High Fe Content Research Articles

Magnetic properties and microstructure of Pr-Fe-B thin films under effect of Fe content

The magnetic properties and microstructure of Pr-Fe-B thin films with addition of Fe composition were investigated. Fe was added during the deposition process of Pr-Fe-B layer on Si3N4 underlayer and glass substrate. XRD measurement indicated the appearance of Pr2Fe14B and Pr2Fe23B3 phases in the thin films. The thin films at low Fe content revealed a strong reflection of Pr2Fe23B3 phase. Magnetic measurement showed that high Fe content caused a decline of the magnetic properties of the thin films. A proper Fe content of at 75.53 at.% showed a high coercivity and the presence of magneto-crystalline anisotropy. SEM and AFM results showed the surface characteristics of the thin films. XRD and TEM results indicated the formation of Fe3Si layer at the interface of Pr-Fe-B layer/Si3N4 underlayer. The Fe3Si phase only promotes the epitaxial growth of Pr2Fe14B phase. XPS depth profile demonstrated the distribution of atoms in microstructure of the thin films.

Nanocrystallization, magnetic properties and bending ductility of antiferromagnetic Mn-doped FeSiBCuPC alloys induced by micro-compressive stress annealing

Insufficient amorphous forming ability (AFA) and thermal instability have always been the bottleneck restricting the application of high Fe content iron-based nanocrystalline soft magnetic materials. In this work, the effects of micro-compressive stress annealing (MCSA) on microstructure, soft magnetic and mechanical properties of high Fe content FeSiBCuPCMn alloys were systematically investigated. We demonstrate that Mn doping effectively increases the AFA of the alloys and improves the thermal stability of the amorphous matrix. The change of coercivity (Hc) is closely related to the grain size, which depends on the Mn content and annealing process. It clearly shows that a small amount of Mn doping (≤3 at%) and MCSA can inhibit the excessive growth of α-Fe grains and reduce the grain size. Moreover, the low Mn-doped amorphous alloys exhibit good bending ductility even after annealing at appropriate conditions. After MCS-annealing at 420 °C for 10 min, the Mn-doped Fe85−xSi1.3B9P4Cu0.5C0.2Mnx (≤3 at%) nanocrystalline alloys exhibit comprehensive and excellent soft magnetic and mechanical properties, such as high Bs of 1.79–1.87 T, low Hc of 4.6–9.9 A/m and low Hv of 737–867.

Corrosion Behaviors of Super Austenitic Stainless Steel Weld Joints in the As-Welded and Post Weld Heat Treated States

The corrosion behaviors of a combined weld (plasma, gas tungsten arc) joint in a super austenitic stainless steel pipe were investigated using a range of experimental and analytical methods. To ensure superior corrosion resistance, a Ni-based super alloy (Inconel 625) was employed as the welding material only in the gas tungsten arc welding (GTAW). Nevertheless, pitting corrosion occurred preferentially around the sigma phase which had been precipitated in the interdendritic region of the GTAW. This indicated that the Inconel 625, which has a higher pitting resistance equivalent number (PREN), became even more susceptible to pitting corrosion than the base metal (BM). The higher Fe content in the Inconel 625 due to the dilution of Fe, supplied by the leading plasma arc welding, may increase the driving force for the precipitation of sigma phase. It was also revealed that the post weld heat treatment conducted at 1050~1150 oC effectively reduced the fraction of sigma phase precipitated in the weld. Even after such heat treatment, however, pitting corrosion occurred unexpectedly in the center region of the BM. This may be due to additional precipitation of the sigma phase in the BM, caused by inadequate control of the cooling rate during heat treatment at the industrial site.

