Recycling of ion-exchange resin 1

[aquatrade]

Hello!
I worked on one of our client's ion-exchanging softening system (we changed the resin) recently, and thought about what to do with old ion-exchange resin.
Usually, when we recharge a softener, we have about 1-2 cubic meters of old resin (this is usual volume in any middle boiler house, for cheese plant or brick plant for example). Huge water stations, for cities, big heat power plants, big metal industry, I suppose, have tens, hundreds and thousands cubic meters of wasted resin.
I found out, in 2001 year, only Russia had 6.5 thousands of big boiler houses (more than 20 Gkal/h), 100 thousands middle boiler houses and more than 600 thousands small boiler houses (for example, in hotels, office centers etc.). I suppose, in 2017 their quantity increases, and in the USA their number is very-very large, much more than in Russia. I mean, that there is a huge amount of used resin, and every year it's enlarges.
I tried to ask on our recycling companies, ecological organizations (Greenpeace Russia for example), are there any technologies of recycling ion-exchange resin, and I have no answers and replies yet.
Other used filter media (Pyrolox, Filter AG, carbon etc.) are good (and often used by our clients) as anti-slipping winter coverings (on ice), road hole fillers etc. The only possible usages of waste resin that I've seen are for crazy jokes on roads or for moving heavy furniture, but of course, this is not serious.
So, do You know any technologies of industrial recycling ion-exchange resins? Or maybe You have any ideas about it?
Sincerely Yours
Anton S. Tyuin
Russia, Nizhny Novgorod

 

[bimr]

Resin is made from polystyrene and may be recycled with packaging material.

http://www.polystyrenepackaging.co.za/files/polystyrene_bob.jpg

 

[adammal44]

bimr - does anyone actually do this with ion exchange resins? Especially for non-softening, industrial use? Seems like the risk of chemical leaching would be too much of a headache...unless the polystyrene converter is equipped to burn off and/or stabilize the chemicals.

Coming from a nuclear standpoint, obviously this isn't an option for our resins as they have considerable buildup of radionuclides, they get either packaged/dewatered in a container or grouted/solidified; in either case, they go right to a low-level waste repository.

 

[bimr]

Not familiar with anyone recycling water softening resin as it will be more expensive than landfilling. There is also not a large market for recycling polystyrene wastes.

Water that is typically treated with a water softener generally contains little or no contaminants. Water softening resin should not have any contaminants on it to prevent the resin from being landfilled as ordinary trash.

Some waters may contain contaminants that can remain on the resin after regeneration. They may include but are not limited to arsenic and lead.

Use of the TCLP test (Toxicity Leachate Characteristic Procedure) may be used to identify possible contaminants.

Other resins such as demineralizer resins may also be acceptable for recycling after conversion of cation resin to sodium form and anion resin to chloride form.

Of course as you point out, specialty resins that are used in particular services such as radium removal will never be acceptable for recycling.

 

[aquatrade]

bimr, adammal44, hello!
Yes, I mean usual resins from softeners. Of course, resins from nuclear industry or from toxic waste treatment etc have the only one way of utilization, without recycling.

 

[adammal44]

Thanks for the clarification, guys. Interesting to hear how other trades deal with the problem of resin disposal.

 

[IRstuff]

The issue with actual recycling probably has to do with the reason you are pulling the resin in the first place. Obviously, if your resin never degrades and is able to deionize with the same efficacy was when you installed it, there would not be a reason to replace it. So, various mechanisms for efficacy loss exist, but some of them include contamination by otherwise benign things, like iron. I would expect that the cost to extract the iron, clean the resin, and then rebuild the resin is relatively high.

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[bimr]

The resin is made of polystyrene plastic and will develop cracks from the swelling and contraction that occurs from regeneration and use. Therefore, resin can not be refurbished. Recycling would convert the resin into some other product such as packing foam.

 

[IRstuff]

The fact that resin is being dumped, instead of recycling, suggests that the cost-benefit is too low. A recycler would need a complete chemical analysis capability and test each incoming batch for contaminants before they could determine where they could recycle the material. If the tests take more than a few hours, the carrying cost alone would be quite high, and, the volume of business required to support the testing would need to be very large.

