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Strip liquor

Stripping characteristics and the production of copper sulfate crystal, saturated copper sulfate solution, powdered copper, or electrolytic copper from the strip liquors... [Pg.305]

Vanadium is stripped from the organic solution with 1.5 mol dm sulfuric acid to a concentration of about 50gdm V. After an iron removal step with strong sulfuric acid, the organic solution is washed with water and recycled. From the vanadium strip liquor, ammonium polyvanadate (APV) is precipitated by oxidation and addition of ammonia. The APV slurry is thickened and pumped to a vacuum belt filter, where the APV cake is carefully washed with fresh water. The APV filter cake is dried and then calcined to vanadium pentoxide. [Pg.623]

The anolyte is evaporated to increase the chloride concentration from 75-250 gdm and cobalt, and most of the iron, is then extracted by the organic solvent. The nickel containing raffinate is diluted by condensate from the evaporation and returned to the Ni-cathode compartments in the diaphragm electrolytic cells for precipitation of nickel. Stripping of cobalt from the organic solvent is performed with the weakly acidic condensate. The strip liquor is fed to the Co-cathode compartment in the electrolytic cells. [Pg.625]

A tertiary amine (Alamine 336) is used as a selective extractant of Cr(VI). The extraction mechanism involves ion pairing between the amine and the dichromate anion, HCr04. After extraction, the Cr(VI)-loaded extractant is stripped with alkali to produce a strip liquor, containing 2% Cr(VI). This solution can be recycled. [Pg.627]

The precipitate is filtered and then calcined at 600 °C to yield high-grade U3Og. Alternatively, stripping with a more dilute solution of ammonium carbonate allows the uranium to remain in solution in the strip liquor and to be precipitated subsequently as U042H20 by the addition of hydrogen peroxide.130... [Pg.798]

It can be seen from Figure 11 that, by the appropriate choice of the equilibrium concentration of chloride ion in the aqueous phase, separations between certain pairs of metals can be made, for example between copper(II) and manganese(II) at a chloride concentration of 3.0 M, and between cobalt(II) and nickel(II) at a chloride concentration of 6 to 8 M. Furthermore, the metals can be stripped from the loaded organic phase by being contacted with an appropriate volume of water so that the equilibrium concentration of chloride ion in the strip liquor lies on the lower portion of the extraction curve, where substantial aquation of the extracted chlorometallate occurs... [Pg.803]

Uranium is recovered from the strip liquor by the introduction of ammonia gas to precipitate ammonium diuranate ... [Pg.805]

Molybdenum can also be recovered economically from some uranium leach liquors, particularly those of the USA. When uranium is stripped from amine extractants by solutions of sodium chloride, any molybdenum present remains in the organic phase, and can be subsequently recovered by being stripped into a solution of sodium carbonate. A process has been operated in which the strip liquor is acidified to a pH value of 4.5 and the molybdenum is reextracted into a solution of quaternary amine chloride in kerosene.218 The extracted metal is stripped into a solution containing sodium hydroxide and sodium chloride to produce liquors containing 30-40 g of molybdenum per litre, from which calcium molybdate can be precipitated by the addition of calcium chloride. [Pg.806]

The back-extraction (stripping) of palladium is achieved in the hydroxyoxime process by contacting the loaded organic phase with a concentrated solution of hydrochloric acid (about 6 M), thus causing the reversal of reaction (76). Palladium can be recovered from the strip liquor by the addition of ammonia, and the precipitated Pd(NH3)2Cl2 can be calcined to yield pure palladium metal. In the dialkyl sulfide process, however, the extraction reaction (75) is independent of acidity, and is therefore reversed by the use of aqueous ammonia, which forms a stable cationic complex with palladium(II) ... [Pg.807]

Palladium is again recovered in the form of Pd(NH3)2Cl2 by the addition of hydrochloric acid to the strip liquor. [Pg.807]

