Salts, purification

There is indeed a striking similarity between the salt separation processes discussed here and the acid retardation process. Consequently, it was possible to use the same basic process flow-sheet and equipment for these salt purification processes that have been extensively used for over 20 years for APU systems. 

The synthesis of non-ionic contrast agents is much more complicated. Due to the higher aqueous solubility of the intermediates, purification processes have to be more sophisticated than for the ionic compounds. Moreover, for the carboxylic acid, salt purification procedures of ionic substances are no longer available for the non-ionic derivatives. Now, recrystallisation. 

Water is the most abundant compound on earth. Seawater, which accounts for 97.3% of the world s water supply, contains 3.5 mass % of dissolved salts. Purification of drinking water involves preliminary filtration, sedimentation, sand filtration, aeration, and sterilization. Hard water, which contains appreciable concentrations of doubly charged cations such as Ca2+, Mg2+, and Fe2+, can be softened by ion exchange. Water is reduced to H2 by the alkali metals and heavier alkaline earth metals, and is oxidized to O2 by fluorine. Solid compounds that contain water are known as hydrates. 

The use of high performance liquid chromatography (HPLC) on-line or off-line is an essential feature for peptide mapping to integrate the removal of buffers and salts (purification) and the separation of analytes (preconcentration) with mass spectrometry. With on-line LC/MS approaches, low flow rates (<100pL/min) have been demonstrated to provide maximum sensitivity with ESI techniques for the analysis of proteins. In the work performed by Arnott and... 

The high-temperature reduction of barium sulfate with coke yields the water-soluble barium sulfide (BaS), which is subsequently leached out. Treatment of barium sulfide with the relevant chemical yields the desired barium salt. Purification of the product is complicated by the impurities introduced in the coke. Pure barium carbonate and barium sulfate are made by precipitation from solutions of water-soluble barium salts. 

Salt purification depends upon electrolysis process to be utilized ... 

Proof-of-principle experiments are being performed to demonstrate the above basic steps. Other experiments include controlled removal of fission products, characterization of salts, salt purification methods, and a proliferation analysis of the process. 

Molten salt purification and chemistry control (research). Molten salt coolant will require cleanup systems to remove impurities from the salt and to control the salt chemistry. A facility to enable researchers to understand, develop, demonstrate, and test alternative cleanup and coolant chemistry control systems is required to ensure effective control of salt chemistry. 

Heparin ( a-heparin ), a blood anticoagulant, is found in liver, lung, thymus, spleen, and blood. It can be extracted from autolyzed beef liver by sodium hydroxide. After tryptic digestion of the proteins, heparin is precipitated with acidic ethanol (57), Heparin is usually crystallized as the barium salt. Purification through the free acid and reformation of the barium salt causes a decrease in the activity, as heparin is labile toward acidic... 

After several runs of the electrolysis process, the active metal fission products such as alkali, alkaline earth and rare earth metals are accumulated in the molten salt. The accumulated fission products must be removed from the molten salt because they will affect the recovery efficiency of U and TRU. Periodically, the molten salt is removed from the electrolysis cell, purified using the salt purification process and recycled to the electrolysis cell. However, the molten salt always contains U and TRU with the fission products because the electrolysis is used to recover pure U and TRU without fission products. Therefore, fission products removed from the molten salt are always accompanied by some amount of U and TRU. It is necessary to optimize between the loss of U and TRU and the quantity of fission products removed because an increased removal of the fission products results in an increased contamination by the TRU in the waste stream. 

The salt purification process is illustrated in Fig. XXIV-9. A fraction of the molten salt is removed from the electrolysis cell and is placed in contact with lithium-rich liquid cadmium. By the exchange reaction between Li and salt-borne TRU and the fission products, the less stable species in the molten salt are transferred to the liquid Cd. Generally, U and TRU are less stable than the rare earth metals and are first transferred to the liquid Cd. The Li concentration in the liquid Cd must be increased to decrease the contamination of the molten salt by TRU. Then, concentration of the fission products is also increased in the liquid Cd. After a forward reductive extraction process, the decontaminated salt with the salt-borne fission products passes through zeolite beds that replace nearly all of the alkali, alkaline earth, and rare earth metals with K and Li by ion exchange. The residual actinides in the molten salt are also adsorbed in the zeolite. The molten salt leaving the zeolite is free of actinides and fission product ions. The purified salt is mixed with an oxidizer such as CdCb and is contacted with liquid Cd that contains U and TRU by the forward reductive extraction process. CdCb will contain U and TRU to be oxidized. U and TRU are transferred to the molten salt from the liquid Cd. The molten salt with U and TRU is recycled to the electrolysis cell. The liquid metal is also recycled to the forward reductive extraction process. 

Before the use of the chemical buffer a salt purification is required for the... 

Primary circuit molten salt purification system pipeline leakage... 

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