For some types of ore roasting with salt can be beneficial, (depending on the ore type and the leach you planned to use), it can help to convert the gold to chloride in the high heat, a down side to this is that it can also fume off some of your gold as gold chlorides are volatile at these red hot temperatures.
Roasting sulfides in air can help to break down the sulfide bond, driving off sulfur oxide gases, sometimes these bonds are hard to break, and an iron powder can help to break the bond, gold giving up its bond with sulfide to the iron, then iron releasing them easier with the heat as sulfur dioxide gases, But of course we are adding more ore to be leached latter.
Grinding fine and roasting red hot in air or oxygen is important to break the chemical bonds, the exposure to oxygen or air is just as important as the heat needed to oxidize the ore.
Sometimes it is best to heat the ore for a while before bringing it up to red hot in the roasting procedure, to help drive of volatile gases, before oxidization in the red heat.
Oxidation can help also with iron in solution, as iron oxides (hydroxides) are not as soluble in many leaches, this can help some to lower the amount of iron your leach pulls into solution before or with your gold. it can help other to oxidize the base metals in the ore, be leached into solutions if you are pre-leaching the ore for base metals before going after the gold.
Like double edged swords, it may work but it may be easier to cut yourself.
Ore as you know is complicated and it can complicate getting gold out, not every leach will work with every ore, and in mining many times they have to do a lot of experimenting to find a way that will work to get the gold.
Be careful with the fumes of roasting and acidifying the ore, some of these can produce extremely deadly gases, arsenic is one you would not want a lung full of.
The SSN leach would be a weak leach in my opinion, even if mixed up fresh, basically how it works is a portion of the nitric acid converts some of the salt in solution to HCl acid, this along with nitric acid forms an aqua regia, in a high brine solution, aqua regia forms gases that oxidize the gold (along with the nitric acid) the oxidized gold is picked up by chlorides in solution, when aqua regia is freshly made these gases are in solution to do work, if the aqua regia was prepared a long time before we used it it would not be as effective as we would not have these volatile gases in solution to attack the gold, this is why you always prepare your aqua regia fresh, and not make it and store it for use later. I suspect the SSN would be the same, sitting on the shelf it would not be as effective, but the salt solution could be regenerated with fresh HNO3.
The SSN leach may or may not work with your ore, or you may be leaching base metals and the leach is so loaded with base metal and there is no room for gold, or you can be getting gold into solution with your base metals from the ore...
Well sounds like you are having fun and are on the right track keep us posted, I would like to know what you get out of this ore.
Roasting sulfides in air can help to break down the sulfide bond, driving off sulfur oxide gases, sometimes these bonds are hard to break, and an iron powder can help to break the bond, gold giving up its bond with sulfide to the iron, then iron releasing them easier with the heat as sulfur dioxide gases, But of course we are adding more ore to be leached latter.
Grinding fine and roasting red hot in air or oxygen is important to break the chemical bonds, the exposure to oxygen or air is just as important as the heat needed to oxidize the ore.
Sometimes it is best to heat the ore for a while before bringing it up to red hot in the roasting procedure, to help drive of volatile gases, before oxidization in the red heat.
Oxidation can help also with iron in solution, as iron oxides (hydroxides) are not as soluble in many leaches, this can help some to lower the amount of iron your leach pulls into solution before or with your gold. it can help other to oxidize the base metals in the ore, be leached into solutions if you are pre-leaching the ore for base metals before going after the gold.
Like double edged swords, it may work but it may be easier to cut yourself.
Ore as you know is complicated and it can complicate getting gold out, not every leach will work with every ore, and in mining many times they have to do a lot of experimenting to find a way that will work to get the gold.
Be careful with the fumes of roasting and acidifying the ore, some of these can produce extremely deadly gases, arsenic is one you would not want a lung full of.
The SSN leach would be a weak leach in my opinion, even if mixed up fresh, basically how it works is a portion of the nitric acid converts some of the salt in solution to HCl acid, this along with nitric acid forms an aqua regia, in a high brine solution, aqua regia forms gases that oxidize the gold (along with the nitric acid) the oxidized gold is picked up by chlorides in solution, when aqua regia is freshly made these gases are in solution to do work, if the aqua regia was prepared a long time before we used it it would not be as effective as we would not have these volatile gases in solution to attack the gold, this is why you always prepare your aqua regia fresh, and not make it and store it for use later. I suspect the SSN would be the same, sitting on the shelf it would not be as effective, but the salt solution could be regenerated with fresh HNO3.
The SSN leach may or may not work with your ore, or you may be leaching base metals and the leach is so loaded with base metal and there is no room for gold, or you can be getting gold into solution with your base metals from the ore...
Well sounds like you are having fun and are on the right track keep us posted, I would like to know what you get out of this ore.
