Litharge Questions for Canadians

[Heavy-Black-Sand]

Hello ..... I'm looking to start doing some smelting of highly concentrated black sands soon ... and in a recent conversation with someone in Canada who has considerable experience in gold mining/smelting/refining told me he no longer personally leaches his concentrates because he basically can "no longer" buy key ingredients in Canada to efficiently perform the leaching process himself ... and that he now ships his black sand concentrates off to a large commercial servcie facility for leaching, as he is producing many tons of high grade black sand per week.

I'm just coming out of the prospecting phase, and looking at doing very small scale production, and i'm really limited/suited to "smelting" the super-concentrated black sand (not producing tons per week) ..... a couple questions i have are .....

* (1) ..... can lead based litharge still be "reliably" purchased or imported into Canada at the retail level?

* (2) ..... if lead based litharge can still be purchased reliably in Canada, is it likely to remain so into the near future? ... or is there pending legislation to take lead based litharge off the retail market?

* (3) ..... if the authorities curtail the retail purchase of lead based litharge ... can a reasonable substitute be obtained that will offer the same/similar smelting benefits for ore containing microscopic gold for a similar cost?

 

[4metals]

he no longer personally leaches his concentrates because he basically can "no longer" buy key ingredients in Canada to efficiently perform the leaching process himself .

Your friend cannot leach anymore but you are looking to smelt and are asking about litharge. Am I missing something here?

 

[Heavy-Black-Sand]

Your friend cannot leach anymore but you are looking to smelt and are asking about litharge. Am I missing something here?

The relationship between the 2 points is .....

* the CDN government has recently removed our ability to buy key ingredients at retail to perform highly efficient leaching ..... so part of my concern is whether the CDN govt will soon severely restrict lead based litharge at retail also.

 

[4metals]

Understood, the government banned the leaching option and you want to be sure they don’t ban the lead smelt option before you get too far down the line.
What chemistries were banned for the leach process for Canadians?

 

[Heavy-Black-Sand]

Understood, the government banned the leaching option and you want to be sure they don’t ban the lead smelt option before you get too far down the line.
What chemistries were banned for the leach process for Canadians?

Correct ..... because if they do intend on restricting lead based litharge, i'd like to start steering towards the development of a alternative with similar performance ..... i guess i could use solid lead pieces as a collector metal, however, from what i've read; the lead based litharge is superior over solid lead for a micron gold collector - in particular becuase the litharge reportedly has a much higher metling temp (around 1,800 F) than the solid (621 F) - hence the lead Litharge may have a better bonding performance with the microscopic Gold over solids, as the lead litharge doesn't start dropping until reaching temperatures much closer to Gold's melting temp .... and the litharge can be much more evenly distributed amongst the charge due to it's micron sized particles.

I haven't studied leaching much, but i believe he said that Aqua Regia and Urea are both basically impossible to buy in Canada at retail now ..... he said you can still buy them in the US, but you can't bring it across the border into Canada at the retail buyer level anymore ..... this was from a conversation just aprox. 2 weeks ago.

 

[4metals]

Is cyanide available in Canada for the small operator?
And what ratio of litharge to black sands do you use?

 

[Heavy-Black-Sand]

Is cyanide available in Canada for the small operator?
And what ratio of litharge to black sands do you use?

I think he may have said cyanide was restricted at retail to ... he basically said all viable options for leaching in Canada at scale at the retail level are now gone.

I'm personally not set up myself to smelt yet ..... however, one of the highest level private gold smelting experts in BC with multi decades of experience did do some smelting tests on my black sand concentrates over a couple years ago - with excellent results ... the sample was concentrated to aprox. 1.5% Gold content & aprox. 98.5% black sand content prior to the smelting test ... after pulling excellent results from a run of each of aprox. 40 crucible charges, the expert smelter/refiner told me he could successfully smelt out the Gold values from the black sand concentrate as long as the Gold content was concentrated to a minimum 1% Gold content to black sand .... i mainly watched him perform the smelting/cupelling processes - i didn't ask him the exact proportions of the fluxing materials in the charge ... although in hindsight, i should have asked more spefici questions in regards to the proportions.

