Quantitative mineralogical characterization of chrome ore beneficiation plant tailing and its beneficiated products

Mineralogical characterization and liberation of valuable minerals are primary concerns in rnineml processing industries. The pre- sent investigation focuses on quantitative mineralogy, elemental deportment, and locking-liberation characteristics of the beneficiation of tailings from a chrome ore beneficiation plant in the Sukinda region, Odisha; methods used for the study of the beneficiated tailings are QEMSCAN~, X-ray diffraction （XRD）, and mineral chemistry by a scanning electron microscope equipped with an energy-dispersive spec- trometer （SEM-EDS）. The tailing sample was fine grained （69.48wt% below 45 μm size）, containing 20.25wt% Cr203 and 39.19wt% Fe203, with a Cr：Fe mass ratio of 0.51. Mineralogical investigations using QEMSCAN studies revealed that chromite, goethite, and gibbsite are the dominant mineral phases with minor amounts of hematite, kaolinite, and quartz. The sample contained 34.22wt% chromite, and chromite liberation is more than 80% for grains smaller than 250 ~tm in size. Based on these results, it was predicted that liberated chromite and high-grade middling chromite particles could be separated from the gangue by various concentration techniques. The tailing sample was beneficiated by hydrocyclone, tabling, wet high-intensity magnetic separation （WHIMS）, and flotation in order to recover the chromite. A chromite concentrate with 45.29wt% Cr203 and a Cr：Fe mass ratio of 1.85 can be produced from these low-grade chromite ore beneficiation plant rejects.

Soil bacterial and fungal communities resilience to long-term nitrogen addition in subtropical forests in China

Atmospheric nitrogen(N)deposition is predicted to increase,especially in the subtropics.However,the responses of soil microorganisms to long-term N addition at the molecular level in N-rich subtropical forests have not been clarified.A long-term nutrient addition experiment was conducted in a subtropical evergreen old-growth forest in China.The four treatments were:control,low N(50 kg N ha^(-1)a^(-1)),high N(100 kg N ha^(-1)a^(-1)),and combined N and phosphorus(P)(100 kg N ha^(-1)a^(-1)+50 kg P ha^(-1)a^(-1)).Metagenomic sequencing characterized diversity and composition of soil microbial communities and used to construct bacterial/fungal co-occurrence networks.Nutrient-treated soils were more acidic and had higher levels of dissolved organic carbon than controls.There were no significant differences in microbial diversity and community composition across treatments.The addition of nutrients increased the abundance of copiotrophic bacteria and potentially beneficial microorganisms(e.g.,Gemmatimonadetes,Chaetomium,and Aureobasidium).Low N addition increased microbiome network connectivity.Three rare fungi were identified as module hubs under nutrient addition,indicating that low abundance fungi were more sensitive to increased nutrients.The results indicate that the overall composition of microbial communities was stable but not static to long-term N addition.Our findings provide new insights that can aid predictions of the response of soil microbial communities to long-term N addition.

Enhancing sustainability in phosphate ore processing:Performance of frying oil as alternative flotation collector for carbonate removal

Recycling waste frying oils for the synthesis of flotation reagents presents a promising avenue for sustainable waste management.Moreover,it offers a cost-effective solution for crafting a specialized collector designed to efficiently remove carbonates and enhance phosphate enrichment in froth flotation processes.This study focuses on the synthesis of an anionic collector using the saponification reaction of a frying oil sample,subsequently applied to the flotation of calcite and dolomite.To elucidate the adsorption mechanisms of the frying oil collector(FrOC)and sodium oleate,a reference collector,on fluorapatite,calcite,dolomite,and quartz surfaces,comprehensive experiments were conducted,including zeta potential measurements and Fourier transform infrared spectroscopy.Results revealed diverse adsorption affinities of the molecules towards these minerals.To assess the practical performance of the collector,flotation tests were conducted using a natural phosphate ore mixture,employing a BoxBehnken experimental design.Notably,under optimized conditions(pH 9,1000 g/t of FrOC,3.5 min of conditioning,and 6 min of flotation),FrOC exhibited excellent performance,with calcite and dolomite recoveries exceeding 80%,while apatite recovery in the concentrate fraction remained below 10%.This work exemplifies both circular economy practices and the distinctive approach to sustainable mineral processing.

