving up white smoke until it is a grey powder.
If the smoke gets dark you are loosing values.
Can you describe point by point what you have done to the yellowish salt is in the filter?