I haven't personally been pursing high-level smelting technology until just very very recently, becuase I've been focused on prospecting a rather large block of claims for the highest grade gravel deposits ... the majority of my prospecting activities is behind me now, and I'm really just now moving towards accumulating the knowledge/equipment to start focusing on smelting technology.

The attatched pict only shows 1 furnace & a tray of cupels coming out of the furnace during the smelting/cupelling test ... he had a row of several furnaces set up in his shop, all vented properly, etc ... this guy really knew what he was doing - getting very high level results on the first test run from each charge.

 

[4metals]

I just looked up the price of litharge at Legend and it ranges between $150-200 for a 55 pound bag. Pretty pricey. From fusion assays I've processed over the years, the litharge was usually half of the composition along with soda ash, flour, and glass or borax. So getting the flux blend to start with would be helpful for you, although you could figure it out by testing.

I am also surprised you are cupelling in an assay furnace in cupels. Years back in Ecuador I set up a cupellation furnace based on Ammens design. I'll add a screenshot from Ammens book of the furnace. The bed of the furnace was packed with bone ash making the entire thing a huge cupel.

 

[Shark]

Years ago while making lead cannon ball sinkers we would use a small electric lead pot that held 40lb of lead for the smaller items. Many times, if over heated, we would notice a yellowish layer form on the surface of the molten lead. Since we operated outside it was usually fairly breezy as well. Seeing that diagram again reminded of an old thought of trying to use one to make litharge with. If I recall correctly Lyman made the large pot I had, and may have made one in 20lb as well.

 

[Heavy-Black-Sand]

I just looked up the price of litharge at Legend and it ranges between $150-200 for a 55 pound bag. Pretty pricey. From fusion assays I've processed over the years, the litharge was usually half of the composition along with soda ash, flour, and glass or borax. So getting the flux blend to start with would be helpful for you, although you could figure it out by testing.

I am also surprised you are cupelling in an assay furnace in cupels. Years back in Ecuador I set up a cupellation furnace based on Ammens design. I'll add a screenshot from Ammens book of the furnace. The bed of the furnace was packed with bone ash making the entire thing a huge cupel.

View attachment 60284

Thanks for the insights ..... i think he used those furnaces for speed ... when i was at his shop, he had multiple 55 gallon drums full of concentrate he was smelting into buttons for a customer ... from the drums of concentrate, he already had processed aprox. 550 oz of Gold/Silver buttons wieghing around an ounce each in the shop that he showed me ... so he was running some decent volume for a 1 man operation.

 

[goldshark]

Hello ..... I'm looking to start doing some smelting of highly concentrated black sands soon ... and in a recent conversation with someone in Canada who has considerable experience in gold mining/smelting/refining told me he no longer personally leaches his concentrates because he basically can "no longer" buy key ingredients in Canada to efficiently perform the leaching process himself ... and that he now ships his black sand concentrates off to a large commercial servcie facility for leaching, as he is producing many tons of high grade black sand per week.

I'm just coming out of the prospecting phase, and looking at doing very small scale production, and i'm really limited/suited to "smelting" the super-concentrated black sand (not producing tons per week) ..... a couple questions i have are .....

* (1) ..... can lead based litharge still be "reliably" purchased or imported into Canada at the retail level?

* (2) ..... if lead based litharge can still be purchased reliably in Canada, is it likely to remain so into the near future? ... or is there pending legislation to take lead based litharge off the retail market?

* (3) ..... if the authorities curtail the retail purchase of lead based litharge ... can a reasonable substitute be obtained that will offer the same/similar smelting benefits for ore containing microscopic gold for a similar cost?

I don't know if the Canadian Guvmint is going to ban PbO (Litharge) in the near, or far future. An acceptable collector metal (s) are Lead, Bismuth, and Copper. Litharge ,I feel, is the best, for the reasons you gave in your research. Bismuth is a little more costly, but is more environmentally friendly. Copper requires a touch more heat, resulting in a very minor loss of Au to evaporation. Metallic Lead works okay, but not as well as PbO. You can make your own, but is kind of a PITA. Many good videos on Youtube about making it.

