scholarly journals Mechanism and Kinetics of Ammonium Sulfate Roasting of Boron-Bearing Iron Tailings for Enhanced Metal Extraction

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 812
Author(s):  
Xiaoshu Lv ◽  
Fuhui Cui ◽  
Zhiqiang Ning ◽  
Michael L. Free ◽  
Yuchun Zhai
Keyword(s):  
Particle Size ◽  
Ammonium Sulfate ◽  
Metal Extraction ◽  
Molar Ratio ◽  
Orthogonal Experimental Design ◽  
Optimal Processing ◽  
Valuable Metals ◽  
Roasting Temperature ◽  
Apparent Activation Energies ◽  
Roasting Time

The large amount of boron-bearing iron tailings in China is a resource for metals that needs to be more completely and efficiently utilized. In this evaluation, the ammonium sulfate roasting process was used to make a controllable phase transformation to facilitate the subsequent extraction of valuable metals from boron-bearing iron tailings. The effects of roasting temperature, roasting time, the molar ratio of ammonium sulfate to tailings, and the particle size on the extraction of elements were investigated. The orthogonal experimental design of experiments was used to determine the optimal processing conditions. XRD (X-Ray Diffractomer), scanning electron microscope (SEM), and simultaneous DSC–TG analyzer were used to assist in elucidating the mechanism of ammonium sulfate roasting. The experimental results showed that nearly all Fe, Al, and Mg were extracted under the following conditions: (1) the molar ratio of ammonium sulfate to iron tailings was 3:1; (2) the roasting temperature was 450 °C; (3) the roasting time was 120 min.; and, (4) the particle size was less than 80 μm. The kinetics analysis indicated that the sulfation of metals was controlled by internal diffusion, with the apparent activation energies of 17.10 kJ·mol−1, 17.85 kJ·mol−1, 19.79 kJ·mol−1, and 29.71 kJ·mol−1 for Fe, Al, Mg, and B, respectively.

Preparation of Barium Aluminate with BaCO3 and Al(OH)3

2015 ◽  
Vol 1096 ◽  
pp. 156-160
Author(s):  
Jun Qi Li ◽  
Ru Kai Wang ◽  
Chao Yi Chen
Keyword(s):  
Particle Size ◽  
Aluminium Hydroxide ◽  
Barium Carbonate ◽  
Average Particle Size ◽  
Average Particle ◽  
Optimum Conditions ◽  
Mean Size ◽  
Roasting Temperature ◽  
Barium Aluminate ◽  
Roasting Time

Synthesizing barium aluminate using barium carbonate and aluminium hydroxide, the optimum conditions in reaction process of synthesizing barium aluminate were discussed. The phase of the products was characterized by XRD. The results indicate that the optimal synthesizing conditions are established with the yield of 88.43% when the roasting time is 80min, the roasting temperature is 1350°C and molecular proportion of Al2O3/BaO is 1.1. The bulk density of barium aluminate is 1.5g/cm3; average particle size is 89.808μm; surface mean size is 65.915μm; and the specific surface area is 0.0246016m2/g.

The Extraction of Potassium from Feldspar by Molten Salt Leaching Method with Composite Additives

2012 ◽  
Vol 524-527 ◽  
pp. 1136-1139 ◽  
Author(s):  
Hao Zhang ◽  
De Si Sun ◽  
Hong Bao
Keyword(s):  
Particle Size ◽  
Molten Salt ◽  
Salt Leaching ◽  
Roasting Temperature ◽  
Roasting Time

Effects of ratios of feldspar to CaCl2 to NaCl, roasting temperature ,roasting time and particle size on the melting-out rate of potassium from feldspar was studied by roasting. Results showed that the highest melting-out rate of potassium reached at 95.35% under the ratio of 1.8:1.1:0.6 of feldspar to CaCl2 to NaCl, particle size 220mesh, roasting temperature 800°C, roasting time 1h.

scholarly journals Effect of Broken Coffee Beans Particle Size, Roasting Temperature, and Roasting Time on Quality of Coffee Beverage

