# Iron and Zinc in the Reactivity Series HCL/CL



## awbrew (Apr 7, 2013)

Ok Guys, this is my main question. Maybe someone can take me to school on this one. I was just looking over the reactivity series and it looks like Iron is lower than Zinc or closer to PGMS than Zinc. So why do we use Zinc first when dropping PGMs instead of iron to begin with ?

And if there was any little iron shaveings in my acid they will now be in my PGM blacks I have Dropped with Zinc correct.

But not to worry a quick wash or two with just a little HCl will remove it correct.

And I remember a quick run threw with a magnet before the acids should fix this problem in the future from Mrs. Hokes book. Rookie Mistake.

Thanks


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## lazersteve (Apr 8, 2013)

I use zinc because it is more reactive than iron as you point out. This means zinc will dissolve easier than iron. Zinc is only used in the recovery stage, not the final refining stage. Zinc is also easier to clean out of the resulting PGM than iron, again due to it's reactivity.

Steve


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## awbrew (Apr 8, 2013)

Thanks Steve, Now that makes sense. it's a little farther away (In the reactivity series), so therefore its more aggressive when the zinc goes into solution than the Fe. I was correct about the HCL Rinse a couple of times, should pull the Iron right back out of the PGM blacks. How long for each rinse 5 Min. or so?


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## lazersteve (Apr 9, 2013)

I don't time my reactions, instead I judge the end point from observations of reaction color and fizzing. When the rinse/wash solution no longer darkens (or fresh liquid color remains unchanged) and when fresh rinse does not produce any further reaction, it's complete.

Steve


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## awbrew (Apr 13, 2013)

ok thanks steve . thanks for the help.


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