Sodium Feldspar Research Articles

The effect of grinding aids on dry micro fine grinding of feldspar

The aim of this study was to investigate dry micro-fine grinding of sodium feldspar (albite) with and without grinding aids using a vertical stirred ball mill. The effect of amine based various grinding aids (BMA 1923, BMA 1517, KATPLAST 54 and GRACE XS 304) and dosages (500, 1000 and 2000g/t) were investigated and test results were evaluated based on the product size (d80) and specific energy consumption. Tests revealed that the grinding energy required to reach target grinding size (d80=10 micron) was reduced up to 60% using grinding aids. BMA 1923 was determined to be the most effective grinding aid in terms of target d80 except that lower sizes could be reached with BMA 1517 at the same dosage and similar energy consumptions.

Study of Porcelain Vitreous Phase Viscosity to Obtain Curve Ceramic Coatings

The porcelain materials are composed of crystalline particles immersed in a vitreous matrix. This study has aimed to calculate the porcelain’s vitreous phase viscosity through the Vogel-Fucher-Tamman equation, VFT, to obtain eventually curved coating. We’ve formulated a standard mass, and over it we’ve added the proportions of 4, 8 and 15% of sodium feldspar, main former of the liquid phase, in order to verify its influence over the viscosity at the final vitreous phase. Concerning the standard mass, the addition of 4 and 8% has provoked a reduction of viscosity, while the addition of 15% resulted in a rise of viscosity. Because porcelain does not present a homogenous vitreous phase and crystalline particles, the VFT equation may have given us relative viscosity values. However, these values are coherent with glasses containing sodium, if one assumes that the crystalline phases have no influence over the system and that the vitreous phase has a homogenous composition.

The Preparation of Iron Ore Tailings Bio Ceramic Filter Material and Domestic Sewage Treatment

The experiment by iron ore tailings as the main raw material, add a small amount of fly ash, coal gangue, limestone and biological admixture, the preparation of iron ore tailings bio-ceramic filter material. The effect of the material proportion and sintering temperature and the ball size on the bio-ceramic filter material processing sewage pollutant removal efficiency was investigated. Research shows that the optimal proportion of bio-ceramic is: 86%iron ore tailings, 6% coal gangue, 4% fly ash, 3% limestone, 1% biological admixture. Under the condition of sintering temperature 1100 °C, bio-ceramic size 3 ~ 5 mm, the bio-ceramic filter material of COD removal efficiency 80% and turbidity of sewage 71% respectively. Through bio-ceramic filter material further analysis of XRD and SEM, in the sintering process of minerals such as sodium feldspar, quartz, hematite, together, make bio-ceramic has high strength. Internal porous bio-ceramic surface is rough at the same time, and the specific surface area is larger. Bio-ceramic has good adsorption performance, therefore, is helpful to remove the pollutant in the domestic sewage.

Effect of Al<sub>2</sub>O<sub>3</sub>, CaCO<sub>3</sub> and MgCO<sub>3</sub> on Physical Properties of Crawling Shino Glaze in Reduction Atmosphere

The purpose of this research was to study the effect of Al2O3, CaCO3 and MgCO3 on the physical properties of crawling shino glaze at 1250 °C in a reduction atmosphere. The raw material used in the study are soda feldspar, lampang kaolinite and silica. Al2O3, CaCO3 and MgCO3 were used in ungrounded form as an additive at 5, 10, 15 and 20%wt. The specimen after fired were tested using eye appearance, texture, color of glaze and shrinkage. The results show that the optimum appearance Shino glaze was gained by adding MgCO3 at 15%wt.

Development of Engobe Samples for Dan Kwian Ceramic Body

This paper developed engobe samples for Dan Kwian ceramic body. Kaolinite clay, zirconium silicate, sodium feldspar and quartz were used as raw materials which were varied to obtain various samples. Mix proportion was designed by the square sampling method to obtain 16 samples. All samples were milled and fired at 1200°C under oxidation and reduction atmospheres. The results showed that the suitable engobe composition of kaolinite clay 10 wt%, zirconium silicate 10 wt%, sodium feldspar 40 wt% and quartz 40 wt% to produce good surface appearance for Dan Kwian ceramics. Engobe surfaces and the body had no defect both in the oxidation and reduction atmospheres. The color and engobe surface were opaque white and glossy, respectively.

