XRF Results Research Articles

Influence of the Addition of Blast Furnace Slag to Alkali-Activated Mixtures Based on Natural Zeolites

This study focuses on a comparison of alkali-activated materials based on natural zeolites without and with the addition of blast furnace slag and their subsequent modification by acid leaching. The addition of slag to alkali-activated mixtures is generally used to increase the strength. The subsequent modification of its chemical, textural and mechanical properties by acid leaching makes this material usable in other industries, especially in the chemical industry. This study aimed to examine the influence of the addition of blast furnace slag to alkali-activated mixtures based on natural zeolites and observe the effect of subsequent acid leaching on the chemical, textural and mechanical properties and CO2 adsorption capacity of these materials. The modification of alkali-activated materials was carried out by acid leaching using 0.1 M HCl and then using 3 M HCl. The properties of these materials were determined using N2 physisorption, Hg porosimetry, XRF, XRD, DRIFT, TGA and strength measurements. The results showed that the addition of blast furnace slag significantly increased the cutting-edge strength of the obtained materials and affected the textural properties, especially in leached samples. The presence of blast furnace slag generated a higher proportion of mesopores, which are attributed to the presence of the calcium silicate hydrate (C–S–H) phase and are easily removed by leaching, as shown by the XRF results. The obtained data showed an improvement in properties and extension of the potential applicability of these materials in the chemical industry, especially for catalytic and adsorption applications.

Characterization of barite ores from selected locations in Nigeria for drilling fluid formulation

Barite is a non-metallic mineral composed of barium sulfate and is largely used by the oil and gas industry during drilling operations to control reservoir pressure. According to the American Petroleum Institute (API) standard, the specific gravity of barite should be a minimum of 4.1 to be applied as an additive in drilling fluid. In Nigeria, barite deposits are found in veins and cavity fillings hosted by varieties of rocks. Despite the abundance of barites reserves in Nigeria, the barites used in the Nigerian oil industry are imported from other countries. Therefore, in this research, barite deposits in some selected troughs in Nigeria were sampled and studied to determine their chemical composition and suitability as drilling fluid additives. The specific gravity of barites in the following states: Nasarawa, Benue, Plateau, Cross River, and Taraba was determined using the Pycnometer method, and their values were found to range from 2.9 to 4.3 on average. The quality of barite varies from location to location and with depth. The barite quality was enhanced when some low-grade barites were blended with a high grade, as shown in the blended samples of Plateau States, where specific gravity increased from 2.9 to 3.7. The results of XRF, E.D.X. and S.E.M. analysis of the samples show a predominance of BaO, Fe2O3, SrSO4, and SiO2. Samples from Benue (89.4% BaSO4) and Taraba (96.5% BaSO4) States met API standard for drilling mud application in terms of chemical composition, specific gravity, and a particle size distribution, while samples from Cross River (83.16% BaSO4), Nasarawa (77% BaSO4), and Plateau (10.88% BaSO4) States need to be upgraded to meet the standard for usage as drilling fluid additives. However, they can be used as extenders or fillers in the rubber and paper industry.

High purity hematite (Fe2O3) from beach sands for soft ferrite magnetic materials application

Actually, the potential and deposites are rich and spread in many place, but the process from raw material to industrial product is not optimal yet. In this work, the manufacture of iron sand was done using direct reduction technique by compact coals as reductor. The carbon compound of coals were using for releasing oxide in magnetite compounds (Fe3O4) of iron sand, so it could be transformed to Fe phase. The iron sand was firstly milled using high energy ball mill (HEBM) for 0, 10, 20, and 40 hours. Then the iron sands samples were mixed with coals, bentonite and compacted using hydraulic press. Then, loaded into furnace and sintered at 700 °C, 800 °C, and 900 °C. As the results, it was identified (using XRF) that the major phase was Fe2O3 (75.40 %). Consistent with XRF results, the phase composition observation by using XRD was shown that the major phase of sample was Fe2O3 (hematite). It was also shown that the crystallite size of the sample was around 8 nm, as calcultaed using Scherrer formula. The magnetic behavior investigation was showed that the decreasing in magnetic saturation value (Ms) and remanent (Br) and followed by increasing the coercivity value (Hc).

