Base metal removal

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In minerals, iron is found as oxides or sulphides eventually, it is difficult to explain how he reduced the iron to metallic, if the iron in the final alloy comes from the ore, since temperatures of the order of 1500 degrees Celsius are required. and very reducing conditions in the molten bath. An alternative, as mentioned, is the fusion of the bar and the blowing of the molten material with pressurized air, forming a fine shot that is leachable with hot hydrochloric or sulfuric acid and with agitation.

Edited by Moderator to get the posters text out of the quote
 
Since we don't know what percentage of different metals there are in the bar it's hard to give good advice. 1,2% silver in iron is a whole different story as 1,2% pgm. Depending on the relative amount of precious metals it would make sense to go after metals in different order.

One thing I've always wanted to test but hasn't done it myself is to use liquid - liquid extraction of gold from iron. Melt a sample with silver as a collector metal. Silver shouldn't alloy with the iron and create a separate phase. It needs mixing for a while to let the gold (or maybe other precious metals) to be absorbed in the silver phase.
At least for gold the affinity for dissolving in silver is a whole lot higher than in iron.

Göran
 
Since we don't know what percentage of different metals there are in the bar it's hard to give good advice. 1,2% silver in iron is a whole different story as 1,2% pgm. Depending on the relative amount of precious metals it would make sense to go after metals in different order.

One thing I've always wanted to test but hasn't done it myself is to use liquid - liquid extraction of gold from iron. Melt a sample with silver as a collector metal. Silver shouldn't alloy with the iron and create a separate phase. It needs mixing for a while to let the gold (or maybe other precious metals) to be absorbed in the silver phase.
At least for gold the affinity for dissolving in silver is a whole lot higher than in iron.

Göran
Nice to see you again😊
 
Since we don't know what percentage of different metals there are in the bar it's hard to give good advice. 1,2% silver in iron is a whole different story as 1,2% pgm. Depending on the relative amount of precious metals it would make sense to go after metals in different order.

One thing I've always wanted to test but hasn't done it myself is to use liquid - liquid extraction of gold from iron. Melt a sample with silver as a collector metal. Silver shouldn't alloy with the iron and create a separate phase. It needs mixing for a while to let the gold (or maybe other precious metals) to be absorbed in the silver phase.
At least for gold the affinity for dissolving in silver is a whole lot higher than in iron.

Göran
Thank you Göran,
It is about 1,1% PMGs and Au and 0,1% silver.
I tried before 2 other method of smelting-

1. Silver collector- was nice and cleaner, but harder to separate the some PGMs because some went to nitric.
At the end I got a powder of of it with mixed precious metals but not all of them.
I got 0,2% in hand of them excluding the silver.

2. I used iron powder as collector, It collected mostly Au and Ir but it was extremely hard to separate.

Those test have been dome before testing it with no collector which I found the fasted and easiest way to extract from the ore.

At this stage I know my best option are with Cu as collector or without any collector.

I will try electroplating with one of those-
solution of sulfuric acid and water, as it can effectively dissolve the iron while leaving the precious metals unaffected.
Alternatively, a solution of sodium chloride can be used as an electrolyte.
 
Thank you Göran,
It is about 1,1% PMGs and Au and 0,1% silver.
I tried before 2 other method of smelting-

1. Silver collector- was nice and cleaner, but harder to separate the some PGMs because some went to nitric.
At the end I got a powder of of it with mixed precious metals but not all of them.
I got 0,2% in hand of them excluding the silver.

2. I used iron powder as collector, It collected mostly Au and Ir but it was extremely hard to separate.

Those test have been dome before testing it with no collector which I found the fasted and easiest way to extract from the ore.

At this stage I know my best option are with Cu as collector or without any collector.

I will try electroplating with one of those-
solution of sulfuric acid and water, as it can effectively dissolve the iron while leaving the precious metals unaffected.
Alternatively, a solution of sodium chloride can be used as an electrolyte.
Also aluminum combines with most precious metals, and it dissolves in alkali
 
I am not sure if rhodium, iridium dissolve in silver. Maybe in such concentrations. Silver also looks too expensive
Lou told it was not ideal as collector for Rhodium, but Iron and Silver do not mix well, which is interesting in this setting.
The Silver will collect the Gold which on the other hand is an excellent collector for Rhodium,if it will carry it into the Silver is another question.
It could be an interesting thing to test though.
 
Thank you Göran,
It is about 1,1% PMGs and Au and 0,1% silver.
I tried before 2 other method of smelting-

Still, doesn't tell us if there is 1% Au, 1%Pd, 1%Pt or 1% Rh... It might be hard to go after all metals in one go. The ratios is an important part in forming a strategy on how to extract the most value.

1. Silver collector- was nice and cleaner, but harder to separate the some PGMs because some went to nitric.
At the end I got a powder of of it with mixed precious metals but not all of them.
I got 0,2% in hand of them excluding the silver.

2. I used iron powder as collector, It collected mostly Au and Ir but it was extremely hard to separate.

Those test have been dome before testing it with no collector which I found the fasted and easiest way to extract from the ore.

At this stage I know my best option are with Cu as collector or without any collector.

I will try electroplating with one of those-
solution of sulfuric acid and water, as it can effectively dissolve the iron while leaving the precious metals unaffected.
Alternatively, a solution of sodium chloride can be used as an electrolyte.

I'm not talking of using silver as a collector metal in the ore. I'm suggesting to melt the iron bar with some silver and stirring. This would transfer the gold and silver at least over to the silver. Molten silver and iron should separate into two layers just as oil and water and I think iron would end up at the top.

An electrolytic cell would separate the PGM:s and gold as a black sludge and the cleaned silver could be used again for more iron bars.
As you process more iron bars you should accumulate more silver over time. The silver cells are easily expanded so you can match the amount of iron bars coming from your mining operation.

If you still have an economic amount of precious metals in the iron bars you could probably mix in some copper and remelt. To remove the iron you could do oxygen sparging (or just air) which would leave you with a copper bar contaminated with PGM:s, nickel and iron.

Göran
 
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