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[Compositepro]

Guys, you keep overlooking the fact that the OP has stated a few times that he is in the nuclear industry. Ion exchange resins are in uranium mining to produce yellow cake.

"Ion-exchange beads are also an essential component in In-situ leach uranium mining. In-situ recovery involves the extraction of uranium-bearing water (grading as low as .05% U3O8) through boreholes. The extracted uranium solution is then filtered through the resin beads. Through an ion exchange process, the resin beads attract uranium from the solution. Uranium loaded resins are then transported to a processing plant, where U3O8 is separated from the resin beads and yellowcake is produced. The resin beads can then be returned to the ion exchange facility where they are reused.

The ion-exchange process is also used to separate other sets of very similar chemical elements, such as zirconium and hafnium, which incidentally is also very important for the nuclear industry. Zirconium is practically transparent to free neutrons, used in building reactors, but hafnium is a very strong absorber of neutrons, used in reactor control rods."

 

[IRstuff]

If you read the OP's second post, he was asking about non-nuclear cases.

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[aquatrade]

Hello!
No, I'm not from nuclear industry. Maybe sometimes my company will participate in water treatment for nuclear industry, as the "aerobatics" in water treatment, but now we are more simple...
In our practice, after 1.5-4 years (depending on water quality) resin begins to reduce total exchange capacity, that causes increasing consumption of salt or other regeneration chemicals and spontaneous skipping or emissions of accumulated contaminations to cleaned water. As I understand, the main reasons are cracking of resin beads and "poisoning" with accompanying iron, manganese etc. So, the refurbishing of such resin as a resin is unreasonable. Also some resins are "unregenerable", they must be changed after their exchange capacity depletion.
Of course, possible recycling of resin, I suppose, is reasonable only on big systems, like boiler houses, heat power plants, municipal water stations etc., where quantity of wasted resin is not less than 1 ton.
Yesterday I talked with one polystyrene recycling company, they never thought about it, but asked me to give them some wasted resin for experiments.
Also, thank You, I missed that some wasted resin can be radioactive or poisonous, so it only must be landfilled.
Sincerely Yours
Anton S. Tyuin
Russia, Nizhny Novgorod

 

[adammal44]

Yeah, some confusion in this one. OP (aquatrade) was not asking for the nuclear case, I just brought it up in my subsequent posts.

My case is actually for nuclear power plants, not uranium mining. We use it in many places: traditional condensate polishing and demineralized water production, removal of radionuclides generated due to activation of corrosion products and slight fuel leaks, and for end-of-cycle deboration of the reactor coolant (cheaper to leach it off with resins than replace thousands of gallons of water, especially when you want to reborate at the start of the next cycle).

Anton - have you talked with your resin vendor about your product life? Potentially, some higher-grade resin with higher cross-linking might last longer...your timelines still seem pretty consistent with my experience though for rougher services.

 

[Compositepro]

Sorry, I'm terrible with names and you both have names that start with A and are about the same length.

 

[aquatrade]

Hello!
Adammal44, we have only one producer of ion exchange resins in Russia - Tokem (here You can see their site in English version -

http://www.tokem.ru/en/).

Also, as You work in nuclear industry, I think, You use nuclear grade resins, which really have bigger lifetime in rougher conditions (You can find the examples also on Tokem site - 06. Resins for nuclear power generation). But it costs about 600-700$ for one bag 25 l, usual resin - 40-80$ for the same bag. Except Tokem (40-55$ for one bag, depending on the quantity) we usually use Dowex HCR-S/S (75$ per bag), Lewatit Lanxess, Purolite, (80-85$); indian Tulsion (70$) sometimes.
Frankly speaking, Tokem is new on our market (the plant is very old, but they produced resins only for military for a long time, and didn't work in mass market), so we have no stats about the usage of it yet.
So, in simple water treatment it become cheaper to change cheap resin more frequently, than to use very expensive high-grade special resin for a long time.
Sincerely Yours
Anton S Tyuin
Russia, Nizhny Novgorod