[maxvortex]

I'm interested in sulphate that has the "same" characteristics such as alum or some aluminium based sulphate, but it should be stronger or at least it should have the same characteristics.

Found some info on net and wiki but its too much for me.
http://www.galleries.com/Sulfates

Any kind help is welcome.

[Arkcon]

I'm interested in sulphate that has the "same" characteristics such as alum or some aluminium based sulphate, but it should be stronger or at least it should have the same characteristics.

Um ... what?  "Same" but stronger but still different?  Physically stronger crystals?  Some other pKa in solution?  Something else?  More soluble/as soluble in water?

[maxvortex]

:-) Yea you are right, i should give some more details.
It all comes dont to aluminium. I want to avoid using aluminium based sulphates but i want to preserve most of chemical characteristics from alum. Basically im looking for substitute for alum sulphate, for chemical purposes of course and not for cooking :-).

- it should be soluble in water
- it should not have aluminium as base 
- when soluble it should react stronger then alum

I know i can not help you much with my comments but in time i will learn to improve :-).

[billnotgatez]

epsom salts?

[maxvortex]

That was my first and only choice that i have tested :-)
It did not work as it should be but i dont know why.

What do you think about Potassium Iron Sulfate Hydroxide ?

[billnotgatez]

http://en.wikipedia.org/wiki/Jarosite

first I heard of it

Why not just iron sulfate
either II or III

[maxvortex]

Because it look like that potassium has big role in whole process.
Alum uses potassium also.

If you could compare those two sulphates
( hydrated potassium aluminium sulfate and  Potassium Iron Sulfate Hydroxide )
what would you say, which one can react stronger ?

Max

[Arkcon]

That was my first and only choice that i have tested :-)
It did not work as it should be but i dont know why.

What do you think about Potassium Iron Sulfate Hydroxide ?

OK, so when trying simple sulfate salts, like potassium sulfate or sodium sulfate, it doesn't work ... how?

But when you use potassium aluminum sulfate, it does ... what you want ... but you want to get away from it ... because, why?  Environmental or health concerns?  Cost?

So maybe you should try other mixed salts, good idea  -- https://en.wikipedia.org/wiki/Alum#Types for some options.  But ... what's the actual application?  Something to do with batteries would be what I guess from your other posts, but ... why not tell us exactly what you're doing, exactly what your results are, quantitatively if possible (you get what voltage or wattage or what other measurement of how its working for you,) and exactly the improvement needed.

[maxvortex]

Yea it is about battery :-)
I use graphite electrode on one side and carbon electrode on the other.
Alum is used as electrolyte. I come to this idea because i did not want to use lead, as in lead alum battery.

After some testing i find out that when you charge those electrodes you get quite good results. One electrode gets coated with some brown layer ( which i don know what it is ) and it will hold charge for some time ( few hours maybe ).

I noticed that i can do this with other sulfates and each of them would work better then alum, so i came to idea to replace this alum with some other sulfate that does not use aluminium as base. Why is this so i have no idea, but now i know i have to remove aluminium based sulphates to get better results. The only question is, which one of those sulfates is stronger then alum...

[billnotgatez]

I do not know if this helps but the WIKI on potassium sulfate was interesting
http://en.wikipedia.org/wiki/Potassium_sulfate

[maxvortex]

Hmm. But when you compare alum an potassium sulfate what do you think which one can react stronger ?

Do you know the percent of potassium in alum or percent of potassium in potassium sulfate ?

[Borek]

Hmm. But when you compare alum an potassium sulfate what do you think which one can react stronger ?

You can't predict which one "reacts stronger" not knowing what the reaction is.

Do you know the percent of potassium in alum or percent of potassium in potassium sulfate ?

This can be pretty easily calculated from atomic masses.

[maxvortex]

This can be pretty easily calculated from atomic masses.

Can you do it ? I dont know how to do this.

[Borek]

Google for molar mass calculation, plenty of tutorials on the web.