Abiotic and biotic regulation on carbon mineralization and stabilization in paddy soils along iron oxide gradients

Iron (Fe) oxides regulate soil organic carbon (C) content via balancing C processes of stabilization and mineralization. However, abiotic and biotic mechanisms are involved in stabilization (e.g., by adsorption and/or co-precipitation) and decomposition (e.g., by shifting the microbial community) of paddy soil rich in iron oxides remains poorly understood. We examined the mineralization and stabilization of maize-straw-derived C (δ13C = 5000‰), soil priming effects (PE), and soil microbial community structure in four paddy soils, along with Fe oxide concentrations gradient ranging from 13.7 to 55.8 g kg−1 soil (Fe-13, Fe-25, Fe-42, and Fe-55). The paddy soil with the highest Fe content (Fe-55) stabilized 20.5 mg 13C kg−1 soil of the maize-straw-derived C, being significantly greater (P < 0.05) than Fe-13 (5 mg 13C kg−1 soil). The high C:Fe molar ratio of Fe-55 suggests the main pathway of stabilizing the maize-straw-derived C via co-precipitation as Fe-OM. Larger stabilization in Fe-55 led to less CO2 emission from maize and SOM, e.g., Fe-55 had 12–16% lower straw mineralization and 8–11% lower PE than Fe-13 during the first 7 days of incubation. Random forest analysis further revealed that Proteobacteria and Actinobacteria (the keystone species, i.e., Gaiella) gave the largest contribution to maize-straw mineralization and PE, while microbial diversity and some microorganisms featured with filamentous hyphae contributed to C stabilization. This study confirmed that the concentration of Fe oxide in paddy soils plays a central role in C sequestration via biotic and abiotic processes, including i) modulation of microbial community diversity and composition, especially the abundance of fungi and Actinobacteria, and ii) physicochemical stabilization of maize-straw-derived C through the formation of Fe-OM complexes via co-precipitation.

Preparation of EDTA modified cotton fiber iron complex and catalytic properties for aqueous Cr(VI) reduction and dye degradation

Abstract Cotton fabric was modified with Na2EDTA using a hydrothermal method to introduce surface hydroxyl groups, and subsequent coordination of Fe(III) ions to produce an Na2EDTA modified cotton-fiber-Fe complex (Fe-EDTA-Cotton). After characterization by SEM and FTIR, Fe-EDTA-Cotton was used as a heterogeneous photocatalyst to reduce Cr(VI) and degrade Reactive Red 195 oxidatively, to evaluate its catalytic activity. The results indicated that high Na2EDTA and/or NaH2PO4 concentrations, and/or high hydrothermal temperature increased the carboxyl group content (QCOOH) of the cotton fiber; high Fe content and elevated temperature could enhance coordination. Fe-EDTA-Cotton had a significant photocatalytic function in reducing Cr(VI). Increasing the QFe value of the complex or stronger irradiation favored photocatalytic reduction of Cr(VI) species. Increasing the system's pH did not help the reduction reaction. Fe-EDTA-Cotton could also remove Cr(VI) and Reactive Red 195 simultaneously from aqueous solution, and showed strong photocatalytic capacity. The reduction or oxidation reaction could be regulated by changing Na2S2O8 concentration in the reaction system, which might provide a new way to treat wastewater containing organic pigments and Cr(VI) species. Highlight Hydrothermal process enhanced EDTA modification of cotton fabric EDTA-modified cotton fiber Fe complex was prepared Cr(VI) removal was improved by its synergistic effect Fe complexes can remove Cr (VI) and organic dyes from aqueous solution in one bath The work might provide a new way to purify the wastewater containing organic pigments and Cr (VI) species.

Iron availability allows sustained cyanobacterial blooms: a dual-lake case study

ABSTRACT Lakes dominated by cyanobacterial harmful algal blooms (CyanoHABs) are geographically widespread. These blooms are associated with fish kills and toxin production and have negative impacts on human health. There is compelling evidence that, in addition to nitrogen and phosphorus, iron (Fe) can also regulate CyanoHABs. Low Fe concentration (tens of ng L−1) has been documented to limit CyanoHABs in freshwaters, whereas high Fe concentration (hundreds of μg L−1) can promote CyanoHABs. However, the extent to which Fe influences CyanoHABs in lakes that lack an extensive anoxic zone and where the Fe concentration ranges from tens to <400 μg L−1 is unclear. The aim of this study was to assess Fe trends, measured as dissolved Fe (DFe), associated with cyanobacteria dynamics in lakes in northwestern Iowa. We utilised a multiwavelength fluorometer to monitor and classify phytoplankton based on their unique fluorescence spectra from chlorophyll a (Chl-a) and accessory pigments. Here we report a declining DFe trend (drawdown) potentially due to phytoplankton uptake in East Okoboji and its effect on CyanoHABs. Multiwavelength fluorescence data show cyanobacteria peaked (>50% cyanobacteria Chl-a) during a DFe minimum. The DFe is inversely correlated with phosphorus, suggesting decoupled Fe and phosphorus cycling. The strong positive correlation between phosphorus and cyanobacteria Chl-a supports a role for phosphorus in triggering CyanoHABs. This study suggests an underlying mechanistic role of Fe on CyanoHABs; the intermediate range of Fe concentrations investigated here may be sufficient to sustain CyanoHABs.

