Calcium removal systems

Consequently, a calcium removal system for the purified solution was installed and it includes a 150 m mix and pumping tank, three cooling towers, one of which is new, and a 1500 m capacity thickener. This modification will reduce gypsum deposition in the electrolysis circuit, and thus, increase the availability of the electrolyte distribution system. 

Most commercial methanator catalysts contain nickel, supported on alumina, kaolin, or calcium aluminate cement. Sulfur and arsenic are poisons to the catalyst, which can also be fouled by carry-over of solvent from the CO2 removal system. 

Process pH, sodium, calcium, and nitrate concentrations, plugging of the ion exchange column, lot variance, and the presence of binders can affect process efficiency. lonsiv IE-911 does not remove anionic radioactive ions such as technetium. The resins are designed for one-time use and must be replaced when loaded. The waste acceptance criteria at the resin disposal facility may limit the loading of the CST resin. Size constraints of the cesium removal system (CRS) may limit system flow rates. 

The involvement of lipid membrane constituents in the interaction of ATP with the protein moiety of the calcium transport system emerges if one compares the reaction of ATP with membrane preparations whose lipid matrix has been removed or modified... 

C02. Unfortunately, S02 is less soluble (and hence less easily removed by scrubbing) in slightly acid solutions, so that it is extremely difficult in practice to operate a calcium-bascd system in such a manner that SO2 removal is maximized while the quantities of calcium chemicals are minimized in order to approach stoichiometric conditions. As calcium-based slurry systems are usually operated at pH 6-10, disposal of the very large masses of used slurry presents a major problem. A typical power station using a caldnm-based SO2-removal slurry system will produce several hundred tons of spent slurry per day. A further disadvantage of lime or limestone systems is their marked tendency to precipitate insoluble calcium salts inside the scrubber. Unless the scale is removed, the scrubber shortly becomes inoperable. 

In other studies, solutions of high supersaturation were employed which yielded complex, poorly defined solid phases. The multi-picity of complex crystal polymorphs and hydrates in the calcium phosphate system is now well recognized and must be considered in the interpretation of experiments involving the removal of phosphate from natural waters (]A, 15). 

The controlling chemical reactions for the lime/limestone wet scrubbing SO2 removal systems have been established. In both the lime and limestone systems, the principal absorption reaction is calcium sulfite plus sulfur dioxide to form calcium bisulfite. Methods of preventing both calcium sulfite and calcium sulfate scaling are presented. 

Following the initial steps of hydration (Reaction 1) and formation of calcium sulfite (Reaction 2), removal of SO2 in the lime or calcium hydroxide system depends on the formation of calcium bisulfite by reaction of suspended calcium sulfite with sulfur dioxide and water (Reaction 3). 

Chemical reactions between two or more species from the analytical sample also can occur. The calcium-phosphorus system has been one of those most extensively studied. Calcium, in the presence of phosphate, produces a stable calcium-phosphorus compound that removes large numbers of calcium atoms from the flame. The result is a severe depression of the calcium absorption signal. The same effect is observed with strontium in the presence of phosphate. 

Calcium removal for adapting calcium content in drinking water on connection of central water supply systems or in the case of private water supply systems and individual water supply systems... 

Arsenic may come from the feed, impurities and some zinc-oxide masses for desulphurisation, or from the C02-removal system (Vetro-coke). In contrast, calcium and zinc transferred from the zinc-oxide vessel has no deactivating effect on the reforming catalyst. 

Formation of emissions from fluidised-bed combustion is considerably different from that associated with grate-fired systems. Flyash generation is a design parameter, and typically >90% of all soHds are removed from the system as flyash. SO2 and HCl are controlled by reactions with calcium in the bed, where the lime-stone fed to the bed first calcines to CaO and CO2, and then the lime reacts with sulfur dioxide and oxygen, or with hydrogen chloride, to form calcium sulfate and calcium chloride, respectively. SO2 and HCl capture rates of 70—90% are readily achieved with fluidi2ed beds. The limestone in the bed plus the very low combustion temperatures inhibit conversion of fuel N to NO. ... 

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