Production of potassium feldspar concentrate from a low-grade pegmatitic ore in Turkey

2005 ◽  
Vol 114 (2) ◽  
pp. 80-86 ◽  
Author(s):  
Ö. Y. Gülsoy ◽  
N. M. Can ◽  
I. Bayraktar
1989 ◽  
Vol 26 (4) ◽  
pp. 665-676 ◽  
Author(s):  
Greg H. Mack ◽  
T. Jerzykiewicz

Late Campanian to Early Paleocene sandstones of the Alberta Foothills were derived from three types of rocks: (i) andesitic–dacitic volcanic rocks that were presumably comagmatic with middle to late Mesozoic plutons in the Omineca Crystalline Belt; (ii) low-grade metamorphic rocks in the suprastructure of the Omineca Crystalline Belt; and (iii) sedimentary rocks in die Rocky Mountain Thrust Belt, principally pelitic rocks in the western Main Ranges and carbonates and chert-arenites in the eastern Main and Front ranges. A paucity of quartzo-feldspathic rocks fragments and potassium feldspar indicates that the core of the Omineca Crystalline Belt was not extensively exposed at that time.Vertical trends in composition of the sandstones reveal five petrographic stages. Stage I is dominated by volcanic rock fragments and plagioclase, suggesting that initial progradation of the sediment was largely a response to coeval volcanism or tectonic emplacement of older volcanic rocks. Stages III and V are characterized by a significant decrease in the relative proportion of metamorphic detritus and an increase in the proportion of carbonate and chert detritus. These stages may represent periods of thrusting in the eastern Main Ranges or Front Ranges. In contrast, stages II and IV display increases in metamorphic detritus and stage II shows a concomitant decrease in carbonate and chert detritus, trends that indicate wearing down of the eastern Main Ranges or Front Ranges thrust sheet(s) and reintegration of the Omineca Crystalline belt and the western Main Ranges into the drainage basin. The compositional stages indicative of thrust events are associated with coarse facies, including the Entrance and High Divide Ridge conglomerates, whereas those stages indicative of tectonic quiescence are associated with fine-grained facies including coal.


2013 ◽  
Vol 826 ◽  
pp. 97-101 ◽  
Author(s):  
Zhen Fu Lv ◽  
Hong Chao Li ◽  
Hong Xin Zhang ◽  
Min Tian

Flotation technology without fluorite was studied to separate low-grade K-feldspar with quartz. It is shown in the results that qualified K-feldspar concentrate can be gained by grinding, desliming, flotation and high intensity Magnetic Separation process. Feldspar concentrate obtained in closed-circuit had a content of K2O and Na2O 12.12%, quartz concentrate with a yield of 19.94% containing 97.12% SiO2 was obtained in the same time.


1970 ◽  
Vol 7 (5) ◽  
pp. 1275-1294 ◽  
Author(s):  
R. A. Burwash ◽  
J. Krupička

Large-scale deformation of crystalline rocks coupled with metasomatic recrystallization during the Hudsonian orogeny (~1800 m.y. ago) determined the main features of a large portion of the western Canadian Precambrian basement (the Athabasca mobile zone) and its subsequent geological history. The following are the main changes resulting from deformation and metasomatic recrystallization in the Athabasca mobile zone:(a) Significant increase in K2O and Rb, significant decrease in CaO, MgO, Na2O, and Sr, and almost unchanged Al2O3 and SiO2. These changes reflect the relative mobility of major oxides. The very marked change in the Rb/Sr ratio constitutes an important disturbing factor for isotopic age dating.(b) Marked increase in potassium feldspar combined with very marked increase in secondary minerals (epidote, chlorite, muscovite), clear-cut decrease in plagioclase and primary dark minerals, and only a slight increase in quartz. The coexistence of newly-formed microcline and low-grade minerals cannot be explained by disequilibrium.(c) Decrease in the average density of deformed and K-metasomatized complexes, and the probable subsequent long-term isostatic adjustments in the western Canadian sedimentary basin.


Author(s):  
Thomas R. McKee ◽  
Peter R. Buseck

Sediments commonly contain organic material which appears as refractory carbonaceous material in metamorphosed sedimentary rocks. Grew and others have shown that relative carbon content, crystallite size, X-ray crystallinity and development of well-ordered graphite crystal structure of the carbonaceous material increases with increasing metamorphic grade. The graphitization process is irreversible and appears to be continous from the amorphous to the completely graphitized stage. The most dramatic chemical and crystallographic changes take place within the chlorite metamorphic zone.The detailed X-ray investigation of crystallite size and crystalline ordering is complex and can best be investigated by other means such as high resolution transmission electron microscopy (HRTEM). The natural graphitization series is similar to that for heat-treated commercial carbon blacks, which have been successfully studied by HRTEM (Ban and others).


