K-oleate

The study of adsorption kinetics of a surfactant on the mineral surface can help to clarify the adsorption mechanism in a number of cases. In the literature we found few communications of this kind though the adsorption kinetics has an important role in flotation. Somasundaran et al.133,134 found that the adsorption of Na dodecylsulfonate on alumina and of K oleate on hematite at pH 8.0 is relatively fast (the adsorption equilibrium is reached within a few minutes) as expected for physical adsorption of minerals with PDI H+ and OH". However, the system K oleate-hematite exhibits a markedly different type of kinetics at pH 4.8 where the equilibrium is not reached even after several hours of adsorption. Similarly, the effect of temperature on adsorption density varies. The adsorption density of K oleate at pH 8 and 25 °C is greater than at 75 °C whereas the opposite is true at pH 4.8. Evidently the adsorption of oleic acid on hematite involves a mechanism that is different from that of oleate or acid soaps. 

Fluosol Green Cross Corp. (Japan) FDC/FTPA 7 3 6/7 11% (20%) Pluronic F68 EYP K oleate Frozen stem emulsion Reconstitute dilute Approved in the U.S. for PTCA 1989. Discontinued... 

FMIQ emulsion Green Cross Corp. (Japan) FMIQ 10 13% (25%) EYP K oleate Not developed... 

The low temperature properties of a dodecane-hexanol-K.oleate w/o microemulsion from 20°C to -190°C were studied vs. increasing water content (C,mass fraction) in the interval 0.021+-0.1+, by Differential Scanning Calorimetry and dielectric analysis (5 Hz-100 MHz). A differentiation between w/o dispersions is obtained depending on whether they possess a "free water" fraction. Polydispersity is evidenced by means of dielectric loss analysis. Hydration processes occurring, at constant surface tension, on the hydrophilic groups of the amphiphiles, at the expenses of the free water fraction of the droplets, are shown to develop "on ageing" of samples exhibiting a time dependent behavior. 

Figure II. Log WeXpt vs. log PEO concentration in wt %/TS latex [ >] = 56 mequiv/l 6.4% K oleate/TS latex...

Figure 13. Surface tension vs. [K oleate] in the presence of PEO Curve 1 ( ), active component of PEO, 2.5 g/l Curve 2 (X), inactive component of PEO, 2.5 g/l ...

Fig. 21, Phase diagram of the system K-oleate, KCl and water at 20° C (Me Bain, 1926).

FIGURE 16.4 5 Effect of phosphate species on the flotation of apatite . K-oleate 2 x 10 kmol/m. ... 

K oleate K oleate K oleate K oleate K oleate K oleate K oleate K oleate... 

FIG. 1 Typical DSC thermograms of K-oleate-hexanol-dodecane-water microemul-sion samples. Surfactant/oil = 0.2 g/mL alcohol/oil = 0.4ml/mL water/(water + oil) = 0.222-0.4 g/g. Curve a, W/O microemulsion sample curve b, D2O/01I microemulsion sample. Endothermic peaks due to the fusion of DjO (277 K), free water (273 K), dodecane and interphasal water (263 K), bound water (233 K), and hexanol (220 K) were identified. (From Ref. 11.)... 

FIG. 2 Differential scanning calorimetric endotherms of the system K-oleate + hexanol 3 5 (w/w)-hexadecane (samples a, b, c) or dodecane (sample d)-water. In all samples, the surfactant/oil weight ratio is 0.68 and the water concentration C was expressed as the weight ratio of added water to total sample. = 0.071, C, = 0.108, = 0.290, Cj =... 

Senatra et al. [35] studied the system HjO-hexadecane or dodecane-K-oleate-hexanol [with mass ratios K-oleate hexanol = 0.6 and (K-oleate + hexanol) oil = 0.4]. They argued that the exothermic scanning mode may provide some information about the structural modifications occurring in the system as a function of water content. Typical thermograms recorded in the exothermic mode are shown in Fig. 3. 

TABLE 1 Thermal Characteristics of W/O Microemulsions in the System Water-Hexadecane-K-Oleate-Hexanol... 

FIG. 9 The effect of different thermal rates on the DSC spectra recorded upon the melting of a previously frozen sample. First-order phase transitions are rate-independent. However, the smaller the final step from the dynamic to the isothermal part of the measurement (iso.T in time units), the lower wiU be the difference between the sample and reference temperatures. Water-hexadecane sample with C = 0.25. (a)-(d), dTIdt = 1, 2, 4, and 8 K/min. Composition is given in Table 2. Symbols A//, w i,x are used to identify the thermal peaks due to the melting of hexadecane (h), water (w), K-oleate-hexanol-water mixture (b), and hexanol (x). (From Ref. 13.)... 

Example 1. A four-component system consists of n-hexadecane (O), n-hexa-nol (CoS), K-oleate (S), and water (W). (The composition is given in Table 2.) The proportions by weight between the components are S/CoS = 0.6 CoS/O = 0.4 (S + CoS)/0 = 0.68. The sample weighs 8.099 mg and has a water concentration = 0.169. The analysis is summarized in Table 5. The columns designate the following parameters (1) weight percent of each components in the stock solution (2) percent composition of the DSC sample (3) weight of each DSC sample component. The enthalpy analysis results are in columns 4-8. Thermal rate applied dTIdt = 8 K/min. 

FIG. 15 Water-hexadecane system (Table 2). DSC-ENDO spectra of the upper isotropic phase of biphasic samples with increasing water concentration of the sample as a whole. Curve 1 Ctoi = 0.372, the first appearance of a birefiingent liquid crystalline lens. Curve 2 Ct = 0.388. Curve 3 Ct = 0.419. Curve 4 Melting endotherms of the Uquid crystalline bottom mesophase of a sample with Ct , = 0.419. AH and AHb are the thermal contributions of the n-hexanol and the water-K-oleate-hexanol mixture, respectively. (From Ref. 23.) Curve 5 DSC-ENDO spectrum of the ternary mixture n-hexanol-K-oleate-water. The proportions between surfactant and cosurfactant are the same as those used to formulate the four-component W/O microemulsions. 

---