Keggin-Al13 Polycations: Influence of Synthesis and Intercalation Parameters on the Structural Properties of Al-Pillared Clays

Pillared clays are interesting materials with applications in catalysis and adsorption processes. To obtain these materials, several preparation procedures are necessary and must be optimized to tune the final properties of the resulting pillared clay. Therefore, this article reports the influence of synthesis parameters (temperature and concentration) of Keggin-Al13 polycations and different intercalation times (0.5 up to 72 h) on the structural properties of Al-pillared clays. The natural clays are from Brazil, and they are composed mainly of montmorillonite. By XRD, N2 sorption, XRF and 27Al NMR results of the Al-PILCs, we verified that the pillaring solution could be prepared at room temperature with an aging time of 24 h. For the cation exchange process, a period of at least 2 h is necessary to ensure the formation of pillared materials. The concentration of the Keggin-Al13 polycations was evaluated by using diluted pillaring solutions followed by applying re-pillaring procedures. After submitting the pillared clay to another pillaring process, the number of pillars in the interlamellar space increased; however, the micropore volume decreased concomitantly. Thus, by optimizing the synthesis conditions of the Keggin-Al13 polycations, Al-PILCs could be obtained with good values of basal spacing and specific surface area.

Experimental study of UV/water-spray coupled hydrothermal accelerated aging on fire resistive of intumescent coatings for steel structures

In this paper, the durability of fire resistive performance of two types of water-borne intumescent coatings was studied using UV/water-spray and hydrothermal accelerated aging. Exposure conditions Type X intended for all environmental conditions with reference to ETAG-018-2 was used as the aging method. The aging effects and mechanism were preliminary analysed using fire test, adhesive test and X-ray Fluorescence spectrometer (XRF). The results show that after 2 stages of aging (for the intended use of 10 years), type-B coating shows better durability while type-A coating losses its basic performance of fire resistive and adhesion. Visually assessment and XRF results show that the aging is mainly caused by surface cracking and the precipitation of fire resistive components.

Vacuum-arc synthesis of metal-organic framework structures based on ZrO2

The vacuum-arc synthesis of nanopowders based on zirconium oxide and metal-organic framework structures was carried out using a low-pressure arc discharge plasma. The obtained material was studied by several methods (XRF, IR, TEM, DTA). The TEM method showed that Zr-MOK is a highly agglomerated particle of an almost spherical shape. The image clearly shows the crystalline ordering of nanoparticles with a large (about 2 nm) lattice parameter. Particle sizes range from 5 to 30 nm. Average particle size 9.4 nm. XRD showed that the proportion of ZrO relative to Zr-MOK, calculated from the most intense lines of the diffractogram, is 65%. XRF results are in good agreement with IR studies. The DTA curve demonstrates a continuous exothermic process associated with a number of features of the plasma-chemical synthesis and morphology of the resulting nanoparticles, which is in full agreement with studies using transmission microscopy.

Elemental analysis of biochar-based fertilizers via portable X-ray fluorescence spectrometry

A complete elemental characterization of biochar samples is needed prior to their use for agronomic and/or environmental purposes. Elemental analyses of biochar are still a challenge mainly due to some difficulties to achieve a total digestion of the samples for clearly identifying and quantifying elements of interest. The hypothesis of this study is that X-ray fluorescence spectrometry will be a useful, fast, and accurate alternative method to obtain the total elemental composition of biochars. Thus, this work aimed to evaluate the performance of pXRF for the determination of P, K, Ca, Mg, S, Na, Al, Fe, Mn, Zn, and Cu in 31 biochar-based fertilizers, comparing these results with the standard method of biochar samples digestion (modified dry-ashing method — MDA). Moreover, the biochar samples were also characterized via wavelength dispersive X-ray fluorescence (WDXRF) for comparison with portable X-ray fluorescence (pXRF) spectrometry. For all elements and biochar samples, adequate linear regression adjustments between methods were achieved. For the lightest elements (P, Ca, Mg, S, Na, and Al) the concentrations obtained via MDA were higher followed by WDXRF and pXRF. Conversely, for the heaviest elements (Fe, Mn, Zn, and Cu), XRF results (pXRF and WDXRF) were higher than MDA. Significant linear regressions between methods were obtained, mainly for plant micronutrients (Fe, Mn, Zn, and Cu), suggesting that standard-curves can be obtained in order to develop pXRF applications like a “Biochar Mode” by the manufacturers. Portable X-ray fluorescence spectrometry showed encouraging results allowing a rapid and environmentally-friendly characterization of biochar-based fertilizers.