The solvent extraction of rare-earth nitrates into solutions of TBP has been used commercially for the production of high-purity oxides of yttrium, lanthanum, praseodymium and neodymium from various mineral concentrates,39 as well as for the recovery of mixed rare-earth oxides as a byproduct in the manufacture of phosphoric acid from apatite ores.272 273 In both instances, extraction is carried out from concentrated nitrate solutions, and the loaded organic phases are stripped with water. The rare-earth metals are precipitated from the strip liquors in the form of hydroxides or oxalates, both of which can be calcined to the oxides. Since the distribution coefficients (D) for adjacent rare earths are closely similar, mixer—settler assemblies with 50 or more stages operated under conditions of total reflux are necessary to yield products of adequate purity.39... [Pg.811]

For solvent extraction of pentavalent vanadium as a decavanadate anion, the leach solution is acidified to ca pH 3 by addition of sulfuric acid. Vanadium is extracted in about four countercurrent mixer—setder stages by a 3—5 wt % solution of a tertiary alkyl amine in kerosene. The organic solvent is stripped by a soda-ash or ammonium hydroxide solution, and addition of ammoniacal salts to the rich vanadium strip liquor yields ammonium metavanadate. A small part of the metavanadate is marketed in that form and some is decomposed at a carefully controlled low temperature to make air-dried or fine granular pentoxide, but most is converted to fused pentoxide by thermal decomposition at ca 450°C, melting at 900°C, then chilling and flaking. [Pg.392]

For vanadium solvent extraction, iron powder can be added to reduce pentavalent vanadium to quadrivalent and trivalent iron to divalent at a redox potential of —150 mV. The pH is adjusted to 2 by addition of NH3, and an oxyvanadium cation is extracted in four countercurrent stages of mixer— settlers by a diesel oil solution of EHPA. Vanadium is stripped from the organic solvent with a 15 wt % sulfuric acid solution in four countercurrent stages. Addition of NH3, steam, and sodium chlorate to the strip liquor results in the precipitation of vanadium oxides, which are filtered, dried, fused, and flaked (22). Vanadium can also be extracted from oxidized uranium raffinate by solvent extraction with a tertiary amine, and ammonium metavanadate is produced from the soda-ash strip liquor. Fused and flaked pentoxide is made from the ammonium metavanadate (23). [Pg.392]

Valenzuela et dl. [77] showed the influence of sulfuric acid concentration as stripping agent on the extent of copper extraction. Extraction is practically constant regardless of acid content in the strip liquor, indicating the reduced effect of the back-extraction step on the overaU process rate. [Pg.174]

The equilibrium concentration of iron without electro-reductive [thus after 30 minutes of contact time] is 2.88 and 5.82 g/1 for the 1 M H2SO4 strip at, respectively, 20°C and 50°C. For the 2 M solution, this is 5.48 and 7.26 g/1. It is obvious from these results that the stripping kinetics without any electro-reductive action are considerably faster at 50 °C than at 20 °C. At the end of the experiment, the iron in the strip phase increased to 5.52, 7.84, 7.56 and 10.08 g/1, respectively. Thus, enhanced stripping with electro-reductive action is observed which is clearly more effective at the higher temperature. It can also be seen that, after the current is switched on, it takes some time before the iron concentration in the strip liquor starts to increase. This indicates that, before iron is stripped from the organic phase, the ferric iron in the strip phase has first to be converted to ferrous iron below a critical level. This is also shown in Figure 4 which depicts the total iron, ferric and ferrous concentrations as a ftmction of time for the 2 M, 20 V, 50°C experiment. [Pg.784]


See other pages where Strip liquor is mentioned: [Pg.288]    [Pg.316]    [Pg.470]    [Pg.611]    [Pg.614]    [Pg.625]    [Pg.627]    [Pg.794]    [Pg.810]    [Pg.810]    [Pg.813]    [Pg.392]    [Pg.89]    [Pg.794]    [Pg.810]    [Pg.810]    [Pg.813]    [Pg.6939]    [Pg.6955]    [Pg.6955]    [Pg.6958]    [Pg.432]   
See also in sourсe #XX -- [ Pg.144 ]




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