Main Mineral Composition Research Articles

Recycled Glass Potential as Porous Ceramic Determine by Spectroscopy Analysis

Recycled glass from domestic waste also known as soda lime silica glass due to its main mineral composition is sodium oxide, calcium oxide and silica. The recycled glass was subjected to XRF in order to identify its chemical composition. Porous ceramic was made up of recycled glass powder added with ball clay and feldspar using ratio 90:5:5. Paper fiber was added as much as 5 wt% to act as foaming agent in the ceramic. Reaction of the ceramic body after sintering at three different temperatures in half an hour soaking time was studied using XRD spectroscopy.

Migration of Heavy Metal in a Sulfide Ore Tailings Impoundment

Heavy metals are a component of sulfide ore tailings, which may pose serious threats to environment and human health. This study focuses on physical and chemical properties of main mineral composition in a sulfide ore tailings impoundment and discusses a series of chemical reaction equations of the main minerals in tailings including FeS, Fe1-xS and Fe7S8. This study aims to examine migration rules of the heavy metal elements in the tailings. To further investigate the migration mechanism, experimental simulation was used to provide some bases for the release and migration law of heavy metals in tailings.

Geochemical constraints on the provenance of surface sediments of radial sand ridges off the Jiangsu coastal zone, East China

The Jiang harbor-centered radial sand ranges (RSRs) off the Jiangsu coast are the largest in the Yellow Sea. However, the provenance of the RSRs remains controversial. In this study, we compare major and trace element geochemistry together with grain size and main mineral composition in carbonate-free sediments from RSRs and potential sources. Onshore and offshore RSR sediments have different grain size characteristics: onshore RSR sediments have mean grain-sizes of < 50 μm whereas offshore RSR sediments are between 50 and 160 μm in mean grain size. Despite these differences in grain size onshore and offshore RSRs have similar mineral compositions. Relative to upper continental crust (UCC), onshore RSR sediments are enriched in SiO 2 , TiO 2 , Li and partly in Cs, Zn and some high field strength elements (Y, Zr, Nb, Pb and Th) while depleted in other elements. Offshore RSR sediments are complicated in geochemical compositions. Some of them have very high contents of high field strength elements, and others are similar to onshore RSR sediments. Onshore and offshore RSR sediments have different controlling factors of geochemical compositions: onshore RSR sediments are influenced by clay-size minerals whereas offshore sediments are controlled by heavy minerals. The identification of Zr/Nb and Ti/Zr vs. K/Rb shows that onshore and offshore RSRs seem to have similar sources. Their differences in grain size are a result of hydrodynamic sorting. The identification of elemental ratios reveals that sources of RSR sediments are variable in space and time and the inputs of the Chinese Rivers, especially the old Yellow River and the Yangtze River are still dominant but the effect of the Korean field cannot be neglected. Our findings also demonstrate the potential of elemental ratios such as Zr/Nb and K/Rb as tracer pairs for provenance of sediments in the Yellow Sea. • The provenance of the RSR off the Jiangsu coast in the Yellow Sea remains controversial. • Identification of elemental ratios reveals that sources of RSR sediments are variable in space. • Contributions of Chinese Rivers, especially the old Yellow River and the Yangtze River are still dominant. • Elemental ratios of Zr/Nb and K/R could be used as tracers for provenance in the Yellow Sea.