New cognitions into three new classified titanaugite in mineralogical characteristics and fundamental performances

Three new classifications of purified titanaugite named as titanaugite-1, titanaugite-2, and titanaugite-3 were studied in chemical composition and structure, magnetic performance, surface property, and flotation performance. The chemical composition and structure analyses showed that titanaugite-1 with high Al content, titanaugite-2 with high Ca, Mg, and Si contents, and titanaugite-3 with high Fe and Ti contents owned the same crystal structure (Mg, Fe, Al, Ti)(Ca, Mg, Fe)(Si, Al)2O6, but displayed some differences in main (310), (220), (221), and (−221) surfaces. The magnetic performance analyses presented that the specific susceptibilities of ferromagnetic titanaugite-3 and paramagnetic titanaugite-2 were greater than that of paramagnetic titanaugite-1. The surface property analyses confirmed that the isoelectric points (IEP) of titanaugite-2 (pH = 5.70) and titanaugite-1 (pH = 4.15) exhibited the positive shifts than that of the titanaugite-3 (pH = 3.73). The flotation performance analyses demonstrated that the floatability differences of three titanaugite were corresponding to the adsorption differences of NaOL on their surfaces, in turn, titanaugite-2 > titanaugite-1 > titanaugite-3. Meanwhile, the differences of interaction energies of NaOL on different surfaces of titanaugite were (310) < (220) < (221) < (−221). Titanaugite-2, titanaugite-1, and titanaugite-3 owed the surfaces of (310), (220), and (−221) with intense diffraction peaks, respectively, which was matched with their floatability differences. This study provided a novel understanding of these mutative titanaugite and their ore properties.

Design of Fe-containing GdTbCoAl high-entropy-metallic-glass composite microwires with tunable Curie temperatures and enhanced cooling efficiency

Through designing the composition and processing approach, the non-equiatomic (Gd36Tb20Co20Al24)100-xFex (x = 0, 1, 2 and 3 at.%) high-entropy-metallic-glass (HE-MG) alloy microwires were successfully fabricated by melt-extraction technique. The microstructure and magnetocaloric properties of the microwires were systematically investigated. The microwires possess tunable Curie temperatures, i.e. 81–108 K, above the typical rare-earth (RE) containing HE-MG reports. The high Curie temperatures are attributed to the designed composition. Magnetocaloric response peak values of Fe-containing GdTbCoAl alloy microwires range 7.6–8.9 J kg−1 K−1 (5 T), which are comparable to those of many outstanding RE-containing magnetocaloric HE-MGs. The characteristics of the melt-extraction method, combining with compositional effects, favor the formation of amorphous and nanocrystalline phases. The increase in the cooling efficiency for microwires with higher Fe content can be attributed to the broadening of the Curie temperature distribution induced by the composition difference between nanocrystalline phase and amorphous matrix. The designed composition and the melt-extraction processing approach for Fe-containing GdTbCoAl alloys can tune their Curie temperatures towards a temperature range of natural gas liquefaction and improve their magnetocaloric properties. This demonstrates that Fe-containing GdTbCoAl HE-MG composite microwires have great potential as high-performance magnetic refrigerants.

Deteriorated corrosion performance of micro-alloyed Mg-Zn alloy after heat treatment and mechanical processing

The corrosion performances of the as-cast and solution-treated Mg-0.5Zn samples were investigated in 0.9% NaCl solution and compared. From the electrochemical measurement results and corrosion morphology observations, it is found that the corrosion resistance of Mg-0.5Zn deteriorated with the extension of solution treatment duration. The main reason was the formation of Fe-Si precipitates with higher Fe concentrations during heat treatment. The Fe-Si precipitates, especially the ones with high Fe contents influenced the corrosion initiation and propagation significantly. In regard of corrosion performance, the solution-treated and then extruded sample was also performing not as good as the cast and then directly extruded sample.

