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How To Dispose Of Rock Tumbling Slurry (Easy Tips)

how to dispose of rock tumbler sludge

How To Dispose of Rock Tumbler Grit

So, your rock tumbler has finally finished off the latest batch of stones. While you’re left with some gleaming, brilliant rocks you also have a bunch of water filled with grit, called slurry or sludge. Disposing of it can seem problematic

The good news is that rock slurry is non-toxic and can be disposed of safely at home. The bad news is that doing so in your sink or tub is going to lead to an expensive plumber’s visit. 

So, let’s dive right in and we’ll help you discover some easy ways to dispose of your rock tumbler’s slurry.

Non-Toxic but Problematic

The majority of rock tumbler slurry is non-toxic. Most commonly collected stones, think agate or jasper, are inert and you’re just dealing with small particles of silica and bits of grit.

Two problems arise from the mixture.

The first is it’s impact on plumbing. The effect is similar to dumping a bucket of sand down your pipes. It’s the sort of thing that’s going to cost a boatload to fix.

The second is that the dense nature of slurry sometimes does damage to landscaping. While you can dump out slurry in your yard, it often strangles grass and other small plants. The dead patch that arises isn’t due to some toxic nature, it’s just too much dust piled on top of your slurry.

One thing to keep in mind: dried out slurry is mostly silica dust. Silica dust is dangerous, and repeated exposure can lead to silicosis.

You may need to take special precautions with some stones, particularly those which contain heavy or toxic metals. Bumblebee Jasper’s arsenic content, for instance, doesn’t magically disappear in the slurry. Likewise the heavy metals like copper in popular ores like malachite.


In that case, use the drying out method outlined below.

For that reason, you should know the chemical composition of the stones you’re tumbling. Ores like malachite and other potentially toxic materials should only be disposed of in the trash.

How To Dispose Of Rock Tumbling Slurry

1. The Easiest Way: Dump It in the Yard

The easiest way to dispose of your slurry is to dump it somewhere in your yard.

I recommend doing it away from plants for the most part, especially if you’re dumping it all at once. If you allow the grit to settle you can use the clear water on top for watering, but if you just dump the whole mess on a plant it may kill it.

Slurry builds up over time if you keep using the same area. It may be a good idea to turn fresh dirt over it after a fresh slurry dump, silica won’t hurt soil anymore than sprinklink some sand in would.

Indeed, burying the silica can keep it from going airborne once things dry. The risk from the compound outdoors is quite small, but every little bit counts.

Just don’t dump it on a hard surface, or it will simply dry into a mud.

2. Dry and Dispose

Not everyone has access to a yard, and you don’t really want a ranger to see you dumping a bunch of suspicious liquid at the local park.

In that case, you can allow the slurry to dry out in a container.

A bucket is one of the best ways to do it, but anything which has a relatively large surface will do it. The wider and shallower your slurry, the quicker it will dry out.

Wait until the slurry is a mud, then scrape it into a separate container. An old tupperware or food container that’s lying around works just fine. 

For a dedicated container a plastic cat litter box is a great idea. You can also use a plastic liner to make collection easier.

Keep in mind that completely dry slurry can allow particles of silica into the air when disturbed. If you constantly have tumblers going this may not be a problem, but take care to remove all of the material when you’re getting ready to dispose of things.

If you’re concerned about using too much water it’s easy to remove the clear water from the top after the slurry settles. A lot of rockhounds use it to water plants, just make sure you don’t have anything toxic left over from the stones.

3. Fill-in Driveway Potholes

Another way to dispose of your slurry takes advantage of it’s cement-like properties.

If you have potholes on your property, you can use a mixture of gravel and slurry mud to fill them in. The gravel takes up the bulk of the space while the smaller bits of grit and stone fill in all of the little spots.

Likewise, you could use small rocks and grit to patch large cracks in concrete if aeshtetics isn’t a concern. I wouldn’t recommend using it in professional construction, but the truth is that slurry mud is pretty close in composition to mortar.

4. Most Efficient Way To Dispose of Rock Tumbler Grit

If you’re serious about tumbling stones, chances are you’ll have to deal with a lot of slurry over the years ahead of you.

So, disposing of it in an efficient and safe matter is a necessity.

I recommend the following procedure:

  1. Dump slurry into a bucket with a liner.
  2. Remove clear water as the grit settles, use the water for plants or anything else you may use non-potable water for.
  3. Maintain just enough water to keep slurry as “mud” instead of letting it dry out, especially if the bucket is kept indoors.
  4. Allow grit to collect over time.
  5. When the bag is ⅓-½ full place bag with slurry outdoors to dry.
  6. Once most of the moisture is evaporated, dispose of the slurry in a trash can.

The above is scalable and easy to do, just make it part of your tumbling routine.

The good news is that slurry disposal isn’t hazardous, it’s just a good idea to exercise a bit of care and responsibility.

So, with that out of the way, what are you going to tumble next?

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