Slaked Lime

[Somtham]

I'm looking for slaked lime, Calcium Hydroxide Ca(OH)₂. Does anybody know if the "poon khao" that is sold in most Ag stores is pure slaked lime or is it something else? If not, what would the Thai name be and what kind of store would sell the stuff? I checked a few pharmacies but no luck.

Thanks for any info.

[jandtaa]

Yes this is what the ag stores sell ! It helps to neutralise acid soil, is used in cooking (soak your pork rinds in solution and then deep fry to puff them up), white wash/plaster and plenty other uses !!

poon khao = quicklime (calcium oxide)

ปูนขาวธรรมดาที่ทําโดยผสมนํากับปูนเเท้ = slaked lime (calcium hydroxide) / hydrolysed lime

calcium oxide is hydrolised or "slaked"  by adding water 

dont know what quantities you require but hydrolysed lime is also used in the chewing of betel nut (its the lurid pink stick which helps release the alkoloids in the chew) and is also available uncoloured at most markets.

(by the way check your pork scratchings next time they often have touches of pink from the dye in the lime!!)

Edited January 6, 2009 by jandtaa

[Somtham]

Yes this is what the ag stores sell ! It helps to neutralise acid soil, is used in cooking (soak your pork rinds in solution and then deep fry to puff them up), white wash/plaster and plenty other uses !!

poon khao = quicklime (calcium oxide)

ปูนขาวธรรมดาที่ทําโดยผสมนํากับปูนเเท้ = slaked lime (calcium hydroxide) / hydrolysed lime

calcium oxide is hydrolised or "slaked"  by adding water 

dont know what quantities you require but hydrolysed lime is also used in the chewing of betel nut (its the lurid pink stick which helps release the alkoloids in the chew) and is also available uncoloured at most markets.

(by the way check your pork scratchings next time they often have touches of pink from the dye in the lime!!)

J - ok, so the stuff sold at the Ag shops needs to be slaked. I don't need much and want to use it for making corn tortillas. The stuff used locally around us for the betel nuts is made up into a pink paste and I cannot find the uncolored stuff. Guess I need to do some googling to find out the method for slaking the calcium oxide.

Thanks for your reply.

[rice555]

Hello Somtham, I bought a 500grm box at a chem supply store in Korat for that same purpose, it should be a little cleaner than ag lime. Why not try wood ash, that was also used?

rice555 off to the Korat ag show.

[rice555]

Hello Somtham, I was trying to gget to the show, Vidhyasom Co. LTD BKK.

Calcium Hydroxide B.P. 450G.(not 500)

387100-2,39115783 3925812, 3926335 and thats the phone numbers on the box, it's been awhile, can't remember the price, but was under B100.

rice555

[Somtham]

Hello Somtham, I was trying to gget to the show, Vidhyasom Co. LTD BKK.

Calcium Hydroxide B.P. 450G.(not 500)

387100-2,39115783 3925812, 3926335 and thats the phone numbers on the box, it's been awhile, can't remember the price, but was under B100.

rice555

Thank you very much for that info. I'll give them a call and see if they can EMS me a couple of boxes. When using the poon khao to make masa I end up shitting eet blocks for a few days!!

thanks again

[WatersEdge]

I'm looking for slaked lime, Calcium Hydroxide Ca(OH)₂. Does anybody know if the "poon khao" that is sold in most Ag stores is pure slaked lime or is it something else? If not, what would the Thai name be and what kind of store would sell the stuff? I checked a few pharmacies but no luck.

Thanks for any info.

Hi Somtham,

I buy it in Chiang Mai, already slaked, B25 for 10 kg bag.

No typo, it is really only B2.50 / kg

Kiln company is right here south side of town on Samoeng Road

Google Earth placemarker attached, for anyone near Chiang Mai

the clear plastic bags are sold at a little shanty across the road

It is pure as the rock it came from,

limestone is always mixed with a little something by merit of its geologic origin

It is roasted at 900C for extended period, so it is certain that nothing biological survived.

Then the slaking reaction releases an enormous quantity of heat that the furnace just locked in.

Lime_Kiln.kmz

[Somtham]

Hi Somtham,

I buy it in Chiang Mai, already slaked, B25 for 10 kg bag.

