The Sintering and Leaching of Low-Grade Diasporic Bauxite by the Improved Lime-Sintering Process

2012 ◽  
Vol 616-618 ◽  
pp. 1051-1054 ◽  
Author(s):  
Hai Yan Yu ◽  
Xiao Lin Pan ◽  
Kai Wei Dong ◽  
Wu Zhang ◽  
Shi Wen Bi
Keyword(s):  
Sodium Carbonate ◽  
Molar Ratio ◽  
High Alumina ◽  
Low Grade ◽  
Leaching Rate ◽  
Sintering Process ◽  
The Real

An improved lime-sintering process was developed to produce alumina from low-grade diasporic bauxite in this paper. Both clinkers sintered by the real bauxite and simulated bauxite at 1350 °C when the molar ratio of CaO to Al2O3decreased to 1.4 were produced, the alumina leaching rates of which reached over 90% in sodium carbonate liquor. The main phases in the clinkers after sintering are 12CaO•7Al2O3, γ-2CaO•SiO2and 2CaO•Fe2O3. Addition of alkali can decrease the C/A ratio and get a high alumina leaching rate of clinker.

Effects of Sodium Citrate on the Ammonium Sulfate Recycled Leaching of Low-Grade Zinc Oxide Ores

2016 ◽  
Vol 35 (3) ◽  
pp. 275-281 ◽  
Author(s):  
Kun Yang ◽  
Shi-wei Li ◽  
Li-bo Zhang ◽  
Jin-hui Peng ◽  
Ai-yuan Ma ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Ammonium Sulfate ◽  
Sodium Citrate ◽  
Energy Dispersive Spectrum ◽  
Molar Ratio ◽  
Phase Method ◽  
Composition Analysis ◽  
Low Grade ◽  
Leaching Rate ◽  
Two Stages

AbstractThe effects of sodium citrate on ammonium sulfate recycled leaching of low-grade zinc oxide ores were studied. By applying various kinds of detection and analysis techniques such as chemical composition analysis, chemical phase method, scanning electron microscopy and energy dispersive spectrum (SEM/EDS), X-ray diffraction (XRD) and Fourier-transforming infrared spectrum (FT-IR), zinc raw ore, its leaching slag and the functional mechanism of sodium citrate were investigated. Based on a comprehensive analysis, it can be concluded that in contrast to hemimorphite (Zn4Si2O7(OH)2 · H2O), amorphous smithsonite (ZnCO3) and zinc silicate (Zn2SiO4) prove to be refractory phases under ammonium sulfate leaching, while sodium citrate has a better chelating action with the refractory phases, resulting in a higher zinc leaching rate. Under conditions of [NH3]/[NH3]T molar ratio being 0.5, [NH3]T being 7.5 mol/L, [Na3C6H5O7] being 0.2 mol/L, S/L ratio being 1:5, temperature being 303 K, holding time being 1 h in each of the two stages, and stirring rate being 300 rpm, the leaching rate of zinc reached 93.4%. In this article, sulfate ammonium recycled technology also reveals its unique advantage in processing low-grade zinc oxide ores accompanied by high silicon and high alkaline gangue.

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.

scholarly journals Extraction of Boron from Ludwigite Ore: Mechanism of Soda-Ash Roasting of Lizardite and Szaibelyite

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 533 ◽  
Author(s):  
Xin Zhang ◽  
Guanghui Li ◽  
Jinxiang You ◽  
Jian Wang ◽  
Jun Luo ◽  
...  
Keyword(s):  
Sodium Carbonate ◽  
Energy Dispersive Spectrometer ◽  
Low Grade ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Selective Activation ◽  
X Ray ◽  
Shed Light ◽  
Soda Ash ◽  
Scanning Electron