Sintesis Hidroksiapatit dari Tulang Ikan Sapu-Sapu (Hypostomus plecostomus) dengan Metode Presipitasi

Fish bone contains about 62.31% CaO and 37.46% P2O5 so that it can be used as hydroxyapatite material. This composition is also contained in the bone of the broom fish (Hypostomus plecostomus) which is known from the XRF test. Therefore, the purpose of this study was to determine the phase and functional group of hydroxyapatite from broomstick fish bones. Synthesis of hydroxyapatite from broomstick fish bones using the precipitation method, namely as much as 7 grams of CaO dissolved in 100 ml of distilled water and heated at 90°C then added 100 ml of 0.6 M H3PO4 to obtain a clear solution. Then the solution was added with 1 M NaOH until it reached pH 10, allowed to stand for 24 hours and a precipitate was formed. After that, it was heated at a temperature of 900°C with a holding time variation of 5 hours and 7 hours and then cooled at room temperature. The results of this synthesis were characterized by XRD and FTIR. Based on the XRF results, the broom fish bone has a CaO content of 81.37%. The main phase of hydroxyapatite was formed optimally at a holding time of 7 hours and had a crystal size of 32.39 nm which was calculated based on the Scherrer equation. FTIR results show that hydroxyapatite consists of three main functional groups, namely phosphate , hydroxyl (OH-) and carbonate in the wave range of 4000 cm -1 – 500 cm -1 . Thus, in this study, hydroxyapatite from broom fish bones was successfully synthesized. Keywords : Hydroxyapatite, CaO, broom fish bone, Precipitation.

Removal performance for thermotolerant coliforms and fecal streptococci from dairy effluents by Kenadsa\u2019s natural green clay (Bechar-Algeria) in a fixed-bed column

This present work is a part of the liquid discharges treatment topic by studying the removal performance for thermotolerant coliforms (FC) and fecal streptococci (F.Strep) by a local natural light green clay from Kenadsa (Bechar-Algeria) under continuous adsorption processes in a fixed-bed column. The study estimated the clay adsorbing efficiency by the adsorption technique for bacteria contaminating the dairy effluent by determining the bacterial load before and after treatment. The mean log counts per 100 ml for FC and F.Strep were assessed by MPN method on liquid medium. The clay material characterizations were made through X-ray diffraction, X fluorescence spectrometry and Fourier transform infrared spectroscopy analysis. Besides, some parameters were estimated such as the breakthrough time tb (clay filter breakdown); the amount of the contaminating bacteria that was removed at the breakthrough time Xb and the exhaustion of disinfection capacity Xe; the total amount of contaminating bacteria flowing through the column Xtotal; and the total removal efficiency (Y). According to the XRD, XRF and FTIR results, the predominant mineral constituents were silicon dioxide, aluminum oxide, ferric oxide and magnesium oxide with rates of 59,44; 18,09; 7,79; and 3,87%, respectively, and hence, their classification among non-swelling clay minerals, illite is the major mineral group of this material. The results of the bacteriological analysis of raw dairy effluents showed an average bacterial load of 3,88 Log10 and 4,1 Log10 CFU/100 mL for FC and F.Strep, respectively, exceeding the thresholds set by the national and the international regulations. The results of the dairy effluents treated by the tested material have shown that the used clay has a relatively high adsorption property for the clay fixed-bed system (3 cm of bed height), expressed by a total removed efficiency Y (%) of FC and F.Strep used to evaluate the column performance ranging from 55 to 84%. It gives a higher log removal for FC and F.Strep (0.98–1.65 Log10) reported from the first adsorption process, and a breakthrough time ranged from 100 to 250 min, which was inversely proportional to the initial bacterial load of discharges and also linked to the nature of the bacterial contaminants. When the breakthrough occurs earlier, the column service life will be shortened. For the studied parameters, the results of treated effluent complied with national and WHO regulations for unrestricted agricultural irrigation, otherwise, as authorized effluents to be discharged into nature without risks. These preliminary results are very promising at laboratory scale as an innovative green technology, treatment method respecting the environment and opens up prospects for the future, where the modification or the optimization of operating conditions such as the bed height of the fixed bed for adsorption, the volumetric flow rate or the clay structure like the particle size distribution of the adsorbents, known as one of the adsorbent classes endowed with an antimicrobial property, can improve the column performance, and further, the removal or even more the disinfection process by adsorption method.

