Cleaning Gooch Crucibles

rae · Post by **rae** » 27 Jul 2006, 15:02

Hi All,

Time to pick all the very knowledgable brains out there.
I bought some lovely glass gooch crucibles recently. They have just been used to filter Barium sulfate.

How on earth do I clean all that really fine powder out of them?

Thanks in anticipation.

Lorrae

estelle · Post by **estelle** » 28 Jul 2006, 10:29

Hello,
I was wondering where you purchased the gooches from. I have been asked to get some for our senior science.
Thanks
Estelle

rae · Post by **rae** » 28 Jul 2006, 12:12

I purchased the crucibles from Science Supply
FaxNo: 1300857533 Ph No: 1300857544

They are listed under Filtration Apparatus Page 40 if you have the catalogue

Cat No: 2585124 Filter Crucible, 30ml, Porosity 4, for BaSO4 $21.75 each

I also bought the rubber sleeves that fit in the top of conical flasks

Cat No: 2920227 Lower rubber sleeve (Guko), size 44 $5.45 each.

It took about 2 weeks and the rubber sleeves were on B/0 so they took a bit longer.

One of our senior chemistry classes have just used them and the teacher was very happywith them.

Hope this helps.

Lorrae

Post by **Robb** » 28 Jul 2006, 13:17

Hi rae,

Dilute acid (Hydrochloric) will be suffice to use. The results will be immediate.

Hope this helps........

judygee · Post by **judygee** » 31 Jul 2006, 10:14

Dear Rae - A hot 0.1M solution of the tetrasodium salt of ethylenediamine tetra-acetic acid is an excellent solvent for many of the precipitates (except metallic sulphides and ferricyanides), these include barium sulphate, calcium oxalate, calcium phosphate, calcium oxide, lead carbonate, lead iodate, lead oxalate and magnesium ammonium phosphate. The crucible may either be completely immersed in the hot reagent or the latter may be drawn by suction through the crucible. I must admit I haven't tried the Hydrochloric acid! But I know this one works! Good luck. Cheers. Judygee.

Post by **Robb** » 31 Jul 2006, 21:53

Hi judygee,

Just to re-iterate what I had mentioned in my previous post, if you use Hydrochloric Acid to clean the crucibles, the added effect is that the acid permeates through the scintillated portion of the crucible and cleans this right through, therefore eliminating any traces of Barium Salts that may otherwise be left behind.

Once these have been washed with the acid then thoroughly wash these with water then allow to dry.

No more hard to remove traces of Barium..

I hope this has been helpful..

Robb..

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