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Advice on Crushing Biochar

 
Tim Ries
Posts: 17
Location: Arkansas - Zone 8a
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I am planning to in a few months to make my own Biochar (a type of Charcoal if you don't know), and I am looking for a simple way to grind it up. I was hoping someone here might have an idea, something I could hopefully build for not a lot. The size I would want it to be crushed etc into is roughly 2 Millimeters. One thought I had was some sort of hand operated rock jaw crusher. Something like they have in this video or something else that would work, but not be 500 dollars. A cheap motorized crusher would work as well.

At any rate I hope someone here might be able to point me in the right direction.
 
John Elliott
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How much volume are we talking about, Tim?

If you want to crush a small amount, say a couple of cupfuls at a time (which is enough for a wheelbarrow full of soil), then put it in a large metal can like a gallon paint can and use a 2x4 for a pestle to pound it into a powder.

Another way to do this, which also takes care of the dust problem, is to use an immersion blender to grind it. Put it in a bucketful of water and work the immersion blender up and down. The largest pieces left over after this method may be about 5mm on a side, but the longer you blend, the fewer large piece are left. I like this method, because I can add the biochar to compost tea right before I apply it.
 
Tim Ries
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Location: Arkansas - Zone 8a
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About a wheel barrow full at a time would be an accurate amount, of how much Biochar would be made. I'll look into the immersion blender, I am also thinking about adding some biochar to my Vermiculture bin.
 
John Elliott
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Then a 30 gallon metal drum and a good size sledge hammer should work. Keep dropping the sledge into the drum and that will crush the biochar small in no time. It does tend to raise a cloud of particulate though. After you've done it a couple of times, I think you will prefer the 5 gallon bucket of water and the immersion blender method.

Biochar is so much easier to apply when it is in the form of a liquid slurry.
 
Tim Ries
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Location: Arkansas - Zone 8a
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You mean an old Kitchen Immersion Blender right?
 
John Elliott
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Yes, like this



Sometimes you can find them on sale for $10. Oh, and by the way, you don't want to be taking this back into the kitchen and trying to clean it. It becomes a tool dedicated to the biochar operation.
 
Tim Ries
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Location: Arkansas - Zone 8a
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What if i like the taste of Charcoal?
 
John Elliott
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Tim Ries wrote:What if i like the taste of Charcoal?


Now you make me nostalgic for my uncle's barbecues when I was a kid. Oh, could put a black crust on a piece of meat!
 
Dale Hodgins
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Nancy Sinclaire
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I would soak the biochar in water for 4 months to soften it. Then I would try putting it between two pieces of plywood and set that in the middle of the driveway so every day it gets driven over. If I had cows that ever stood on cement I would put the softened char where they stand. Can the object the char is made out of be ground before being made into char? Can the char be used for something like filtering water or capturing the nutrient in urine before being crushed for char? Filtering water for people to drink or for a tank of fish?

Please do not breath biochar dust.

The biochar needs to have a living biofilm added to it so one might as well get that by using it for something useful other than the garden first.
 
Dale Hodgins
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Nancy Sinclaire wrote:I would soak the biochar in water for 4 months to soften it. Then I would try putting it between two pieces of plywood and set that in the middle of the driveway so every day it gets driven over. If I had cows that ever stood on cement I would put the softened char where they stand. Can the object the char is made out of be ground before being made into char? Can the char be used for something like filtering water or capturing the nutrient in urine before being crushed for char? Filtering water for people to drink or for a tank of fish?

Please do not breath biochar dust.

The biochar needs to have a living biofilm added to it so one might as well get that by using it for something useful other than the garden first.


Why four months? Sawdust is a pre ground feedstock that could be used. Ground biochar would blow away very quickly if driven over daily. When charcoal is ground in a ball mill to make gun powder, it is processed until it reaches a fineness called "air float". I think we want to stop long before that point. Large quantities could go into pond filters. I doubt that this would improve the char, but it would clean the pond. Now, imagine that a million little water creatures live and die in the char. It may stink of dead fish. I don't much care for the smell, which is part of why I have never ground a dead fish.
 
