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Advice on Crushing Biochar  RSS feed

 
Tim Ries
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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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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 Dobbson
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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.
 
Bruce Taylor
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This is a few years late as I've only recently started making biochar, so I apologise!

I second John Elliott's solution. I use a powerful stainless steel Electrolux stick blender with a longish shaft. I dump my 12 litres of char out of the retort straight into a 20L bucket half filled with urine, and then pound it for a couple of minutes with a piece of 2x4 to initially break it up into smaller chunks. Then, using the stick blender at an angle, and set to turbo, it soon creates a vortex and the char becomes a very fine slurry which is then poured onto the garden or around plants. The particle size would be around 1 mm and it takes just a minute or two to complete. I use the Back to Eden garden method so the char gets itself to the root zone naturally, with rain, planting activity and worms. Where the bed is empty, I rake it in to a depth of about 100 to 200mm.

The beauty of this method is that there is no dust and the newly made biochar is at its most adsorbant (is this the right word?!). It fairly hisses while it sucks up the liquid. It also ensures that the biochar is fully charged with nitrogen and moisture to kick things off with a bang in the soil. The reason I like to micronise it is because I'm only making biochar on a small scale (12 litre batches), so micronising it gives me the biggest surface area and therefore the most bang for the small volumes I'm producing.
 
Greg Martin
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For use in the soil I don't bother crushing mine at all.  It gets mixed with my food scraps to eliminate smell in the bucket under my sink and then it goes through composting with those scraps which causes composting to go faster/hotter.  The Biochar holds onto a lot of nutrients that would have leached out of the pile and holds them for the soil.  Then when I incorporate the compost my soil gets the nutrient loaded Biochar.  Crushing seems unimportant for this and some publications show no difference with crushed or non-crushed.  I mostly use softwood and it breaks down with freeze/thaw cycles pretty well over the years.  If you want to crush a lot fast then finish your char making by water quenching, let it drain so that the Biochar has water in the pores and then send it through a chipper shredder.  The water in the Biochar pores will help keep dust down, which would otherwise be dreadful.  I do like a lot of the suggestions here, but I don't plan to ever crush mine....don't see a reason to do the extra work.  I make quite a few yards every year and the extra work would add up.
 
Greg Martin
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William Bronson wrote:Designed for the job:
http://www.appropedia.org/Corn_Cob_Charcoal_Crusher


For the roller I wonder if you could get away with an oak roller/log with the expanded steel screwed on....seems like it would be much easier/cheaper to make.
 
Mark Morgan
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We sift the ashes from the wood burner several times during the heating season. In the spring I make a fresh compost pile and incorporate the char I've collected. I don't usually worry about the size of the char going in the pile. If I do find large chunks. I will just throw them all into a metal bucket, then drop a sledge hammer vertically into the bucket a few times. After that just throw them in the compost with everything else.
 
Isa Delahunt
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Big biochar movement where I live.  We have way too much "biomass in a vertical orientation" for fire safety, so lots of remediation going on.  I'm talking three or four or five foot diameter char kilns--lots and lots of them!  It works pretty well to put char on a tarp, fold the tarp over it and drive a tractor or truck over the whole thing to break it up.  I suppose you could do the same tarp thing and run the cattle or whatever over it too, as you can when mixing cob.
 
Greg Martin
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I don't think I'll ever have a need for this, but it's pretty cool!
https://www.youtube.com/watch?v=IMjLPjUUedg
 
Travis Johnson
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I pulverize a variety of things with my cement mixer. I would think just putting in the biochar, throwing in some rocks or bricks, then letting it churn for awhile would work. Your degree of pulverization would depend on how long you let it churn.

Used cement mixers can be had pretty cheap, or you can buy small inexpensive ones at Harbor Freight or Home Depot.

They are a worthwhile investment. We use ours all the time for mixing garden starter soil, potting soils, white-wash, compost...and sometimes even for making concrete. A very versatile machine to have!
 
Todd Parr
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Greg Martin wrote:I don't think I'll ever have a need for this, but it's pretty cool!
https://www.youtube.com/watch?v=IMjLPjUUedg


That thing works great. 
 
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