I have alot of gold bearing sand &black gold bearing sand, where can I send it to Refine it & get my gold out?

I have like 10 pounds now of gold/silver/platinum bearing sand and gold/platinum/silver bearing black sand. I have already had a metalurgist Identify that I do have these metals. Where can I send it to refine it and extract the gold and other metals? Please only serious answers, and YES platinum can be found in nature, people have argue with me that it cant be found in nature. But if anyone knows of a refinery that accepts ores like this PLEASE let me know! thanks!