Ion exchange recovery

N). This area of the process has received considerable attention in recent years as companies strive to improve efficiency and reduce waste. Patents have appeared describing addition of SO2 to improve ion-exchange recovery of vanadium (111), improved separation of glutaric and succinic acids by dehydration and distillation of anhydrides (112), formation of imides (113), improved nitric acid removal prior to dibasic acid recovery (114), and other claims (115). 

TOO Juang, R.S., Kao, H.C., and Liu, F.Y. (2006) Ion exchange recovery of Ni(II) from simulated electroplating waste solutions containing anionic ligands. Journal of Hazardous Materials, 128 (1), 53-59. 

Provided that the mixed solution of CX and BX is removed from column I, column II, with flow reversal at both ends should be used for the ion-exchange recovery of B. The ion is obtained as a by-product on column II s upper section which serves for the mbcture transfer into the ion-exchange resin. The B substance is concentrated in the lower section upon displacement (Fig. 7b). 

C. Main Approaches to Ion-Exchange Recovery of Valuable Mineral Components from Seawater... 

In Chapter 3, Ruslan Khamizov and coworkers describe the economic recovery of minerals from seawater and brines formed in desalination plants and solar evaporation operations. The employment of ion-exchange technology for this purpose is critically reviewed. They carefully examine the economic aspects of optimal ion-exchange recovery of minerals from these sources by combining various techniques of the operation discussed in Chapter 2. The great rapid depletion of land-based mineral resources of the world make this a problem of great interest. 

K. A. Prisbey, J. G. Williams and H. Lee, Ion Exchange Recovery of Cobalt and Copper from Blackbird Mine drainage, Research Technical Completion Report, Project A-067-IDA, Office of Water Research and Technology, U.S. Department of the Interior, 1980. 

Effectiveness Both Mn02 and Fe are reduced by the reagent The latter is important for the ion exchange recovery of Sc, which does not occur in the presence of ferric ion. 

Blokhin A.A., Abovskii N.D., Murashkin Yu.V. Ion-exchange recovery of palladi-um(II) from multicomponent chloride solutions. Russian Journal of Applied Chemistry 2007 80 1058-1062. 

Everest, D. A., Napier, E. and Wells, R. A. Resin poisons in ion-exchange recovery processes. Proc. 2nd Int. Conf. on the Peaceful Uses of Atomic Energy, Geneva, 1958. Paper 101. 

The ratio of reactants had to be controlled very closely to suppress these impurities. Recovery of the acrylamide product from the acid process was the most expensive and difficult part of the process. Large scale production depended on two different methods. If soHd crystalline monomer was desired, the acrylamide sulfate was neutralized with ammonia to yield ammonium sulfate. The acrylamide crystallized on cooling, leaving ammonium sulfate, which had to be disposed of in some way. The second method of purification involved ion exclusion (68), which utilized a sulfonic acid ion-exchange resin and produced a dilute solution of acrylamide in water. A dilute sulfuric acid waste stream was again produced, and, in either case, the waste stream represented a... 

However, the quantity of Pa produced in this manner is much less than the amount (more than 100 g) that has been isolated from the natural source. The methods for the recovery of protactinium include coprecipitation, solvent extraction, ion exchange, and volatility procedures. AH of these, however, are rendered difficult by the extreme tendency of protactinium(V) to form polymeric coUoidal particles composed of ionic species. These caimot be removed from aqueous media by solvent extraction losses may occur by adsorption to containers and protactinium may be adsorbed by any precipitate present. 

The plutonium usually contains isotopes of higher mass number (Fig. 1). A variety of industrial-scale processes have been devised for the recovery and purification of plutonium. These can be divided, in general, into the categories of precipitation, solvent extraction, and ion exchange. 

In contrast to trace impurity removal, the use of adsorption for bulk separation in the liquid phase on a commercial scale is a relatively recent development. The first commercial operation occurred in 1964 with the advent of the UOP Molex process for recovery of high purity / -paraffins (6—8). Since that time, bulk adsorptive separation of liquids has been used to solve a broad range of problems, including individual isomer separations and class separations. The commercial availability of synthetic molecular sieves and ion-exchange resins and the development of novel process concepts have been the two significant factors in the success of these processes. This article is devoted mainly to the theory and operation of these Hquid-phase bulk adsorptive separation processes. 

Ion-Exchange Resins. Some attempts have been carried out to recover galHum by ion exchange (qv). Only the commercially available amidoxime resin has proved to be effective for the recovery of galHum from Bayer Hquor. The process has been developed and patented (13) and is reported to be under operation in Japan. 

Miscellaneous. Hydrochloric acid is used for the recovery of semiprecious metals from used catalysts, as a catalyst in synthesis, for catalyst regeneration (see Catalysts, regeneration), and for pH control (see Hydrogen-ION activity), regeneration of ion-exchange (qv) resins used in wastewater treatment, electric utiUties, and for neutralization of alkaline products or waste materials. In addition, hydrochloric acid is also utilized in many production processes for organic and inorganic chemicals. 

The aqueous sodium naphthenate phase is decanted from the hydrocarbon phase and treated with acid to regenerate the cmde naphthenic acids. Sulfuric acid is used almost exclusively, for economic reasons. The wet cmde naphthenic acid phase separates and is decanted from the sodium sulfate brine. The volume of sodium sulfate brine produced from dilute sodium naphthenate solutions is significant, on the order of 10 L per L of cmde naphthenic acid. The brine contains some phenolic compounds and must be treated or disposed of in an environmentally sound manner. Sodium phenolates can be selectively neutralized using carbon dioxide and recovered before the sodium naphthenate is finally acidified with mineral acid (29). Recovery of naphthenic acid from aqueous sodium naphthenate solutions using ion-exchange resins has also been reported (30). 

---