The effect of abiotic stresses on plant C:N:P homeostasis and their mitigation by silicon

In crop plants, various environmental stresses affect the balance of carbon, nitrogen, and phosphorus(C:N:P), leading to biochemical and physiological alterations and reductions in yield. Silicon(Si) is a beneficial element that alleviates plant stress. Most studies involving silicon have focused on physiological responses, such as improvements in photosynthetic processes, water use efficiency, and antioxidant defense systems. But recent research suggests that stressed plants facing either limited or excessive resources(water, light, nutrients, and toxic elements), strategically employ Si to maintain C:N:P homeostasis, thereby minimizing biomass losses. Understanding the role of Si in mitigating the impact of abiotic stresses on plants by regulating C:N:P homeostasis holds great potential for advancing sustainable agricultural practices in crop production. This review presents recent advances in characterizing the influence of environmental stresses on C:N:P homeostasis, as well as the role of Si in preserving C:N:P equilibrium and attenuating biological damage associated with abiotic stress. It underscores the beneficial effects of Si in sustaining C:N:P homeostasis and increasing yield via improved nutritional efficiency and stress mitigation.

Offshore high-grade limemud resources of west coast of India:Economic potential and industrial applications

Limestone is one of the essential raw materials in the cement,paint,steel,ceramic,glass,chemical,pharmaceutical,paper,and fertilizer industries.In India,only 8%of the limestone resources are placed under the reserve category,of which 97%is of cement grade.Thus,India depends on imports to bridge the demand‐supply gap of steel,blast furnace,and chemical‐grade limestone.Efforts of Geological Survey of India(GSI)to locate alternate sources for limestone led to the discovery of enormous quantities of carbonate minerals called limemud from the continental shelf margin of the west coast of India.GSI carried out systematic studies to explore the nature of the disposition,quality,quantity,and suitability of the offshore limemud for various industrial applications.A preliminary estimate of resources using high‐resolution subbottom profiling and sediment core sample studies established the occurrence of more than 172 billion tonnes of high‐grade(The content of CaCO3 is greater than 80 wt%)limemud in 0.4–28.0m thick stratified sediment layers spread over an area of 18000 km2.Chemical,physical,mineralogical,beneficiation,and agglomeration studies found the offshore limemud as a potential replacement for limestone in the cement,filler,blast furnace,steel melting shop,lime production,paint,and Grade‐I steel industries.An assessment of mining and transportation costs indicates that the offshore limemud(USD 5–6/ton)is more cost‐effective than that imported from other countries(USD16‐18/ton).With several advantageous factors like low impurity,mode of occurrence in overburden‐free stratified form,fine‐grained slurry nature,and shallow water depth,sustainable mining of offshore limemud could be a future reality with controllable technological,economic,and environmental challenges.

Relationship between nutritional therapy and beneficial bacteria ratio in severe disease

Objective:To evaluate relationship between changes in the beneficial bacteria in intensive care unit(ICU)patients and nutritional therapy type.Methods:Ten patients aged≥18 years admitted to the ICU between January and December 2020,were included.Good enteral nutrition was defined as early achievement of target calorie intake through enteral feeding.The ratio of beneficial bacteria at the first and second bowel movements after each patient’s admission was calculated and the patients were classified into the increase or decrease group.Among all patients,five each were in the increase and decrease groups.We investigated patient background,changes in sequential organ failure assessment(SOFA)and acute physiology and chronic health evaluation(APACHE)Ⅱscores,nutritional doses or methods,and clinical outcomes.Results:No relationship was found between changes in the ratio of beneficial bacteria and changes in SOFA/APACHEⅡscores at the time of admission.The rate of good enteral nutrition was significantly higher in the increase group than in the decrease group(4/5 vs.0/5,P=0.01).Conclusions:An increase in beneficial bacteria may be significantly related to the early establishment of enteral nutrition.In the future,accumulating cases may make it possible to establish a new nutritional strategy for critically ill patients from an intestinal microbiota perspective.

