scholarly journals Effect of different carbon sources on vacuum carbothermal reduction of low-grade phosphorus ore

2021 ◽  
pp. 13-13
Author(s):  
Xuan He ◽  
Run Huang
Keyword(s):  
Carbothermal Reduction ◽  
Phosphate Rock ◽  
Carbon Sources ◽  
Coal Ash ◽  
Pulverized Coal ◽  
Reduction Ratio ◽  
Low Grade ◽  
Maximum Reduction ◽  
Reduction Effect ◽  
The Cost

In this study, the effect of different carbon sources on the carbothermal reduction of low-grade phosphate ore were examined using FactSage7.2 calculations and vacuum reduction experiments. The thermodynamic calculations showed that the trend of the effect for three types of reducing agents was generally consistent under 1 Pa pressure and 14% carbon dosage. The reduction effect was maximum when graphite was used as the reducing agent, and a maximum mass of P was obtained at 1250 ?C. The vacuum experiment results showed that the reduction and volatilization ratios of phosphate rock increased with temperature for different carbon sources. Maximum reduction ratio was obtained using graphite in the temperature range 1250-1300?C. The reduction effect of pulverized coal was optimal at 1350?C, when SiO2, Al2O3, and MgO in the pulverized coal ash were exposed to form low-melting eutectics with CaO due to the increased degree of reaction, and the heat and mass transfer rates were increased. At this time, a maximum reduction ratio of 51.77% of the sample and a maximum volatilization ratio of 82.44% of P were achieved. Considering the cost effectiveness, pulverized coal was the optimum carbon source for the treatment of low-grade phosphate rock using vacuum carbothermal reduction.

scholarly journals Effect of different carbon sources on vacuum carbothermal reduction of low-grade phosphorus ore

2021 ◽  
pp. 17-17
Author(s):  
Xuan He ◽  
Run Huang
Keyword(s):  
Carbothermal Reduction ◽  
Phosphate Rock ◽  
Carbon Sources ◽  
Coal Ash ◽  
Pulverized Coal ◽  
Reduction Ratio ◽  
Low Grade ◽  
Maximum Reduction ◽  
Reduction Effect ◽  
The Cost

In this study, the effect of different carbon sources on the carbothermal reduction of low-grade phosphate ore were examined using FactSage7.2 calculations and vacuum reduction experiments. The thermodynamic calculations showed that the trend of the effect for three types of reducing agents was generally consistent under 1 Pa pressure and 14% carbon dosage. The reduction effect was maximum when graphite was used as the reducing agent, and a maximum mass of P was obtained at 1250 ?C. The vacuum experiment results showed that the reduction and volatilization ratios of phosphate rock increased with temperature for different carbon sources. Maximum reduction ratio was obtained using graphite in the temperature range 1250-1300 ?C. The reduction effect of pulverized coal was optimal at 1350 ?C, when SiO2, Al2O3, and MgO in the pulverized coal ash were exposed to form low-melting eutectics with CaO due to the increased degree of reaction, and the heat and mass transfer rates were increased. At this time, a maximum reduction ratio of 51.77% of the sample and a maximum volatilization ratio of 82.44% of P were achieved. Considering the cost effectiveness, pulverized coal was the optimum carbon source for the treatment of low-grade phosphate rock using vacuum carbothermal reduction.

scholarly journals Feasibility of fly ash as fluxing agent in mid- and low-grade phosphate rock carbothermal reduction and its reaction kinetics

2021 ◽  
Vol 10 (1) ◽  
pp. 157-168
Author(s):  
Biwei Luo ◽  
Pengfei Li ◽  
Yan Li ◽  
Jun Ji ◽  
Dongsheng He ◽  
...  
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Reaction Time ◽  
Carbothermal Reduction ◽  
Industrial Waste ◽  
Phosphate Rock ◽  
Molar Ratio ◽  
Low Grade ◽  
Carbon Excess ◽  
Fluxing Agent

Abstract The feasibility of industrial waste fly ash as an alternative fluxing agent for silica in carbothermal reduction of medium-low-grade phosphate ore was studied in this paper. With a series of single-factor experiments, the reduction rate of phosphate rock under different reaction temperature, reaction time, particle size, carbon excess coefficient, and silicon–calcium molar ratio was investigated with silica and fly ash as fluxing agents. Higher reduction rates were obtained with fly ash fluxing instead of silica. The optimal conditions were derived as: reaction temperature 1,300°C, reaction time 75 min, particle size 48–75 µm, carbon excess coefficient 1.2, and silicon–calcium molar ratio 1.2. The optimized process condition was verified with other two different phosphate rocks and it was proved universally. The apparent kinetics analyses demonstrated that the activation energy of fly ash fluxing is reduced by 31.57 kJ/mol as compared with that of silica. The mechanism of better fluxing effect by fly ash may be ascribed to the fact that the products formed within fly ash increase the amount of liquid phase in the reaction system and promote reduction reaction. Preliminary feasibility about the recycling of industrial waste fly ash in thermal phosphoric acid industry was elucidated in the paper.