Characterization of Young׳s modulus and fracture toughness of albite glass by different techniques

This work compares values of Young׳s modulus and fracture toughness of amorphous albite measured from different experimental techniques. Sodium feldspar powder was used to synthesize the albite glass. After quenching, the microstructure of the amorphous solid was analyzed via scanning electron microscopy and X-ray diffraction. Several nanoindentations on albite samples were carried out with two purposes: determination of Young׳s modulus by continuous stiffness measurement, and critical stress intensity factor by crack size evaluation. Concurrently, impulse excitation technique and three point bending single-edge notched test were adopted for providing the comparison of elasticity and toughness, respectively. Young׳s modulus measured by continuous stiffness yielded a value of 71.8±0.9GPa, which was in agreement with the value obtained by impulse excitation (72.5±1.3GPa). The fracture toughness determined by nanoindentation was slightly higher (0.86±0.06MPam1/2) than that (0.78±0.06MPam1/2) obtained by single-edge notched beam.

Influence of Phosphate-Substituted Flux on Microstructure and Technological Properties of White Porcelain Stoneware Tiles

Calcium phosphate in the range of 3 to 10 mass-% partially substituted soda feldspar in five recipes in an attempt to produce white porcelain stoneware tiles. The added phosphate had a double effect on the behavior of the ceramic body during firing. The penta-valent phosphorous accommodated into the tetrahedron co-ordination of the glass melt and lowered its viscosity, leading to the early dissolution of the primary mullite and the crystallization of acicular secondary mullite, as well as fine grained nano-anorthite grains. The calcium ion played its role in increasing the degree of whiteness of the body.

Thermal and mineralogical characterization of loess heavy clays for potential use in brick industry

Abstract This paper describes a study of 11 selected samples of loess soil from Serbia, by using differential scanning calorimetry, simultaneously with thermogravimetry and its differential calculation, known as simultaneous thermal analysis (STA). This survey is supplemented by chemical and mineralogical analysis, particle size distribution, and plasticity and drying susceptibility tests. Correlation analysis of major oxides content and certain technological test results were used for better understanding of the raw material composition and product physical properties. The results indicate that the samples were rich in carbonates, with the highest content of alevrite fraction and variable content of clay-sized particles. Mineralogical analysis confirms significant correlations between major oxides content and reveals that the most common non-clay mineral present is quartz, followed by calcite, dolomite and sodium feldspar. Major clay minerals include illite, chlorite, smectite and, in some cases, low quantities of kaolinite. Although STA method is well-known, this is the first time that it was used for discussion about its practical aspect, for characterization of the loess deposits, in terms of exploitation in brick industry.

Determination of Sintering Activity of Sodium-Potassium Feldspar

The aim of the article is to describe the sintering activity of industrially milled sodium potassium feldspar to determine of optimal firing temperature during fast firing typical for e.g. production of dry pressed ceramic tiles. The change of porosity, flexural strength, firing shrinkage and mineralogical composition in dependence on the firing temperature (1120 1210 °C) were determined on the test samples made from dry granulate prepared from the pure feldspar. Tested alkali sodium potassium feldspar is characterized by low sintering temperature (1190 °C) during fast firing (heating rate 10 °C/min). During the sintering process, feldspar gradually disappears in phases first of all potassium feldspar (microcline), sodium feldspar (albite) we can find in the fired body at firing temperature 1180 °C.

Research on Volcanic Rock Types and Characteristics in Ou Area

Through core observation and description, whole rock chemical analysis, thin section identification and logging identification method, The volcanic rock of this area is mainly basalt, trachyte and tuff, three major categories, further divided into 10 subclasses. Basalt intergranular-intersertal structure, the main minerals are plagioclase , sodium feldspar and mafic pyroxene , belong to alkaline series,infrasonic wave, low natural gamma, high resistance, high density; Trachyte ,typical rough structure, high content of feldspar, the negative anomaly of naturalelectric potential, high resistance, high natural gamma measurement, infrasonic wave;Tuff, tuffaceous texture, massive structure, rock is composed of lithic, vitric, crystal and volcanic ash, ingredients to alkali feldspar, biotite, plagioclase etc, low natural gamma, low resistivity , low density.

U(VI) ion adsorption thermodynamics and kinetics from aqueous solution onto raw sodium feldspar and acid-activated sodium feldspar

The raw sodium feldspar (RSF) is activated with the concentrated sulfuric acid solution and the acid activated sodium feldspar (AASF) is obtained. The results obtained from the mercury intrusion method show that the acidification can increase the porosity and the specific surface area. The effects of the initial pH, contact time and ambient temperature on the adsorption of U(VI) ions are investigated in a batch process. The adsorption efficiency amounts to the highest at pH 6 and the adsorption equilibrium is reached in 600 min. The pseudo-second-order model is found to be more suitable for the adsorption process than the pseudo-first-order model and intra-particle model, indicating that the chemical adsorption is the predominant step for the adsorption process. Langmuir model is found to describe the adsorption process better than Freundlich model. This proves that the main form of U(VI) ions attached to RSF and AASF is the monolayer coverage. The thermodynamic parameters prove that the adsorption process is a spontaneous endothermic one. It was also found that acid activated treatment can help increase the adsorption rate and capacity. The results show that RSF and AASF can be used as a novel low cost adsorbent for removal of U(VI) ions from the low concentration aqueous solution.

