Lithium Ion Exchange on Zeolite 13 x granule

It may be that the flow rate is too high and not allowing enough time for the chemical reaction to take place effectively.

Suggest you decrease the flow rate in stepped intervals, observe results, and record values so that you can trend the DATA to determine where optimal ion exchange occurs. (You may have to put the system in manual control in order to override the automation and vary the input valve(s).)

If decreasing the flow rate improves the process enough to meet the 97% exchange requirement but does not satisfy the process throughput requirement, you will have to increase the size or quantity of filters.

Thanks sir , we perform ion exchange process 9 times with 5 normal licl solution. We have collected data after each exchange process as described as follows. Before exchange 0% Lix After one exchange 43% Lix After single exchange 64% Lix After third exchange 77% Lix After four exchange 84% Lix After fifth exchange 87% Lix After sixth exchange 92% Lix After seven exchange 92% Lix After eight exchange 92% Lix After nine exchange 92% Lix We also observed the process equilibrium at first fifteen minutes of lithium ion exchange recirculation process. And after six exchange , no progress achieved in degree of exchange. We also tried low and high flow recirculation ion exchange process. But not get positive result Do we have any option . (Uop , and ceca 98% Lix as reference sample)

One of the options is to hire a competent Chemical Engineer.

Although I have had my required chemistry classes plus some additional advanced classes and I am certified as a water treatment operator, I am not by any stretch of the imagination a chemical engineer.

Is this a new problem or a long-time existing one? If it is an existing problem,; How often are you regenerating the filters? Are you certain the regeneration procedure is being strictly adhered to at all times and the correct chemicals are being used?

If you know for certain that the flow rate is correct, the filter size is correct, the regeneration procedure is being done correctly and on the right interval and the strength of the chemical compounds are adequate, I would suggest you contact the OEM that provided the filter system, Zeolite, and whatever other chemicals you are using and discuss your issues in detail with their applications engineering group.

The obvious answer (to me), is that 92% recovery for the makeup of your water represents the selectivity ratio of the Li ion to other (alkali metal) ions in solution.

Why are you using zeolite, why not use a specialty resin from a reputable ion exchange resin OEM?

To get the 98% recovery you want, you need to find out the solubility limits of each and every salt in present solution, and go there until you drop out some of whatever is kicking the Li ion off the granules of zeolite.

Thanks for reply... We are using zeolite 13 x granule, and exchange with lithium. Zeolite has a good nitrogen adsorption capacity. After 98% ion exchange with lithium, the nitrogen capacity gain 3 times. That's why we are using zeolite 13 x granule for lithium ion exchange. Our ion exchange process is well tuned and efficient . We have achieved 92% lithium ion exchanged zeolite easily . But above 92% , we tried a lot but can't succeed . Do any other way to get 98% lithium exchange zeolite 13 x granules. We also referred old us reference but can't succeed. Please help us. Best regards.

Perhaps you need an added ingredient or alteration in your existing materials or environment....

http://www.ncbi.nlm.nih.gov/pubmed/17141259

http://onlinelibrary.wiley.com/doi/10.1002/sia.1262/abstract

http://web.chem.fsu.edu/~latturner/GinaLiSodPEO.pdf

http://aussiezeolite.com.au.p8.hostingprod.com/yahoo_site_admin/assets/docs/DK2772_ch21.166185140.pdf

If performance drops too low after repeated operations, and you are using a regeneration process, then making improvements to it might help.

May I inquire as to what this process is supposed to be for?

My first guess is that they are attempting to make a pure lithium zeolite molecular sieve the hard way. Apparently, whatever is exchanging with the lithium has a finite affinity for the granules that is nonzero, and results in 8% of the sites non-available to lithium ion.

Thanks for reply . Uop Honeywell , ceca Germany, zeochem Switzerland already supplying 98 % lithium exchanged lithium exchanged zeolite 13 x granules for nitrogen adsorption. They are using low silica alumina ratio sodium alumino silicate (zeolite 13 x granule) for ion exchange . We also do same so . We also referred references and old patents . But we can't get degree of exchange above 92% . Do we have any other option ? Please help us.

Why are you being secretive about who you are, and where you are? In fact, that might have something to do with your problem.

Do you:

(1) have completely clean water with no residuals from the purification?

(2) Have a complete analysis of what is on your Zeolite 13 prior to the ion exchange, and what ion you are trying to replace with lithium?

(3) Have you considered that a direct process may simply fail due to ion selectivity at the ionic strength you are employing?

(4) Try to come up with an alternative scheme where whatever ion you have before the lithium is replaced (at high solution strength) with a very facile ion, that is much more loosely bound than lithium. This all depends on the relative swings of ionic strenth (or at least solute strength), pH, temperature, etc. The thing is so complex, that a direct answer may not be correct. One has to actually do the research to reap the rewards.

Suppose you first exchange your zeolite carefully using ion exchange resin loaded at H+ ion, and a dialysis membrane, then once your material is loaded with H+/Na+ (you will not achieve 100%), you then exchange with Li+.

You may wish to attempt other pH (carefully), and other temperature. Have you also considered the use of other counter ions for the lithium feedstock (other than chloride) as if that could make a slight difference?

I think the loading between Li+/Na+ exchange characteristic may be your limiting factor. The affinities of H+ and Li+ are probably more similar for your zeolite.

Here is something to consider: Do you have any interfering impurities in your lithium source such as heavy metals, or stray ammonium ion? Perhaps you need to consider having some sacrificial zeolite to take the offending interferences out of solution first, then use the cleaned up solution to load your material.