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Disposing of garnet from waterjet

Spencer46

Plastic
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Mar 24, 2020
We have a waterjet that we run 5-7 hours per day, so we have a lot of garnet to dispose of. We currently dispose of this through Waste Management as non-hazardous waste. Has anyone ever tried to sell the garnet waste to a landscaper or anybody like that? Thanks.
 
You need to consider the materials you're cutting. If steel or stone, no likely hazardous waste risks, but if you're cutting stainless or cobalt-bearing alloys, you might have to treat this as Haz-waste.

I really doubt a landscaper would want this, it's finer than beach sand and would make a hell of a mess if tracked into a house. Contractors looking for clean fill might work, but only if it really is "clean".

Heck, check out concrete or people making reinforced plastic castings - garnet might make a good filler for those purposes.
 
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can you magnetically separate the steel particles and sell for scrap?

Twenty some years ago I toured a Triumph Twist Drill facility and they installed a huge filter system to separate the steel and abrasives from the oil. they were selling the abrasives and likely the steel also.

Dave
 
In fact ,fine garnet or even the dust is very effective for sandblasting,the finer particles cut faster than the coarse grit new garnet......Downside is the fines is more abrasive on pipes ,hoses and nozzles ......but with garnet being $1 a kg,its quite economic to use the fines . Of of course,for sandblasting the garnet must be dry and free flowing.
 
The danger here is if you have characterized your waste as non-hazardous, and are disposing to landfill (which is common for this type of material in my experience) then the special waste company is going to be at least doing periodic testing, primarily for D-listed metals content.

So now you switch over to selling it for some type of reuse, and then you start cutting a bunch of Chrome-containing alloys in the near future and now you're responsible for tons of hazardous waste being land-applied at a bunch of residences and parks where kids play. No one thinks about how process changes alter their waste characterization; the sales staff will sell what they sell and no one will think twice.

Bottom line is you're handling it in the most responsible and safe (from a liability standpoint) way you can. If you do decide to do this, I would suggest getting TCLP testing performed for D-listed metals before sending out each lot of waste to cover your ass. At least if you cut a variety of materials and have 3-5 lots worth of these tests, your state authority and EPA will agree that you followed best practices to properly characterized your waste and they will be a lot more helpful rather than putative if something bad happens.
 
I would think the waste would quickly turn into a solid rust coloured mass,due to any steel content ....I looked in to a disposal plan for sandblasting waste ,which was costing 20c/kg to dispose of.....Ended up making a deal with a solvent and oil waste refining company ,where they installed a rotary kiln and used the waste to make bitumen mixes,at the same time burning some of the liquid waste for heat.....Some time later ,after I quit ,the solvent recycler got busted for various environmental crimes ,and selling untaxed diesel.....Sandblasters had closed by then ,anyway.
 
One use that comes to my mind, assuming there is no haz waste issue, is for pipe bedding. Most contactors around here when installing underground pipes bed the pipe with limestone sand or even fine limestone prior to backfill.
 
An old time sandblaster here bought a block of swampland bayside ,and started to dump all his waste there ....not a problem......then he bought a big collection of old dust collectors,blowers ,bins etc.,and dumped them on the land ...neighbours complained repeatedly about the old iron there ,and the council inspectors came out.....the old junk was legal,but they also took samples of the dirt piles dumped .....EPA test found high concentrations of lead and ship anti fouling ,like tri methyl tin.....If the old geezer had not upset neighbours with the junk ,he would not have got two years jail for dumping toxic waste in the bay.
 
A bit off topic but at that waste company where I was working in the lab, we stopped handling dust collector waste and other metal fines after having several metal fires in our solidification pit.

"Well, boys, time for a coffee break. Bob, you're on fire watch. I'll call corporate and try to get a purchase order cut for another dozen Class D fire extinguishers."

Once someone tried to make an oil immersion in the drums prior to solidification and that went about as well as expected. Adsorption is generally an exothermic process so we had a bunch of drums sitting around spitting little clouds of combustible metal dust and too hot to safely tough with bare hands.

For as much as I bitch about dumb safety stuff and practices in machine shops I sure don't miss the dangers of production chemistry or waste disposal.
 
We have a waterjet that we run 5-7 hours per day, so we have a lot of garnet to dispose of. We currently dispose of this through Waste Management as non-hazardous waste. Has anyone ever tried to sell the garnet waste to a landscaper or anybody like that? Thanks.

We have to dispose out garnet as HAZ-Waste because we cut different types of materials. But, we have had people ask if they can buy/have the garnet for various things, outdoor projects and land filler. Unfortunately we can't give or sell it to them.
 
We have a waterjet that we run 5-7 hours per day, so we have a lot of garnet to dispose of. We currently dispose of this through Waste Management as non-hazardous waste. Has anyone ever tried to sell the garnet waste to a landscaper or anybody like that? Thanks.

We have two waterjets and all our used garnet goes to WM. One of the guys here took some home, maybe 1/2yd, and used it to fill a spot of land of his. He mixed it up with dirt or topsoil then tried planting something in it, grass or flowers, I don't recall. Anyway, he couldn't grow anything in it at all. Maybe if it was absolutely clean it would have worked.
 
I did a quick check on garnet recycling for reuse, and it seems it's a tough balance unless you're using a great deal of it each day.

I'm coming back to the idea of checking with area cement plants to see if it would work as part of a mix. It might take some testing to come up with an answer, but could be a free disposal even if you don't get paid for it.
 
It would be nice if you had a secondary use for it, like sandblasting.

Then you'd get more mileage out of it, before paying for disposal.
 
For the record, there is also a potential to "beneficially reuse" the material which excepts it from RCRA Part C requirements, but you better have your ducks in a row on stuff like that. For instance, in wastewater treatment, we were able to use acid that was otherwise hazardous waste, and as long as it was more or less the same as commercially available products, could be used in similar concentrations, and did not negatively impact our process, it was good to go.

There may be something out there for that but again, I would never chance it myself.

People think special waste handlers really know their shit - I'll tell you right now most of them don't. I would very commonly have to ask for code/statutory references for exemptions that don't exist that entire industries think are there.
 
If I was to go around again,I would definitely be using the waste to make bitumen hotmix product with....this was the only viable solution apart from landfill dumping.....now landfill dumping is OK if you go about it right .....flat land,preferably swamp,no runoff,just standing water ,...then you need a big excavator ,and dig deep slit trenches,and dump the waste well below surface level .This isnt difficult,you just keep the trench moving ,never too much exposed...........Now ,comes the best part .....40 years later you sell the land for a million bucks.
 








 
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