Concentrate processing applications

Applications for coolers include caustic being transferred to Storage, low-concentration solutions prepared by exothermic dilution, circulating caustic in vent scrubber systems, and full-concentration process applications. Stainless steel plates are used frequently at temperatures up to about 60°C. Nickel or one of its alloys is the... 

Analysis of such a correlation may reveal the significant variables and interactions, and may suggest some model, say of the L-H type, that could be analyzed in more detail by a regression process. The variables Xi could be various parameters of heterogeneous processes as well as concentrations. An application of this method to isomerization of /i-pentane is given by Kittrel and Erjavec (Ind. Eng. Chem. Proc. Des. Dev., 7,321 [1968]). 

Anodic protection against acids has been used in a number of processes in the chemical industry, as well as during storage and transport. It is also successful in geometrically complicated containers and tubings [12], Carbon steel can be protected from nitric and sulfuric acids. In the latter case, temperature and concentration set application limits [17]. At temperatures of up to 120°C, efficient protection can only be achieved with concentrations over 90% [ 18]. At concentrations between 67 and 90%, anodic protection can be used at up to 140°C with CrNi steels [19]. 

Micro-organisms with resistance to environmental stresses such as solvents, extremes of pH, high salt concentration, and having broad temperature and dissolved oxygen optima are more suited to process applications. Improved process instrumentation and... 

With regard to the sulfidic sources of copper, the main emphasis, as far as hydro-based process applications are concerned, has been on the chalcopyrite concentrates. Of the copper-bearing minerals, chalcopyrite (CuFeSJ is by far the most abundant but its reactivity in... 

Our review of the use of organoboron compounds in radical chemistry will concentrate on applications where the organoborane is used as an initiator, as a direct source of carbon-centered radicals, as a chain transfer reagent and finally as a radical reducing agent. The simple formation of carbon-heteroatom bonds via a radical process is not treated in this review since it has been treated in previous review articles [3,9]. 

Albany International Research Co. has developed an advanced hollow fiber composite reverse osmosis membrane and module under the name of Quantro II . This composite membrane is comprised of a porous hollow fiber substrate on which has been deposited a rejection barrier capable of fluxes of commercial importance at high rejection of dissolved salts at elevated temperatures. Resistance to active chlorine has been demonstrated. Proprietary processes have been developed for spinning of the fiber, establishment of the rejection barrier and processing of the fiber to prepare modules of commercial size. Prototype modules are currently in field trials against brackish and seawater feed solutions. Applications under consideration for this membrane include brackish and seawater desalination as well as selected industrial concentration processes. 

Freeze concentration involves the concentration of an aqueous solution by partial freezing and subsequent separation of the resulting ice crystals. It is considered to be one of the most advantageous concentration processes because of the many positive characteristics related with its application. Concentration processes such as evaporation or distillation usually result in removal of volatiles responsible for arom in addition the heat addition in these processes causes a breakdown in the chemical structure that affects flavor characteristics and nutritive properties. In contrast freeze concentration is capable of concentrating various comestible liquids without appreciable change in flavor, aroma, color or nutritive value (1.2.3) The concentrate contains almost all the original amounts of solutes present in the liquid food. 

The application of the fteeze concentration process has been successful in various cases such as the preconcentration of wine (. The application of the process for the concentration of fruit juices, which are mainly consumed for their flavor and taste, seems to be ideal because of the improved volatile retention. Nevertheless, the process is not as widely accepted because of its increased economic r uirements. These are related to the difficulty of effectively separating the resulting solid phase from the liquid phase (mother liquor). The formation of a large number of very fine... 

Maintaining dissolved solids at the level required to prevent foaming requires continuous or periodic blowdown of the boiler. Table 2 gives the recommended total solids concentration for the prevention of excessive carryover at various operating pressures. Most operators find it convenient and advisable to ran well below these limits, Exceeding them may endanger the superheater, the turbine, or the process application. 

The world of codes and standards is an absolute labyrinth, so the emphasis here will be only on the main issues from ASME and PED, which cover about 80% of all worldwide requirements. The exceptions are China and India, who follow their own guidelines, although they are mostly focused on boiler applications. Also, we will concentrate on the industrial process applications and only refer to these applicable codes. 

Chemisorption systems are sometimes used for removing trace concentrations of contaminants, but the difficulty of regeneration makes such systems unsuitable for most process applications so most adsorption processes depend on physical adsorption. The forces of physical adsorption are weaker than the forces of chemisorption so the heats of physical adsorption are lower and the adsorbent is more easily regenerated. Several different types of force are involved. For nonpolar systems the major contribution is generally from dispersion-repulsion (van der Waals) forces, which are a fundamental property of all matter. When the surface is polar, depending on the nature of the sorbate molecule, there may also be important contributions from polarization, dipole, and quadmpole interactions. Selective adsorption of a polar species such as water or a quadrupolar species such as CO2 from a mixture with other nonpolar species can therefore be accomplished by using a polar adsorbent. Indeed, adjustment of surface polarity is one of the main ways of tailoring adsorbent selectivity. 

In this formula V represents the final quantity (or volume) of material after the reaction has destroyed part of the original quantity Vo. It is applicable only for small increases in N. The amount of the reactants in the initial material is N0 and the amount in the final material is N while a is a coefficient derived from the ratio of the two specific rate constants by the subtraction of unity. Applied to the particular problem of concentrating the carbon isotopes, No represents the amount of C13 in ordinary carbon and is taken as one per cent and N is the amount after the concentration process. When the concentration is effected by removing material through the rupture of the carbon-carbon bond, a has the value 1.05 — 1.00 or 0.05 as already explained. Assuming as a special case that ninety-nine per cent of the material is destroyed by breaking the carbon-carbon bond,... 

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