Hello butcher- In response to your question regarding a flux recipe for black sands- try to avoid firing black sands as they can be very difficult to break down even @2200 degrees. If your hell bent to try to fire a black sand concentrtrate (containing gold), better test it for PGM's first cause the temperture difference for PGM's is a lot higher than gold, and iron in the con's can compound the difficulties of seperating the metals upon pouring. So, if you can determine that your black sands are just"gold bearing", try this flux recipe- 2 parts Borax(glass), 1 part Silica sand, 1 part Sodium Nitrate, and to make the smelt really fluid add 1 part lime. Fill crucible with cons and flux (mixed 50/50) to 2/3"s and cap with a thin layer of Borax. When there is no more reaction visible in crucible, usually an hour will do it, it's time to pour it. Always give the crucible a good swish before pouring. Also, you had asked about using a "collector", which is often used in firing hard rock gold for making "dore" bars. Typically lead is used as a "collector", but can be very difficult to get rid of, cuppelation being the one proven method of seperating the metals. If you think you should use a collector, try using a penny, as copper is closely aligned with gold for melting temperature @ 1946 degrees , remember also that the collector should have an affinity for the metal you are trying to recover. SMELTING is a very involved process!!!! - if you want to have any kind of saleable return you need to ensure that the material you are trying to fire is carrying at least 10% precious metals and be completely magnetic free (de-magged). Any form of iron in a smelt can be a serious problem, requiring vast amounts of Soda Ash to correct and usually ending up as "speece", worthless junk!!! Gabor J. Kadar