The Effect of Cu (II) on Swelling and Shrinkage Characteristics of Sodium Bentonite in Landfills

Wastes in municipal landfills will release heavy metal cations over a long period of time. Therefore, the objective of this paper was to investigate the effect of copper (Cu) in the leachate from landfill on the swell-shrinking potential of bentonite liner. Copper sulfate solution with 4 different groups of concentrations (0 g/L, 2.5 g/L, 5 g/L, 10 g/L) were added to bentonite for conducting a series of swelling and shrinkage experiments. Then the Does Response model was used to describe the swelling and shrinkage process of bentonite in different copper sulfate solutions and the applicability of the model was evaluated. At the same time, clay mineral analysis experiments (XRD and XRF) were carried out to analyze the variation of interlayer space and element content of montmorillonite. The results show that the swell volume of bentonite decreases with the increase of the concentration of Cu (II). The rate of swelling was high and inversely proportional to the concentration of Cu (II). The shrinkage curve of bentonite could be divided into uniform velocity stage, variable velocity stage, and stable stage. The shrinkage rate at the uniform velocity stage and shrinkage at the stable stage decreased with the increase of the concentration of Cu (II). The model was suitable for describing swelling (or shrinkage) curves with smaller expansibility (or shrinkage). Results of XRD and XRF show that the erosion of Cu (II) led to the decrease of Na+ content in sodium bentonite, and then narrowed interlayer space of montmorillonite. When the solution concentration increases, both values of interlayer space of montmorillonite and Na+ content in sodium bentonite become lower, and that led to swelling and shrinkage of bentonite liner was getting smaller and smaller.

Effective removal of hydrogen sulfide using Mn-based recovered oxides from recycled batteries

The use of clean and environmentally friendly renewable energy as well as the minimization of waste disposal are fundamental aspects to be considered nowadays in a circular economy approach. In this way, the development of efficient systems for sulfur removal in biomass and waste gasification is of key relevance and the use of recycled materials will provide an opportunity to combine the reduction of waste‘s production and the application of circular economy principles.Sorbents from waste powder of recycled batteries have been prepared at laboratory scale. Subsequently, their potential application to syngas cleaning is evaluated specifically for H2S removal. Lab-scale tests at 400°C, 10 bar and space velocity of 3500 h−1 were carried out using first a simplified gas mixture of 0.9% H2S in N2 and then a more complex one consisting of 20% H2, 40% CO and 0.45% H2S/N2 to investigate the effect of reducing components, CO and H2 co-existing with H2S in any syngas. Sorbent utilization values as high as 80% (w/w, %) were obtained when tested under realistic syngas composition. XRF, XRD, XPS, TEM and textural characterization results of fresh and sulfided samples showed that those materials with higher Mn contents showed higher H2S removal capacity although the Mn/Zn ratio demonstrated to play a crucial role in their selectivity to form sulfides. Additionally, plausible mechanisms for H2S removal are discussed where the influence of composition, structure and morphology of the recovered binary metal oxides on sulfur removal efficiency is analysed.

Trace elemental fingerprinting of Ayurvedic formulation Nishakatakadi using XRF and NAA

XRF and NAA techniques have been used for the determination of major, minor, and trace elements in Ayurvedic compound formulation Nishakatakadi, a preparation used for the treatment of diabetes mellitus. The concentration of major elements Al, Ca, Cl, K, Mg, P, S, and Si, minor elements Na, Fe, and Ti, and trace elements, Ba, Br, Cr, Co, Cs, Cu, Mn, Pb Rb, Sr, La, Sm, W, and Zn, were determined. The accuracy of the result was evaluated by analyzing NIST certified reference sample. A good correlation between the results of XRF and NAA has been observed for elements detected using both the methods in the individual herbs analyzed. Elemental profile of the herbs and formulations so generated can serve as a fingerprint data of the herbs and formulation that can be used for quality assurance of the formulations

