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K-feldspar was severely altered, which was evident at all T, but more pronounced at 230 °C. Alteration included surface pitting and cracking (Fig. 2b). Additionally, point concentration analysis with EPMA (Supporting Information EPMA) confirmed chemical alteration, with particles of K-feldspar shown to be depleted in K and slightly …
Potassium, which is included in certain contents in the structure of K-feldspar minerals, has a very important function in the growth of plants. Turkey hosts the largest feldspar reserves in the world and is by far the leader in feldspar mining. The production of potassium salts from local natural sources can provide great contributions both socially …
The aplitic K-feldspar has similar Ti concentrations to the granitic K-feldspar with an average of 38 ppm. Li and Ge concentrations in the K-feldspar from granite and aplite are indistinguishable and widely overlap with each other at concentrations from 0.2 to 14.2 ppm and from 0.4 to 5.2 ppm, respectively.
K-feldspar shows the same relationship between CL intensity and Ti concentration as its coexisting quartz, such that increased Ti concentration is reflected by increased CL …
Introduction K-feldspar is a typical insoluble potassium resource with large reserves and wide distribution. Because there are few sources of soluble potassium in natural …
The K-feldspar was hydrothermally decomposed in alkaline solutions by mixing KOH and NaOH having 8.5 M concentration within 240 °C to 280 °C temperature range. Show abstract The third crucial macronutrient required for the development and growth of plants in addition to nitrogen and phosphorous is potassium.
The K concentration effects on K-O bond length and the reduced partition function ratios of 41 K/ 39 K in alkali feldspars have been explored using the density functional theory (DFT) method. In alkali feldspars, the average K-O bond length increases with increasing K …
Thus, the concentration of K feldspar is markedly different among the different glacial lobes depending on provenance, with higher K feldspar concentrations in 'red' till compared to 'gray' till. Soils throughout the Piedmont (Fenneman and Johnson, 1946) are old and have undergone long–term weathering in a humid to semi–humid environment.
For plagioclase, the concentration of SiO 2 is usually less than that in K-feldspar (61–63%), whereas the content of Al 2 O 3 is increased (23–25%). The CaO content varies between 4 and 5%, K 2 O shows a concentration of 0.2 to 0.4%, and the concentration of Na 2 O ranges from 8 to 9% ( Table 2 ).
K-feldspar crystals >5 cm in greatest dimension are common in calc-alkaline granites and granodiorites worldwide. ... Bachmann et al. 2005), leads to concentration of celsian into K-feldspar. K-feldspar megacrysts from the Cathedral Peak Granodiorite typically average ~1 wt% BaO (Kerrick 1969; Johnson and Glazner 2010), and sawtooth …
The K-feldspar is completely decomposed at 280 °C for 120 min. The concentration of potassium hydroxide has little effect on the decomposition of K-feldspar. The transformation of K-feldspar in the proposed hydrothermal process is as follows: Microcline → kaliophilite (as metastable materials) → kalsilite.
The mixture of K-feldspar and mixed alkaline solution was pretreated for 3 min under 400 W in a microwave chemistry reactor, and at a reaction temperature of 200 °C for 180 min, when the mass ratio of CaO/NaOH was 1:3 and the concentration of NaOH ranged from 1.25 mol/L to 6.25 mol/L. Different from above, the second set of …
potassium from K-feldspar were as follows: cultured at 28-30℃ for ten days, initial pH value of 7.4-8, 60 mL medium in a 250 mL conical flask, and 170 r/min shaking speed on a rotary shaker. The K-feldspar concentration, inoculation volume, K-feldspar granularity, and ammonium sulfate dose were 2 g/L, 20%, 0.02-0.03 mm, and 0.4 g/L, respectively.
The Li concentrations of alkali feldspar, quartz and muscovite in Moblan consistently exceed those of Li-poor pegmatites ... K-feldspar crystals may exhibit the cross-hatched twinning typical of microcline, but simple Carlsbad twins are dominant. The K-feldspar and albite crystals commonly contain numerous smaller feldspar crystals ...
The concentration of potassium hydroxide has little effect on K-feldspar decomposition. The effect of excess rate on the decomposition of K-feldspar is intermediate between temperature and concentration. The disappearance and reduction of some Si-O bonds result in the transformation of K-feldspar into kalsilite with fully Si/Al ordered …
K-feldspar concentrations are relatively similar in the fractions with smaller grain sizes ... K-feldspar displays an obvious grain-size effect, with concentrations increasing with increased grain size (Figure 4). During weathering, plagioclases are more easily hydrolyzed than K-feldspars. Consequently, K-feldspars display a higher …
The atmospheric INP concentration changes by orders of magnitude from terrestrial to marine environments, which typically contain much lower concentrations. ... We found that a kind of dust (K-feldspar), together with marine organic aerosols, can help to improve the representation of INPs and explain most of their observations.
