Extraction operation

Among the properties sought in the solvent are low cost, avadabihty, stabiUty, low volatiUty at ambient temperature, limited miscibility in aqueous systems present in the process, no solvent capacity for the salts, good solvent capacity for the acids, and sufficient difference in distribution coefficient of the two acids to permit their separation in the solvent-extraction operation. Practical solvents are C, C, and alcohols. For industrial process, alcohols are the best choice (see Amyl alcohols). Small quantities of potassium nitrate continue to be produced from natural sources, eg, the caUche deposits in Chile. 

In commercial extraction operations, the fractions that contain butadiene, isobutene, and 1- and 2-butenes usually first go through a butadiene extraction unit in which the butadiene is removed. This may be followed by isobutylene removal via reaction between isobutylene and methanol to form methyl /-butyl ether [1634-04-4] (MTBE). The butenes are then distilled from the MTBE. 1-Butene may then be separated from 2-butene by distillation. 

Roger W. Cusack, Vice President, Glitsch Process Systems, Inc. Member, American Institute of Chemical Engineers (Section 15, Liquid-Liquid Extraction Operations and Equipment)... 

FIG. 22-85 Phase diagram for a PEG/Dextran, hiphasic, aqueous-polymer system used in liquid-liquid extraction operations for protein separations. Alheiisson, Partition of Cell Particles and Macromolecules, 3d ed., Copyright 1986. Reprintedhy petTTUssion of John Wiley Sons, Inc.)... 

For a multi-stage counter-current extraction operated in true equilibrium without side reactions, the partitioning of a solute into the metal phase (fm) and the salt phase (fs) is defined as follows ... 

S. A. VARIAN BSc, PhD, Fermentation Extraction Operations Manager, Glaxo Wellcome Operations, Ulverston, Cumbria... 

The present description pertaining to copper refers to solvent extraction of copper at the Bluebird Mine, Miami. When the plant became operational in the first quarter of 1968 it used L1X 64, but L1X 64N was introduced in to its operation from late 1968. The ore consists of the oxidized minerals, chrysocolla and lesser amounts of azurite and malachite. A heap leaching process is adopted for this copper resource. Heap-leached copper solution is subjected to solvent extraction operation, the extractant being a solution of 7-8% L1X 64N incorporated in kerosene diluent. The extraction process flowsheet is shown in Figure 5.20. The extraction equilibrium diagram portrayed in Figure 5.21 (A) shows the condi-... 

Sanders N. 1993. Food legislation and the scope for increased use of near-critical fluid extraction operations in food, flavoring and pharmaceutical industries. In King MB and Bott TR, editors. Extraction of Natural Products Using Near-Critical Solvents. Glasgow Blackie Academic, pp. 34 19. 

The pK of Ca2+aq (204), 12.6 at zero ionic strength, rising to over 13 as ionic strength increases, means that concentrations of CaOH+aq will be negligible in body fluids (lpolluted waters, and under all conditions of biological relevance, from the very low pHs of 0.5 (Thiobacillus thiooxidans) to 1.5 at which bacteria used for oxidative metal extraction operate (205), through acid soils and acid rain (pH 3 to 6), streams, rivers, and oceans (pH 6 to 8), soda lakes (pH 10), up to the pHs of 11 or more in Jamaican Red Mud slurry ponds (206) (cf. Section II.C.l below). 

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