Estudio de materiales de construcción vernáculos empleados en el patrimonio cultural: guía para la restauración arquitectónica del Colegio Máximo de Cartuja. Granada-España (siglo XIX)

El Colegio Máximo de Cartuja en Granada fue construido por los jesuitas en el siglo XIX. El estudio arqueométrico de sus materiales: ladrillos, azulejos, vidrieras y morteros, define el concepto vernáculo de esta construcción, referenciada en el marco geológico de la “formación Alhambra”, junto a la identificación de materias primas y técnicas utilizadas por los nazaríes desde el siglo XIII. Los resultados de XRD, XRF y DTA confirman el uso de arcillas locales para fabricación de ladrillos y losetas que se hornearon a temperaturas de ≤750 ºC. Las arcillas debieron contener aditivos de NaCl que beneficiaron la sinterización cerámica, y se comprobó el uso de colores de tradición nazarí (Cu, Fe, Sn) en los esmaltes y vidrieras. Las materias primas locales también se usaron para producir aglomerantes aéreos. Estos resultados se han combinado para crear una guía de buenas prácticas para la restauración sostenible de los edificios del patrimonio cultural.

Assessing the role of lichens in the prevention of dust emission in dryland: Case study at north-eastern Iran

Abstract The dominance of aeolian processes in arid areas created a harsh environment in these regions for soil and vegetation where soil fertility, ecosystem productivity, air clarity, and human health is dependent to aeolian activities and rate of dust emission. Biological soil crusts (bio-crusts) are the communities of living organisms on the soil surface which play an important role in soil ecosystem services in arid land. Lichens are known as organisms that can accumulate certain elements or substances at high concentrations in the atmosphere. The relation between lichens species and soil geochemistry as well as dust capture in geomorphic zones in north-eastern Iran were studied. Different lichens species and soil particles were analyzed by a scanning electron microscopy (SEM-EDS). The results of XRF and XRD analysis showed lichen crusts affected soil mineralisation. By creating microtopography, indicated the lichens trapped dust. They also increased the amount of clay on the soil surface. The results indicted the significant role of lichens in soil ecosystem services dryland.

Top-Down Synthesis of NaP Zeolite from Natural Zeolite for the Higher Removal Efficiency of Cs, Sr, and Ni

A solid phase of natural zeolite was transformed to Na-zeolite P (NaP zeolite) by a “top-down approach” hydrothermal reaction using 3 M of NaOH solution in a 96 °C oven. Time-dependent X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), XRF, and scanning electron microscopy (SEM) analysis as well as kinetic, isotherm, and cation exchange capacity experiments were performed to understand the mechanism of mineral transition from natural zeolite to NaP zeolite. The XRD crystal peaks of the natural zeolite decreased (decrystallization phase) first, and then the NaP zeolite XRD crystal peaks increased gradually (recrystallization phase). From the XRF results, the dissolution rate of Si was slow in the recrystallization phase, while it was rapid in the decrystallization phase. The specific surface area measured by BET analysis was higher in NaP zeolite (95.95 m2/g) compared to that of natural zeolite (31.35 m2/g). Furthermore, pore structure analysis confirmed that NaP zeolites have more micropores than natural zeolite. In the kinetic experiment, the results showed that the natural zeolite and NaP zeolite were well matched with a pseudo-second-order kinetic model, and reached equilibrium within 24 h. The isotherm experiment results confirmed that both zeolites were well matched with the Langmuir isotherm, and the maximum removal capacity (Qmax) values of Sr and Ni were highly increased in NaP zeolite. In addition, the cation exchange capacity (CEC) experiment showed that NaP zeolite has an enhanced CEC of 310.89 cmol/kg compared to natural zeolite (CEC = 119.19 cmol/kg). In the actual batch sorption test, NaP zeolite (35.3 mg/g) still showed high Cs removal efficiency though it was slightly lower than the natural zeolite (39.0 mg/g). However, in case of Sr and Ni, NaP zeolite (27.9 and 27.8 mg/g, respectively) showed a much higher removal efficiency than natural zeolite (4.9 and 5.5 mg/g for Sr and Ni, respectively). This suggests that NaP zeolite, synthesized by a top-down desilication method, is more practical to remove mixed radionuclides from a waste solution.