Adsorption of U(VI) ions from low concentration uranium solution by thermally activated sodium feldspar

The thermally activated sodium feldspar (TASF), a novel material, was prepared by calcinating the micron sodium feldspar (SF) at 450 °C for 45 min. The TASF and the SF were characterized using X-ray diffraction and mercury injection porosimetry, and the TASF was found to have larger specific surface area and larger porosity than SF. The effects of the initial pH, temperature, contact time and initial U(VI) ions concentration on the adsorption of U(VI) ions from the low concentration uranium solution by TASF were investigated. The maximum adsorption efficiency of TASF for 0.5 mg/L uranium solution amounted to 95.49 % when the initial pH was 5.0, the temperature, 318 K, and and the contact time, 600 min. The relationship between the adsorption capacity q e and equilibrium concentration C e can well be described by Freundlich equation. Adsorption isotherm and the analysis by FT-IR coupled with SEM revealed that U(VI) ions were adsorbed onto the surface of TASF in multimolecular or cluster states, and that the intraparticle diffusion occurred in spontaneous process. The basic thermodynamic parameters including free energy change, entropy change and enthalpy change were calculated to comprehend the intrinsic features and spontaneous nature of the adsorption process. The FT-IR spectroscopic characterization for the TASF indicated that many groups were involved in the adsorption process of U(VI) ions, and the –OH group played a more important role. The experimental results suggested that TASF had great adsorption efficiency and strong potentiality of enrichment and recovery for the low concentration U(VI).

Geochemical characteristics of the coal gangues from the Du’erping coal mine, Xishan coalfield, North China

Inductively coupled plasma mass spectrometry, inductively coupled plasma optical emission spectroscopy, hydride generation-atomic fluorescence spectrometry, emission spectrometry, X fluorescence spectrometry, and X-ray diffraction were employed to study the geochemistry and mineralogy of coal gangues from Nos. 2, 3, and 8 coal seams of the Du’erping coal mine, Xishan coalfield, Taiyuan, Shanxi Province. The study revealed that compared with the sedimentary cover, upper continent crust, Carboniferous-Permian coal from North China, as well as most coal in China, coal gangues from Nos. 2 and 3 coal seams are rich in Li, Be, Sc, Cr, Cu, Ga, Ba, Th, Nb, Cd, Pb, Ta and rare-earth elements, and coal gangues from No. 8 coal seam are rich in Li, Sc, V, Cr, Ga, U, and rare-earth elements. Compared with the Carboniferous-Permian coal from North China and most coal in China, coal gangues from Nos. 2, 3 and 8 seams are rich in Rb, V, Cs and Sr. Therefore, The Du’erping coal gangues in the Xishan coalfield are rich in most hazardous trace elements and rare-earth elements, wherein the contents of Ga and Li reach the industrial grade and have significance for industrial utilization. On the whole, coal gangues of the Shanxi Formation from the Permian are rich in more trace elements than those of the Carboniferous Taiyuan Formation. The distributions of REE show obviously dipping rightwards with negative Eu anomalies. The contents of rare-earth elements in the three seams are quite different. All of the above indicate that the source of the rare-earth elements is terrigenous debris. Minerals in No. 2 seam identified by X-ray diffraction mainly include quartz, kaolinite, in addition to calcite, pyrite, apatite, epidote, and epsomite. No. 3 seam mainly contains quartz, kaolinite, in addition to a small amount of sodium feldspar, calcium nitrate, iron ore, gypsum, and vivianite. No. 8 seam mainly contains kaolinite, dickite, quartz, illite, and a small amount of hematite and U. The correlations between major elements and trace elements in coal gangues of the Du’erping coal mine analyzed by using SPSS (Statistical Product and Service Solutions) indicate that the trace alkali elements and rare-earth elements occur mainly in such clay minerals as kaolinite.

