solo_voyager Posted November 16, 2006 Report Share Posted November 16, 2006 Several years ago I separated all the tweasable nuggets from my poke. The balance, mostly a coarse to fine dust mixed with lead minerals was treated with quick silver and then retorted to remove the mercury. I've had an approximately 2/3 oz button laying around ever since. I don't remember exactly what happened, but my impression was that the lead was taken up along with the gold. As I look at it now it seems to be pretty clean.So, my questions:1. Has the amalgamation process separates the gold from the lead ore, or was the lead ore included in the button with the gold?2. If the lead has been taken up by the amalgamation process and is also in the button along with the gold, how can I remove it so that only the gold is left? Thxs-v Quote Link to comment Share on other sites More sharing options...
Reno Chris Posted November 17, 2006 Report Share Posted November 17, 2006 THe lead is taken up with the gold. Your gold button will contain a certain amount of lead, depending on how much was in the original mix.Chris Quote Link to comment Share on other sites More sharing options...
solo_voyager Posted November 17, 2006 Author Report Share Posted November 17, 2006 OK, that is what my first impression was way back when. Since posting my original inquiry, I've broken up the button up with a pair of pliers. I placed the pieces into a mortar and worked the pieces back down to a coarse to fine powder again by gringing and pounding with the pestle. The results looks "dirty". Probably the lead and maybe some reduced iron oxide from the retort it was stored in for years. I think I'll grab my pan out of storage tomorrow and try panning it down again to see if I can remove some of the "black" portions. I may not get much of it out because the "black" portions are very very fine. Now, I'm still looking for an answer to question #2: How to remove the lead?I also have a bottle of concentrated sulphuric acid stored away with my mineralogy gear. Will that effectively remove the lead from the gold or is there a better way to accomplish that? Quote Link to comment Share on other sites More sharing options...
dave wiseman Posted November 17, 2006 Report Share Posted November 17, 2006 You might try Nitric acid in a very well ventilated space,such as outdoors with the wind not blowing,or you can make royal water out of nitric and muriatic(pool acid).This will turn the gold into solution...Dave Quote Link to comment Share on other sites More sharing options...
dave wiseman Posted November 17, 2006 Report Share Posted November 17, 2006 You can try typing "basement chemistry for the prospector" into google.Be very careful with the acids,wicked and dangerous stuff.....Dave Quote Link to comment Share on other sites More sharing options...
solo_voyager Posted November 17, 2006 Author Report Share Posted November 17, 2006 Just a little update on my project.After my last post I played with the gold fines a bit more. I tried grinding lightly with the pestel while the gold fines were covered with soapy water in the mortar. The "black" portion became suspended in the water and could be poured off. The soap kept the gold fines from floating on the surface. I was able to remove virtually all the black portion. My assumption is that the "black" was probably lead sulphate and/or iron oxide which was groung finely enough to become suspended and be pourd off with the water. The gold has cleaned up quite nicely with only a couple of possible problems now. It appears that there are some particles of the ceramic material from the mortar and pestel now mixed into the fines. Not a problem. Those will pan out easily. The other problem is that the gold fines are lighter in color than the small nuggets that were removed prior to retorting. My assumption is that this is caused by either residual mercury or possibly metalic lead bonded to the gold. Heating to red heat in an open area should remove any residual mercury and possibly oxidize any metalic lead. Then, treating it with dilute sulphuric acid should turn any resiudual metalic lead to lead sulphate. Finally, I should be able to go back to the "pour it off in water" process again. Does that sound reasonable. Or am I off in la-la land again? Quote Link to comment Share on other sites More sharing options...
Reno Chris Posted November 17, 2006 Report Share Posted November 17, 2006 It is probably lightened because the lead is alloyed with the gold. Heat will not remove the lead. Dilute sulfuric will not remove much of the lead as the gold will protect it. Nitric will do the job as Dave mentioned. Chris Quote Link to comment Share on other sites More sharing options...
solo_voyager Posted November 17, 2006 Author Report Share Posted November 17, 2006 OK then, what would be the easiest and cheapest way to obtain a small amount of nitric acid? Quote Link to comment Share on other sites More sharing options...