Exercise sustains the hallmarks of health

Exercise has long been known for its active role in improving physical fitness and sustaining health.Regular moderate-intensity exercise improves all aspects of human health and is widely accepted as a preventative and therapeutic strategy for various diseases.It is well-documented that exercise maintains and restores homeostasis at the organismal,tissue,cellular,and molecular levels to stimulate positive physiological adaptations that consequently protect against various pathological conditions.Here we mainly summarize how moderate-intensity exercise affects the major hallmarks of health,including the integrity of barriers,containment of local perturbations,recycling and turnover,integration of circuitries,rhythmic oscillations,homeostatic resilience,hormetic regulation,as well as repair and regeneration.Furthermore,we summarize the current understanding of the mechanisms responsible for beneficial adaptations in response to exercise.This review aimed at providing a comprehensive summary of the vital biological mechanisms through which moderate-intensity exercise maintains health and opens a window for its application in other health interventions.We hope that continuing investigation in this field will further increase our understanding of the processes involved in the positive role of moderate-intensity exercise and thus get us closer to the identification of new therapeutics that improve quality of life.

Synergically enhanced piezocatalysis performance of eco-friendly(K_(0.52)Na_(0.48))NbO_(3) through ferroelectric polarization and defects

Piezocatalysis has attracted unprecedented research interest as a newly emerging catalysis technology.However,the inherent insulating property of ferroelectric materials ultimately leads to the poor vibration-electricity conversion ability.Herein,this work reports the(K_(0.52)Na_(0.48))NbO_(3) ferroelectric ceramics(KNNFCx),for which the FeCo modification strategy is proposed.The substitution of the moderate amount of FeCo(x=0.015)at Nb site not only optimizes ferroelectricity but also produces beneficial defects,notably increasing Rhodamine B water purification efficiency to 95%.The pinning effect of monovalent oxygen vacancies on ferroelectric domains is responsible for the excellent ferroelectric polarization of KNNFC0.015 through the generation of an internal field to promote charge carriers separation and reduce nonradiative recombination.Importantly,the accompanying electron carriers can easily move to the material surface and participate in redox reactions because they have low activation energy.Therefore,ferroelectric polarization and defects play synergetic roles in enhancing piezocatalytic performance.

Current situation of carbon emissions and countermeasures in China's ironmaking industry

The iron and steel industry(ISI) involves high energy consumption and high pollution. ISI in China, a leading country in the ISI,consumed 15% of the country’s total energy and produced more than 50% of the global ISI’s carbon emissions. Therefore, in the context of global low-carbon economy and emission reduction requirements, low-carbon smelting technology in the ISI has attracted increasingly more attention in China. This review summarizes the current status of carbon emissions and energy consumption in China’s ISI and discusses the development status and prospects of low-carbon ironmaking technology. The main route to effectively reducing carbon emissions is to develop a gas-based direct reduction process and replace sintering with pelletizing, both of which focus on developing pelletizing technology. However,the challenge of pelletizing process development is to obtain high-quality iron concentrates. Consequently, the present paper also summarizes the development status of China’s mineral processing technology, including fine-grained mineral processing technology, magnetization roasting technology, and flotation collector application. This paper aims to provide a theoretical basis for the low-carbon development of China’s ISI in terms of a dressing–smelting combination.

