Admagistr - 24-12-2023 at 17:55
I have obtained sand from ground Zircon mineral,it is used in metal casting in a foundry,it is very cheap and available in 25 kg bags.I would like to
separate Zr,Hf and Th compounds from it. The sample shows a higher radioactivity due to the Thorium content,which is related to Zirconium and
Hafnium.It is clear to me that I have to start by dry melting it with alkaline hydroxide,but separating the very close Hf from Zr will probably be a
difficult task in more modest conditions. I have read that one can use some complexes I think using KSCN.Has anyone attempted something similar under
home chemist conditions?Getting hafnium compounds,which is expensive and zircon contains more than 4% of it is an interesting possibility.Also
separating Th compounds would be useful,so that thorium interfere via its radiation action with zirconium minerals and compounds and damages natural
mineral zircon structurally and breaks its crystal lattice into amorphous form over millions of years.
Fery - 25-12-2023 at 04:23
Just guessing, but cannot it be dissolved in an acid (very likely hot conc. H2SO4) or acid mixture (like HF+HNO3) and separated electrolytically due
to differences in redox potential?
Here they facilitated the dissolution by milling ZrSiO4 with Al2O3:
https://sci-hub.ee/10.1016/0254-0584(94)01459-T
Stokes - 25-12-2023 at 05:28
It is quite difficult to separate zirconium and hafnium, even industrially, and they have very similar chemical properties. Unless you're wanting to
do this for the interest, it probably isn't worth it to separate the two, particularly since a small amount of hafnium won't make any difference for
most reactions. If you're wanting to try, this patent is the simplest method I've seen that ought to give good yields, though it certainly isn't easy unless you have plenty of sodium.
Admagistr - 25-12-2023 at 07:54
Thanks a lot for the advice! The concentrated H2SO4 looks good,I'll try it,possibly melting with KHSO4 might help,as it is done when we want to
dissolve corundum.SiO2 is separated and we are left with zirconium,hafnium,Th salt.Zirconium contains lanthanides,its chemical composition is
interesting and varied in terms of impurities. I'll study the patent,let you know and send photos when I try it.I've always been attracted to hafnium
compounds because of their affinity to zirconium,Zr makes up many gems and Hf does too,but in some ways they have slightly different properties and
that's what attracts me;-)