Leaching behaviour and the solution consumption of uranium-vanadium ore in alkali carbonate–bicarbonate column leaching

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Although heap leaching using sulfuric acid was introduced to the uranium industry in the 1950s, sodium carbonate–bicarbonate (alkaline) heap leaching of low-grade Ca-carbonate-rich uranium ores has recently gained popularity. This study presents the results of two column tests on a calcrete-type uranium–vanadium (carnotite) ore using a mixture of sodium carbonate and bicarbonate (Na2CO3/NaHCO3) as the leach solution. This data was kindly supplied by Toro Energy Ltd. The experimental data comprised physical–chemical leach information and two different irrigation rates (10 and 20 L/h·m2). The experimental data indicated that the carnotite ore with high calcium carbonate (CaCO3) can be leached effectively using the alkaline leach solution. The increase in the irrigation rate increased the uranium and vanadium extraction and decreased their concentration in the effluent. The column leach data was therefore fitted to a simplified first-order kinetic model using two approaches, a general form and a second based on the reagent consumption per unit mass of the initial valuable species (U and V). As reagent consumption is a key economic factor in the heap leaching process, having a kinetic leaching model incorporating reagent consumption would provide useful techno-economic information. In this regards a new leaching index of (β) is also introduced. Both approaches of the first order kinetic model provide a good agreement with the column testing data

Reproductive biology of Mossul bleak (Alburnus mossulensis) in Bibi-Sayyedan River of Tigris basin in Iran

Reproductive characteristics of Mossul bleak, Alburnus mossulensis, a native species of Cyprinidae family in Bibi-Sayyedan River of Semirom, Isfahan, were investigated by monthly sampling during December 2010 to December 2011. Five hundred and fourty three specimens (256 females, 159 males and 31 immature) were caught by a sein net (5 mm mesh size). The collected sampeles were anesthesized in 1% clove oil solution and transported to the laboratory on ice and subjected to dissection and biometric measurments. Age of males and females ranged from 0+ to 5+ years. The sex ratio was 1M: 2.2F (p < 0.05). The females outnumbered the males in all age classes. The largest female was 16.8cm in total length and 49.12g in weight and the largest male was 14.1cm in total length and 28.19g in weight. The age and total length at first maturity of females and males were estimated as 1 year and 5.3cm total length, and 2 years and 4.4cm, respectively. The minimum, maximum, and avarge absolute fecundity were 2064, 10316, and 5505 ± 2686, respectively and also the relative fecundity was 203 ± 58 egg/g body weight. Macroscopic analysis of gonads and gonadostomatic index values suggested that spawning of A. mossulensis occurs from March to June with a peak in April. Thus, A. mosullensis is considered a group-synchronous type species with a capacity for multiple ovulations within a reproductive season (multiple spawner)

Age and growth of Alburnus mossulensis (Cyprinidae) in Bibi-Sayyedan River of Isfahan Province

Population structure and growth of Mossul bleak, Alburnus mossulensis, a native species of cyprinids in Bibi-Sayyedan River of Semirom, Isfahan, were investigated by monthly sampling during December 2010 to December 2011. For this purpose, 543 specimens (353 females, 159 males and 31 immature) were caught using seine net (5 mm mesh size) and a cast net. Age groups of males and females were 0+ to 5+. The most frequent age group was 2+ in both sexes. The sex ratio was 1M:2.2F (p0.05). The largest female was 16.80 cm in total length and 49.12 g in weight, while the largest male was 14.10 cm in total length and 28.19 g in body weight. The length-weight relationship was calculated as W = 0.0169L^3.0355 (r^2=0.95) for males, W=0.0061L^3.1751 (r^2=0.98) for females and W=0.0066L^3.139 (r^2=0.99) for all fish (males, females and immature). Regression coefficient (b) based on Pauly test, was significantly different from 3 in females, but not in males (p<0.05), indicating an isometric growth pattern in males and a positive allometric growth pattern in females and all fish

Direct measurements of the magnetocaloric effect in pulsed magnetic fields: The example of the Heusler alloy Ni50_{50}Mn35_{35}In15_{15}

We have studied the magnetocaloric effect (MCE) in the shape-memory Heusler alloy Ni$_{50}$Mn$_{35}$In$_{15}$ by direct measurements in pulsed magnetic fields up to 6 and 20 T. The results in 6 T are compared with data obtained from heat-capacity experiments. We find a saturation of the inverse MCE, related to the first-order martensitic transition, with a maximum adiabatic temperature change of $\Delta T_{ad} = -7$ K at 250 K and a conventional field-dependent MCE near the second-order ferromagnetic transition in the austenitic phase. The pulsed magnetic field data allow for an analysis of the temperature response of the sample to the magnetic field on a time scale of $\sim 10$ to 100 ms which is on the order of typical operation frequencies (10 to 100 Hz) of magnetocaloric cooling devices. Our results disclose that in shape-memory alloys the different contributions to the MCE and hysteresis effects around the martensitic transition have to be carefully considered for future cooling applications.Comment: 5 pages, 4 figure

Monitoring hydroperoxides formation as a measure of predicting walnut oxidative stability

It is believed that lipids are the most important factor affecting nuts shelf-life. In the present study, an accelerated shelf-life testing by means of elevated temperatures 62, 72, and 82 °C was conducted to predict the oxidation stability of walnuts over a long-term storage. Peroxide value (PV) was employed to monitor the lipid oxidation progression in the walnuts. A range of 74.01–79.57 kJ mol−1 K−1 energy was required for formation of primary oxidation products. The reaction changes followed an apparent first-order kinetic. Formation of hydroperoxides in walnut kernels was found to be a temperature-dependent reaction with Q10 of 2.1. Walnut kernels were also kept in normal condition (temp: 20–30 °C; relative humidity (RH): 35–45%) for 12 months to validate the shelf-life estimation approach. The results showed that PV could provide a proper estimation for oxidative stability of the walnuts stored in ordinary condition

