That would be one damn hot campfire to separate gold, zinc and lead from iron.
Zinc
- Thread starter OctaRon1
- Start date
That would be one damn hot campfire to separate gold, zinc and lead from iron.
It was just there to keep the lead in molten state. The induction furnace was to melt the iron sands.
High gold yield iron sands from a gold mine. I was using the lead to separate the gold from the iron. The iron was removed. Zinc was used to remove the gold and silver from the lead. The zinc had to be removed from the lead to continue the separation of the gold from the iron.
The OP is starting with an alloy of lead containing 0.6% zinc. It is not the same as a mixture of solid lead and solid zinc. An alloy is a solution of one metal dissolved in another similar to antifreeze in water. A mixture is like sand in water. A mixture can be separated by physical means such as filtering or picking out the bits of sand. An alloy/solution, on the other hand, requires chemical means for separation such as selective oxidation of the more reactive metal in the alloy.
Typically when casting one adds a flux such as wax or sawdust. This is done to counteract the oxidation that goes on when a hot metal is in contact with air. In bullet alloy the tin is more reactive than lead and would form tin oxide which would float on top. Fluxing reverses that process and keeps the tin in solution where it is wanted. These are chemical processes. So by the same token one could theoretically remove zinc from a lead alloy by bubbling air through the molten alloy. Both lead and zinc would form oxides but the zinc is much more reactive than the lead. The oxides could be skimmed off. The downside is twofold. One would not know when all of the zinc has been oxidized and if there would be any tin in the alloy it would also get oxidized and get skimmed off with the zinc.
In summary, it's not practical to remove a small amount of zinc from the lead as posters above have suggested. The percentage may be too low to cause any casting grief. The OP has to experiment with the alloy. Secondly, the alloy can be diluted with more lead, some antimony, and some tin. That is the practical approach. In any case, it is not possible to selectively remove zinc from a lead alloy with a reducing flux like carbon or a burning stick. These fluxes are designed to keep the component metals in their metallic states.
Typically when casting one adds a flux such as wax or sawdust. This is done to counteract the oxidation that goes on when a hot metal is in contact with air. In bullet alloy the tin is more reactive than lead and would form tin oxide which would float on top. Fluxing reverses that process and keeps the tin in solution where it is wanted. These are chemical processes. So by the same token one could theoretically remove zinc from a lead alloy by bubbling air through the molten alloy. Both lead and zinc would form oxides but the zinc is much more reactive than the lead. The oxides could be skimmed off. The downside is twofold. One would not know when all of the zinc has been oxidized and if there would be any tin in the alloy it would also get oxidized and get skimmed off with the zinc.
In summary, it's not practical to remove a small amount of zinc from the lead as posters above have suggested. The percentage may be too low to cause any casting grief. The OP has to experiment with the alloy. Secondly, the alloy can be diluted with more lead, some antimony, and some tin. That is the practical approach. In any case, it is not possible to selectively remove zinc from a lead alloy with a reducing flux like carbon or a burning stick. These fluxes are designed to keep the component metals in their metallic states.
The process involved lead and zinc which rang your bell and caused you to spill your "knowledge" using the passive voice. So exactly how was the zinc removed from the lead so that you could continue the separation of the gold from the iron? Inquiring minds want to know. In #18 above you stated "The lead was then stirred with a burning branch to remove the excess zinc that was in there,... snip...". That's more occult than chemistry, it gives me the creeps. By bringing all of this information of yours to the fore are you suggesting the OP should be using a burning stick to remove his 0.6% zinc from his lead? If not, what are you suggesting? What is this all about?
read the rest of the post... When you've proven that you've read to the end of the post, we can move on. I spend most of my time that I read doing technical reading which is almost all passive, so for the most part, I write that way when it's technical writing and requires extra clarity for the reader. Trying to remove confusion.
My reasons for the burning branch is far from occult. (BTW, occult means hidden. doesn't mean magic) I have stated my reasons several times here. Most of it purely boils down to convenience. BTW, cedar wood is a bad choice for this...
Zinc is reactive enough to react with carbon as well. Lead is much less likely to do that.
No zinc of lead poisoning here.
If the zinc is of concern to the OP, I'm telling him a simple method to remove it. That's all....
Thanks for your explanation. With the background, I'll take it on faith that you know what is accomplishing what in that little bit of chemistry!
That must have bloody well hurt to lose the equipment in the gullywasher! Ouch.
Cheers
Trev
with Zinc polluted alloy I use about 675 degree f temperature and mix (flux) with a spruce stick that is Charcoaled from the lead. If there is Zinc in the mix, I get an Oatmeal like blob on top. I scoop it out and all is well for casting.
I stir and scoop a few times, but whatever floats your boat... I hear the lead will cast well with up to 1% zinc. Some books even recommend adding zinc for hardening...
If you get an oatmeal like blob it is zinc oxide with some lead oxide. It's the reaction of the hot metals with oxygen. The function of the stir stick is to expose fresh metal to the air. Carbon acts as a reducing agent to keep metals in their reduced states. There isn't enough surface area on your stick to flux the alloy adequately. Normally when fluxing bullet alloy you stir in sawdust (lots of surface area) or wax to keep all of the components in their reduced states including lead, antimony and tin. If zinc is present it will also remain in its reduced state. However, if you don't flux but keep stirring to expose fresh alloy to the air, you will get lots of oatmeal like blobs floating on your alloy. If you scoop this off you are changing the composition of your bullet alloy.
The short answer is this: carbon will not react with zinc. I know carbon is what you see with your eyes, but it's the unseen oxygen in the air that is reacting with the metals to form the oxide slurry floating on top. A proper flux reverses that process.
Amosfella, I apologize for the unprofessional and unkind way that I responded to your posting. I was in an unhappy mood having to work on our washing machine rather than the military Mauser that was waiting for me in my shop.
Peter
Peter
No worries. However I will take contention on one issue. Stirring with a steel spoon with holes in it did not yield the same results as the tree branch...
Well here's an update on this thread, I melted 300 lbs of the bars ( and added some tin ) into ingots on the weekend.
They came out great, at the same time I cast 100 bullets for my 50-70 and they came out great no problems or imperfections at all.
Long story short a little zinc won't hurt.
Thanks
They came out great, at the same time I cast 100 bullets for my 50-70 and they came out great no problems or imperfections at all.
Long story short a little zinc won't hurt.
Thanks