Development of phenotypic markers and contrast genotype candidates of target minerals related to cassava

Abstract. Pratama SN, Sudarsono, Ardie W, Khumaida N, Sukma D. 2021. Development of phenotypic markers and contrast genotype candidates of target minerals related to cassava. Biodiversitas 22: 3049- 3056. Cassava leaves have various macro and micro-nutrients with varying levels, such as magnesium, iron, and zinc. The differences in genotypes of cassava may result in different mineral content in cassava leaves. This study aims to determine the estimator phenotypic markers and contrast genotype candidate selection related to target minerals. This study used a one-factor treatment composed of 12 cassava genotypes and arranged in a randomized block design (RBD) which each treatment was repeated 3 times. The observation was conducted on the leaves' qualitative and quantitative characters such as plant growth, leaf morphology, and leaf mineral content characters. The observation was performed at 3 and 6 months after planting. The results showed that the quantitative and qualitative characters that could be used as estimator for mineral content in cassava leaves are the Soil Plant Analysis Development (SPAD)- Chlorophyll value and leaf color. Genotypes G6-1-15-4-3, G6-2-15-1-1, G6-2-15-3-3 (lowest) and Malang (G4D0), G4D1-222, G3D2-413 (highest) could be categorized as contrast genotypes based on SPAD-value and mineral content. The strong positive correlation between Mg and Fe content with SPAD suggested that SPAD is a possible marker for high Mg and Fe content in leaves. Adversely, a weak relationship between SPAD and Zn content in leaves showed that SPAD is a weak marker for Zn content in leaves. Further research related to molecular markers development can be carried out based on these results.

Nutritional, Physico-Chemical and Mechanical Characterization of Vegetable Fibers to Develop Fiber-Based Gel Foods

The aim of this research was to evaluate the nutritional and physico-chemical properties of six different vegetable fibers and explore the possibility of using them as a thickener or gelling agent in food. To determine the technological, nutritional and physical parameters, the following analyses were carried out: water-holding capacity, water retention capacity, swelling, fat absorption capacity, solubility, particle size, moisture, hygroscopicity, pH, water activity, bulk density, porosity, antioxidant activity, phenolic compounds and mineral content. Gels were prepared at concentrations from 4% to 7% at 5 °C and analyzed at 25 °C before and after treatment at 65 °C for 20 min. A back extrusion test, texture profile analysis and rheology were performed and the pH value, water content and color were analyzed. As a result, all the samples generally showed significant differences in all the tested parameters. Hydration properties were different in all the tested samples, but the high values found for chia flour and citrus fiber are highlighted in functional terms. Moreover, chia flour was a source of minerals with high Fe, Mn and Cu contents. In gels, significant differences were found in the textural and rheological properties among the samples, and also due to the heat treatment used (65 °C, 20 min). As a result, chia flour, citrus, potato and pea fibers showed more appropriate characteristics for thickening. Moreover, potato fiber at high concentrations and both combinations of fibers (pea, cane sugar and bamboo fiber and bamboo, psyllium and citric fiber) were more suitable for gelling agents to be used in food products.

Effect of high Fe content on the microstructure, mechanical and corrosion properties of AlCoCrFeNi high-entropy alloy coatings prepared by gas tungsten arc cladding

Abstract Arc cladding high-entropy alloy (HEA) coatings have the advantages of low cost and flexibility. It exhibits economic value to increase the proportion of Fe element in HEA systems. As a result, low-cost AlCoCrFeNi (Fe content of 42.5 at.%, 44.9 at.%, 47.5 at.%, 50.4 at.%) HEA coatings are prepared by gas tungsten arc (GTA) cladding and their microstructure, mechanical properties, and corrosion properties are investigated by XRD, SEM, EBSD, microhardness, nanoindentation, OCP, potentiodynamic polarization, and EIS. The valence electron concentration (VEC) plays an important role in the formation of phase structure. With the increase of Fe content, the phase structure of coating alloys changes from BCC to BCC + FCC, and the morphology changes from equiaxed grains to a dendritic structure. Coating alloy with higher Fe content displays lower microhardness and more active creep deformation due to the higher FCC fraction. The dual-phase (BCC + FCC) structure induces galvanic corrosion and deteriorates the corrosion properties. This work contributes to the fabrication of large-thickness and large-area HEA coatings at a low cost and provides an experimental basis for Fe-rich HEA design.