Geology, Petrography and Geochemistry of Rhyolite-Hosted Uranium Mineralization at Mohar, Shivpuri District, Madhya Pradesh

Abstract: In the westernmost part of the Bundelkhand Granitoid Complex (BGC), a mesa structure represents a unique outlier, surrounded by brecciated granite and filled with Vindhyan sedimentary rocks locally known as the Dhala Formation near Mohar village of Shivpuri district, Madhya Pradesh. Uranium mineralisation located in the area is mostly associated with rhyolite of peralkaline to peraluminous in nature, that has a high average uranium concentration (30 ppm). The mineralization is in or adjacent to caldera and is hydrothermal vein-type. Radioactivity is mainly due to coffinite with limited radioactivity due to U-Ti complex, uranium adsorbed in clay and labile uranium along fracture. Coffinite occurs in association with pyrite and chalcopyrite or chlorite with presence of fluorite. Features such as chloritisation, clay formation and sulfide mineralisation manifest hydrothermal alteration. Chemical analysis indicates the aluminous nature of the rock and their high K2O / Na2O (3.81-12.84) ratios are suggestive of predominance of potash feldspar over sodic. The alteration index varies from 49.88-92.40, which, reflects high intensity of hydrothermal alteration. Chlorite-carbonate-pyrite index (CCPI), a measure of the intensity of replacement of sodic feldspars and glass by sericite, chlorite, carbonate, and pyrite associated with hydrothermal alteration proximal to the ore bodies varies from 3.84-49.66. On the basis of core study, geochemistry and mineralogy, it is envisaged that epigenetic hydrothermal solutions were responsible for concentration of uranium as coffinite, radioactive carbonaceous matter and adsorbed uranium phases in rhyolite with sulfide confined to weak planes.

Fracture toughness and temperature dependence of Young's modulus of a sintered albite glass

Albite glass is an important component in many ceramic compositions, often used as liquid phase during the sintering process. Nevertheless, in spite of its almost ubiquous presence in the final microstructure of these compositions, some properties such as Young's modulus or fracture toughness have not been extensively studied in literature. This paper presents an experimental study on a sintered albite glass obtained from sodium feldspar powder. The microstructure of the resultant amorphous solid was analyzed via scanning electron microscopy and X-ray diffraction. Fracture toughness was determined at room temperature from the critical stress intensity factor (KIC) with a three point bending single-edge notched test (SENB). Young's modulus and coefficient of thermal expansion (CTE) were measured as a function of the temperature. A value of CTE of 6.6×10−6°C−1 within the temperature range 300–500°C was found. Young's modulus values of the albite glass were within the range from 63.6 to 65.2MPa. SENB tests revealed a fracture toughness of KIC=0.78±0.06MPam1/2, which is of similar value to those found for borosilicate and soda-lime glasses.

Review of flotation of feldspar

This paper reviews the application of flotation for the separation of feldspar from the other minerals with which it naturally occurs (such as quartz, clay minerals, mica, ilmenite, rutile, anatase and magnetite) as well as the separation of the individual feldspar minerals themselves. Much of the published information on feldspar flotation relates to fundamental studies seeking to elucidate the mechanism of the separation and recovery of feldspar with anionic or cationic collectors and activators. However, the separation schemes currently being used industrially are largely the same as those first proposed 60 years ago because the processes used are very efficient. The general circuit for commercial separation of feldspar consists of three sequential stages of flotation, all of which are carried out in an acid medium. Usually, before flotation, the feed is deslimed, removing any fine clay minerals present. In the first flotation stage, mica is removed with an amine collector. In the second stage, titanium and iron oxide minerals, such as ilmenite and magnetite, are removed using an anionic collector. In the third stage, feldspar is activated with fluoride ions and floated with an amine. The residual product is usually high grade quartz. This procedure results in feldspar products that meet market specifications, including low iron levels. Depending on the nature of the ore being treated and the particular contaminants it contains, one or more of these stages are used. A commercial feldspar product usually contains more than one feldspar mineral, and flotation conditions for the separation of individual feldspar minerals have been developed to produce individual feldspar minerals for specific applications. Potassium feldspar can be floated from sodium feldspar in a sodium chloride solution with an amine collector at neutral or acidic pH values. To overcome environmental issues when fluoride ions are used to activate the feldspar in the third flotation stage, fluoride free flotation conditions that utilise a combination of anionic and cationic collectors have been developed.