Ken Peavey
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I betcha this would work

 
Craig Dobbelyu
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Dale you may have answered your own question there. If you were to soak the charcoal in a pond for a good long while, it would act as a filter for the water and a home for tons of microorganisms. Four months is about right for setting up these colonies in the biochar structure. I'm not sure if it would soften it up but I know it would be loaded with all kinds of nutrients that would be great in garden or forest soils. Aquarium filters use charcoal for the chemical absorption power of carbon AND also because it has a really porous structure for lots of bacteria and other micro-critters to live in. If the goal of the biochar is to help hold nutrients in the soil, then soaking up nutrients from a pond and then "transplanting" them via biochar to the garden would seem to be a solid idea to me.
You probably can't add a lot of biochar to an established pond because it might throw it all out of whack. maybe
 
Tim Ries
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Location: Arkansas - Zone 8a
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Ken Peavey wrote:I betcha this would work



Thanks Ken, It took me to their Projects Site!
 
George Bowman
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Location: Catawba NC
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I'd like to reopen this subject ..... Has anyone found a GOOD way to grind/crush Bio Char ?
 
Michael Cox
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Nothing beyond hitting the occassional bigger bit with the fork while spreading it or turning it in. Personally I don't worry too much about it - plant roots force their way through chunks of biochar and it doesn't seem to take too long before the bigger chunks get broken down smaller. I wouldn't attempt to fine grind it unless I had some specific purpose. But then my garden and veggie beds are rather on the messy side anyway.
 
Landon Sunrich
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I've been using a plastic tote type container and a 4 inch wide alder poll as a mortar/pedestal sort of deal. It works pretty well. I wet it down first. I also use WAY more than a couple cups per wheelbarrow full. Hope I'm not over doing it. MY potting soil w/ biochar is producing some amazing results.

Edit: Its a smash/twist/grind... smash/twist/grind... rhythmic sort of crush job, if that makes sense.
 
Peter Ellis
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George Bowman wrote:I'd like to reopen this subject ..... Has anyone found a GOOD way to grind/crush Bio Char ?


There is a real need for a definition of "good" in your question I think that the suggestion of the stick blender made by John Elliott early in the thread would qualify as a good way of doing it, but the fact that you are asking suggests it does not meet your criteria.

So, what do you mean by "GOOD" ?
 
R Scott
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I bet a garbage disposal would make a good rough slurry on a wheelbarrow at a time scale.
 
Tim Malacarne
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R Scott, I bet you're right!

I've wondered about a garbage disposal to grind up the stuff that goes to the compost pile, but really, all you gotta do is wait......
 
Steven Edholm
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I've used a garbage disposal, but but on dry char. It worked well with a cloth bag over the outlet to keep dust in. It stopped working though, as my friend put it, "because you were grinding charcoal in it!" :-/

It worked pretty good though, fast, about the grind I wanted, 1/4 inch and down with lots of powder too. This was a heavy duty kitchenaid unit of 1 hp I had modified as an apple grinder (mixed results on apples).
 
William Bronson
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Steven Edholm
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that corn cob crusher looks pretty good. It's a lot like an apple scratter. The grape crushers are made with two ridged cylinders like that and both turn at once. Scratters are usually a larger cylinder with metal teeth, but they turn against a "wall" like the cob charcoal crusher. So it's kind of a hybrid between the two. Single cylinder is esier, because they don't need gearing to turn two cylinders at once. I'm inclined to think that the fruit crusher's two cylinders might work a little faster, but there is a lot to be said for accessibilty and i think making one from scratch could be difficult. After all, accessibility is the main problem with charcoal crushing. I mean, we could all go out and buy something awesome if we could spend the money. I might try to make something like this. Thanks for the link.
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