Author(s):  
V.K. Berry

There are two strains of bacteria viz. Thiobacillus thiooxidansand Thiobacillus ferrooxidanswidely mentioned to play an important role in the leaching process of low-grade ores. Another strain used in this study is a thermophile and is designated Caldariella .These microorganisms are acidophilic chemosynthetic aerobic autotrophs and are capable of oxidizing many metal sulfides and elemental sulfur to sulfates and Fe2+ to Fe3+. The necessity of physical contact or attachment by bacteria to mineral surfaces during oxidation reaction has not been fairly established so far. Temple and Koehler reported that during oxidation of marcasite T. thiooxidanswere found concentrated on mineral surface. Schaeffer, et al. demonstrated that physical contact or attachment is essential for oxidation of sulfur.


Author(s):  
Gejing Li ◽  
D. R. Peacor ◽  
D. S. Coombs ◽  
Y. Kawachi

Recent advances in transmission electron microscopy (TEM) and analytical electron microscopy (AEM) have led to many new insights into the structural and chemical characteristics of very finegrained, optically homogeneous mineral aggregates in sedimentary and very low-grade metamorphic rocks. Chemical compositions obtained by electron microprobe analysis (EMPA) on such materials have been shown by TEM/AEM to result from beam overlap on contaminant phases on a scale below resolution of EMPA, which in turn can lead to errors in interpretation and determination of formation conditions. Here we present an in-depth analysis of the relation between AEM and EMPA data, which leads also to the definition of new mineral phases, and demonstrate the resolution power of AEM relative to EMPA in investigations of very fine-grained mineral aggregates in sedimentary and very low-grade metamorphic rocks.Celadonite, having end-member composition KMgFe3+Si4O10(OH)2, and with minor substitution of Fe2+ for Mg and Al for Fe3+ on octahedral sites, is a fine-grained mica widespread in volcanic rocks and volcaniclastic sediments which have undergone low-temperature alteration in the oceanic crust and in burial metamorphic sequences.


2020 ◽  
Vol 134 (17) ◽  
pp. 2243-2262
Author(s):  
Danlin Liu ◽  
Gavin Richardson ◽  
Fehmi M. Benli ◽  
Catherine Park ◽  
João V. de Souza ◽  
...  

Abstract In the elderly population, pathological inflammation has been associated with ageing-associated diseases. The term ‘inflammageing’, which was used for the first time by Franceschi and co-workers in 2000, is associated with the chronic, low-grade, subclinical inflammatory processes coupled to biological ageing. The source of these inflammatory processes is debated. The senescence-associated secretory phenotype (SASP) has been proposed as the main origin of inflammageing. The SASP is characterised by the release of inflammatory cytokines, elevated activation of the NLRP3 inflammasome, altered regulation of acetylcholine (ACh) nicotinic receptors, and abnormal NAD+ metabolism. Therefore, SASP may be ‘druggable’ by small molecule therapeutics targeting those emerging molecular targets. It has been shown that inflammageing is a hallmark of various cardiovascular diseases, including atherosclerosis, hypertension, and adverse cardiac remodelling. Therefore, the pathomechanism involving SASP activation via the NLRP3 inflammasome; modulation of NLRP3 via α7 nicotinic ACh receptors; and modulation by senolytics targeting other proteins have gained a lot of interest within cardiovascular research and drug development communities. In this review, which offers a unique view from both clinical and preclinical target-based drug discovery perspectives, we have focused on cardiovascular inflammageing and its molecular mechanisms. We have outlined the mechanistic links between inflammageing, SASP, interleukin (IL)-1β, NLRP3 inflammasome, nicotinic ACh receptors, and molecular targets of senolytic drugs in the context of cardiovascular diseases. We have addressed the ‘druggability’ of NLRP3 and nicotinic α7 receptors by small molecules, as these proteins represent novel and exciting targets for therapeutic interventions targeting inflammageing in the cardiovascular system and beyond.


2001 ◽  
Vol 120 (5) ◽  
pp. A298-A298
Author(s):  
M IWANO ◽  
Y MATSUSHIMA ◽  
K OKAZAKI ◽  
T CHIBA
Keyword(s):  

2001 ◽  
Vol 120 (5) ◽  
pp. A733-A733
Author(s):  
C LIM ◽  
A AXON ◽  
A VAIL ◽  
D FORMAN ◽  
M DIXON

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