Ludwigite ore is a typical low-grade boron ore accounting for 58.5% boron resource of China, which is mainly composed of magnetite, lizardite and szaibelyite. During soda-ash roasting of ludwigite ore, the presence of lizardite hinders the selective activation of boron. In this work, lizardite and szaibelyite were prepared and their soda-ash roasting behaviors were investigated using thermogravimetric-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), and scanning electron microscope and energy dispersive spectrometer (SEM-EDS) analyses, in order to shed light on the soda-ash activation of boron within ludwigite ore. Thermodynamics of Na2CO3-MgSiO3-Mg2SiO4-Mg2B2O5 via FactSage show that the formation of Na2MgSiO4 was preferential for the reaction between Na2CO3 and MgSiO3/Mg2SiO4. While, regarding the reaction between Na2CO3 and Mg2B2O5, the formation of NaBO2 was foremost. Raising temperature was beneficial for the soda-ash roasting of lizardite and szaibelyite. At a temperature lower than the melting of sodium carbonate (851 °C), the soda-ash roasting of szaibelyite was faster than that of lizardite. Moreover, the melting of sodium carbonate accelerated the reaction between lizardite with sodium carbonate.

Ammonia Leaching of Zinc from Low-grade Oxide Zinc Ores Using the Enhancement of the Microwave Irradiation

2017 ◽  
Vol 16 (3) ◽  
Author(s):  
Shiwei Li ◽  
Haoyu Li ◽  
Weiheng Chen ◽  
Jinhui Peng ◽  
Aiyuan Ma ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Microwave Irradiation ◽  
Solid Phase ◽  
Ammonia Concentration ◽  
Low Grade ◽  
Leaching Rate ◽  
Small Particles ◽  
Mineral Phase ◽  
Total Ammonia ◽  
Ammonia Leaching

AbstractIrradiated roast treatment and the ammonia leaching processing were conducted to deal with the low-grade oxide zinc ores. The ZnCO3phase was hard to be attended, which was the reason for the low leaching rate of the complicated zinc ores. The mineral phase transformation of the ZnCO3phase was generated after the ores irradiated in the microwave at the temperature of 673 K. The irradiated ores generated more small particles, it was the reason that the leaching rate of the complicated zinc ores was increased. When the leaching processing of the irradiated roasted ores was conducted under the conditions of the total ammonia concentration of 6 mol/L, the liquid to solid phase ratio of 11:1, the leaching temperature of 298 K, the leaching time of 150 min and the stirring speed of 400 rpm, 88.3 % of zinc could be achieved, which was the maximum leaching rate of the irradiated ores.

Analysis the Effect of Charcoal Mass Variation to Ni Content, Sinter Strength and Yield on Sintering Process of Limonitic Laterite Nickel Ore

2020 ◽  
Vol 867 ◽  
pp. 25-31
Author(s):  
Fakhreza Abdul ◽  
Sungging Pintowantoro ◽  
Ari Maulidani
Keyword(s):  
Nickel Content ◽  
Low Grade ◽  
Sintering Process ◽  
Mass Variation ◽  
Feed Material ◽  
Nickel Iron ◽  
Sinter Strength ◽  
Ni Content ◽  
Drop Tests ◽  
Alternative Processes

The depletion of sulfide nickel ore and the growing of stainless steel demand each year cause the use of low-grade laterite nickel ore continues to increase. Due to very low nickel content, there is no optimal process to extract them. One of the alternative processes being developed now is the sintering-blast furnace process which produces Nickel Pig Iron (NPI). This research was conducted by sintering limonitic laterite nickel ore using charcoal as fuel and limestone as a flux. This research aims to analyze the effect of charcoal mass variation on Ni content, sinter strength, and the yield on the sintering process of limonitic laterite nickel ore. Charcoal and limestone demand calculated using energy balance and mass balance, then varied charcoal mass to feed material. Feed materials are fed in the furnace, heated at a temperature of 1200oC with 4 hours holding time. Next, the sinter yield was calculated. EDX, XRD, and Drop tests were also performed to determine Ni content, sinter compounds, and strength. The highest Ni content was 3.66% which was obtained by adding 9.9 kg charcoal. The highest sinter strength and yield also obtained by adding 9.9 kg charcoal (72.30% and 86.44%, respectively). Mayor phases which formed on sinter with 9.9 kg charcoal addition is nickel-iron oxide.