Natural feldspar group minerals are mostly the solid solution of orthoclase (KAlSi 3 O 8), albite (NaAlSi 3 O 8) and anorthite (CaAlSi 3 O 8).The K-felspar starting material used in this study is a pegmatitic Kfs crystal (Fig. 1 a) of 82% K-feldspar, 17% albite and volumetrically insignificant quartz (<0.5%).The volume percentages of …
The concentration of K + in the solution is one order of magnitude higher than that in acetic acid solution. The results showed that the dissolution ability of oxalic acid to feldspar is greater than that of acetic acid. ... Diagenetic K-feldspar pseudomorphs in the Triassic Buntsandstein sandstones of the Iberian range. Spain Sedimentol 36(4 ...
In water, the concentration criterion value for the separation of spodumene from other silicate minerals ranged from 1.18 (for muscovite) to 1.38 (for K-feldspar). It is
The quartz:K-feldspar ratios ranged from 3.5 to 11.3 (Table 1), except for sample RC1 (ratio of 31). RC1 had an exceptionally high quartz:K-feldspar ratio due to its large concentration of quartz (85%) (Table 1). Similar quartz:K-feldspar ratios were observed for the DJP loess and the deserts to the north and west of the CLP (Figure 3).
The internal dose rate of K-feldspar was calculated using a K concentration of 13 ± 1% and a Rb content of 400 ± 100 ppm (Huntley and Hancock, 2001;Zhao and Li, 2005; Li et …
In K-feldspar, the concentration variations of minor elements depend on certain factors, such as isomorphic substitution in the structure of K-feldspar, PT-conditions of …
From XRD results (Fig. 1 ), the potential sources of K are altered K-feldspar and K-incorporating phases such as K-tobermorite and the amorphous phase (Ciceri et al. 2017a ). An additional K-bearing carbonate phase not detected by XRD was also shown to exist in the hydrothermal material (Ciceri et al. 2017a ). Fig. 2.
The K-feldspar flotation resulted in a K-feldspar concentrate of 14.3% K 2 O at 77% K-feldspar recovery and K 2 O/Na 2 O ratio of 10.4. The NaOH conditioning of the fluorine …
The mechanism of re-equilibration of albite in a hydrothermal fluid has been investigated experimentally using natural albite crystals in an aqueous KCl solution enriched in 18 O at 600°C and 2 kbars pressure. The reaction is pseudomorphic and produces a rim of K-feldspar with a sharp interface on a nanoscale which moves into the parent albite …
Feldspar - Mineral Composition, Uses, Types: All the rock-forming feldspars are aluminosilicate minerals with the general formula AT4O8 in which A = potassium, sodium, or calcium (Ca); and T = silicon (Si) and aluminum (Al), with a Si:Al ratio ranging from 3:1 to 1:1. Microcline and orthoclase are potassium feldspars (KAlSi3O8), usually designated Or in …
According to Aitken (1998), the concentration ratio of K to Rb in K-feldspar is 200-400:1. In this study, the Rb concentrations of K-feldspar grains from two sediment samples (DaLi and D4) are 643.5 and 765.2 ppm, respectively. For sample DaLi, the ratio of concentration between K and Rb is 210:1.
Boose et al. (2016b) showed a correlation between the INP activity of nine desert dusts and the concentration of K-feldspar at temperatures of − 20 ∘ C. However, at lower temperatures (− 35 to − 28 ∘ C) the ice-nucleating activity of the dusts correlated with the combined concentration of quartz and K-feldspar. Boose et al. (2016b ...
The dissolution of K-feldspar in mixed alkaline solutions (KOH and/NaOH) are also reported by Hongwen et al. ... Canic N, Bartulovic Z, Dakovic A (2004) Application of different collectors in the flotation concentration of feldspar, mica and quartz sand. Miner Eng 17:77–80. Google Scholar Diaz AA, Castro JT, Bastante FG, Fernandez MA (2014 ...
The Rb in K-feldspar and muscovite is also strongly enriched with K-feldspar K/Rb ratios ranging from 30 to as low as 3.5 and those in muscovite from 21.4 to 7.6. ... (1971) Concentrations of Li, Rb, and Cs in potash feldspar and muscovite as criteria for assessing the rare-metal mineralization in granite pegmatites. Inter Geol Rev 13:134–142.
Radiogenic Pb isotopes of K-feldspar have been extensively used as tracers for many geological processes including petrogenesis of granitic rocks (e.g., Doe et al. 1965; Doe …
The K-feldspar flotation resulted in a K-feldspar concentrate of 14.3% K 2 O at 77% K-feldspar recovery and K 2 O/Na 2 O ratio of 10.4. The NaOH conditioning of the fluorine-amine activated feldspars resulted in rapid desorption of fluorine, and the selectivity of the process was assumed to result from the more rapid desorption of fluorine ...
