Geo
Well-known member
Epsom salt (magnesium sulfate) is used in industry as a flocculent and clarifier.
Precipitate tin from HCl
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Martijn
Well-known member
It will be an alloy, not pure Mg, So the most reactive metal will cement out everything below it. Even covering lesser reactive metals in the alloy. Or the alloy acts as a combined metal with its own reactivity.
test and find out. Please do share the results here.
test and find out. Please do share the results here.
Martijn
Well-known member
Lead Chloride is only slightly soluble in cold water. But first: is it actually lead? And not tin?
Be very extremely carefull "evaporating down" H2SO4!! It craves water and will only let it go at high temperatures!, meaning you'll have H2S04, much hotter than boiling water in a glass beaker or flask.
Extremely dangerous and corrosive.
Diluted works just as fine. No need to concentrate it for precipitation of Pb and risk your health.
stay safe.
Martijn
What is the benefit of using some other metal higher in the series? It would not be better to cement out more valuable things from copper down? Is there something I am missing here in this cementing processes? I will share my results once I got a handle of it.
Geo
Well-known member
Copper will only cement less reactive metal. That will be any precious metal. Copper will not cement a more reactive metal. The more reactive the metal is, the more base metals it will cement. Keep in mind that there are metals that will not be removed from acidic solution through ionic exchange.
Cementation is happening through ionic exchange?
I mean , I have read so many things about cementation with zinc, iron, etc. but for PM recovery it would make sense first to cement out the PM with a metal which is lower in the reactivity series table and then cement out the rest again with something higher in the list to cement out the base metals. There might be more sides here to take into consideration which I don't get. AP usually is full of copper which went in solution but there could be others higher in the list like nickel, lead.
Those base metals higher on the list would cement out the lower ones like copper (which would go back in solution and cement out others below)?
Geo
Well-known member
Yes. Cementation is an ionic exchange process. You are replacing one ionized salt in solution with a more reactive salt. The salt being replaced in solution normally comes out as metal. The salt going into solution is you sacrificial metal. The first metal to use is copper. Copper is considered a Noble metal. Any metal that is found in nature in metallic form is a noble metal. The two elements that is responsible for all non-noble metals being found in nature in salt form is hydrogen and oxygen. In the hydrometallurgical process, there are two constants that is responsible for almost everything else. You are either adding or removing oxygen or you are either adding or removing hydrogen. Everything else is secondary to these two things. The electrical potential is next. That's the electromotive series of metals. The next thing you should study after getting a handle on all that is ORP. The ORP of a solution is what tells you what it's going to take to selectively cement what you want while keeping unwanted metals in solution or the other way around in selectively removing unwanted metals and keeping the target metal in solution.
By the way, nickel does not cement from solution through ionic exchange.
I hope it's OK to butt in here.
How do you preciptate or cement out nickel from a HCL solution?
How do you preciptate or cement out nickel from a HCL solution?
I looked it up, it is the alloy az91d which contains many things like zinc, silicon,aluminum,iron,copper and other stuff however there should be Mg up to 90 percent. The most is aluminum at 9.7 percent.
| Aluminum, Al | 8.3-9.7 |
| Manganese, Mn | 0.15-0.50 |
| Zinc, Zn | 0.35-1 |
| Silicon, Si | 0.1 |
| Copper, Cu | 0.03 |
| Iron, Fe | 0.005 |
| Nickel, Ni | 0.002 |
| Others, each max | 0.02 |
| Magnesium, Mg | Remainder |
From what I have learned from the other members and still trying to learn, if you look up the reactivity series chart which arranges these elements in the order of their reactivity. I understood that once you put in solution a more reactive metal like cobalt which will go in solution and those metals below come out if they are present in solution.
So to isolate nickel my understanding is that you should first cement out those metals below the metal you want and then after removing them cement out the one you want with a more reactive metal like cobalt, iron, etc (according to the chart). Also my understanding is that if you want to make sure there isn't other metal mixed with nickel you should use the one immediately above nickel on the chart (cobalt) unless you know for sure there is none.
Or use iron if you know there is no cadmium and cobalt in the solution.
Martijn
Well-known member
Although you seem to understand and explain it yourself in your last post, I feel like I'm repeating myself when it comes to displacement reactions or ion exchange. May I challenge all new members to thoroughly read this:
https://goldrefiningforum.com/threads/when-in-doubt-cement-it-out.30236/Together with this:
https://en.wikipedia.org/wiki/Reactivity_seriesAnd this:
https://goldrefiningforum.com/posts/40800/
After reading this, let's discuss if you have any questions left.
And last, before posting another question that can be easily found here by using the search button, read this:
https://goldrefiningforum.com/threa...imple-question-and-get-a-simple-answer.21412/
After you died from a You tube copied chemistry experiment gone horribly wrong, your family's lawyer may find this forum and will look for a scapegoat to hold responsible for your mistake.
That's why YOU must research and think for yourself, instead of asking for help and directions.
Martijn.
https://goldrefiningforum.com/threads/when-in-doubt-cement-it-out.30236/Together with this:
https://en.wikipedia.org/wiki/Reactivity_seriesAnd this:
https://goldrefiningforum.com/posts/40800/
After reading this, let's discuss if you have any questions left.
And last, before posting another question that can be easily found here by using the search button, read this:
https://goldrefiningforum.com/threa...imple-question-and-get-a-simple-answer.21412/
After you died from a You tube copied chemistry experiment gone horribly wrong, your family's lawyer may find this forum and will look for a scapegoat to hold responsible for your mistake.
That's why YOU must research and think for yourself, instead of asking for help and directions.
Martijn.
Geo
Well-known member
Neutralize the acid. The nickel precipitates as a salt of what ever base you neutralize with.