Adsorption of chromium (VI) and iron (III) ions onto acid-modified kaolinite: Isotherm, kinetics and thermodynamics studies

The pollution of aquatic bodies by heavy metals effluent from many industrial activities is a significant environmental challenge affecting the ecosystem. Batch process was conducted to remove Cr (VI), and Fe (III) with hydrochloric acid modified clay (HMC) and acetic acid modified clay (AMC). The adsorbents morphology, chemical properties were measured by scanning electron microscope (SEM), X-ray fluorescence spectrometry (XRF), cation exchange capacity (CEC), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET). The effects of time, adsorbent dose, temperature and pH of effluent on adsorption were studied. The acid activation increased the BET surface area from 84.223 m2/g raw clay (RC) to 389.37 m2/g (HMC) and 319.955 m2/g (AMC), total pore volume increased to 0.2168 and 0.2285 cm3/g, respectively. The CEC increased from 8.4 cmol/g to 22.30 cmol/g (HMC) and 20.73 cmol/g (AMC). The results of XRF, SEM and XRD studies show disintegration and a porous structure of the treated clay, and also changes in the intensity of the bands. The HMC had a maximum removal of Cr (VI), and Fe (III) of 79% and 90% at pH 7.0 and AMC recorded 60% and 57% at pH 6.0, respectively. The adsorption process equilibrium was attained at 50 and 90 min for HMC and AMC, respectively. Langmuir isotherms had the best fit. HMC and AMC adsorption capacity are, Cr (VI):18.15 mg/g and Fe (III):39.80 mg/g; Cr (VI): 10.42 mg/g and Fe (III):19.34 mg/g. The interaction of Cr (VI) and Fe (III) ions onto HMC/AMC was spontaneously endothermic. It agreed with the second-order equation. The maximum desorption efficiency recorded on HMC is 92.45 and 85.67% for Cr (VI) and Fe (III) and for AMC is 76.58 and 65.32% for Cr (VI) and Fe (III). The process is economically important because it provides an avenue for safe disposal or reuse of adsorbent. This attempt has shown the potential of modified clay as a suitable eco-friendly sorbent for removing heavy metals.

Results accuracy of the simultaneous Na, K, Li, Rb and Cs determination in geochemical objects using the flame atomic emission spectrometry

One of the most important challenges in the simultaneous determination of the five alkaline elements is that their abundance differs thousands of times in natural samples. Therefore, usually the analysis of the same samples is performed using several analytical methods or techniques. An atomic emission spectrometry is the most selective method for the determination of alkaline elements in wide ranges of their contents. The reliable and correct simultaneous determination of major and trace elements contents by one method is economically attractive for classifying rocks, reconstructing the conditions of their formation, etc. The atomic emission spectrometry technique of the simultaneous determination of the five alkaline elements was developed with the use of the modern equipment. The accuracy and trueness of the developed technique results were evaluated in the current study. The technique features were the preparation and the analysis of the high-salt solutions of the geochemical samples, and the use of a low-temperature propane-butane flame and multichannel photoelectric recording of the spectra for the simultaneous determination of alkali metals contents. A specific data processing ensured accounting for the spectral background and minimizing the interferences when calibrating by CRMs with various compositions and genesis. The determined concentrations ranges of alkaline elements in natural and man-made environments had been expanded by improving the detection limits and using several analytical lines of Na, K and Rb with different spectral features. FAES results were compared with the results of XRF, ICP-MS, the standard addition and dilution methods, and its accuracy and trueness were found to be satisfactory for the requirements of geological and geochemical studies.

Evaluation of heavy metal content of salts between Eskıkışla and Ocakbaşı (Kırıkkale) villages