Overview of Current Phosphoric Acid Production Processes and a New Idea of Kiln Method

2020 ◽  
Vol 17 ◽  
Author(s):  
Guangya Zheng ◽  
Jupei Xia ◽  
Zhengjie Chen
Keyword(s):  
Phosphoric Acid ◽  
Acid Production ◽  
Phosphate Rock ◽  
Low Grade ◽  
Production Methods ◽  
Production Processes ◽  
Major Equipment ◽  
Development Prospects ◽  
Great Competitiveness

: China primarily contains medium and low-grade phosphorus ores that are used to produce phosphoric acid. Here, we provide an overview of phosphoric acid production processes, including wet, thermal, and kiln methods, as well as the fundamental principles, major equipment, and technological aspects of each process. Progress in the kiln method using lowgrade phosphate rock is described, which involves the KPA and CDK processes. The literature shows that the addition of admixtures adds great competitiveness to kiln phosphate production methods and has considerable development prospects.

scholarly journals Investigations into the Role of Metabolism in the Inflammatory Response of BV2 Microglial Cells

Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 109
Author(s):  
Pamela Maher
Keyword(s):  
Oxidative Stress ◽  
Mitochondrial Dysfunction ◽  
Enzyme Inhibitors ◽  
Carbon Sources ◽  
Microglial Cells ◽  
No Production ◽  
Low Grade ◽  
Potent Inducer ◽  
Lps Activation ◽  
Bv2 Microglial Cells

Although the hallmarks of Alzheimer’s disease (AD) are amyloid beta plaques and neurofibrillary tangles, there is growing evidence that neuroinflammation, mitochondrial dysfunction and oxidative stress play important roles in disease development and progression. A major risk factor for the development of AD is diabetes, which is also characterized by oxidative stress and mitochondrial dysfunction along with chronic, low-grade inflammation. Increasing evidence indicates that in immune cells, the induction of a pro-inflammatory phenotype is associated with a shift from oxidative phosphorylation (OXPHOS) to glycolysis. However, whether hyperglycemia also contributes to this shift is not clear. Several different approaches including culturing BV2 microglial cells in different carbon sources, using enzyme inhibitors and knocking down key pathway elements were used in conjunction with bacterial lipopolysaccharide (LPS) activation to address this question. The results indicate that while high glucose favors NO production, pro-inflammatory cytokine production is highest in the presence of carbon sources that drive OXPHOS. In addition, among the carbon sources that drive OXPHOS, glutamine is a very potent inducer of IL6 production. This effect is dampened in the presence of glucose. Together, these results may provide new prospects for the therapeutic manipulation of neuroinflammation in the context of diabetes and AD.

scholarly journals Enhanced Thermoelectric Performance of n-Type Bi2Se3 Nanosheets through Sn Doping

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1827
Author(s):  
Mengyao Li ◽  
Yu Zhang ◽  
Ting Zhang ◽  
Yong Zuo ◽  
Ke Xiao ◽  
...  
Keyword(s):  
Figure Of Merit ◽  
Cost Effective ◽  
Low Grade ◽  
Hot Press ◽  
Processing Technologies ◽  
Sn Doping ◽  
Practical Applications ◽  
Alternative Materials ◽  
The Cost ◽  
Low Grade Heat

The cost-effective conversion of low-grade heat into electricity using thermoelectric devices requires developing alternative materials and material processing technologies able to reduce the currently high device manufacturing costs. In this direction, thermoelectric materials that do not rely on rare or toxic elements such as tellurium or lead need to be produced using high-throughput technologies not involving high temperatures and long processes. Bi2Se3 is an obvious possible Te-free alternative to Bi2Te3 for ambient temperature thermoelectric applications, but its performance is still low for practical applications, and additional efforts toward finding proper dopants are required. Here, we report a scalable method to produce Bi2Se3 nanosheets at low synthesis temperatures. We studied the influence of different dopants on the thermoelectric properties of this material. Among the elements tested, we demonstrated that Sn doping resulted in the best performance. Sn incorporation resulted in a significant improvement to the Bi2Se3 Seebeck coefficient and a reduction in the thermal conductivity in the direction of the hot-press axis, resulting in an overall 60% improvement in the thermoelectric figure of merit of Bi2Se3.

The Engineering Design of Helical Spur Gear Transmission with Single Gear Pair for Electric Scooter

2015 ◽  
Vol 764-765 ◽  
pp. 374-378 ◽  
Author(s):  
Long Chang Hsieh ◽  
Tzu Hsia Chen ◽  
Hsiu Chen Tang
Keyword(s):  
Engineering Design ◽  
Spur Gear ◽  
Gear Transmission ◽  
Reduction Ratio ◽  
Gear Pair ◽  
Engineering Drawing ◽  
Electric Scooter ◽  
High Reduction ◽  
Cost Of Production ◽  
The Cost

Traditionally, the reduction ratio of a spur gear pair is limited to 4 ~ 7. For a spur gear transmission with reduction ratio more than 7, it is necessary to have more than two gear pairs. Consider the cost of production, this paper proposes a helical spur gear reducer with one gear pair having reduction ratio 19.25 to substitute the gear reducer with two gear pairs. Based on the involute theorem, the gear data of helical spur gear pair is obtained. According to the gear data, its corresponding engineering drawing is accomplished. This manuscript verify that one spur gear pair also can have high reduction ratio (20 ~ 30).

