smb fumes!!

[butcher]

I like using ferrous sulfate for several reasons, like when I do a second refining with a different reducing agent...

It is great for testing solutions in the spot plate (testing for gold and remove the gold from solution to prepare for the next test of metals. One of the many tricks I learned from Harold.

I also like the sulfite (substitutes for SO2 gas).
I generated SO2 and used it, that is the cat's meow as far I can see, but trouble to set up the generator for a small batch now and then. bottles would be the way to go if you worked on a larger scale than I do.

copperas (FeSO4) has its place and so does copper.

I find copper also a great reducing agent, for dirty solutions loaded with base metals in a recovery process, but also I will use it in a refining process where I have a fairly pure solution of gold and very little, or troublesome base metals (karat gold) it can be very useful where excess HNO3 is in solution and you cannot precipitate all of your gold (I normally refine the gold a second time anyway).

I guess, I just like having more tools in my tool box to choose from, and find uses for each one of them.

 

[autumnwillow]

Sooo. I'm thinking I should try and switch to copperas but I still have about 15 kilos of SMB left. What other purposes can it do?

 

[jason_recliner]

Sooo. I'm thinking I should try and switch to copperas but I still have about 15 kilos of SMB left. What other purposes can it do?

Other than for processing roughly a good delivery bar's worth of gold, a few teaspoons per gallon is also useful for washing brewing equipment.

 

[Aeon13]

Sooo. I'm thinking I should try and switch to copperas but I still have about 15 kilos of SMB left. What other purposes can it do?

I am always here for donations sir autumn!

 

[FrugalRefiner]

I still have about 15 kilos of SMB left. What other purposes can it do?

It works well for removing tree stumps.

Dave

 

[zachy]

Ferrous sulfate introduces iron to my gold? or the iron is in solution ,? I do not want to contaminate my gold with iron, I have not precipitated with it for fear of contamination, better use metabisulfite, in the first precipitation and gaseous sulfur dioxide in the second precipitation.

 

[anachronism]

Ferrous sulfate introduces iron to my gold? or the iron is in solution ,? I do not want to contaminate my gold with iron, I have not precipitated with it for fear of contamination, better use metabisulfite, in the first precipitation and gaseous sulfur dioxide in the second precipitation.

No it doesn't. And frankly if it introduced a tiny amount the first HCl wash will get rid of it. I've never had any iron in my gold from using this.

 

[Shark]

I am with Jon on this one. When properly prepared, there will be no iron introduced to your gold. I say "if properly prepared" because I don't use the high quality stuff that Jon and many others use, and it still doesn't pose any problems for me. I use ferrous sulfate for the first drop and sodium metabisulfite for the second, most of the time.

 

[nickvc]

I think Shark has this right, if your aim is high quality gold then different reactants and precipitates are the way to go.
I have always used ferrous on the first drop and in the rare occasions another refine was needed changed to ascorbic for the re refine drop.

 

[ARMCO]

I agree with Lou,

Ferrous sulfate AKA copperas produces much less stink and I have found it precipitates a much more consistent volume of precipitate. SO2 and metabisulfite can produce fine dense packing sponge powders or large clumpy powders depending on the conditions, ferrous is always consistent.

I like to make up a solution using 4 pounds of ferrous sulfate crystals per gallon of warm water and add about 600 ml of Hydrochloric acid. Slowly add this solution while mixing it and the gold drops easily. I should add that, like SO2 and metabisulfite, you have to be nitric free.

THe hood however is still a good idea.

Thanks for the solution formula.
Agree, agree, agree, agree. Got to have a hood

 

[ARMCO]

If the crystals are bright green, I could not find good copperas or iron sulfate any time I bought it (as a soil supplement) it was always oxidized brown or white, which in reality is no longer copperas, you want a copperas (iron sulfate) that the crystals are bright green, these will reduce gold, the oxidized salt of this will not work.

Ferrous sulfate also known as copperas, iron II sulfate, or FeSO4, can easily be made with a soft fairly pure iron (not steel), transformer laminate, or the iron laminate from motors are a good source.

Transformers the laminate is normally welded in a couple of spots, you can cut the weld with a grinder, and pull the laminate sheets apart, these normally will have oils and shellac that you will want to burn off, and rinse off with water (do not do this until you are ready to use the iron to prevent rusting).

Cutting the iron sheets into small strips or pieces, tins snips work good here, and heating them with dilute sulfuric acid, I dilute the sulfuric acid to about 10% acid and 90% water, heating the solution to dissolve the iron.

This will give you a green solution of iron sulfate, once dissolved I remove the solution from the Corning Pyro Ceram dish, and filter the solution, after filtering it is returned to the dish for evaporation, and the solution is heated until a layer of green crystals form, I remove these as they build up in the dish, and put them into a jar the remaining ferrous sulfate in the dish is evaporated to crystals, once most of the ferrous sulfate solution has been crystalized.

I put all of the crystals back into the dish, add some more dilute acid, and heat to re-dissolve the crystal back into solution, (heat helps with the reaction, and so you do not have to add too much more liquid). once re-dissolved, I filter the solution again, doing so hot, so that the concentrated solution does not crystalize that bad in the filter, this saves me from adding more liquid which I will need to evaporate again, the ferrous sulfate is recrystallized to give me a more pure ferrous sulfate.

On evaporating to crystals the second time, as the crystals form, I put them into a white plastic HDPE bottle, it does not hurt to have a little of the ferrous sulfate solution and wet crystals in the bottle, the
bottle is labeled, the remaining ferrous sulfate in the dish is evaporated to crystal to fill this bottle, a little fresh H2SO4 is added to the crystals in the bottle to keep them acidic, the solution covers the crystals keeping them from being oxidized by exposure to air, with a good lid these bright green crystals can be stored, and will be ready to precipitate, or to test for gold in solution.

Thank you!