Microbiome Engineering:A Promising Approach to Improve Coral Health

The world’s coral reefs are threatened by the cumulative impacts of global climate change and local stressors.Driven largely by a desire to understand the interactions between corals and their symbiotic microorganisms,and to use this knowledge to eventually improve coral health,interest in coral microbiology and the coral microbiome has increased in recent years.In this review,we summarize the role of the coral microbiome in maintaining a healthy metaorganism by providing nutrients,support for growth and development,protection against pathogens,and mitigation of environmental stressors.We explore the concept of coral microbiome engineering,that is,precise and controlled manipulation of the coral microbiome to aid and enhance coral resilience and tolerance in the changing oceans.Although coral microbiome engineering is clearly in its infancy,several recent breakthroughs indicate that such engineering is an effective tool for restoration and preservation of these valuable ecosystems.To assist with identifying future research targets,we have reviewed the common principles of microbiome engineering and its applications in improving human health and agricultural productivity,drawing parallels to where coral microbiome engineering can advance in the not-too-distant future.Finally,we end by discussing the challenges faced by researchers and practitioners in the application of microbiome engineering in coral reefs and provide recommendations for future work.

Ingredients from integral valorization of Isabel grape to formulate goat yogurt with stimulatory effects on probiotics and beneficial impacts on human colonic microbiota in vitro

Isabel grape(IG)products have high contents of phenolic compounds and fiber recognized for their positive impacts on microorganisms associated with health benefits to host.This study evaluated the effects of goat yogurts formulated with ingredients from IG integral valorization on the growth and metabolism of different probiotic strains,as well as on the population of selected bacterial groups and metabolic activity of human colonic microbiota in vitro.Goat yogurts with IG ingredients(IGI)stimulated the growth of tested Lactobacillus and Bifidobacterium probiotic strains during a 48-h cultivation,as well as decreased the pH values and enhanced the organic acid production.Goat yogurts with IGI increased the population of Lactobacillus spp.and Bifidobacterium spp.during a 24-h in vitro colonic fermentation.A stable Firmicutes:Bacteroidetes ratio close to 1 was found in media with goat yogurt formulations during the colonic fermentation,being similar to the effect caused by fructooligosaccharides.Goat yogurt formulations with IGI caused increased production of short-chain fatty acids and sugar consumption during colonic fermentation.Goat yogurts with IGI should be a valuable strategy for development of novel added-value foods with beneficial effects on gut microbiota and human health.

Evaluation of VSK separation in the classification of two mineralogically different iron ore fines

With gradually diminishing Fe grade in tandem with the ever-increasing demand for high-grade iron ores,iron ore industries are now focusing on the beneficiation of low-grade iron ore fines,mainly considered waste.Besides,the scarcity of water at many of the mines’sites and the new water conservation policies of the governments have necessitated research on suitable dry beneficiation routes.In this context,an effort has been made to evaluate the efficacy of a dry classification unit,such as the VSK separator,in upgrading the iron values of two low-grade Indian iron ore fines,named Sample 1 and Sample 2.The mineralogical studies,involving scanning electron microscopy and X-ray diffraction,suggest that Sample 1 is a low-grade blue dust sample(51.2wt%Fe)containing hematite and quartz as the major minerals,while Sample 2(53.3wt%Fe)shows the presence of goethite in addition to hematite and quartz.The experiments,carried out using Box-Benkhen statistical design,indicate that blower speed,followed by feed rate,is the most influencing operating parameter in obtaining a good product in the VSK separator.At optimum levels of the operating factors,a fines product with~55wt%Fe at a yield of~40%can be obtained from Sample 1,while Sample 2 can be upgraded to~56wt%Fe at a yield of~85%.The results suggest that the VSK separator can be employed as an efficient intermediate unit operation in a processing circuit to upgrade the iron contents of iron ore fines.

Backwash Effects of Language Testing in EFL Classrooms

The article presents some major researches concerning the concept of backwash effect of language testing; analyses both the positive and negative effects and their implications in EFL classrooms; then provides some suggested ways to be followed when creating positive backwash effects on teaching and learning.