Efeito da adição do resíduo de rocha ornamental nas propriedades e microestrutura de porcelana elétrica aluminosa

As porcelanas aluminosas são utilizadas como materiais de isoladores elétricos de alta tensão. Este tipo de porcelana se caracteriza por apresentar excelentes propriedades físicas, mecânicas e elétricas. As porcelanas aluminosas são fabricadas usando-se formulação de massa do tipo composta contendo caulim, argila plástica, feldspato e alumina. Na literatura é encontrada uma larga faixa de composições para essas porcelanas. Por outro lado, o setor de rochas ornamentais gera enormes quantidades de resíduos sólidos ricos em compostos fundentes, que podem ser usados como matéria-prima alternativa na fabricação de porcelanas. Neste trabalho foi estudada porcelana elétrica aluminosa incorporada com até 35 % em peso de resíduo de rocha ornamental em substituição do feldspato sódico, que é uma matéria-prima natural. As massas cerâmicas foram preparadas pelo processo via seca. Peças de porcelanas aluminosa em forma de disco foram preparadas por prensagem uniaxial a 50 MPa. As amostras foram sinterizadas em forno tubular a 1350 ºC por 1h. As seguintes propriedades tecnológicas foram avaliadas: retração linear, absorção de água, massa específica aparente, porosidade aparente, resistência à compressão e resistividade elétrica. A microestrutura sinterizada foi acompanhada por microscopia eletrônica de varredura e difração de raios X. Os resultados experimentais mostram que o resíduo de rocha ornamental pode substituir em até 10 % em peso o feldspato sódico na formulação de porcelana aluminosa. A microestrutura sinterizada foi fortemente influenciada pela adição do resíduo de rocha ornamental.

The lithospheric mantle and lower crust–mantle relationships under Scotland: a xenolithic perspective

Abstract: In the British Isles the majority of volcanic rocks containing upper mantle and lower crustal xenoliths occur in Scotland. Most of the occurrences are of Carboniferous–Permian age. This paper presents new data on the mineral chemistry of spinel lherzolite xenoliths from the five principal Scottish tectonic terranes. Compositional variations among the minerals emphasize the broad lateral heterogeneity of the subcontinental lithospheric mantle across the region. The remarkable range of Al 2 O 3 v. CaO exhibited by the clinopyroxenes compared with data from other ‘xenolith provinces' emphasizes the extremely complex tectonomagmatic history of the Scottish lithosphere. The generalized age increase from southern and central Scotland to the Northern Highland and Hebridean terranes of the north and NW, with concomitant complexity of geological history, is reflected also by trace element and isotopic studies. Reaction relationships in lherzolites from the Hebridean Terrane, owing to pervasive metasomatism, involve secondary growth of sodic feldspar. This, and light REE enrichment of clinopyroxenes, points to involvement of a natro-carbonatitic melt. Most pyroxenitic xenoliths are inferred to form a basal crustal layer with a generally sharp discontinuity above the underlying (dominantly lherzolitic) mantle. A second discontinuity is inferred to separate these ultramafic cumulates from overlying, broadly cognate metagabbroic cumulates.

Na 2O, K 2O, SiO 2 and Al 2O 3 release from potassic and calcic–sodic feldspars into alkaline solutions

The potential release of elements from potassic and calcic–sodic feldspars into the concrete pore solution was evaluated by ICP-MS using 1 N NaOH and KOH solutions at 80 °C in accordance with the conditions set in the chemical test method. Materials were characterized by petrography, XRD and by XRF analysis. The influence of textural and microstructural characteristics on the leaching process was also analyzed by immersing polished plates of each mineral in 1 N NaOH at 80 °C for 7 days. Optical microscope and SEM observations indicate that microstructural characteristics, such as cleavage zones, twins, grain–grain contact and the finer and less abundant phases in perthites, play a key role in the leaching process under alkaline conditions. Na 2O, K 2O, SiO 2 and Al 2O 3 are supplied by hydrolysis, although the participation of other processes cannot be ruled out.

Non-resonant X-ray/laser interaction spectroscopy as a method for assessing charge competition, trapping and luminescence efficiency in wide band-gap materials

Using a conventional fast-shuttered laboratory X-ray source in combination with pulsed laser diode modules, the possibilities for undertaking X-ray/laser interaction spectroscopy in wide band-gap luminescent materials are explored. It is shown that in such materials, a variety of X-ray/laser timing sequences can extract complimentary information regarding the charge-carrier trapping, de-trapping and recombination processes. The effects on the luminescence are illustrated for six example materials (YPO 4:Ce,Sm, Lu 3Al 5O 12:Pr, Al 2O 3:C, natural sodium feldspar NaAlSi 3O 8, cubic BN and type IIa natural diamond). By ramping the temperature from 10 to 320 K during repeated X-ray pump/laser-probe activation cycles, a rapid assessment can be made of the important thermally dependent changes to the charge carrier trapping competition processes.