When formulating a plan to dispose of rock tumbler grit, the most relevant point (so we can answer your question) is what is in the end-product of your rock tumbling efforts?
What did you put into the rock tumbler (rocks, grit, other substances/chemicals), and what state is it in now (water solution, dried up)?
Not every disposal plan is going to work with every solution.
Disposing of Silicone Carbide Grit Sludge
When entering into the work of rockhounding and rock tumbling/polishing, it can feel pretty strange to take the advice of some of the more experienced folks in the community to simply throw the silicone carbide grit mixture from your tumbler out the back door into the driveway or yard.
After all….”silicone” is part of its name.
However, that is actually what many people do…just throw it out the door and forget about it.
Silicon carbide grit is quite hard, and doesn’t break down easily. Further, in the post-tumbling mixture, you’ll also have fine particular matter from the rocks that were tumbled.
Depending on what you tumbled, you may actually not want to just throw the solution onto the ground to be absorbed into the soil.
This could kill the plants/grass where you’ve throw the mixture (by poisoning it or suffocating it), or discolor the concrete/stones.
The sludge looking spot probably won’t be absorbed into anything, and depending on how much you’ve got, the sludge spot might be really obvious and visible for quite some time.
Or it could do the opposite of killing the grass (as some plants might really thrive on the additional minerals).
If you’ve put Ivory soap into the mixture, will it create a slippery spot when it is wet?
I have also seen a few instances where animals have taken it upon themselves to consume the grit when thrown out onto the ground. I do not know of the results, but I can’t imagine it was a good thing for the dog, especially when the rocks being tumbled contained copper or arsenic.
This is yet another good reason to clean up the mess and not leave the sludge lying out on the ground in the backyard.
In general, best practices are to be mindful of what is in your slurry (arsenic, copper, soap flakes, etc) as you decide how to dispose of it.
Most Responsible Method To Dispose of Rock Tumbler Grit
In general, we would set the mixture aside when you are done with it, such as in a bucket lined with a strong plastic bag.
Then we’d like let the water evaporate out of it, even as we continue to tumble rocks and create more solution to get rid of. When the bag gets full enough (and dry enough), you can simply tie it off and throw it in the trash.
That being said, others do this with their leftovers:
- throw the slurry mixture (water and all) into the vegetable garden
- dig a hole in the yard, pour the slurry in, and cover it up
- take the bucket with the dried up sludge to the dump/landfill and chuck the whole thing in
- pour it outside into the street wherever
- mix with gravel to fill in potholes
Notes for Tumbling With Borax
Borax is a familiar product in most homes.
We use it to clean, and also to help kill sugar ants when they march into the house.
Some rockhounds throw a tablespoon or two of Borax to their grit to help produce a better looking end product, while others use it to prevent gas build up in the tumbler.
If you are using Borax, we do not recommend that you throw your slurry into the lawn, as it will kill the and other vegetation/plants. Animals (such as dogs) may also investigate and decide to lick or eat.
Best to let the water evaporate out and toss it in the garbage can instead of the yard.
Disposing of Rock Polishing Grit
Rock polishing grit is a finer grit, that is most often make up of some kind of metal oxide, such as aluminum oxide.
As for disposing of a solution containing rock polishing grit, in general we recommend that you follow the plan of setting aside the sludge when you are done with it, and letting the water evaporate out, then tossing the mixture out with the trash.
What we don’t recommend is negligently mixing the polishing grit sludge with other chemicals or solutions, especially if you don’t know or remember the contents.
This will prevent any unexpected chemical reactions.
Don’ts of Disposing of Rock Tumbler Grit
First and foremost, whatever you do, don’t just throw the solution into the sink, bathtub, or the toilet.
You are inviting pipe problems either immediately or in the future. The slurry could and likely will harden on the inside of your pipes.
Next, rinse your rocks in a bowl or bucket that, again, you are not throwing down the sink.
Next, know what you are disposing of. If you are disposing of multiple tumbles, make sure that any additives you might have thrown in with the tumbler won’t react negatively or dangerously with anything else you’ve thrown in there (such as bleach, vinegar, acids, etc).
If you are handling the tumbler leftovers dry, make sure you aren’t breathing any of the dust, as the fine particles that would otherwise be non-toxic and non-dangerous can be the opposite once you let them get inside your body.
It is important to know what is in your tumbler slurry before you dump it. Avoid creating an accidental chemical reactions. And think about the animals.
You might also like:
- Rockhounding Arizona: Ideas For The First Time Visitor
- How To Get Rid Of Tumbler Water Safely
- Tips For Polishing Selenite
- How To Brighten Up River Rock
If you have more questions about tumbling rocks, check out the articles in our Yes Dirt Rockhounding Knowledge Vault.