Performance of B-Doped SrTiO3/ Ni Sheet for Supercapacitor Material Application

2020 ◽  
Vol 851 ◽  
pp. 25-31
Author(s):  
Markus Diantoro ◽  
Ahmad Al Ittikhad ◽  
Thathit Suprayogi ◽  
Nasikhudin ◽  
Joko Utomo
Keyword(s):  
Electrode Materials ◽  
Solid State Reaction Method ◽  
Raw Material ◽  
Molar Ratio ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Energy Storage Devices ◽  
Xrd Pattern ◽  
X Ray ◽  
Storage Devices

The development of energy storage devices encourages the sustainability of research on basic materials of supercapacitor technology. SrTiO3 is one of metal oxide called as titanate alkali metal ATiO3 (A = Ba, Sr, Ca). This material shows an excellent dielectric constant, thus expected to be potential as raw material of supercapacitor. In this work, boron was used as a dopant on the SrTiO3 system to modify its local structure and enhance the electrical properties. Synthesis SrTi1-xBxO3 was carried out using a solid-state reaction method followed by the sintering process in various molar ratio. The microstructure of SrTi1-xBxO3 compound was identified by X-ray Diffraction with Cu-Kα. XRD pattern identified the presence of SrTi1-xBxO3 phase with a slight change in the lattice parameters. I-V measurement confirmed that the electrical conductivity increased gradually up to 16.04 Ω-1cm-1. For investigating their application for electrode materials, CV was employed and it presents that the specific capacitance and energy density of x = 0.08 were 5.488 Fg-1 and 0.110 Jg-1.

Effect of Control Technology on Properties of Quartz Porous Brick

2018 ◽  
Vol 777 ◽  
pp. 564-568 ◽  
Author(s):  
Long He ◽  
Jin Shi Li ◽  
Mei Hua Chen ◽  
Yan Yang ◽  
Xin Peng Lou ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Quartz Sand ◽  
High Performance ◽  
Performance Test ◽  
Holding Time ◽  
Raw Material ◽  
Process Conditions ◽  
Low Grade ◽  
Sintering Process ◽  
Foaming Agent

A high-performance quartz sand insulation brick was prepared by using low grade quartz sand under different sintering process conditions. The optimum sintering process conditions were obtained by analyzing the relationship between microstructure and sintering process. Through the compounding, pulping, forming, drying and sintering processes, and the performance test of the porous brick, the following conclusions can be drawn, the comprehensive performance in all aspects, the porosity is similar, the preferred high compressive strength conditions, in order to get a best The bonding point, brick body sintering temperature of 1150 °C, porosity of 74.56%, compressive strength of 2.1 MPa of porous brick, and the pores are smooth, more uniform distribution. With the prolonging of the holding time, the porosity of the porous brick is reduced, and the performance is 1h, the porosity is 77.22% and the compressive strength is 2.05 MPa. When the raw material ratio is 60% quartz sand, 30wt% kaolin, calcium carbonate 9.6wt%, foaming agent 0.4wt%, water ratio 0.9 holding time at 1h sintering at 1150°C can get better porosity and compressive strength of the insulation brick. The porous material was sintered at 1150 °C, the content of foaming agent was 0.2wt%, the ratio of water to material was 0.9, and the compressive pressure and porosity were the better.

Bioleaching of Low-Grade Copper Sulfide Ore Using a Colum Reactor

2009 ◽  
Vol 71-73 ◽  
pp. 409-412
Author(s):  
Wen Qing Qin ◽  
Yan Sheng Zhang ◽  
Shi Jie Zhen ◽  
Jun Wang ◽  
Jian Wen Zhang ◽  
...  
Keyword(s):  
Iron Concentration ◽  
Mixed Cultures ◽  
Copper Recovery ◽  
Low Grade ◽  
Leaching Rate ◽  
Ministry Of Education ◽  
Copper Ore ◽  
Copper Leaching ◽  
Pure Cultures ◽  
Mixed Bacteria