A Study of Wall Ironing by the Finite Element Technique

1978 ◽  
Vol 100 (1) ◽  
pp. 31-36 ◽  
Author(s):  
E. I. Odell
Keyword(s):  
Finite Element ◽  
Lower Bound ◽  
Cone Angle ◽  
Reduction Ratio ◽  
Operating Parameters ◽  
Finite Element Technique ◽  
Elastic Plastic ◽  
Maximum Reduction ◽  
Load Displacement ◽  
Element Technique

Wall ironing has been analyzed using an elastic-plastic finite element technique. The effects that the ironing ring semi-cone angle and friction have on the maximum reduction ratio are studied in detail. Stress contours are given for a typical set of operating parameters. Several ram load/displacement curves are provided and compared with upper and lower bound loads.

scholarly journals Experimental study of the thermochemical treatment of the low-grade coal prior to boiler combustion at coal-fired power station

2019 ◽  
Vol 109 ◽  
pp. 00119
Author(s):  
Volodymyr Yemelianenko ◽  
Vitalii Pertsevyi ◽  
Oleksandr Zhevzhyk ◽  
Iryna Potapchuk ◽  
Oleksandr Lutai
Keyword(s):  
Experimental Study ◽  
Power Plants ◽  
Thermal Power ◽  
Thermochemical Treatment ◽  
Gas Pressure ◽  
Pulverized Coal ◽  
Time Range ◽  
Low Grade ◽  
Boiler Furnace ◽  
Coal Fuel

Analysis of the perspectives of the coal fuel for thermal power plants is carried out. The necessity of the experimental study for temperature measurement in the boiler furnace. The results of the experimental study are presented: temperature change over time at the burner outlet for different constant pressure value of the backlighting gas, dependence of the temperature at the burner outlet from the backlighting gas pressure for constant concentration value of pulverized coal in coal-air mixture, dependence of the temperature at the burner outlet from the concentration of pulverized coal in coal-air mixture for constant value of the backlighting gas pressure, temperature measurements for constant backlighting gas pressure value, constant value of the concentration of pulverized coal in coal-air mixture when plasmatron is switched and operates for some time range. The results of the study could be applied to the solid fuel treatment for different thermal units.

Development of Animal Fibres Composites for Construction Applications

2022 ◽  
Author(s):  
Anna Alfocea-Roig ◽  
Sergio Huete-Hernandez ◽  
Alex Maldonado-Alameda ◽  
Jessica Giro-Paloma ◽  
Josep Maria Chimenos-Ribera ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Raw Materials ◽  
Industrial Process ◽  
Economic Cost ◽  
Low Grade ◽  
Environmental Consequences ◽  
Potential Applications ◽  
Competitive Prices ◽  
New Material ◽  
The Cost

Climate change has become one of the world’s leading threats. Currently, the construction industry has a high environmental footprint. For this reason, the scientific and technological sector is looking for new materials to reduce the environmental consequences of this division. It is well known that the valorisation of different by-products can contribute to the reduction of the energy global consumption and CO2 emissions. Magnesium Phosphate Cement (MPC) can be obtained by using Low Grade Magnesium Oxide (LG-MgO) as a by-product from the industrial process of magnesite calcination. In this research, a Sustainable MPC (Sust-MPC) for different construction purposes is developed by using LG-MgO along with monopotassium phosphate KH2PO4 (MKP) as raw materials. The increasing use of synthetic fibres in clothing, as well as China’s competitive prices on Animal Fibres (AF) market, have led to a commercial interest fibre decrease for wool-like AF in Spain. This study aims to formulate a Sust-MPC cement with Animal Fibre (AF) to reduce the cost of the new material (Sust-MPC-AF) and to increase the thermal insulation, allowing the use of Sust-MPC-AF in several potential applications. Besides, it should be emphasized that the final pH of Sust-MPC is neutral, which allows containing natural fibres. To develop Sust-MPC-AF, some properties such as thermal conductivity, density, Modulus of Elasticity (MoE), flexural strength, and economic cost were evaluated using the Design of Experiments (DoE). The DoE studies allowed obtaining a model for further optimization considering minimum thermal conductivity and cost dosages. The formulation 30L-25EW presents the minimum conductivity (λ=0.140 W·m-1·K-1). Therefore, two optimal dosages (36L-25EW and 24L-22EW) are obtained by considering mixing variables such as AF/Cement ratio (AF/C) and AF/Extra Water ratio (AF/EW).

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