 

[Darkthirty]

I don't know if the Canadian Guvmint is going to ban PbO (Litharge) in the near, or far future. An acceptable collector metal (s) are Lead, Bismuth, and Copper. Litharge ,I feel, is the best, for the reasons you gave in your research. Bismuth is a little more costly, but is more environmentally friendly. Copper requires a touch more heat, resulting in a very minor loss of Au to evaporation. Metallic Lead works okay, but not as well as PbO. You can make your own, but is kind of a PITA. Many good videos on Youtube about making it.

The plates in lead/acid batteries are made of litharge and Pb mesh.

 

[4metals]

Have they also banned products by Eco Goldex? They claim to be a cyanide replacement. They operate out of Quebec. There is some discussion on the forum from members who have used it.
https://eco-goldex.com/

 

[BGDOCK]

Could bismuth be used as collector
It has a Lower melting point and is less toxic

 

[4metals]

Could bismuth be used as collector
It has a Lower melting point and is less toxic

It can but it is a lot more costly. There was an attempt to get the fire assay community to switch to bismuth years back but it never caught on, because of price.

 

[Heavy-Black-Sand]

Have they also banned products by Eco Goldex? They claim to be a cyanide replacement. They operate out of Quebec. There is some discussion on the forum from members who have used it.
https://eco-goldex.com/

The guy i talked with a couple weeks ago who ships out his concentrate is in his late 80's, and not a big computer research guy ... i suspect he's not aware of Eco-Goldex ..... from the looks of the Eco-Goldex website & youtube channel, the product certainly looks worthy of further investigation ... thanks for the tip.

 

[4metals]

Years ago I used to strip a lot of small parts with Cyanide. I preferred to use a plastic 55 gallon drum with a removable top. We would fill the drum half full and add the cyanide, lock the lid back on (securely!) and tip it over to tumble for an hour on a drum roller. It was quite effective.
I can envision you doing the same with about 200 pounds (approx 4, 5 gallon pails) full of sands, adding the stripper and letting it tumble.
They actually make drum tumblers that also allow you to tip the drum over to tumble it and stand it up when finished. Making it quite easy.

 

[Heavy-Black-Sand]

Years ago I used to strip a lot of small parts with Cyanide. I preferred to use a plastic 55 gallon drum with a removable top. We would fill the drum half full and add the cyanide, lock the lid back on (securely!) and tip it over to tumble for an hour on a drum roller. It was quite effective.
I can envision you doing the same with about 200 pounds (approx 4, 5 gallon pails) full of sands, adding the stripper and letting it tumble.
They actually make drum tumblers that also allow you to tip the drum over to tumble it and stand it up when finished. Making it quite easy.

The Eco-Goldex product certainly looks worthy of further investigation ... and possibly a small-scale test ... although i suspect the black sand would need a fine grind, as when you inspect some of the black sand closely, many of the AU/AG/PT/PD type peices have what looks like a thin dark varnish covering all or parts of them ..... also, i know very very little about leaching, so i'd have to start building a small library/knowledge base essentially from scratch.

Further potential evidence of a grinding benefit is; ... i get much higher icp gold assay results when i carefully grind the barren black sands into flour sized dust vs. the uncrushed control group.

 

[FrugalRefiner]

Before you invest money in eco-goldex, study what has been written about it here on the forum. You would be better advised to use potassium or sodium ferri- or ferro- cyanide.

Dave

 

[4metals]

It never mattered when I stripped plated parts but you could possibly take advantage of the tumbling action and add a few steel crusher balls which may effectively crush and leach at the same time. The drums are pretty tough and adding a lifter bar plastic welded into the drum will lift and drop the balls on the charge. And plastic drums are cheap enough to replace when they wear thin.

I don’t know if using the rotating plastic drum would abrade the varnish you mention but it may be just enough to avoid a separate ball mill step.