Application of a Fuzzy Logic Based Methodology to Validate the Hydrochemical Characterization and Determining Seasonal Influence of a Watershed Affected by Acid Mine Drainage.

The Odiel River Basin, located in the Iberian Pyrite Belt (IPB), is heavily affected by acid mine drainage (AMD), which occurs when pyritic minerals from sulfide mining areas are exposed to atmospheric, hydrological or biological weathering. This paper presents a hydrochemical characterization of parameters in the Odiel River Basin by means of Fuzzy Logic and data mining methodologies to determine the seasonal influence of AMD in polluted waters that have not been used before for a basin in this environmental area. This technique was proven to be effective, providing results that could not be achieved by using classic statistics, because it allows us to characterize the different parameters separately and also their relationships in waters affected by AMD in a qualitative manner based on the antecedents and according to the conditions (rules) imposed by the consequents (in this case, the Fe(II) and accumulated rainfall over 30 days). Thus, it was possible to confirm that hydrochemistry is greatly affected by seasonal changes, with a higher pH in the wet season (up to 8.59) compared to 2.12, the minimum pH value reached in the dry season. Accordingly, higher concentrations of most of the metals were observed in the dry season (e.g., up to 4000 mg/L of Fe (II)), with the exception of the values found after the first rains that occur in the early fall. With the use of the Fuzzy Logic technique, it was observed that, during the wet season, lixiviates with a higher Fe content have higher metal concentrations, and in the dry season, the behavior is the opposite.

Geochemical and mineralogical correlations between the bog iron ores and roasted iron ores of the Podravina region, Croatia

Throughout the Podravina region, NE Croatia, over one hundred locations with signs of iron production, dating to the late Antique period and the Middle Ages, have been discovered in the last 30 years. Recently, signs of various bog iron ore types and formations were discovered throughout the area. This study investigates the mineralogical and geochemical characteristics of local bog iron and roasted iron ores. Furthermore, statistical clustering of different geochemical components in the ores is presented, while the abundance and distribution of macro-, micro- and rare earth elements (REE) and how they correlate within the bog iron ores and roasted iron ores is considered. A total of 15 samples acquired from geological investigations and 13 samples found during archaeological excavations were analysed using geochemical and mineralogical methods. In bog iron ores, X-ray diffraction (XRD) confirmed goethite and quartz as the primary mineral phases, while roasted iron ores contained several Fe minerals and had variable quartz and clay mineral contents. Chemical analyses confirmed high Fe contents in both bog iron ores (up to 70.89 mass. %) and roasted iron ores (up to 84.97 mass. %), with a distinct differentiation of Fe and Si between the different bog iron ore types. Scanning electron microscopy with attached EDS detector (SEM-EDS) showed features of laminar Fe and Mn mineralization, confirming the theory that bog iron ore forms as seasonal precipitation from groundwater. Using the hierarchical clustering analysis, a geochemical correlation of the iron component in bog iron ores and roasted iron ores was compared to other major oxides, micro- and REEs. It was established that the iron component has very little influence on REE and microelements behaviour. Therefore, microelements and REEs were used as a tracer for establishing a geographical connection between the bog iron ores and roasted iron ores in the Podravina region.