Exploring the convergence between religious beliefs with psychological distress in medical students of Jahrom University of Medical Sciences in 2014

Introduction: The main purpose of psychological health is to prevent worries and to maintain psychological health. Strengthening religious beliefs at all stages of life is a preventive action in order to reduce psychological disorders. The aim of this study is to investigate the consistency between the religious beliefs and psychological distress in medical students in Jahrom University of Medical Sciences.Method: This analytical study was carried out on 751 students of Jahrom University of Medical Sciences in 2014. Data collection was performed by religious beliefs questionnaire and psychological distress questionnaire. Data were analyzed using descriptive statistics (mean and standard deviation) and inferential statistics.Results: Results showed that there was no significant consistency between religious attitudes of students with severity indicators of psychological distress, stress (0.128), anxiety (0.726) and depression (0.128).Conclusion: The results of this study demonstrated that there was an inverse relationship between religious attitudes of students with psychological distress.As a result, it is suggested that a spirituality-based care program can reduce the students’ psychological distress.Keywords: Religious beliefs, psychological distress, medical student

Use of some isolated fungi in biological Leaching of Aluminum from low grade bauxite

In this investigation the biological leaching of aluminum by isolated fungi from low grade bauxite

A Process Mineralogy Approach to Gravity Concentration of Tantalum Bearing Minerals

This is the final version of the article. Available from MDPI via the DOI in this record.The historic Penouta mine in northwest Spain is the focus of efforts to extract tantalum from tin mining waste. This paper describes the characterisation of the tantalum mineralogy of waste material from the deposit. Characterisation was realised using quantitative mineralogy and geochemistry. This paper further identifies other phases of interest and investigates the potential for extraction using gravity separation techniques. The gravity concentrate obtained through these tests was analysed using quantitative mineralogy and electron probe microanalysis. Following characterisation of the sample material to identify the key Ta-bearing mineral phases and assess liberation, a series of gravity separation trials were conducted using Heavy Liquid Separation (HLS), Mozley table, Knelson concentrator separation and shaking table. The laboratory shaking table used to conduct a rougher test and a rougher/cleaner test to simulate a spiral-table circuit using the Penouta material. Mass balance calculations were carried out to calculate the contained metal content of the feed material and concentrate products in order to assess recovery rates for Ta, Sn and Nb across a range of grains sizes. Ta was found to be present predominantly in the solid-solution columbite-group mineral, along with minor Ta present as microlite and as impurities within cassiterite. It was found that over 70% of the Ta is contained within the −125 μm fraction, with the Ta-bearing minerals tantalite and microlite being closely associated with quartz. Mozley table separation resulted in recoveries of 89% Ta and 85% Nb for the −125 μm fraction. The Knelson Concentrator trial was carried out on the −625 μm size fraction, thereby eliminating low grade material found in the coarsest fractions. Size analysis of the recovery rate for each product, shows that the Knelson concentrator is most efficient for recovery of −125 μm particles.This work is part of the OptimOre project. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 642201. Authors are thankful from the Strategic Minerals enterprise for their help in sampling, visit and information provided

Optimization of folic acid nano-emulsification and encapsulation by maltodextrin-whey protein double emulsions

Due to susceptibility of folic acid like many other vitamins to environmental and processing conditions, it is necessary to protect it by highly efficient methods such as micro/nano-encapsulation. Our aim was to prepare and optimize real water in oil nano-emulsions containing folic acid by a low energy (spontaneous) emulsification technique so that the final product could be encapsulated within maltodextrin-whey protein double emulsions. A non ionic surfactant (Span 80) was used for making nano-emulsions at three dispersed phase/surfactant ratios of 0.2, 0.6, and 1.0. Folic acid content was 1.0, 2.0, and 3.0 mg/mL of dispersed phase by a volume fraction of 5.0, 8.5, and 12. The final optimum nano-emulsion formulation with 12 dispersed phase, a water to surfactant ratio of 0.9 and folic acid content of 3 mg/mL in dispersed phase was encapsulated within maltodextrin-whey protein double emulsions. It was found that the emulsification time for preparing nano-emulsions was between 4 to 16 h based on formulation variables. Droplet size decreased at higher surfactant contents and final nano-emulsions had a droplet size. < 100 nm. Shear viscosity was higher for those formulations containing more surfactant. Our results revealed that spontaneous method could be used successfully for preparing stable W/O nano-emulsions containing folic acid. © 2016 Elsevier B.V

Investigation of the effect of mineralogy as rate-limiting factors in large particle leaching

Although heap leaching is by now well established in the mining industry, the process remains limited by low recoveries with different rate-limiting factors that are not clearly understood. In this study, three large particle size classes (+19/-25, +9.5/-16, +4.75/-5 mm) were prepared from a sphalerite ore by two different methods of comminution (HPGR and cone crusher). The particles were then packed into leach reactors that were operated continuously for eleven months with well-mixed internal circulation of the leach solution. Characterization of the residue of the leach reactors indicated that there are areas within the ore particles where although sphalerite grains are accessible to the solution, they remain unreacted. X-ray tomography and QEMSCAN® analysis of the selected samples before, during and after leaching, showed increased leaching of sphalerite grains associated with pyrite due to galvanic interactions. Mineral chemistry (Fe, Mn content of sphalerite) and jarosite precipitation were also investigated as factors influencing sphalerite leaching