Sifting Manure

We have this big ol' pile of horse manure out back, which we can't spread out in the pasture because it is full of rocks that are just about exactly the right size for causing problems with horses feet (according to SWMBO, at least). The sizes range from sand to 3-4 inches.

Since clean, rock-free horse manure is pretty easy to get around here, I'm assuming I cannot give it away. So I'd like to build a sifter for the stuff, to separate the good rocks from the good fertilizer.

I'm considering making a big drum with a 1/4" screen, rotating it with either an electric motor or a Vibration & Stratton engine. I'll load in dirty manure in one end with my loader, get clean manure out the bottom, and occasionally dump slightly odiferous rocks out of the drum.

What I need to know is:

  1. Is this a good approach?
1a. How do quarries sift their rock? 1b. Is there something out there that I can get my hands on that does this task? It doesn't have to look like what I think will work, it just needs to separate the rock from the crap.
  1. Anyone have any suggestions for screen? I'm considering expanded metal, but it looks like I can't get really thick expanded metal with
1/4" holes. I'm afraid that the 18 gauge that it seems I can get will wear too quickly, particularly if I get a big rock bonking around in there.
Reply to
Tim Wescott
Loading thread data ...

I would spread it and then run through the area with a Harley rake if you have a skid steer or drag it with a York rake behind a tractor after it dries. Any material that is sticky or wet, similar to compost, is going to have a tendency to bridge and clog . If time is no object, maybe set a few bucketfuls at a time on top of a suitable horizontal screen and let the rain wash it through.

Reply to
ATP*

"Tim Wescott" wrote: (clip) Is there something out there that I can get my hands on that does this task? It doesn't have to look like what I think will work, it just needs to separate the rock from the crap.(clip) ^^^^^^^^^^^^^^^^^^^ If you have horses, maybe you have a watering trough that's not in use. Consider floating the manure and sinking the rocks. I'm pretty sure manure will float, but you could double check with David Letterman ;-)

Reply to
Leo Lichtman

How did those get _in_ there?

You could offer to deliver it, and warn about the rocks. Mind you, I do try to go dig mine from the place that's given me the least rocks (and weird plastic trash), but I have a truck. Even they are not rock-free, but it's pretty occasional and usually large - they can't be bothered to build a proper flat raised area to start the pile on, so they scoop up crap from the (mucky) ground when rearranging it. The rocks show up in the garden or in processing (ala rake and shovel) from truck to garden, and get hurled in the pile with the rocks that started life in the garden. Not such a big deal when expensive, delicate animules are not going to step on it.

Someone else will have better details of the small rock sorting process

- big rock seem to be removed at the local gravel pit by dumping a front-end-loader-bucketload onto a 45 degree "screen". This is quite similar to the hand-powered screening we did at home when I was a kid, as we dug up the garden beds and got the rocks and other detritus out with a considerably smaller screen (of expanded metal mesh).

You idea sounds basically OK, but I suspect that it may require considerably more engineering and investment to pull off (in a manner that won't break in the first 5 minutes, and every 15 minutes thereafter) than simply dumping the current pile in a horse-free-zone, and keeping the rocks out of the next pile. Add a few pumpkin seeds to the dumping zone and have a happy halloween...

If you have a brush pile anywhere, dump the manure pile on top of it, and you'll save burning the brush pile if you can give it a few years.

Reply to
Ecnerwal

Your rotary drum is called a trummel. They very common in placer mining for gold. I have seen huge plate steel trummels with three inch holes in them. Obviously they were for big operations. I would expect that unless the manure is very fine and dry it will plug up the holes. The other alternative is a screen deck. It is a large steel box with one or more layers of woven steel mesh or perforated sheet steel. The box is slanted slightly and hung on springs. A shaft with counterweights is rotated by a small gas engine via a long flexible Vee belt. The whole box vibrates working the material down the slope. You might look up gravel screening equipment websites for ideas. I worked for a guy who built these units regularly... Any size and screen spacing the customer wanted. Part of gold fever is the need to have bigger and better screen decks and bigger, longer and better sluice boxes. Randy

"Tim Wescott" wrote in message news: snipped-for-privacy@web-ster.com... We have this big ol' pile of horse manure out back, which we can't spread out in the pasture because it is full of rocks that are just about exactly the right size for causing problems with horses feet (according to SWMBO, at least). The sizes range from sand to 3-4 inches.