Structural and Mineralogical Characterization of Green Nephrite in Hetian, Xinjiang, China

The green Hetian nephrite, which has delicate textures, spinach-like green and less cracks, contains three types of aggregates: primary nephrite, placer nephrite and Gobi nephrite. The deposits were located in the south part of the Tarim Basin, Xinjiang, China. In the orebodies of the deposits, primary nephrites occurr as veins or lenses along faults or fissures of adjacent ultramafic rocks. Samples with fine-grained and felted cohesive textures were collected from Hetian-Yutian County, Xinjiang Uyghur Autonomous Region, its mineralogical characteristics, H-O isotopic characteristics and forming mechanism have been discussed by means of SEM, EPMA, XRD, IR spectrum, Raman spectrum, DTA and TG study, and H-O isotope study. Microscopic observation and SEM show that green nephrite has interlocking-felted cryptocrystalline blastic texture with fine topography and high compactness. Tremolite, as a main mineral composition of the green nephrite, has high amounts of Si, Ca, and Mg; it turns into actinolite with the help of increasingly large amount of Fe. XRD, IR spectrum and Raman spectrum identified the occurrence of accessory minerals of chromite, chlorite, serpentine, clinopyroxene and apatite. DTA study demonstrates that the structure of tremolite was destroyed at 900 – 1100°C, while TG study demonstrates the tremolite has such little water that it lost only 0.89 – 1.33% of its weight when heated to 900 – 1100°C. The petrogenesis of green Hetian nephrite deposits are implied to be a result of metasomatic alteration of ultramafic-mafic rocks, and the black, spot-like chromite implies ultramafic-mafic rocks. The analysis of H-O isotope study indicates that the ore-forming hydrothermal fluids of Gobi nephrites are primary magmatic water, but details of hydrothermal fluids of primary and placer nephrites are still remained unknown and needed to be investigated furthermore.

Research on a "Green" Industry Chain of Phosphate Fertilizer

In the production of phosphate fertilizer, large amounts of phosphorus gypsum can be produced, which can be used for the preparation of ammonium sulfate. In which process, a large number of secondary emissions-calcium carbonate residue can be produced as well, whose main mineral composition was CaCO3. Calcium carbonate residue can be conversion to high activity Lime by roasting at high temperature. This research used high solid/gas ratio suspended roasting technology to deal with calcium carbonate residue, and built a calcium carbonate residue test preparation of active lime production line with Wengfu Group at 2011,earned product with 97.7% CaCO3 apparent decomposition rate,59% CaO content and with high activity(160s to 180s).Relative to the traditional roasting device such as rotary kiln and shaft kiln, suspended roasting has a better thermal efficiency (4402kJ/kg), which can be used for large-scale industrial production. And this process will not generate new secondary emissions,thus we can get a complete "green" phosphate fertilizer industry chain.

Impact of Gas Storage on Reservoir Rocks – Long-Term Study to Investigate the Effects on Mineral Content and Fluid Chemistry

To study the effects of gas storage, long-term autoclave experiments with rock cores originating from a natural gas reservoir and brines taken from a gas well were conducted at 40bar and 80o C in a CO2 atmosphere. While the main mineral composition of the sandstones was not affected due to CO2 exposure over a period of 31 months, the dissolution of rock-forming minerals such as feldspar, quartz or pore-filling anhydrite and calcite was noted. Changes in the brine composition were also detected. A release of iron and total organic carbon (TOC) from the rock samples to the saline fluid was observed. Temporary changes in the acetic acid concentration might have contributed to the dissolution processes. Precipitation and dissolution of minerals in sandstones were mostly related to diagenetic fluid-rock reactions and CO2 exposure, but in general the impact of CO2 on rock composition was only minor.

Micro-Structure of a Special Sericite-Jade: A Preliminary Study Using XRD and SEM Analysis

A preliminary study on the micro-structure of a special sericite-jade material has been carried out by using the XRD and SEM methods. By XRD analysis, the 2M1 type sericite is identified as the main mineral composition of the white-colored, yellow-colored and green-colored jade. Quartz, as the secondary mineral, is also common in the green-colored jade. However, the dominant mineral composition of the black-colored jade is chlorite. SEM analysis reveals both the micro-morphology of the jade-forming minerals and the micro-structure of the mineral aggregates are various, which have significant relationships with the Guangning jade quality. Minuscular mineral grains and compact micro-structure make jade materials exquisite. Conversely, large mineral grains and the loose micro-structure make jade materials more rougher.