Leukocytes and oxidative stress： dilemma for sperm Function and male fertility

Spermatozoa are constantly exposed to the interphase between oxidation through high amounts of reactive oxygen species （ROS） and leukocytes, and reduction by means of scavengers and antioxidants. Considering the very special functions as being the only cells with such high polarization and exerting their functions outside the body, even in a different individual, the female genital tract, the membranes of these cells are chemically composed of an extraordinary high amount of polyunsaturated fatty acids. This in turn, renders them very susceptible to oxidative stress, which is defined as an imbalance between oxidation and reduction towards the oxidative status. As a result, ROS deriving from both leukocytes and the male germ cells themselves cause a process called ＇lipid peroxidation＇ and other damages to the sperm cell. On the other hand, a certain limited amount of ROS iS essential in order to trigger vital physiological reactions in cells, including capacitation or the acrosome reaction in sperm. The treatment of patients with antioxidants to compensate the oxidative status caused by oxidative stress is highly debated as uncontrolled antioxidative treatment might derail the system towards the reduced status, which is also unphysiological and can even induce cancer. This paradox is called the ＇antioxidant paradox＇. Therefore, a proper andrological diagnostic work-up, including the evaluation of ROS levels and the antioxidant capacity of the semen, has to he carried out beforehand, aimed at keeping the fine balance between oxidation and scavenging of vital amounts of ROS.

Mineralogy and carbothermal reduction behaviour of vanadium-bearing titaniferous magnetite ore in Eastern India

Vanadium-beaxing titaniferous magnetite bands hosted by Precambrian gabbro-norite-anorthositic rocks or their metamorphic equivalents were discovered in some parts of Eastern Indian Shield, containing 48%-49% Fe （total）, 10%-25% TiO2, and 0.3%-2.20% V2O5 by mass. Mineralogical and petrological study, composition, and characterization of the vanadium-bearing titaniferous magnetite ore were carried out by scanning electron microscopy-energy dispersive X-ray （SEM-EDX）, wave length X-ray florescence （WDXRF）, inductively coupled plasma-atomic emission spectroscopy （ICP-AES）, X-ray diffraction （XRD）, etc. Chemical beneficiation for valuable metals, such as Fe, Ti, andV, was performed by reduction roasting. The direct and indirect reduction were investigated by mixing the lump ore with solid activated charcoal in a closed reactor and purging the reducing gas mixture in standard reducibility index apparatus at different temperatures and time intervals. The reduction roasting parameters were optimized. Finally, the reduced samples were crushed and upgraded by magnetic separation. The results show that, the maximum mass fractions of magnetic and nonmagnetic parts achieved axe 69.36% and 30.64%, respectively, which contain 10.6% TiO2 and 0.84% V205 in the magnetic part and 36.5% TiO2 and 0.22% V205 in the nonmagnetic part.

Beneficiation of the gold bearing ore by gravity and flotation

Gold concentration usually consists of gravity separation, flotation, cyanidation, or the combination of these processes. The choice among these processes depends on the mineralogical characterization and gold content of the ore. Recently, the recovery of gold using gravity methods has gained attention because of low cost and environmentally friendly operations. In this study, gold pre-concentrates were produced by the stepwise gravity separation and flotation techniques. The Knelson concentrator and conventional flotation were employed for the recovery of gold. Gold bearing ore samples were taken from Gümüshane Region, northern east part of Turkey. As a result of stepwise Knelson concentration experiments, a gold concentrate assaying around 620 g/t is produced with 41.4wt% recovery. On the other hand, a gold concentrate about 82 g/t is obtained with 89.9wt% recovery from a gold ore assaying 6 g/t Au by direct flotation.