Since clean, rock-free horse manure is pretty easy to get around here, I'm assuming I cannot give it away. So I'd like to build a sifter for the stuff, to separate the good rocks from the good fertilizer.

I'm considering making a big drum with a 1/4" screen, rotating it with either an electric motor or a Vibration & Stratton engine. I'll load in dirty manure in one end with my loader, get clean manure out the bottom, and occasionally dump slightly odiferous rocks out of the drum.

What I need to know is:

  1. Is this a good approach?
1a. How do quarries sift their rock? 1b. Is there something out there that I can get my hands on that does this task? It doesn't have to look like what I think will work, it just needs to separate the rock from the crap.
  1. Anyone have any suggestions for screen? I'm considering expanded metal, but it looks like I can't get really thick expanded metal with
1/4" holes. I'm afraid that the 18 gauge that it seems I can get will wear too quickly, particularly if I get a big rock bonking around in there.
Reply to
R. Zimmerman

Get a cannon, load in black powder, wad material (maybe not necessary) manure and rocks, touch off the powder. The rocks will be at the longest range an the 'sifted' manure will be close to the cannon. With a few practice shots, a few well placed blue tarps will collect the sifted manure and the rocks will land on your road.

Get the neighbors involved and let'em touch off the cannon for a few buck.

Reply to
John Miller

In article , Tim Wescott wrote:

Sort of... It's a "bad" variation on a unit called a Trommel-screen.

Trommel-screen... Often a series of several of them with graduated size elements.

Trommel-screen. But unless you home-brew it, it's gonna be *REAL* pricey

- The smallest "ready-made" one I've ever personally laid eyes on was used by the Mackinac Island dump/recycling center for *ALMOST* exactly what you're looing to do - They started up a recycling/composting operation there a few years back - Basic concept: Trash separation is mandatory - You've got three containers: "Landfill", "recyclable", and "compostable". You're welcome to buy only "Landfill" containers - at a price intentionally set to "over the moon and then some" specifically to discourage their use. Compost & recycle containers are practically free. Misuse of compost or recycle containers for landfill means you get *NO* garbage service whatsoever, and are legally obligated to transport it all yourself (at exhorbitant prices) to get it off the island. Anyway, long story shorter, "compost" bags get opened, spot-checked for "illegal" trash, then run through a grinder. The output of the grinder then gets mixed with some of the output from the 500-odd horses that populate the island in the summer months, and stuffed into composting frames. Once it's "cooked" enough (about 6 weeks from start to finish) it gets fed to the trommel-screen, where any "chunks" that didn't compost down nice the first time through get sent back through the grinder for a repeat processing, and the "final product" that comes through the side of the barrel gets sterilized and bagged for sale as landscaping/topsoil material. (at premium prices, I might add! Even though expensive, it is worthwhile if your're in the market for such stuff)

There's where your plan goes bad...

Trommel-screens are more or less like the barrel of a cement mixer, only tubular instead of conical, and open at both ends, with the size screen needed to let "OK" stuff fall out along the length, while keeping the "too big" stuff inside the barrel until it falls all the way to, and eventually out through, the lower end, where it can either be loaded out to a dump-site, or run into another Trommel-screen with a different sized mesh for further size-grading if desired.

Basically, take your idea of the drum, make both ends open, cut out the sides of the drum leaving a framework of "spokes" to suppot your screen, and line the inside with plain old quarter-inch hardware cloth. Mount it slanted so that the barrel can be spun on its long axis (doesn't need to be very fast) and start shoveling stuff in at the top. "Clean" stuff falls out through the screen, oversize "stuff" ends up piled at the bottom end - Continuous cycle - As long as you keep feeding it, you keep producing sifted stuff to be used, and oversized chunks to be disposed of, with no need to stop to empty the barrel, and litle problem with "big chunks" beating it to death, since they're only inside for as long as it takes them to fall thorugh the barrel to the other end.