No typo, it is really only B2.50 / kg

Kiln company is right here south side of town on Samoeng Road

Google Earth placemarker attached, for anyone near Chiang Mai

the clear plastic bags are sold at a little shanty across the road

It is pure as the rock it came from,

limestone is always mixed with a little something by merit of its geologic origin

It is roasted at 900C for extended period, so it is certain that nothing biological survived.

Then the slaking reaction releases an enormous quantity of heat that the furnace just locked in.

Thanks for the added info. I already bought a supply from Vidhasom Co in Bangkok based on the info provided by Rice555.

thanks

[IraqRon]

I'm looking for slaked lime, Calcium Hydroxide Ca(OH)₂. Does anybody know if the "poon khao" that is sold in most Ag stores is pure slaked lime or is it something else? If not, what would the Thai name be and what kind of store would sell the stuff? I checked a few pharmacies but no luck.

Thanks for any info.

Hi Somtham,

I buy it in Chiang Mai, already slaked, B25 for 10 kg bag.

No typo, it is really only B2.50 / kg

Kiln company is right here south side of town on Samoeng Road

Google Earth placemarker attached, for anyone near Chiang Mai

the clear plastic bags are sold at a little shanty across the road

It is pure as the rock it came from,

limestone is always mixed with a little something by merit of its geologic origin

It is roasted at 900C for extended period, so it is certain that nothing biological survived.

Then the slaking reaction releases an enormous quantity of heat that the furnace just locked in.

Hello Watersedge, I am also looking for Bpoon Khoow but in the Hydrated form, that is as a powder. It sounds like what you are getting is slaked quicklime and is in a paste form. I may just use that as well as it usually makes a great plaster!! And your price of 25 baht for 10kg is great! Has it worked well for you?

This stuff is different from ag lime as I am sure you are aware, but maybe some on here aren't.

[cm das]

I too am looking for lime paste in Chiang Mai. I went to the source mentioned above, at least I went to the place marked on google earth, but found no lime & no kiln. Lots of mearby places sold poon khao in powder form, but I can't find slaked lime/lime paste anywhere & it ain't for lack of looking & asking - from roadside shacks to global house. Anyone know another source?

[WatersEdge]

So mix a bit of water in the Slaked Lime dry powder, <br>and you have Wet Slaked Lime putty.<br><br>The place I marked on Google Earth was a large factory as I recall.<br>on the south side of Samoeng road<br>I was mistaken that they are the manufacturer.<br>Sorry for leading you astray.<br><br>On the North side of Samoeng Road and back toward the Canal Road perhaps 500 meters, <br> is a very small roadside shack, <br>With ten kg and smaller clear plastic bags.<br>The man is there selling during standard business hours.<br><br>I never saw a lot of such shops there, only that one.<br><br>There are some chunks in that material, <br>so you may want to screen the dry powder before mixing the water into it.<br><br>I went to look again on Google Earth, <br>Try this new location or perhaps a little further toward the Canal Road intersection, <br>in which case it would be hidden by the trees.<br><br>One more item that all may find helpful.<br>I buy <b>Limestone CaCO3 powder grit chips</b> from the Mae Sot stone Quarry,<br>which works great as Ag Lime, Pond Water pH adjuster, Livestock feed supplement, etc.<br>It will bring the pH up to a maximum of 8.3 as this is the solubility limit of Limestone.<br>It comes in ten wheel truck loads of 15,000 kg, for a delivered cost of B3,000 which calculates out to B0.20/kg.<br>I prefer it to Slaked Lime because it is not as severe.<br>True, it's not as fast acting, but it's much more forgiving if applied in excess.<br><br>For many applications that you might use Slaked Lime for, this will work just as well.<br>And at 1/12 the price. <br><br>If anyone needs a comparative spreadsheet calculator, <br>to see the difference between<br>Limestone CaCO3<br>Quick Lime CaO<br>Slaked Lime Ca(OH)2<br>I can knock one out right quick<br><br>If there is a large ongoing need for it, <br>I'm eager enough to build a kiln, wiith unlimited raw materials immediately at hand.<br>

Slaked Lime Sales Hut.kml

Slaked Lime Sales Hut.kml

Edited February 17, 2011 by WatersEdge

[WatersEdge]

Sorry guys,

I am not sure what I did wrong to make that come out so awful on the Edit.