Experimental Study on the Pumice Aggregate Concrete

Pumice is a kind of natural lightweight aggregate with well-developed porosity and moderate-intensity. Amorphous Si-Al oxide is its main mineral composition. This paper focused on the performance and features of the pumice pozzolan and aggregate firstly. Then a kind of pumice concretes was prepared with the ordinary Portland cement, ordinary sand and strengthened coarse pumice aggregates. And its mechanical properties, durability, insulation and absorbing performance were investigated. The result showed that the compressive strength of pumice concrete was 20MPa, anti-freezing durability was more than 100 freeze-thaw cycles, electric flux within 6 hours was 1749C, thermal conductivity coefficient was 0.318W/ mK, and the electromagnetic wave absorption was-5dB ranging from 8 to 18GHz. The results indicated that the pumice concrete could be developed as the green and multi-functional concrete materials in the future.

Study on cementitious properties of steel slag

The converter steel slag chemical and mineral components in China?s main steel plants have been analysed in the present paper. The electronic microscope, energy spectrum analysis, X-ray diffraction analysis confirmed the main mineral compositions in the converter slag. Converter slag of different components were grounded to obtain a powder with specific surface area over 400m2/kg, making them to take place some part of the cement in the concrete as the admixture and carry out the standard tests. The results indicate that the converter slag can be used as cementitious materials for construction. Furthermore, physical mechanic and durability tests on the concrete that certain amount of cement be substituted by converter steel slag powder from different steel plants are carried out, the results show that the concrete with partial substitution of steel slag powder has the advantages of higher later period strength, better frost resistance, good wear resistance and lower hydration heat, etc. This study can be used as the technical basis for ?Steel Slag Powder Used For Cement And Concrete?, ?Steel Slag Portland Cement?, ?Low Heat Portland Steel Slag Cement?, ?Steel Slag Road Cement? in China, as well as a driving force to the works of steel slag utilization with high-value addition, circular economy, energy conservation and discharge reduction in the iron and steel industry.

Controlling Factors of the Color of Jade Material – Taking Jilin An’lv Jade as Example

Produced in Ji’an of Jilin Province, An’lv jade is named after Lvshui River in that region. The research shows that the main mineral composition of An’lv jade is lizardite and the type and content of the chemical constituent has great influence on the color of jade. Due to the “chromophore” of Fe, the jade is mainly in green, varying from light yellow green to dark green and even to blackish green along with the increment of content. However, some “non-chromophores” also affect depth (intensity) of the color of jade, for example, the color of jade becomes light and its transparency becomes better along with the increment of the content of Si, Al, Mg, OH.

Mechanical mechanism and support design analysis on bolt-beam-net support in soft rock roadway in Qigou Coal Mine

The deformation and failure mechanical mechanism in soft rock roadway is related to the stability of supported tunnels, which is important to coal mine production and construction. By physical mechanics experiments and X-ray diffraction (XRD) tests, the engineering mechanical properties of soft rock, as well as main mineral composition of the surrounding soft rock of Qigou Coal Mine, were obtained. Based on analysis results, a method using bolt-beam-net combination to support was put forward. Mechanical analysis of the support form was done by using the calculation software FLAC3D. Results show that clay minerals of this mine are kaolinite and illite mixed layer, of which the water absorption is relatively obvious and presented mudding characteristic after absorbing water, with the plasticity index of 0.35, with small expansibility, which is weakly consolidated colloid with strong connected force in unit cell. The rock blocks have the characteristics of moisture absorption softening, and the deformation mechanical mechanism of which is with the coexistence of molecular expansive mechanism, colloid expansive mechanism, and weak layer trend type. The calculation results show that the bolt-beam-net support structure makes the bolt, beam, and roof deform compatibly. The beams make the force in the bolt relatively homogeneous, which restricts the displacement of the tunnel roof as well. Finally, using in situ monitoring, the numerical results were verified.