Reply to
Don Bruder

From the paddock. Either from the native soil or because the previous owner was confused about the right stuff to floor a paddock with. At any rate, the paddock is essentially 1 minus, with some bigger things thrown in. That's the other part of the project -- stripping the old manure, covering the too-big stuff with road cloth, and covering _that_ with 1/4 minus ("rock dust" if you're on the east coast).

Reply to
Tim Wescott

Tim do a little Googling on the types of vibratory sifters that archaeologists use to find artifacts in 'dig' soil.

They're simple to build, and easy to use. You might check out the College of William and Mary. They have an active site right now in the Jamestown area, digging a civil war escarpment.

LLoyd

Reply to
Lloyd E. Sponenburgh

We work with topsoil places that do the float method...float off sticks and such that need to be ground so the rocks don't get into the grinder. It's just a tank with water flowing on one end (flume) and a conveyor bottom that pulls the rocks out in the opposite direction of the water flow.

The same thing is used to de-rock potatoes on a volume basis.

Of course the thought of wet sloppy manure is probably not appealing so I would just sift. Not sure how big a "big ol'" pile is but a simple screen set at a slope is easy to shovel through by hand. Bigger volumes than that and I'd go rotary or vibratory, scabbed together from whatever you can get your hands on.

Reply to
Koz

The pile is probably four yards, and we'll be generating at least a yard a year unless we let it compost longer (these things do eventually reach equilibrium).

My intention is to compost it first, and well-done manure compost is reasonably dry and quite crumbly. So I really don't like the idea of floating it. I thought of doing a vibratory trummel* but I think I can hack together a rotary one easier than a vibratory one, and I think a rotary one will be more reliable.

Now I just need to inventory my round tuits.

  • Well, vibratory thingie -- but now I know the name.
Reply to
Tim Wescott

Just stop feeding the rocks to the horses!

"Tim Wescott" wrote in message news: snipped-for-privacy@web-ster.com...

Reply to
Tom Miller

Dunno, but I ask myself the same question when reading this newsgroup

Reply to
Tony

Saw something in a scrap yard that might work. They were feeding cars into a huge grinder. Came out the bottom in small pieces that were dumped onto a conveyer belt. These pieces included plastic, cloth, metal, etc. The belt was moving fairly quickly at an upward angle. When the pieces got to the end of the belt, they would fly off in an arc. The heavy metal pieces would fly farther then the lighter plastics and cloth. Boards were set to deflect the pieces into different piles. If your manure is dry it should be lighter then the rocks and this might work.

Reply to
Chief McGee

| "Tim Wescott" wrote in | message | news: snipped-for-privacy@web-ster.com... | > We have this big ol' pile of horse manure out | > back, which we can't spread out in the pasture | > because it is full of rocks that are just about | > exactly the right size for causing problems with | > horses feet (according to SWMBO, at least). The | > sizes range from sand to 3-4 inches.

I was just thinking about that deck grating used in industrial environments. It's a bunch of metal strips laid on end and held together by various means, so that ought to sift out anything larger than about 3/4" or so. It's used for a billion things, and great for stables and barns so that you have something solid to walk on while muck falls away between the slats and can be washed away later. Stand it up on a mild incline somehow and connect it by whatever means works for you to whatever piece of machinery you have that vibrates the most. The rocks will continue out to the low side of the grate while the manure falls through. Another thing that came to me was to connect it to a front loader so that all you have to do is to drive the grate into the pile, pick up a load, back away over the piles of clean manure previously deposited, which will give you a nice shaking motion, then dump the rocks left behind wherever you see fit. This way you get to move the rocks and screen them out at the same time.

And you should smack whoever had the bright idea of mixing rocky soil and manure together.

Reply to
carl mciver

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.