So mix a bit of water in the Slaked Lime dry powder,

and you have Wet Slaked Lime putty.

The place I marked on Google Earth was a large factory as I recall.

on the south side of Samoeng road

I was mistaken that they are the manufacturer.

Sorry for leading you astray.

On the North side of Samoeng Road and back toward the Canal Road perhaps 500 meters,

is a very small roadside shack,

With ten kg and smaller clear plastic bags.

The man is there selling during standard business hours.

There is only one such shop there

There are some chunks in that material,

so you may want to screen the dry powder before mixing the water into it.

I went to look again on Google Earth,

Try this new location or perhaps a little further toward the Canal Road intersection,

in which case it would be hidden by the trees.

One more item that all may find helpful.

I buy Limestone CaCO3 powder grit chips

from the Mae Sot stone Quarry,

which works great as Ag Lime, Pond Water pH adjuster, Livestock feed supplement, etc.

It will bring the pH up to a maximum of 8.3 as this is the solubility limit of Limestone.

It comes in ten wheel truck loads of 15,000 kg, for a delivered cost of B3,000 which calculates out to B0.20/kg.

I prefer it to Slaked Lime because it is not as severe.

True, it's not as fast acting, but it's much more forgiving if applied in excess.

For many applications that you might use Slaked Lime for, this will work just as well.

And at 1/12 the price.

If anyone needs a comparative spreadsheet calculator,

to see the difference between

Limestone CaCO3

Quick Lime CaO

Slaked Lime Ca(OH)2

I can knock one out right quick

If there is a large ongoing need for it,

I'm eager enough to build a kiln, wiith unlimited raw materials immediately at hand.

Calcining Limestone is a suitable coProduct for making Charcoal,

because it makes good use of the otherwise wasted volatile portion of the original fuel.

[cm das]

Hey, thanks for the quick reply. I'm looking for lime for plastering a rice hull hut I'm building. I'm fairly sure I've read somewhere that for my purposes it's preferable to have quicklime powder (calcium oxide) or lime putty made from that rather than the hydrated lime powder (calcium hydroxide) that everyone seems to be selling here. Something about the "fresher" lime having greater adhesive qualities when dried. Slaking quicklime sounds like a long & potentially dangerous process - that's why I'd like to find someone selling the aged putty. Calcium carbonate is out of the picture for me. Anyway, I've got some of the hydrated powder already & I'll give that a try.

And if anyone's heading up to Samoeng, you can pick up loads of poon khao in the first village you come to once you're in the hills. Lots of small shacks with big stacks. I was told it's all made somewhere on the mountain "bon doi".

[WatersEdge]

Hi cm das,

If the Quick Lime CaO is ground fine, it will hydrate very quickly, releasing a lot of heat.

An easy way to understand the amount of heat involved,

If you place 1/3 the weight of Quick Lime

under a pot containing water that you want to boil vigorously for half an hour,

then steadily add water to the CaO below,

you have a nice perfectly clean oven.

A wafer of CaO about the size of two Saltine Crackers is used to heat the US military field meals.(MRE)

CaO isn't dangerous in the sense of poisoning,

but you certainly have to treat it with respect

because of the chemical heat contained in it.

If it gets on your body even in small amounts,

it will vigorously snatch any moisture it can reach,

and deliver the heat as well, simultaneously dehydrating and burning.

If you want Quick Lime but have only Slaked Lime available,

you can roast it at 570C,

and it will revert to CaO, requiring the same large amount of heat put back into it.

Since you need a putty, that says you need Slaked Lime.

When I next travel to Chiang Mai I'll look up the village you refer to.

I knew the man who sells there had to have a source nearby,

because he always has a good supply and it's dirt cheap.

After I posted the location of the supposed kiln above,

I went to the big warehouse as you did recently,

and was told that they had never produced Lime there.

Sorry I didn't update that information here, and therefore led you to inconvenience.

[WatersEdge]

One Point of Interest I just read.

http://thenauhaus.com/blog/index.php/2009/09/lime-101/

Putty has been soaked in water (slaked) and is sold in a mixture of roughly 50% lime and 50% water.