Rock Salt

[Tywais]

I realize this is an odd request but has anyone seen rock salt available in CM? I know it's used in home made ice cream but I need the large crystal type as shown below. I'm designing a high power CO2 laser for a student project and need it as an optical coupler (output window). The alternative and best choice is a ZnSe window but at around 10,000 Baht not realistic and even harder to find.

[Crossy]

How about a field trip to the salt pits at Bo Kluea? Pick from the source

EDIT OK it's nearly 500km

[kaptainrob]

You could try Yok, on the superhighway near bus arcade ... I've not seen it tho their cooking and baking stocks is very extensive and if they do not have it, perhaps they'll know who does.

[cloudhopper]

i wonder if you could grow your own from a super saturated solution a la rock candy.

[Tywais]

i wonder if you could grow your own from a super saturated solution a la rock candy.

I've been looking into that also but from what I've seen it needs to be a single large crystal and not sure if the above can achieve that.

[Tywais]

Just looked a bit further and I was looking at the wrong item - appears rock salt is not actually salt. Maybe more difficult than I though. Will Google some more and also check the university chemical facilities. Getting confusing now as to the difference.

Rock salt is the common name for halite. It is a rock, rather than a mineral, and this is what makes it different to the salt you might find on your table, although it does share many characteristics.

http://www.onlineroc...-rock-salt.html

Halite /ˈhælaɪt/, commonly known as rock salt, is the mineral form of sodium chloride (NaCl).

//edit - appears it is still NaCl just how it was grown in crystal form.

[alaninlamphun]

Ive only seen it at a market in ko samui years ago when we lived there

[Lobo4819]

The many shops that stock supplies for fish and koi ponds sell bags of large-crystal salt for use in inhibiting algae growth. Cheap and easy to find. Khan Tiem, outside Big C Don Chan, Fishmania, etc.

[uptoyoumyfriend]

on the eastern side of suriwongse rd between cm gate and the small local market is a warehouse where they sell it in big bags....

the lfs (local fishstore) has it maybe 10 bt per kg. ask for "grua"

[Joop50]

Don't know if it is the right kind but Himalaya salt is halite, the pink coloured form you can find in health food stores like Aden at Nimmanhemin road.

[Tywais]

Thanks for your answers. Gives me places to look now.

[jko]

How about a field trip to the salt pits at Bo Kluea? Pick from the source

EDIT OK it's nearly 500km

Been there happily, and done that - very nice place, and a wonderfully scenic twisty road to finally reach it. Bought 2 kilos of salt there but it is so heavily iodised (it turned the our plastic container black!) that we're reluctant to use it. Maybe somebody knocked their hand their hand when it was being added (apparently all salt must be iodised in Thailand?) so it might not all be like ours was. Whatever, it's worth a trip.

If not, I've seen it at Rimping. (where else?)

[jaideeguy]

Check 'World Chemicals' on Mihidol rd [airport superhiway] just past the Chiangmailand rd and under the big PSI sign.

[whimsy]

Could you ask the Faculty of Chemistry to help you out? Cylindrical salt plates about 2.5cm in diameter are used to sandwich samples going into the IR Spectrometer. These are highly transparent (when new) , defect free and pre-polished.

Like the ones in this article http://orgchem.colorado.edu/Technique/Procedures/IR/IRliquid.html

[whimsy]

Btw, the salt plates will go cloudy fairly quickly if not stored in a dessicator

[Tywais]

Could you ask the Faculty of Chemistry to help you out? Cylindrical salt plates about 2.5cm in diameter are used to sandwich samples going into the IR Spectrometer. These are highly transparent (when new) , defect free and pre-polished.

Like the ones in this article http://orgchem.color...R/IRliquid.html

Actually that would be perfect, IR spectrometer windows. We have our own lapidary if worse comes to worse. Thanks for that.

[Dr. G]

Hi.

It is very likely we have a coupler that could be sent to you.

I need to know :-

Wavelength.

Radius of curvature.

Reflection coeffecient.

Transmission coefecient.

Aperture.

When I have these I'll ask one of our Post docs to check we have something suitable.

Please reply to my Glasgow addres

g

1

[Tywais]

Hi.

It is very likely we have a coupler that could be sent to you.

Thank you for your kind offer but one of the things I like to do when designing a student project is to be able to make it the simplest, cheapest and with as much readily available local parts. Gives the student some more interest and use his imagination as to how to build something with bare minimums. Of course, not as efficient a device as using proper OC and laser bore mirrors. If this one works out, there maybe interest in my designing a proper one for commercial use or internal to our research facility at which point a proper mirror and OC will be needed.

Have most of the design done and will give it to the student(s) to locate the necessary parts including recommended locations given above for the rock salt. Now need to locate a small diamond core drill for putting a hole in the exit mirror.

[cloudhopper]

Just curious but what is the dimension of that halite OC in your frickin high power laser?

[Tywais]

Just curious but what is the dimension of that halite OC in your frickin high power laser?

Around 1cm to 1.5cm and 3 or 4mm thick. Depends on my final decision on the laser bore tube inside diameter and that depends in part on the tube length which will be around 1 meter long. Just rough calculations at the moment depending on what parts availability will be.

[cloudhopper]

Just curious but what is the dimension of that halite OC in your frickin high power laser?

Around 1cm to 1.5cm and 3 or 4mm thick. Depends on my final decision on the laser bore tube inside diameter and that depends in part on the tube length which will be around 1 meter long. Just rough calculations at the moment depending on what parts availability will be.

Looks like 4-6 weeks to grow a crystal that large if you can't source one that size locally. Could be fun though (in a Feynmanian sort of way).