Salt, which is the main nutrient, is a very important raw material in the life of living organisms and industry. Salt production and consumption have improved and increased due to technological developments and industrialization. Salt has been used in the world and in our country since very ancient times. It is used in many fields, especially in the chemical industry, metallurgy, textile, medicine, and agriculture. In addition to sea, lake and spring salts, Turkey has very rich rock salt reserves. The Neogene aged Çankırı-Çorum Basin is one of the important basins where evaporitic formations are observed in the Central Anatolia region. Chemical analyses were carried out to determine the amount of heavy metal in salt samples taken from Oligocene aged units observed in the area between Ocabaşı and Eskikışla springs (Delice) in the Çankırı-Çorum basin. SEM-EDX, XRF and ICP-OES devices were used to determine the geochemical properties and quantities of heavy elements. According to the results of XRF, Na % ( 33.70-38.30), Cl %(52.10 - 57.70) SO3 %(0.75-1.93), Al2O3 %(0.90-1.93), CaO %(0.58-2.69), MgO %(0.40-1.41) Fe2O3 % (0.18-0.64), SiO2 %(1.75-4.95), SrO, % (<0.010), BaO % (<0.010), Cr2O3 %(<0.010), K2O %(0.008-0.25), MnO %(<0.010) results are found. In the determination of heavy metals made with ICP-OES, it was determined that the heavy metals (Hg, As, Pb, Cd) published in the Turkish food codex salt communiqué were below the limit values.

Investigation on Metal Adornments From Ancient Eastern Europe

This study focuses on the investigation of certain bronze adornment objects from the First Iron Age (the so-called middle Hallstatt period), dating to the ninth–eighth c. BC. These objects are part of a bronze and iron hoard (labeled Cx 116) discovered in the present Romanian territory, at Tărtăria–Podu Tărtăriei vest archaeological site, in Alba County. Along with a second hoard of bronze and iron objects, this represents a unique discovery for the present Romanian territory, namely, for the inner Carpathian area and the Lower and Middle Danube Basin, where no such votive discovery had been made by archaeological excavations. The objects, approximately 450 bronze and iron objects—weapons, tools, adornments, and harnesses—were found in the two hoards, in the Southern ditch, which outlines the archaeological site. Digital radiography has been used to assess the physical state of the objects and to identify potential specific craftsmanship details. It showed a fairly good preservation status, with incipient corrosion processes located in the core of some of the objects and some specific traces of the crafting process and subsequent mechanical defects were highlighted. The relatively good state of preservation of the objects can result from the fact that they had been protected from the humid environment by the ceramic vessel they were placed in. XRF and LIBS were used to identify the materials and to stratigraphically evaluate the objects. XRF scanned the surface of the objects, revealing elements related to both the raw material—a copper alloy with tin and lead, together with trace elements related to the specific mining location of the ores, and the depositional environment of the objects–such as iron. LIBS allowed a more in-depth stratigraphic analysis, which indicated a higher copper ratio—compared to iron—as the kinetic series advance, fact that sustains the idea that the major iron input was coming from the depositional environment. Both XRF and LIBS results were consistent with high elemental variability, probably due to the nature of the original material and the influence of the deposition soil conditions.

Studi Konsentrasi Pada Bauksit Asal Tayan Dengan Menggunakan Metode Flotasi Kebalikan

This paper is one of a study that implements reverse flotation methods as an alternative beneficiation on bauxite processing. This study is aimed to increase alumina content in bauxite so its qualified as feed of Bayer Process (Al2O3> 51%, SiO2 <7%, Al2O3 / SiO2 > 10 ratio). The experiments was focused to increase alumina content from bauxite were carried out in a 1375 mL of flotation cell tank. Dodecylamine (DDA) was used as the collector, starch as the depressant, and Dowfroth 1012 as frother. The overall experiments were conducted on solid content to solution 25% w/w and speed rotation of impeller were 900 rpm. The characterization results showed that the feed ore had Al2O3 and SiO2 content, respectively 61,24% and 27,9%. Experiments were carried out in several variations to determine what variables were most affected in the study. There were 4 variations used in this study, size fraction of particle, collector dosage, pH of slurry and with the addition of / without the addition of depressants. Alumina content as results of flotation was analyzed by XRF. The results of XRF of flotation products show that increasing of alumina content. The optimum pH range of bauxite flotation using DDA as collectors can be achieved at pH 4 – 10. From the results, The increasing of collector dosage at pH 10 gives a good result on Al 2 O 3 content is 62% with 50,44% recovery of Al 2 O 3 obtained at dosage of collector at 500 g/ton. The Al 2 O 3 content which higher in conditions without the addition of depressant is 66,8%. While for the size fraction variation, it shows that separation better in the finer particle which gives an increasing of alumina and decreasing of silica as a result. The best condition in this study were achieved by 400 g/ton of DDA dosage, 400 g/ton of depressant dosage and size fraction of particle in -325 mesh at pH 10 with increasing alumina to 79.1%.