Poon Khao.. calcium ?? (Oxide, hydroxide, carbonate) what is it??

[sirquest007]

Calcium. Confusing topic.

 

There is:

 

calcium carbonate

Calcium oxide

Calcium hydroxide

 

English people speak of lime, as it can originate from limestone.

But also sea shells, egg shells and many more.

Actually, it's Calc, yes?

The one that used to be used on the blackboard (modern times it is gypsum)

 

The confusion starts with

lime,

quick lime and

Slaked lime.

 

What is what?

And what is poon Khao?

 

To my best knowledge, calcium oxide is the dangerous stuff.

It is created by heating calcium carbonate to 850 degrees.

 

Funny fact is that even after it have cooled down, it possesses extreme heating power.

And if I am correct, this is called quick lime.

 

Adding water (H2O) will give a thermal reaction, producing a LOT of heat (e.g. the dangerous stuff) and it becomes calcium hydroxide.

 

In time, calcium hydroxide reacts with the CO2 in the air, and becomes calcium carbonate again.

 

Some sites suggest that poon Khao is CaCO3, Calcium carbonate.

 

Other sites suggest that Poon Khao is Calcium hydroxide.

 

I like to use it in different ways,

For soil, for plaster, and for paint.

The simple chalk paint for chalking trees, the henhouse, and much more.

 

With all the different naming and explanations, I'm getting lost.

 

Is Poon Khao the chalk I know in Europe used for so many things?

(Is calcium carbonate)

 

Of is it calcium hydroxide, that will have a Reaction with the air before it is the chalk?

 

The biggest difference is that the hydroxide will have a bonding reaction like cement.

 

Please help me with this confusion!

Thanks!

 

 

 

 

 

[drtreelove]

Good luck sorting it out.  Even if you know the substances by definition, products in Thailand are not always labeled true to their actual identity. Or they are provided in cheap impure forms that don't resemble or perform according to what I am used to in the US.  And explanations don't make sense, misrepresentations are common and many vendors don't really know the products they sell. 

 

I ordered Calcium sulfate, agricultural gypsum as described by a manager at a major Thai producer.  When I got to the head office to pick it up, the product bags were labeled Calcium oxide.  They told my wife and I that they had to label it that way to get around regulations, but swore up an down that it was actually gypsum.  I cracked a bag and examined it and it didn't appear like any gypsum I had ever used. I wasn't confident in the explanation so I rejected it. 

 

The only supplier I would trust is TV member Evolare and his wife's family business http://www.bonemeal.net/

They are increasing their product line of organic agricultural products well beyond their primary bone meal business.

 

https://sodimate-inc.com/differences-hydrated-lime-quicklime/

 

http://www.essentialchemicalindustry.org/chemicals/calcium-carbonate.html

[sirquest007]

Thank you for your reply.

 

I will look at the links you provided.

 

I hope it was not calcium oxide, that seems to be quite effective in taking the skin and the rest of your bones....

 

555

 

It stays confusing !!

[sirquest007]

8 hours ago, sirquest007 said:

 

It stays confusing !!

 Thank you for the links provided.

They are an excellent source of information.

 

It was confusing, now it makes sense.

 

Especially the link 

http://www.essentialchemicalindustry.org/chemicals/calcium-carbonate.html

 

Gave good insight on how it can improve our clay soil!!

 

We have quite some soil to improve, now need to find locally Poon Khao for low price ????

(A 50kg bag is not expensive, but when you need a lot, the numbers add to expensive..)

 

I have some soil test kits, our soil (or actually the soil of my wife) is crap.

 

All things go in phases, next year improve (a part) of the soil with compost, manure and calcium hydroxide.

 

I'm already looking forward to see the crops love the improved soil !

 

For now it will be paint ????

 

thank you again.

 

 

 

[drtreelove]

Soil tests kits don't give you a complete picture of mineral deficiencies and balance.  Be aware that calcium hydroxide may not be a good soil amendment, especially if your soil is already alkaline.  Gypsum is more neutral and has many benefits for clay soil. But the best is a complete soil analysis. 

 

www.soilminerals.com

 

Test 1: Is your soil acidic, alkaline, or neutral? Use this simple home test to find out. Note that this test will not give you a specific pH reading, just a general idea of alkalinity or acidity.

Take a soil sample of a few tablespoons from 2 to 6 inches below your soil’s surface. Avoid sampling the top inch or two of soil as pH may be more variable within the “O” layer near the soil surface, and may be different than the pH of mineralized topsoil that we want to test a few inches down. Remove and keep out mulch, surface amendments, fertilizers, compost, organic matter such as roots and leaf litter, and anything else other than soil from your sample as much as possible. The soil sample can be dry or wet. 

Add vinegar. Put your soil sample into a clean glass or ceramic container and add 2 or 3 tablespoons of vinegar. If the soil fizzes or bubbles, this indicates soil alkalinity. 

 

If no fizzing with vinegar, make a small mudpie. Put a new soil sample into a clean glass or ceramic container, and add enough distilled water to make a soft, very-wet mudpie, about the consistency of thin oatmeal or a semi-melted milkshake. Add a tablespoon or two of baking soda. If the mudpie fizzes or bubbles, this indicates soil acidity.

 

If neither vinegar nor baking soda produces fizzing, this suggests that your soil sample is neutral or near-neutral, with a pH of about 7.0.