Test for nickel

[Justincase]

I have had an impurity dogging my efforts.
I had discounted nickel as when in chloride solution it did not react with D.M.G.
I have just been thinking in all the Test for nickel it prescribes rubbing the sample with ammonia and then applying D,M.G. for a color change.
Is there an other test I can use to rule out Nickle when it is in a chlorate instead of D.M.G.??
J

 

[etack]

If you have your values dissolved into a chloride solution you can precipitate it with Al. Ni will no precipitate from a chloride solution when Al is added.

Eric

 

[Justincase]

If you have your values dissolved into a chloride solution you can precipitate it with Al. Ni will no precipitate from a chloride solution when Al is added.

Eric

Thanks Eric.
Why will Al not replace Ni in solution?I thought Al was much more reactive than Ni?
Is this an example where the reactive series is not the most prominet action?
Much thanks
Justin

 

[butcher]

Aluminum will precipitate nickel from a nickel chloride solution.
3NiCl₂ (aq) + 2Al (s) --> 2AlCl₃ (aq) + 3Ni (s)

Aluminum is more reactive than nickel, as its place shows in the list of reactivity series of metals.

 

[g_axelsson]

It feels like this discussion have taken a wrong turn. How would for example cementing nickel with aluminum help with the impurity?

I have had an impurity dogging my efforts.
I had discounted nickel as when in chloride solution it did not react with D.M.G.
I have just been thinking in all the Test for nickel it prescribes rubbing the sample with ammonia and then applying D,M.G. for a color change.
Is there an other test I can use to rule out Nickle when it is in a chlorate instead of D.M.G.??
J

Check your pH, DMG is a reagent on palladium in an acidic solution. To get a reaction with nickel the solution has to be alkaline.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=48&t=9477

Göran

 

[Justincase]

It feels like this discussion have taken a wrong turn. How would for example cementing nickel with aluminum help with the impurity?

I have had an impurity dogging my efforts.
I had discounted nickel as when in chloride solution it did not react with D.M.G.
I have just been thinking in all the Test for nickel it prescribes rubbing the sample with ammonia and then applying D,M.G. for a color change.
Is there an other test I can use to rule out Nickle when it is in a chlorate instead of D.M.G.??
J

Check your pH, DMG is a reagent on palladium in an acidic solution. To get a reaction with nickel the solution has to be alkaline.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=48&t=9477

Göran

I see,that is why it is the goto test for ores.
ores are processed using an alkaline base instead of the acid digestion I am use to.
so ither try to dissolve the chlorate or metal in and alkaline solvent or raise the P.H. in an existing solution.
Thanks I will try both.
I may just get a freind to send off a small amount to one of the bigger P.M. refiners and see what they say.
I know it is a little bit noughty but they have the kit and over charge to use it. :lol:

 

[g_axelsson]

You only need to adjust the pH up, not dropping!
According to http://amrita.vlab.co.in/?sub=2&brch=193&sim=348&cnt=1 the pH should be in the interval 5-9 for the precipitate to form, so neutral works best it seems.

Göran

 

[Justincase]

You only need to adjust the pH up, not dropping!
According to http://amrita.vlab.co.in/?sub=2&brch=193&sim=348&cnt=1 the pH should be in the interval 5-9 for the precipitate to form, so neutral works best it seems.

Göran

Thanks Göran!!
I had noticed the mistake on P.H. direction and amended it..I always do that think it is one way and correct myself in error.
your link is very useful.I had known some precipitating reagents but I had not seen such a concise list before.
Very useful.
I start to trade as of next month so the acquisition of them should not be a problem any more.
Thank you for the help.
Justin

 

[etack]

Aluminum will precipitate nickel from a nickel chloride solution.
3NiCl₂ (aq) + 2Al (s) --> 2AlCl₃ (aq) + 3Ni (s)

Aluminum is more reactive than nickel, as its place shows in the list of reactivity series of metals.

I got this from what lazersteve said in this thread about MLCCs.

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=51&t=17376#p176090

Eric

 

[Justincase]

May be it is one of the time delay drop's.
Like waiting for P.G.M.'s to drop from a silver solution using silver as a sacrifical..LOL
Well I have tried every thing I can think of,cant aford any Cinchonine hemisulfate for just one little job.
So do not know for sure but I am still thinking tungsten.
I found an itresting Patent US 3256058 A ..that say's I can heat with alkali, which takes the tungsten in solution as sodium tungstate and leaves a large portion of the impurities in an insoluble form, such as iron and manganese.
As that is what I have on hand I will try with my sample and if it reacts as set out I may have answered my question,or not and I will be scratching my head for some time to come.

 

[Lino1406]

Nickel ions will react with DMG, no matter what anion

 

[Justincase]

Nickel ions will react with DMG, no matter what anion

Thank you Lino1406
that is very helpful.I was pretty sure it was not Nickel but as that is a large part of the material I am processing I wanted to make sure it was not being brought down.
Can you tell me if Tungsten interferes with a stannous test,I have been trying to positively identify an impurity but I have not a full set of test reagents so the problem has been interesting.The impurity only seems to be digested by hydrochloric so must be below copper in reactivity and drops out of solution with S.M.B. which is a pain.
Much thanks
Justin