Reno Chris Posted November 17, 2006 Report Share Posted November 17, 2006 Prospecting shop or chemical supply wharehouse. Chris Quote Link to comment Share on other sites More sharing options...
solo_voyager Posted November 17, 2006 Author Report Share Posted November 17, 2006 Well, It looks like this project is grinding to a halt for now. After checking around town the only place I can obtain nitric acid is from a chemical supply, 500ml at almost $60. Not worth it to me. I know I said 2/3 oz. in the original post. Don't ask me where I got that number from. I meant 1/3 oz. Not enough to justify that much of another acid sitting around.Thank you both Dave and Chris for your advice on this. If I can find a source for a smaller quantity, I'll give it a try. Quote Link to comment Share on other sites More sharing options...
kamikaze Posted November 18, 2006 Report Share Posted November 18, 2006 While we're on the subject, what does the borax and heat with torch process do? I think it refines the metal or something... Quote Link to comment Share on other sites More sharing options...
BIGFOOT Posted November 18, 2006 Report Share Posted November 18, 2006 s-v,I've been there before with a large amalgam ball of gold,copper,lead,iron and everything was well alloyed together AFTER the retort.I boiled off everything with Nitric Acid (accept the Au which was left as a BLACK powder on the bottom of the Pyrex jar)and seperated the BLACK gold using a funnel and coffee filter,dried it completely then melted it into a pure product in button form.Dont EVER throw away that black stuff TILL ya know what it is first..........save everything your workin with! Blackfoot Quote Link to comment Share on other sites More sharing options...
SGTFDA Posted November 19, 2006 Report Share Posted November 19, 2006 When melting scrap gold to recast I use borax and a graphite rod. I place the scrap gold in a crucible, heat it up until it forms a melted ball, sprinkle on some borax from a salt shaker, stir with the rod which will suck up impurities then pour the gold into my mold. If the gold is extra dirty I will do the borax and rod twice. Ove time the crucible will build up a borax coating as will the rod and that helps remove impurities. After you sprinkle some borax on the hot metal you will see it floating about sucking up the crap. Hope that helped. Quote Link to comment Share on other sites More sharing options...
Uncle Ron Posted November 19, 2006 Report Share Posted November 19, 2006 If you have a smelting oven that will get up to 1,945 degrees, you can place the contaminated gold in a bone cuple, available at many prospecting sources....The bone will absorb the lead, copper, etc., and will leave the gold/silver as a button...Many years ago we had a cat battery blow up in our placer pit...It was a nightmare, but the process above, tedious as it may be on large quantities, works perfectly....Cheers, Un Quote Link to comment Share on other sites More sharing options...
grubstake Posted November 20, 2006 Report Share Posted November 20, 2006 Been lookin all over this forum can't find the Amalgumation button no where! So I can push it to see what it does!, Did learn something though! I just found out from Uncle Ron Cats had batteries, now if I can just catch the ones under my trailer, I can take the batteries out of them to make them shut up at night! Grubstake Quote Link to comment Share on other sites More sharing options...
Reno Chris Posted November 20, 2006 Report Share Posted November 20, 2006 Ron: There used to be a place here in Reno that processed spent carbon. The BIG Nevada mines use activated carbon to take the gold out of the cyanide solutions that capture it. The gold is then stripped off the carbon and the carbon re-used. The cabon can be re-used many times, but not forever. Eventually it wont load up right, so they have to get new carbon. The old carbon is then burnt, and the ash smelted like a gigantic fire assay in an arc-furnace. They then pour the lead/gold/silver mix out in 25 pound bricks. The 25 pound bricks were cupeled just as you say in a custom giant bone ash cupel. The lead is oxidized and the gold and silver remain behind. It is just as you describe, but on a giant scale. They still do the same thing with the spent carbon, but it is now shipped overseas for processing and the Nevada plant is closed.They used to produce some very nice gold bricks. Chris Quote Link to comment Share on other sites More sharing options...
dave wiseman Posted November 20, 2006 Report Share Posted November 20, 2006 Ah yes,follow the yellow brick road,the dream of all prospectors....Dave Quote Link to comment Share on other sites More sharing options...
kamikaze Posted November 20, 2006 Report Share Posted November 20, 2006 Hi Chris, I remember your old avatar which was of you and a bunch of huge ingots...of Silver I believe. Too bad it wasn't yours! Quote Link to comment Share on other sites More sharing options...
Reno Chris Posted November 20, 2006 Report Share Posted November 20, 2006 That was from a mine in the Humboldt Range, across the valley from the Rye Patch placer area.Here's a larger version of it. The full size bars are over 400 pounds of silver and about 4 pounds of gold each. Quote Link to comment Share on other sites More sharing options...
kamikaze Posted November 20, 2006 Report Share Posted November 20, 2006 That's the grin a guy has when he' thinkin' "I wonder how fast I can run carrying 400 pounds?" Thanks for reposting that pic. Sure would be nice to dig one of those up. It could fall off the courier truck... Quote Link to comment Share on other sites More sharing options...
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