A hydro-mechanical-chemical coupling model for geomaterial with both mechanical and chemical damages considered

A general framework of hydro-mechanical-chemical coupling model is proposed for geomaterial subjected to the dual effects of mechanical loading and chemical degradation. Mechanical damage due to microcracks in solid matrix and chemical damage induced by the increase of porosity due to dissolution of matrix minerals as well as their interactions are considered. A special model is proposed for sandstone. The reaction rate is formulated within the framework of mineral reaction kinetics and can thus take into account different dissolution mechanisms of three main mineral compositions under different pH values. The increase of porosity is physically defined by the dissolution of mineral composition and the chemical damage is related to the increase of porosity. The mechanical behavior is characterized by unified plastic damage and viscoplastic damage modeling. The effective stress is used for describing the effect of pore pressure. The elastic parameters and plastic evolution as well as viscoplastic evolution are dependent on chemical damage. The advection, which is coupled with mechanical damage and chemical damage, is considered as the dominant mechanism of mass transfer. The application of model proposed is from decoupled experiments to fully coupled experiment. The model offers a convenient approach to describing the hydro-mechanical-chemical coupled behavior of geomaterial.

Study on Technological Mineralogy of Slag Film of Medium Carbon Steel

The mineral composition and microstructure of slag film of medium carbon steel are studied systematically with the methord of the technological mineralogy. The result shows that: The main mineral compositions of slag film are melilite and glass phase, and the texture of slag film is of two-layer or three, in which glassy-layer and crystallizing-layer appear alternately, the crystallization rate is from 2% to 5%. The melilite in slag film is good for improving lubrication and controlling heat transfer, so melilite can be promote in slag film for improving the quality of medium carbon steel.

Experiment and Thermodynamic Analysis on Mineral Formation of Cement Clinker Cogeneration from Coal in Pulverized Coal Combustion Boiler

Take Changguang high-sulfur coal as experimental coal type; carry out the experiment of mineral formation rule of co-generation cement clicker on two-section multiphase reaction test stand and conduct XRD, SEM and EDS analyses on the mineral composition of the obtained co-generation clicker sample. It can be found from the experimental results that the mineral composition of co-generation clinker presents great difference with the temperature change in the furnace on the test stand; when the temperature in the furnace reaches to 1,330°C, the main mineral species in co-generation clinker sample are 2CaO•SiO2, Q phase and 3CaO•3Al2O3•CaSO4with excellent hydration activity. Conducted thermodynamic calculation on the mineral formation reaction probably occurring in the chemical compositions of Q-phase cement clinker co-generated from Changguang coal. It is shown in the findings of computational analyses that, according to the chemical composition of clinker, the direct synthesis reaction of 2CaO•Al2O3•SiO2firstly occurs, followed by the direct synthesis reaction of 2CaO•SiO2, the next is the indirect synthesis reaction of Q-phase mineral, and the last is the indirect synthetic reaction of 3CaO•3Al2O3•CaSO4; the final main mineral compositions of co-generation clinker should be 2CaO•SiO2, Q phase and 3CaO•3Al2O3•CaSO4. The conclusion of thermodynamic analyses on co-generation clicker mineral formation reaction basically conforms to the mineral composition in experiment of Changguang coal co-generating Q-phase cement clinker.

Differentiation of organic and non-organic ewe's cheeses using main mineral composition or near infrared spectroscopy coupled to chemometric tools: A comparative study

Two independent methodologies were investigated to achieve the differentiation of ewes’ cheeses from different systems of production (organic and non-organic). Eighty cheeses (40 organic and 40 non-organic) from two systems of production, two different breeds of ewe, different sizes, seasons (summer and winter) and ripening times up to 9 months were elaborated. Their mineral composition or the information provided by their spectra in the near infrared zone (NIR) coupled to chemometric tools were used in order to differentiate between organic and non-organic cheeses. Main mineral composition (Ca, K, Mg, Na and P) of cheeses and stepwise lineal discriminant analysis were used to develop a discriminant model. The results from canonical standardised coefficients indicated that the most important mineral was Mg (1.725) followed by P (0.764) and K (0.742). The percentage of correctly classified samples was 88% in internal validation and 90% in external validation, selecting Mg, K and P as variables.Spectral information in the NIR zone was used coupled to a discriminant analysis based on a regression by partial least squares in order to obtain a model which allowed a rate of samples correctly classified of 97% in internal validation and 85% in external validation.

