One good thing to do is to chrush the Sodium Carbonate with your mortar and pestle, cause they don’t mix so well in that “prilled” form.Very frustrating final step setback last nite. I had gold powder. I had a glazed crucible, a MAPP gas torch, borax flux and sodium carbonate. I managed to melt the material to a red hot liquid form. But, whenever I’d sprinkle the sodium carbonate, the gold would not coalesce into a bb or button. After cool down, there was visible gold through out the product. The material seemed more like hard graphite with gold throughout instead of metal. I washed it with dilute sulphuric. That step produced no noticeable change. I was obviously disappointed, So I crushed the material back to a fine powder with my mortar and pestal. Apparently about half of what I began with was incinerated in the process. I have more gold bearing material to add, if need be. This effort was a trial with a relatively small amount of precipitated and dried gold material. What should I do to make the gold content coalesce and form a bb or button? Thank you in advance for your help and advice.
I only use borax to glaze the new crucible when melting gold. Does often not need any borax with a good glazed crucible, that you ONLY use for gold.
With melting silver I use 2 parts of Sodium Carbonate (as powder) and 1 part borax mixed together, when it needs. And in its OWN crucible
/Dennis