The effects of several variables on the column bioleaching of copper sulphide ore have been investigated. The copper ore contained chalcopyrite as the main sulfide minerals and bornite and chalcocite as the minor minerals. The experiment was carried out using bench-scale column leach reactors designed in Key Lab of Biometallurgy of Ministry of Education, which were inoculated with the pure mesophile bacteria (Acidithiobacillus ferrooxidans) and thermophile bacteria (Sulfobacillus), respectively, and the mixed bacteria which contain both iron- and sulfur-oxidizing bacteria. The results show that the mixed cultures were more efficient than the pure cultures alone and the maximum copper recovery 53.64% was achieved using the mixed cultures after 85 days. The leaching rate of chalcopyrite tended to increase with the increased dissolved ferric iron concentration. The effect of particle size on the rate of the copper leaching was also investigated, and it was shown that the copper bioleaching rate decreases as the amount of fines increase, which limits the permeability, thus decreases leaching rate. Jarosite and elemental sulphur formed in the column were characterized by the X-ray and EDS.

scholarly journals Optimization of Bi2O3, TiO2, and Sb2O3Doped ZnO-Based Low-Voltage Varistor Ceramic to Maximize Nonlinear Electrical Properties

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Masoumeh Dorraj ◽  
Azmi Zakaria ◽  
Yadollah Abdollahi ◽  
Mansor Hashim ◽  
Seyedehmaryam Moosavi
Keyword(s):  
Low Voltage ◽  
Quadratic Model ◽  
Molar Ratio ◽  
Sintering Process ◽  
Spinel Type ◽  
Factors Affecting ◽  
Milling Method ◽  
Level 3 ◽  
Central Composite ◽  
Good Agreement

In ZnO-based low voltage varistor, the two essential features of microstructure determining its nonlinear response are the formation Bi-enriched active grain boundaries as well as a controlled ZnO grain size by secondary spinel-type phases. Besides, the microstructure and phase composition are strongly affected by the dopant concentration during sintering process. In this study, the optimal dopant levels of Bi2O3, TiO2, and Sb2O3to achieve maximized nonlinear electrical property (alpha) were quantified by the response surface methodology (RSM). RSM was also used to understand the significance and interaction of the factors affecting the response. Variables were determined as the molar ratio of Bi2O3, TiO2, and Sb2O3. The alpha was chosen as response in the study. The 5-level-3-factor central composite design, with 20 runs, was used to conduct the experiments by ball milling method. A quadratic model was established as a functional relationship between three independent variables and alpha. According to the results, the optimum values of Bi2O3, TiO2, and Sb2O3were obtained 0.52, 0.50, and 0.30, respectively. Under optimal conditions the predicted alpha (9.47) was calculated using optimal coded values from the model and the theoretical value is in good agreement with the value (9.43) obtained by confirmation experiment.

Experimental Study on the Cyanidation of a Low-Grade Gold with High Content of Arsenic in Myanmar

2013 ◽  
Vol 734-737 ◽  
pp. 1041-1044
Author(s):  
Peng Yang ◽  
Gui Fang Zhang ◽  
Qing Rong Yang
Keyword(s):  
Experimental Study ◽  
Pulp Density ◽  
Low Grade ◽  
Leaching Rate ◽  
Mixing Effect ◽  
Gold Ore ◽  
Lime Water ◽  
Content Of Gold

The content of gold ore in Wa region of Myanmar is 3.52 g/t ~5.87g/t, and it contains 9.32% arsenic, it belongs to awkward gold ore with gold embeds in pyrite as fine granular. so the drawbacks of low leaching rate and wasting of resources existed in the early cyanide production. A technology of adjusting pH in lime water and further leaching after regrinding was confirmed by contrasting the mixing effect in different reagent. The experiment results showed that a leaching rate of 81.63% has been obtained by adopting the conditions which pulp density is 40%, the pH of pulp adjusted in lime water is 10, the total NaCN dosage of three additions is 3 and the material is reground before third addition.

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