Source origin and ore-controlling factors of hydrothermal sulfides from the Tianzuo hydrothermal field, Southwest Indian Ridge

A newly confirmed hydrothermal sulfide ore hosted by ultramafic rocks was identified in the Tianzuo field on the Southwest Indian Ridge. In this study, detailed mineralogy, geochemistry, and stable isotope analyses were carried out to assess the source origin and mineralization of the Tianzuo field sulfide deposits. The mineralogical examination indicates that the massive sulfides recovered from the seafloor in this area exhibit multi-stage deposition features with four distinct mineralization stages. In terms of geochemistry, the deposit is characterized by high Fe (31.57–44.59 wt%), Co (up to 2400 ppm), and Ba contents (up to 47.89 ppm), and relatively low Cu + Zn (0.17–7.25 wt%) and Ni contents (3.74–30.6 ppm). These results somewhat different from the features of massive sulfides of the ultramafic-hosted ridge in the Atlantic Ocean. The elevated Ba and Co contents presumably reflect a contribution of deep gabbroic intrusions that, together with serpentinization, drove the high-temperature (~335 °C) hydrothermal vent activity in the Tianzuo field. The Co distribution is influenced by high-temperature and high-gradient conditions apart from the basement rock. In contrast, the depletion of Ni suggests that most of the Ni-rich sulfides are concentrated in the deep stockwork mineralization, whereas the low Cu + Zn content indicates a partial influence of the depleted mantle. With regard to isotopic composition, the sulfide in the Tianzuo field shows relatively heavy in situ S isotopic values, which implies that the widely developed transform faults and episodic hydrothermal events allowed cold seawater to repeatedly rinse the entire plumbing system. In comparison, the bulk Pb isotopic composition indicates that Pb in these sulfide deposits is mainly derived from the leaching of basalts and peridotites by seawater. By integrating all of the evidence, we demonstrate that, apart from the basement rock composition, the pervasive transform faults and multistage hydrothermal activity are important factors that affect the composition of the Tianzuo field sulfide.

Distribution of recoverable metal resources and harmful elements depending on particle size and density in municipal solid waste incineration bottom ash from dry discharge system

Although municipal solid waste incineration bottom ash (BA) has the potential to be used as a metal resource, it raises concerns about the potential release of harmful elements into the environment. Element distribution in terms of particle size and density should be assessed to determine the fractions for the metal resources’ recovery and to remove harmful elements. For this purpose, this study proposed a series of sorting processes based on the distribution of 25 elements in the sorted fractions by sieving, magnetic separation, air table sorting, and milling from dry BA < 8 mm. The Ca, Na, Mg, P, S, Cl, and Ti contents exhibited a decreasing tendency with increasing particle density and could affect the formation of low-density particles. The highest density fraction of non-magnetic components of 0.5–8 mm had abundant metal particles and recorded high Cu, Zn, Cr, Ni, Mo, Fe, Pb, Sb, and Au contents. In particular, the Cu (132000 mg-Cu/kg) and Zn (43000 mg-Zn/kg) contents demonstrated potential as metal resources. The fraction contained considerable proportions of Mo (77%), Cd (46%), Cu (39%), Zn (34%), Pb (26%), Au (40%), and Ag (18%) of the total amount. After milling and sieving of the highest density fraction, a substantial amount of Cd (44%), Cu (18%), Zn (12%), Pb (13%), and Ag (11%) were found in residual minerals; they could become harmful elements when recycled for construction purposes. The results show that air table sorting can separate metal resources and harmful elements before milling of BA.

A pretreatment method for effective utilization of copper product manufacturing waste

In South Korea, the manufacturing system from chalcopyrite (CuFeS2) to Cu products is divided into two parts: electrolytic Cu manufacturing and Cu product manufacturing (CPM). Most of the CPM waste is deposited in landfills unlike the waste generated in electrolytic Cu manufacturing that has a good recycling ability. Therefore, in this study, a method to improve the utilization of CPM waste was proposed as a case study for South Korea. Furthermore, the CPM was investigated and classified into five types in terms of the raw materials, major products, additives, main processes, and characteristics of the CPM waste (waste type, particle size, and chemical composition). Next, the CPM waste was environmentally assessed via leaching toxicity tests using the Korean standard official method, ES 06150. In addition, the amount of specific heavy metals (Pb, Cu, Cd, As, Hg, and Cr6+) was determined to confirm the presence of substances labeled as hazardous waste. Based on these results, a pretreatment method with grinding (under 0.1 mm), screening (0.15 mm grid), magnetic separation (1.0 T), and alkali leaching (30–90 °C and 1–5 mol/dm3) was proposed. The final materials can be categorized into groups, such as fine-particle groups with high Zn and Fe contents, leachate groups with high Cu and Zn concentrations, and metal-scrap groups. Moreover, material flow analysis of all CPM waste streams in the designed pretreatment method was conducted in South Korea in 2019.

