Loading impurity

Sugar quality is enhanced by removal of colored impurities and by the extent and type of refining which is obtained. It is believed that this type of refining is the most valuable not only because of its extent but also because it is applied early in the process. This reduction of the impurity load near the forepart of the process avoids potential trouble... 

In each step in the process there is a change in the adsorbate (impurity) loading on the adsorbent bed and a change in the total gas storage within the adsorber vessel. These changes are caused by ... 

These results also suggest that (since plutonium and americium are tightly held) it might be possible to wash impurities loaded with plutonium and americium (e.g. calcium and magnesium) off the column with dilute acid (1 to 3M) before eluting plutonium and americium with 7M HNO3. 

Physical impurities consist mainly of the cells, cell debris, and insoluble medium components, most of which will be removed by the initial clarification stages. This process may be facilitated by preliminary broth conditioning for example, the addition of flocculating agents, pH adjustment, or heat treatment. Such operations may have the added advantage of promoting the release of intracellular products to the liquid phase, thereby removing the need for wholecell extraction. Cell lysis will, of course, also increase the biochemical impurity load (11). 

Subsequent analysis suggested that the cold trap had not always been operated in the most efficient maimer. Attempts to trap impurities too rapidly had led to the use of too large a differential between the actual sodium temperature and the impurity saturation temperature. The overcooled sodium precipitated its impurity burden preferentially at the bottom of the vessel and on the outer surfaces of the mesh doughnuts, so that the trap rapidly became blocked with an impurity loading well below the expected maximum. Modified operating techniques and led to improved loading and the final cold trap basket trapped in excess of 140 kg of mixed oxide and hydride. 

Inefficient operation of the PFR secondary cold trap led to impurity loadings below the theoretical maximum. Improved trapping techniques aimed at avoiding cooling the sodium too far below its saturation temperature, and more careful operation solved the problem after 1981. 

Besides fixed and fluidized bed adsorbers also stirred vessels filled with an impurity loaded liquid and powdered active carbon are used. The suspension is separated by filtration or centrifugation after a certain residence time necessary for... 

Cleaning at Mine Face. Efforts to reduce the impurities loaded in the mine usually result in increased mining cost hence economics plays an important part in determining the amount of cleaning done. 

Loaded Adsorbents. Where highly efficient removal of a trace impurity is required it is sometimes effective to use an adsorbent preloaded with a reactant rather than rely on the forces of adsorption. Examples include the use of 2eohtes preloaded with bromine to trap traces of olefins as their more easily condensible bromides 2eohtes preloaded with iodine to trap mercury vapor, and activated carbon loaded with cupric chloride for removal of mercaptans. 

The purified acid is recovered from the loaded organic stream by contacting with water in another countercurrent extraction step. In place of water, an aqueous alkafl can be used to recover a purified phosphate salt solution. A small portion of the purified acid is typically used in a backwashing operation to contact the loaded organic phase and to improve the purity of the extract phase prior to recovery of the purified acid. Depending on the miscibility of the solvent with the acid, the purified acid and the raffinate may be stripped of residual solvent which is recycled to the extraction loop. The purified acid can be treated for removal of residual organic impurities, stripped of fluoride to low (10 ppm) levels, and concentrated to the desired P2 s Many variations of this basic scheme have been developed to improve the extraction of phosphate and rejection of impurities to the raffinate stream, and numerous patents have been granted on solvent extraction processes. 

Yield for the process at low catalyst loading is 95%. AJ-Methyl-toluenediamiae, one of the reaction by-products, represents not only a reduction ia yield, but also a highly objectionable impurity ia the manufacture of toluene diisocyanate. Low concentrations of CO (0.3—6% volume) control this side reaction. 

Mullite Refractories. MuUite refractories are classified under ASTM C467. This brick must have an Al O content between 56 and 79% and contain less than 5% impurities. Impurities are considered metal oxides other than those of aluminum and siUcon. The hot-load subsidence is 5% max is 1593°C. 

Figure 1 shows the particulate loading of a pipe containing gas and particulates where the nonuniformity induced by a disturbance, ie, a 90° bend, is obvious (2). A profile of concentration gradients in a long, straight, horizontal pipe containing suspended soHds is shown in Figure 2. Segregation occurs as a result of particle mass. Certain impurities, eg, metal-rich particulates, however, occur near the bottom of the pipe others, eg, oily flocculates, occur near the top (3). Moreover, the distribution may be affected by Hquid-velocity disturbances and pipe roughness.

Mechanical history, heat, and impurities gready affect the mechanical properties. Pure zinc is ductile at room temperature and does not have a definite yield point as do most stmctural metals. Rather, it creeps under sufficient constant load. The impurities of commercial zinc and alloying metals are carefully controlled to achieve the desired mechanical properties. 

Low ionic impurity levels are imperative. In order to reduce the coefficient of thermal expansion of the final mol ding, and hence minimise stresses on the encapsulated siHcon chip, the highest possible filler loading is desired. This has to be balanced against the need to maintain as low a melt viscosity as possible to minimise the possibiHty of damage to the device during the encapsulation process. 

Asay and Gupta [25] measure elastic precursor amplitudes as functions of propagation distance for two different divalent impurity concentrations in <100)-loaded LiF. It is shown that not only does the presence of divalent ions affect the precursor amplitude, but also that the state of the dispersion plays an important part. It is concluded that, for a given concentration of defects, the rate of precursor attenuation is reduced if the defects are clustered. 

In seawater, HCO3 ions lead to surface films and increased polarization. In aqueous solutions low in salt and with low loading of the anodes, less easily soluble basic zinc chloride [10] and other basic salts of low solubility are formed. In impure waters, phosphates can also be present and can form ZnNH4P04, which is very insoluble [11]. These compounds are only precipitated in a relatively narrow range around pH 7. In weakly acid media due to hydrolysis at the working anode, the solubility increases considerably and the anode remains active, particularly in flowing and salt-rich media. 

Amongst the factors that will influence service performance are the effect of additives and impurities, temperature, detailed geometric size and shape, orientation and morphology, surface condition, energy and speed of any impacting blow, the shape of the impacting instrument, the environment, and strains in the article due to external loads. For this reason it is desirable, but not always feasible, to test prototype articles under conditions as close to service conditions as possible. 

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