Spatial heterogeneity of soil main mineral composition in manmade forest in karst peak-cluster-depression region

The soil samples were collected with gridding method based on a dynamic monitoring plot (200 m × 40 m) in manmade forest of karst peak-cluster-depression region. By the methods of classical statistics and geostatistics, spatial heterogeneity of main mineral composition (SiO2,Fe2O3,CaO,MgO,Al2O3,MnO) in surface soil (0?20 cm) was studied. The differences of the six mineral compositions were large with SiO2 having the highest contents followed by Al2O3, Fe2O3, MgO, CaO, and MnO and the variance coefficients ranged from 6.90% to 28.89%. Spherical model fitted best for Fe2O3, CaO, and MgO, Gaussian model best for SiO2 and MnO, and Exponential model best for Al2O3. MgO and CaO had medium spatial autocorrelation, while the others were characterized by strong spatial autocorrelation. The Kriging contour map of CaO was similar with that of MgO. The Kriging contour maps of SiO2 and MnO were similar. Fe2O3 and Al2O3 presented spatial distribution of fragmented patches.

Effect of Mold Flux for Casting on Microstructe of Mould Powder

The microstructe of mold fluxes of low-carbon steel and mould powders were researched by means of polarizing microscope. The result shows that the mineral compositions of the mould fluxes primarily are glass phase, wollastonite, quartz, melilite, pyroxene and feldspar. The main mineral compositions of mould powders is melilite. The quartz, pyroxene and glass phase are helpful to reduce the crystalline portion of mould powder, but the melilite, wollastonite help to improve the crystalline portion and promote crystallization of melilite. It is good for the crystalline portion when the casting speed droop.

Patinas developed in environmental burial conditions: the Neolithic steles of Reguers de Seró (Lleida, Spain)