A novel and high-strength Ti–Al–V–Fe alloy prepared by spark plasma sintering

ABSTRACT Ti–1Al–8V–5Fe (Ti-185) is a unique low-cost β-Ti alloy, containing lower cost alloying elements, notably Fe, as compared to Ti–10V–2Fe–3Al (Ti-1023) and Ti–5Al–5V–5Mo–3Cr (Ti-5553) while offering high strength. However, with higher Fe content (>5 at.-%), the ‘β-flecks’ are prone to form because strong segregation in traditional casting, which seriously deteriorates the mechanical properties of the alloys. In this work, Spark plasma sintering (SPS) was successfully used to produce Ti-185 components starting from elemental Ti and Al powders, and a V–Fe master alloy powder with different particle size (106, 45, and 23 μm). SPS can be used to produce a very fine grain microstructure with decreasing particle size master alloy powder and non-detrimental Fe segregation, and which result in a significant improvement of the mechanical properties. As the particle size of the FeV80 powder decreases, the compressive strength, yield strength and compressive strain of the alloy gradually increase.

Trace element and S isotope characterization of sulfides from skarn Cu ore in the Laochang Sn-Cu deposit, Gejiu district, Yunnan, China: Implications for the ore-forming process

Laochang is one of the main ore deposits in the world-class Gejiu polymetallic Sn district, Southwest China. Skarn Cu ore is an important mineralization type in the Laochang deposit. In this study, in situ trace element compositions of chalcopyrite and sphalerite and S isotope compositions of sulfide minerals (arsenopyrite, chalcopyrite, pyrrhotite and sphalerite) of the skarn Cu ore in the Laochang deposit are investigated. The results show that the studied chalcopyrite is enriched in Zn, Ag, In and Sn, and is depleted in Co, Ni, Ga, Ge, As, Cd, Sb, Bi and Pb. The sphalerite is enriched in Fe, Co, Cu, Ag, Cd, In and Bi and depleted in Ni, Ga, Ge, As, Sn, Sb, Tl and Pb. The high Fe, Cd and Co contents of the sphalerite indicate the simple substitution mechanism Zn2+↔ (Fe2+, Cd2+, Co2+). The S isotope compositions of arsenopyrite, chalcopyrite, pyrrhotite and sphalerite fall into a narrow range of − 2.9‰ to + 1.4‰, indicating a magmatic source of the sulfur. The high Sn contents (6.20 ~ 3339 μg/g) and moderate Cd/Zn ratio (0.009 ~ 0.023) of the chalcopyrite and the high In (271 ~ 723 μg/g) contents and Zn/Cd ratio (120 ~ 172) of the sphalerite imply that the skarn Cu mineralization in the Laochang deposit was influenced by high temperature, magmatic-hydrothermal fluids.

Fe and Zn content of various genetic background of released rice varieties in Indonesia

Fe and Zinc deficiency is one of the most prevalence micro nutrient disorder in Indonesia. Increasing of Fe and Zn content in rice grain is expected to be useful to reduce the micronutrient deficiency. This research was aimed to identify rice varieties containing high Fe and Zn content and initially study the correlation among some related traits. The experiment was conducted in October – December 2016 by testing 176 released varieties and 4 elite rice lines. The samples were prepared as brown rice. Fe and Zn contents were measured using XRF Oxford machine which is validated by ICP method. The results showed that Fe content of the tested genotypes is normally distributed ranged from 9.70 ppm to 17.40 ppm with the mean of 13.03 ppm and the Zn content is not normally distributed ranged from 15.80 ppm to 31.10 ppm with the mean of 22.41 ppm. Majority of the released rice varieties in Indonesia had lower Fe and Zn content compared to the most popular variety, Ciherang (12.20 ppm and 24.70 ppm). Kalimutu had the highest both for Fe and Zn content (17.40 ppm and 31,10 ppm). Fe and Zn content are positively correlated and breeding effort for both traits is prospective.