Antidiabetic and haematological effect of aqueous extract of stem bark of Afzelia africana(Smith) on streptozotocin-induced diabetic Wistar rats

Objective:To investigate the antidiabetic properties of aqueous extract of stem bark of Afzelia africana(A.africana)and its beneficial effect on haematological parameters in streptozotocin induced diabetic rats.Methods:A total of 30 rats including 24 diabetic and 6 normal rats were used for this study.Diabetes was induced in male Wistar rats by intraperitoneal injection of streptozotocin.After being confirmed diabetic,animals were orally treated with distilled water or extracts at 100 or 200 mg/kg body weight daily for 10 days.The haematological parameters including red blood and white blood cells and their functional indices were evaluated in diabetic treated groups compared with the controls.Results:The extract significantly reduced the blood glucose levels while the best result was obtained at 200 mg/kg body weight The feed and water intake in diabetic rats were significantly reduced while weight loss was minimized at both dosages.Similarly,the levels of red blood,white blood cells and their functional indices were significantly improved after extract administration at both doses.Conclusions:It can be concluded that the aqueous extract of bark of A.africana possesses antihyperglycemic properties.In addition,the extract can prevent various complications of diabetes and improve some haematological parameters.Further experimental investigation is needed to exploit its relevant therapeutic effect to substantiate its ethnomedicinal usage.

Recovery of iron from copper slag by deep reduction and magnetic beneficiation

Aiming at recovering iron from high-iron-content copper slag, this article introduced a combination technol- ogy of deep reduction and magnetic beneficiation, investigated the iron recovery efficiency and optimized the technical conditions. When coke powder with 86wt% fixed carbon was used as a reductant, iron was successfully extracted from the copper slag. Under the optimized condition of the coke powder content of 14wt%, the calcium-to-silicon mass ratio （Ca/Si） of 0.2, the roasting temperature of 1300℃, the roasting time of 3 h, the grinding time of 20 min, and the magnetic field intensity of 61 kA-m-1, the iron recovery rate of the copper slag can reach 91.82%, and the extracted iron powder has an iron grade of 96.21%. With the characteristics of high iron grade and low impurity content, the extracted iron powder can be used as high-quality raw materials of weathering steel.

Magnetic and flotation studies of banded hematite quartzite (BHQ) ore for the production of pellet grade concentrate

To identify and establish beneficiation techniques for banded hematite quartzite （BHQ） iron ore, a comprehensive research on BHQ ore treatment was carried out. The BHQ ore was assayed as 38.9wt% Fe, 42.5wt% SiO2, and 1.0wt% Al2O3. In this ore, hematite and quartz are present as the major mineral phases where goethite, martite, and magnetite are present in small amounts. The liberation of hematite particles can be enhanced to about 82% by reducing the particle size to below 63 μm. The rejection of silica particles can be obtained by magnetic and flotation separation techniques. Overall, the BHQ ore can be enriched to 65.3wt% Fe at 61.9% iron recovery. A flowsheet has been suggested for the commercial exploitation of the BHQ ore.

Effect of desliming on the magnetic separation of low-grade ferruginous manganese ore

In the present investigation, magnetic separation studies using an induced roll magnetic separator were conducted to beneficiate low-grade ferruginous manganese ore. The feed ore was assayed to contain 22.4% Mn and 35.9% SiO2, with a manganese-to-iron mass ratio （Mn：Fe ratio） of 1.6. This ore was characterized in detail using different techniques, including quantitative evaluation of minerals by scan- ning electron microscopy, which revealed that the ore is extremely siliceous in nature and that the associated gangue minerals are more or less evenly distributed in almost all of the size fractions in major proportion. Magnetic separation studies were conducted on both the as-received ore fines and the classified fines to enrich their manganese content and Mn：Fe ratio. The results indicated that the efficiency of separation for deslimed fines was better than that for the treated unclassified bulk sample. On the basis of these results, we proposed a proc- ess flow sheet for the beneficiation of low-grade manganese ore fines using a Floatex density separator as a pre-concentrator followed by two-stage magnetic separation. The overall recovery of manganese in the final product from the proposed flow sheet is 44.7% with an assay value of 45.8% and the Mn：Fe ratio of 3.1.