Hello, i want to make some experiment with different things, i would like for exemple mix clay with manure to make small ball like aquasoil ones or even bigger, the problem is that i don't want them to dissolve too fast, i was thinking to cook it but how to cook it, which temperature, etc ? thx so much
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How to cook clay to make it insoluble in water ?
- Thread starter eminor
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_Maq_
Member
So it happens that I know. No, I'm not a professional brick maker, I'm a hobbyist who - against my mom @Hufsa 's advice - wants to know anything concerning our hobby. 
So, if you burn clay in temperature over 1000 °C, you make a brick. Such a change is basically irreversible. I haven't got it explicitly confirmed but I believe it'll lose CEC, too.
Manufacturers of aquasoils burn their blends of clay and humus soils at temperatures btw. 300 and 400 °C. Still, to emulate their products, I suspect there are more secrets and tricks to reveal.
You don't get 300 or more degrees in an ordinary oven, but 'baking' clay at 225 °C makes some sense, too. Some of my compatriots prepare DIY clay balls containing fertilizer for underground nutrition. Some of them report it works well. I do not comment - never tried and don't intend to.
So, if you burn clay in temperature over 1000 °C, you make a brick. Such a change is basically irreversible. I haven't got it explicitly confirmed but I believe it'll lose CEC, too.
Manufacturers of aquasoils burn their blends of clay and humus soils at temperatures btw. 300 and 400 °C. Still, to emulate their products, I suspect there are more secrets and tricks to reveal.
You don't get 300 or more degrees in an ordinary oven, but 'baking' clay at 225 °C makes some sense, too. Some of my compatriots prepare DIY clay balls containing fertilizer for underground nutrition. Some of them report it works well. I do not comment - never tried and don't intend to.
zozo
Member
I'm not sure what you are after, I assume you want to push it into the soil...
Clay is actually nothing more than a nomer for glacial sediment ground into a microscopic grain size of sand smaller than 2 µm and is named Lutum. Size comparing sand is made of tiny rocks much bigger in size and therefore less compact. It's the percentage of Humus content and minerals that make the clay either rich or poor from a fertilizer perspective, 25% to 35% Lutum is light clay and 50% is heavy clay. Because the compactness of this small grain size makes clay very resistant to water penetration and holds its mineral content very tight and very well for ages if not disturbed. It releases its minerals very slowly and is able to suck minerals from outside in the water back up. (CEC more or less)
So when you dry it in the sun on a hot day till it is bone dry it takes quite a long time before the water reaches its core and then still it stays compacted that's the natural property of clay.
Anything of the same material from 2 µm up to 642 µm is named Silt or Loam
Anything larger than 642 µm up to 2mm in grain size is called Sand... And it's not per definition Silica, silica sand is the most common. But if you grind a baked house brick that once was clay into 642 µm / 2mm grain size you end up with sand. Bigger in size becomes gravel and so on.
Thus it's the size that makes the clay and or Loam or sand and not the content.
What I'm trying to say is you actually don't need to bake it to render its hardness, it will not dissolve and it will stay in the soil if you put it in there. Of course, this will change if you disturb the soil where it's in it too much and clouds the water then it will be filtered out.
If the balls you made aren't compact, much too coarse and it falls easily apart when wet then it aint clay or not enough clay... Than baking wouldn't likely make a difference. Anyway, even if it falls apart and is no longer a ball, its contents stay in the soil, just stick it in deep enough.
Clay is actually nothing more than a nomer for glacial sediment ground into a microscopic grain size of sand smaller than 2 µm and is named Lutum. Size comparing sand is made of tiny rocks much bigger in size and therefore less compact. It's the percentage of Humus content and minerals that make the clay either rich or poor from a fertilizer perspective, 25% to 35% Lutum is light clay and 50% is heavy clay. Because the compactness of this small grain size makes clay very resistant to water penetration and holds its mineral content very tight and very well for ages if not disturbed. It releases its minerals very slowly and is able to suck minerals from outside in the water back up. (CEC more or less)
So when you dry it in the sun on a hot day till it is bone dry it takes quite a long time before the water reaches its core and then still it stays compacted that's the natural property of clay.
Anything of the same material from 2 µm up to 642 µm is named Silt or Loam
Anything larger than 642 µm up to 2mm in grain size is called Sand... And it's not per definition Silica, silica sand is the most common. But if you grind a baked house brick that once was clay into 642 µm / 2mm grain size you end up with sand. Bigger in size becomes gravel and so on.
Thus it's the size that makes the clay and or Loam or sand and not the content.
What I'm trying to say is you actually don't need to bake it to render its hardness, it will not dissolve and it will stay in the soil if you put it in there. Of course, this will change if you disturb the soil where it's in it too much and clouds the water then it will be filtered out.
If the balls you made aren't compact, much too coarse and it falls easily apart when wet then it aint clay or not enough clay... Than baking wouldn't likely make a difference. Anyway, even if it falls apart and is no longer a ball, its contents stay in the soil, just stick it in deep enough.
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This thread might be if interest
Darrell's (dw1305's) soil thread
Hi all That's interesting :) It's literally soil dug up, burnt and sieved. is 100% correct. I've got quite a lot of soil samples, out of the furnace in the lab (this burns out the OM at 500 oC to give you the percentage organic for your soil) if any-one wants to experiment with them? The...
www.ukaps.org
Thanks, if only i saw those answer before... I mixed montmorillonite clay with composted manure, i made ball for the substrate, put them in the oven for 30 minutes @235°c, looks like calcined clay now, it's not hard at all, kind of like coal. It seems that the nutrients are still in there, i tested it in a glass, the ppm is rising. I baked only a few, i still have the big part of it unbaked, i won't cook it anymore =)
Attachments
I tested the conductivity of one ball of 1 gram in RO water, conductivity rised from 7 ppm to 100ppm when "mixed" completly. On the manure package they say that there is Chicken,Cow,Horse manure, green compost, marine algae. they said there is 1% nitrogen, 0.9 phosphate 1% Potassium, Carbon/nitrogen ratio is 11.
In the glass, the balls actually disintegrate, if i'm right, organic matter have really high CEC ? The ball stay long enough hard to the water to put them in the bottom which is perfect. How that organic matter will behave under clay substrate ? will it rot ? the conductivity in the aquarium is still the same so maybe flow is not fast in the substrate.
The clay i mixed with the manure/compost/algae organic is Green French Clay, which is Illite, Kaolinite, Mont... the last one is supposed to have really high CEC. The clay is actually called "Clay of velay" which is supposed to be unique because there is no qwartz in it. They claim that CEC of that clay is high, but maybe it's nothing to worry about because of the high cec of the organic matter ? thx
In the glass, the balls actually disintegrate, if i'm right, organic matter have really high CEC ? The ball stay long enough hard to the water to put them in the bottom which is perfect. How that organic matter will behave under clay substrate ? will it rot ? the conductivity in the aquarium is still the same so maybe flow is not fast in the substrate.
The clay i mixed with the manure/compost/algae organic is Green French Clay, which is Illite, Kaolinite, Mont... the last one is supposed to have really high CEC. The clay is actually called "Clay of velay" which is supposed to be unique because there is no qwartz in it. They claim that CEC of that clay is high, but maybe it's nothing to worry about because of the high cec of the organic matter ? thx
