kjavanb123
Well-known member
All,
We recieved 200 lbs of pulverized ores to be smelted.
The head ore assayed (xrf) for Platinum, which I let the customer know that is not reliable and should do a fire assay.
He insisted to proceed with smelting so we did our usual process, and final stage when we remove the silver with all PMs from the furnace, it is dissolved in nitric acid.
It left with no residue, so customer asked us to dilute the nitrate solution, then added lye which cleared the solution and grayish residue remained.
Here is some photos for better visual,
Precipitant from adding lye to nitrate solution,
We collected the above dried it then using an oxy torch melted that powder,
This was the first for me at least, as can be seen below, a gold color solid appeared on top of silvery white metal on the buttom of crucible,
Upon more heat from torch it became like the following,
I made into a roll, cut a piece of it and tried with hot aqua regia, it was in a beaker in a bath, when nitric acid added reaction starts, avout 30 minutes into reaction still no signs of gold or platinum in solution by testing stannous,
Another thing it wont dissolve in nitric acid either, but when AR solution gets the room temperature, small white silver chloride precipitates.
I am going to try hcl and peroxide leach tommorow, at room temperature as suggested by Lou many years ago in one of my posts.
I wanted to share this with you all.
Thanks and regards
Kj
We recieved 200 lbs of pulverized ores to be smelted.
The head ore assayed (xrf) for Platinum, which I let the customer know that is not reliable and should do a fire assay.
He insisted to proceed with smelting so we did our usual process, and final stage when we remove the silver with all PMs from the furnace, it is dissolved in nitric acid.
It left with no residue, so customer asked us to dilute the nitrate solution, then added lye which cleared the solution and grayish residue remained.
Here is some photos for better visual,
Precipitant from adding lye to nitrate solution,
We collected the above dried it then using an oxy torch melted that powder,
This was the first for me at least, as can be seen below, a gold color solid appeared on top of silvery white metal on the buttom of crucible,
Upon more heat from torch it became like the following,
I made into a roll, cut a piece of it and tried with hot aqua regia, it was in a beaker in a bath, when nitric acid added reaction starts, avout 30 minutes into reaction still no signs of gold or platinum in solution by testing stannous,
Another thing it wont dissolve in nitric acid either, but when AR solution gets the room temperature, small white silver chloride precipitates.
I am going to try hcl and peroxide leach tommorow, at room temperature as suggested by Lou many years ago in one of my posts.
I wanted to share this with you all.
Thanks and regards
Kj