The present invention provides a method for removing a divalent metal cation from a macromolecular compound having an anionic functional group and containing the divalent metal cation, including (1) suspending a macromolecular compound having an anionic functional group and containing a divalent metal cation in a solution in which an electrolyte that releases an alkali metal ion is dissolved at a concentration at which the macromolecular compound is salted out, and (2) performing, in the obtained suspension, an ion exchange reaction to exchange the divalent metal cation contained in the macromolecular compound with the alkali metal ion.

The present disclosure relates to methods of protein purification by attaching an intein-C fragment to a target protein, passing a sample containing the intein-C tagged protein over a chromatographic resin carrying an intein-N fragment so as to create an intein-N intein-C complex, releasing the target protein from the intein-C fragment, and regenerating the column under conditions that disrupt the intein-N intein-C complex while preserving column functionality for multiple reuses.

The present disclosure relates to methods of protein purification by attaching an intein-C fragment to a target protein, passing a sample containing the intein-C tagged protein over a chromatographic resin carrying an intein-N fragment so as to create an intein-N intein-C complex, releasing the target protein from the intein-C fragment, and regenerating the column under conditions that disrupt the intein-N intein-C complex while preserving column functionality for multiple reuses.

A process for the reactivation of an acidic ion exchange resin is described. The invention relates to the treatment of an at least partially deactivated resin which has been deactivated by contact with an impure ethylenically unsaturated acid or ester containing target impurities. The reactivation includes the step of contacting the at least partially deactivated resin with an alcohol to thereby increase the activity thereof. The invention extends to reactivating a resin deactivated by contact with an impure ethylenically unsaturated acid, ester or nitrile containing target impurities by contacting the at least partially deactivated resin with an alcohol and a carboxylic acid to thereby increase the activity thereof. A reactivated resin and a process for preparing and purifying an ethylenically unsaturated acid or ester of the following formula:
R.sup.1—C(═(CH.sub.2).sub.m)—COOR.sup.2
are also described.

Embodiments of the present disclosure are directed to methods for recycling waste ion exchange materials comprising a first alkali metal salt and a second alkali metal salt comprising reducing the size of the waste ion exchange materials to produce a plurality of waste ion exchange particles having particle sizes from 0.10 mm to 5.0 mm, and regenerating the plurality of waste ion exchange particles to produce a plurality of regenerated ion exchange particles having a concentration of the first alkali metal salt greater than a concentration of the first alkali metal salt in the waste ion exchange materials. Systems for recycling a waste ion exchange materials comprising a first alkali metal salt and a second alkali metal salt are also disclosed.

Embodiments of the present disclosure are directed to methods for recycling waste ion exchange materials comprising a first alkali metal salt and a second alkali metal salt comprising reducing the size of the waste ion exchange materials to produce a plurality of waste ion exchange particles having particle sizes from 0.10 mm to 5.0 mm, and regenerating the plurality of waste ion exchange particles to produce a plurality of regenerated ion exchange particles having a concentration of the first alkali metal salt greater than a concentration of the first alkali metal salt in the waste ion exchange materials. Systems for recycling a waste ion exchange materials comprising a first alkali metal salt and a second alkali metal salt are also disclosed.

Implementations herein relate to methods for reducing a desorption solution for regeneration of ion exchange resins in the field of regeneration of resins. The implementations solve problems related to low utilization rates of regeneration agents and high volumes of desorption solutions during the desorption process. The implementations include regenerating the ion exchange resins, and the regeneration solution becomes the desorption solution. After coagulating sedimentation of the desorption solution and slurry separation, a large amount of organic contents are removed from coagulation serum and a large amount of regenerate agents are left. The implementations further include adding the regeneration agent to the coagulation serum to form new or refreshed regeneration solution to regenerate the ion exchange resins. Accordingly, the coagulation serum may be generated from the desorption solution. These operations may be repeated multiple batches for resin regeneration.

In alternative embodiments, the invention provides processes and methods for the recovery, removal or extracting of, and subsequent purification of uranium from a wet-process phosphoric acid using a continuous ion exchange processing approach, where the uranium is recovered from a phosphoric acid, or a phos-acid feedstock using either a dual or a single stage extraction methodology. In both cases an intermediate ammonium uranyl-tricarbonate solution is formed. In alternative embodiments, in the dual cycle approach, this solution is contacted in a second continuous ion exchange system with a strong anion exchange resin then subsequently recovered as an acidic uranyl solution that is further treated to produce an intermediate uranyl peroxide compound which is ultimately calcined to produce the final uranium oxide product. In alternative embodiments, in the single cycle case, the intermediate ammonium uranyl-tricarbonate solution is evaporated to decompose the ammonium carbonate and produce an intermediate uranium carbonate/oxide solid material. These solids are digested in an acid medium, and then processed in the same manner as the secondary regeneration solution from the dual cycle process to produce an intermediate uranyl peroxide that is calcined to produce a final uranium oxide product.

In alternative embodiments, the invention provides processes and methods for the recovery, removal or extracting of, and subsequent purification of uranium from a wet-process phosphoric acid using a continuous ion exchange processing approach, where the uranium is recovered from a phosphoric acid, or a phos-acid feedstock using either a dual or a single stage extraction methodology. In both cases an intermediate ammonium uranyl-tricarbonate solution is formed. In alternative embodiments, in the dual cycle approach, this solution is contacted in a second continuous ion exchange system with a strong anion exchange resin then subsequently recovered as an acidic uranyl solution that is further treated to produce an intermediate uranyl peroxide compound which is ultimately calcined to produce the final uranium oxide product. In alternative embodiments, in the single cycle case, the intermediate ammonium uranyl-tricarbonate solution is evaporated to decompose the ammonium carbonate and produce an intermediate uranium carbonate/oxide solid material. These solids are digested in an acid medium, and then processed in the same manner as the secondary regeneration solution from the dual cycle process to produce an intermediate uranyl peroxide that is calcined to produce a final uranium oxide product.

A reclaiming method is disclosed including conducting evaporation by introducing a part of the absorbent to recover CO.sub.2 or H.sub.2S in a gas in a closed system recovery unit and separating a degraded substance contained in the absorbent from the absorbent to be introduced into an evaporator and obtain recovery steam containing an absorbent and CO.sub.2 or H.sub.2S by a heating section that is provided on a circulation line that circulates in the evaporator; and removing ionic degraded substance by cooling the concentrate obtained in the evaporation and removing an ionic degraded substance in the concentrate after the cooling, wherein a purified concentrate from which the ionic degraded substance has been removed is reused as a purified absorbent.