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Precipitation and Crystallization Processes in Reprocessing, Plutonium Separation, Purification, and Finishing, Chemical Recovery, and Waste Treatment
Published in Reid A. Peterson, Engineering Separations Unit Operations for Nuclear Processing, 2019
Calvin H. Delegard, Reid A. Peterson
By these definitions, precipitation and crystallization share a degree of overlap. For example, a crystallization process, as achieved “by lowering of the temperature or evaporation of a solvent” would cause precipitation; i.e., “the sedimentation of a solid material from a liquid solution.” In general, however, separations chemists understand precipitation and crystallization by the manners in which they are instigated. Thus, precipitation generally is understood more narrowly as the process in which the mixing of two clear solutions results in a solid forming (precipitating) from the mixture. For example, mixing a clear solution of silver nitrate with a separate clear solution of sodium chloride produces a solid precipitate of silver chloride with soluble salts remaining in solution. Crystallization is understood by separations chemists in the manner as defined by the IUPAC. For example, the salt pan evaporation of seawater results in sodium chloride crystallization. As might be inferred by these descriptions, precipitates generally have lower solubilities than solids formed by crystallization.
Special Fill Materials and Problematic Subsoils
Published in Jan van ‘t Hoff, Art Nooy van der Kolff, Hydraulic Fill Manual, 2012
Jan van ‘t Hoff, Art Nooy van der Kolff
The deposits can generally be described as follows (Nooy van der Kolff, 1993): Sabkha: Gently dipping salt flats along the coast line, consisting of alternating layers of algae matts, clastic materials and evaporites; accumulation by evaporation of groundwater and seawater during periodical inundation; salts originating from seawater.Salina: Salt pans usually occurring in depressions near the capillary fringe; capillary rise of groundwater is the main accumulating medium; salts are originating from evaporitic deposits included in the bedrock.Salt playa: Inland salt pans usually occurring in depressions; (rain)water and wind are the main accumulating media; salts are originating from evaporitic deposits included in the bedrock: sulphates (gypsum, anhydrite), chlorites (halite), carbonates.
Assessment of potentially vulnerable zones using geospatial approach along the coast of Cuddalore district, East coast of India
Published in ISH Journal of Hydraulic Engineering, 2022
K. S. S. Parthasarathy, Subbarayan Saravanan, Paresh Chandra Deka, Abijith Devanantham
The major types of geomorphology (Figure 3(a)) found in the study area are alluvium, mudflat, brackish water, salt pan, waterbody, and beach. The study area consists majorly of alluvium since the river carries the deposits of sand, silt, and clay confluences into the ocean. These alluvium plains are highly risked zone for the vulnerability of the coast. In the same aspect beaches also contains sand and silt materials are more vulnerable to the tides occurring in the regions. Other geomorphological features the study area constituting of brackish waters, mudflat, salt pan, and waterbody falls under very high vulnerability. As the mudflats are sensible region consisting of mild slopes and are more vulnerable to the coast. Brackish water and the waterbodies are more susceptible to flash floods during the extreme flood events. Therefore, by considering these features, the vulnerability risk rating is performed on the coastal buffer line (Figure 3(b)).
Nuclear Air-Brayton Power Cycles with Thermodynamic Topping Cycles, Assured Peaking Capacity, and Heat Storage for Variable Electricity and Heat
Published in Nuclear Technology, 2021
Charles W. Forsberg, Patrick J. McDaniel, Bahman Zohuri
Initial studies19 are underway on a third-generation nitrate salt–crushed rock system for high-temperature nuclear reactors to further lower capital costs to a few dollars per kilowatt hour of heat storage. The tank structure would be replaced by an insulated trench up to 60 m wide and 20 m high and lengths that may exceed 1000 m with no internal structures. The trench would be filled with crushed rock with more than 1 GWh of heat storage for every 10 m in length. The design minimizes structural components and insulation by minimizing the surface-to-volume ratio. The bottom and sides have three layers. Facing the crushed rock is the salt pan that collects salt. It is backed up by insulation with cooling tubes between the insulation and soil to prevent increases in soil temperature, which is a structure similar to the foundation structure for CSP nitrate salt storage tanks. Above the crushed rock is a roof with insulation and salt spray equipment.
Market Basis for Salt-Cooled Reactors: Dispatchable Heat, Hydrogen, and Electricity with Assured Peak Power Capacity
Published in Nuclear Technology, 2020
Initial studies37 are underway on a third-generation nitrate salt–crushed rock system for high-temperature nuclear reactors to further lower capital costs to a few dollars per kilowatt hour of heat storage. The tank structure would be replaced by an insulated trench up to 60 m wide and 20 m high and lengths that may exceed 1000 m with no internal structures. The trench would be filled with crushed rock with approximately 1 GW·h of heat storage for every 10 m in length. The design minimizes structural components and insulation by minimizing the surface-to-volume ratio. The bottom and sides have three layers. Facing the crushed rock is the salt pan that collects salt. It is backed up by insulation with cooling tubes between the insulation and soil to prevent increases in soil temperature, which is a structure similar to the foundation structure for CSP nitrate salt storage tanks. Above the crushed rock is a roof with insulation and salt spray equipment.