Weathering patinas in rocks are the result of interaction processes between rock surfaces and atmosphere, biosphere and soil. Therefore, their textural and mineral composition is strongly related to environmental and bioactivity conditions. Whereas the development of weathering patinas in atmospheric conditions is well documented (e.g. typical Mediterranean patina), only very few studies focus on their formation in a burial environment. Our study of patinas developed on the tumular structure of Reguers de Seró deals with the knowledge of burial patinas from a textural and mineralogical point of view. The aims of this study include: (1) the characterisation of the rock used in this megalithic monument as well as inferences regarding the origin of the raw material; (2) the evaluation of the patinas developed on the surface of the carved steles; and (3) the discussion of the environmental conditions (atmospheric or burial) that favoured the development of the patinas. Whole rock and related patinas (powdered samples and small single pieces) were carefully sampled in five of the seven Neolithic steles discovered during a municipal excavation. Some whole rock samples from the surrounding outcrops were also collected in order to correlate them with the stone forming the megalith. Samples were analysed macroscopically, using a glass binocular, and microscopically, by means of a polarising light microscope and a scanning electron microscope (SEM-EDAX). The mineralogical composition was determined by X-ray diffraction, and a colorimetric analysis was also carried out in all the sampled patinas. The obtained results evidence a strong textural and mineralogical correlation between the whole rock of the megalith and the collected samples of the nearby outcrops; both are classified as calcarenite. A uniformly distributed beige-orange patina (35-100 microm thick) covering the surface of the steles modifies their aspect. A layer of calcite (micrite) with granular texture was detected in all the sampled patinas, being the main mineral compositions (approximately 60-90%). In contrast, a discontinuous external layer (25-50 microm thick) of botryoidally gypsum occurs on only a few patinas. SEM-EDAX analyses evidenced that Ca is related to several processes, including inorganic processes, as well as to minor bioactivity. The textural and mineralogical characteristics of the Reguers patinas differ from typical Mediterranean patina sequences, suggesting different environmental conditions for their formation. Several arguments supporting the formation of the Reguers patinas in a burial environment include: (1) patinas cover the entire surface of the steles, iconograhic motifs and fractures. The uniform colour, texture and composition of the patinas throughout the steles suggests their development after the construction of the megalithic tomb during a period in which the archaeological site was buried and sealed by the products of the Senill ravine; (2) the absence of heavy metals mainly contained in flying ashes and other depositions from atmospheric dust and pollutants in the micritic patina; (3) non-appearance of minerals directly formed by biological activity (i.e. oxalates and phosphates); (4) the absence of a well-defined textural sequence (typically of the Mediterranean area) already defined for patinas developed in an atmospheric environment; and (5) the discontinuous occurrence of an external gypsum layer (only present in a few samples) without the presence of the typical spherules related to atmospheric particulate matter. The petrographic characteristics of the Neolithic steles of Reguers de Seró show that the raw material came from a nearby outcrop. The formation of beige-orange patinas is related to a burial environment attending their textural and mineralogical features. The protective role played by these patinas indicates that no previous treatment of such steles would be necessary on an eventual exhibition in atmospheric conditions. Further in-depth studies, similar to those that already exist for patinas developed in atmospheric conditions, are recommended in order to better define the petrographic characteristics and mechanisms on the formation of patinas in burial environments.

Study on the Mechanical Property and the Evolutionary Neural Network Constitutive Model for Limestone under Chemical Corrosive Environments

In this paper, the experimental study on the mechanical property of limestone under triaxial compression with different hydrochemical environments is conducted and the non-linear characteristics of complete stress-strain process of limestone subjected to chemical corrosion, are analyzed. The behaviors of deformation and strength of limestone eroded by different chemical solutions are obtained. It is known from the experimental and analytical results that different chemical environments such as chemical composition, pH value etc can affect the mechanical property of rock differently. How to establish a multifactor characteristic constitutive model which can reflect different chemical environments is the key problem to study the coupling corrosion effect of stress and chemistry of rock. The constitutive model of evolutionary neural network for rock under chemical corrosive environments is put forward, and the neural network constitutive relationship under stress-chemistry coupling corrosion is established by applying the theory of evolutionary computation and neural network. The neural network constitutive model established in this presented paper mainly takes into account the following three aspects: chemical environments of rock specimens, content of main mineral compositions that are liable to being eroded by chemical solution, and mechanical environments. The results are in good agreement with the experimental data.

The composition of Arnoia peppers (Capsicum annuum L.) at different stages of maturity

‘Arnoia’ peppers (Capsicum annuum L. var. annuum cv. Arnoia) are cultivated in areas surrounding the Arnoia River, in Galicia (northwest Spain). Some physical and chemical changes associated with maturation and storage conditions have been reported. Changes in gross composition, the main physico-chemical parameters and mineral composition were evaluated in peppers collected directly from plants and at two different states of maturity (green and red fruits), and in commercially available peppers (green fruits). The total soluble solid content and titratable acidity increased significantly during ripening. The fat, ash and protein contents were generally significantly higher in the red pepper than in the green peppers. The total ascorbic acid in red peppers was 27% higher than that of green peppers. The vitamin C content of commercially available green peppers was up to 39% lower than in the freshly picked peppers. Potassium was the most abundant mineral in green and red peppers. Green peppers purchased in the supermarket contained higher amounts of calcium and sodium than the freshly picked peppers. The levels of zinc, manganese and copper were similar in all of the different samples.