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Ezana Getaneh ◽  
Solomon Workneh Fanta ◽  
Neela Satheesh
Keyword(s):  
Particle Size ◽  
Temperature Distribution ◽  
Physical Properties ◽  
Initial Moisture Content ◽  
Coffee Bean ◽  
Sensory Acceptability ◽  
Coffee Beans ◽  
Roasting Process ◽  
Roasting Temperature ◽  
Roasting Time

Optimum flavor and aroma of the coffee are developed during the roasting process. However, certain problems exist in the coffee roasting process such as partial charring, over roasting, and poor temperature distribution across the coffee bean (due to the low thermal conductivity of bean), if conditions are not optimized. Hence, uniform temperature distribution across the coffee bean in the roasting process is highly desirable. To achieve these requirements, the broken coffee beans were positioned in a single layer packed bed arrangement using the closed system by circulating hot air. In this experiment, three factors were arranged in a completely randomized design with three levels and three replications. The first factor considered was roasting temperature (200°C, 230°C, and 260°C), second factor was roasting time (5 min, 10 min, and 15 min), and third was particle size (4–6 mm, 2.36–3.35 mm, and 1.7–2.36 mm). The initial moisture content of raw beans (cv. Limu) was determined. The data were collected on selective physical properties of roasted coffee beans and sensory acceptability of prepared beverage. The results showed that the physical properties and sensory acceptability are significantly high ( P < 0.001 ). It depends on the interaction effect of all the studied factors. Among the studies parameters, roasting temperature of 230°C with a particle size range of 4–6 mm showed the steady transition in dry mass loss and change in bulk density with increase in roasting duration. Coffee roasted at 230°C for 10 min with a particle size of 4–6 mm showed the highest sensory acceptability score (89.21). In conclusion, it can be said that a temperature of 230°C, a time of 10 min, and a particle size between 2.36–3.35 mm and 4–6 mm are recommended conditions for the roasting process of coffee beans.

EFFECTS OF ROASTING AND PARTICLE SIZE ON THE UTILIZATION OF SOYBEANS BY PIGS AND RATS

1975 ◽  
Vol 55 (3) ◽  
pp. 431-440 ◽  
Author(s):  
E. M. OLSEN ◽  
L. G. YOUNG ◽  
G. C. SMITH ◽  
G. C. ASHTON
Keyword(s):  
Particle Size ◽  
Dry Matter ◽  
Growth Response ◽  
Maximum Response ◽  
Particle Sizes ◽  
Regression Analyses ◽  
Discharge Temperature ◽  
Roasting Temperature ◽  
Roasting Time

Three experiments involving 96 pigs and 48 rats were conducted to evaluate the effects of roasting temperature and particle size on the utilization of soybeans. The discharge temperature of roasted soybeans ranged from 110 to 162 C with an average roasting time of 1 min. A range of particle sizes was obtained by using three different screen sizes (2.38-, 3.14- and 4.76-mm holes) in a hammermill used to process the soybeans. Regression analyses of the data indicated that the response in terms of liveweight gain to changes in roasting temperature was quadratic, with maximum response between 130 and 150 C. The digestibility coefficients were slightly lower for diets containing soybeans roasted to temperatures below 130 C than for diets containing soybeans roasted to higher temperatures. The grinding treatments applied to the soybeans did not significantly affect the growth response or the digestibility coefficients for dry matter and protein.

Desulfurization and Structural Transformation Behavior of Lead Sulfate in Sodium Hydroxide Molten Salt

2012 ◽  
Vol 518-523 ◽  
pp. 3310-3315 ◽  
Author(s):  
Zhao Han ◽  
Ling Li ◽  
Jie Li ◽  
Hai Chuan Wang
Keyword(s):  
Molten Salt ◽  
Sodium Hydroxide ◽  
Structural Transformation ◽  
Lead Sulfate ◽  
Raw Material ◽  
Molar Ratio ◽  
Transformation Behavior ◽  
Series Of Experiments ◽  
Roasting Temperature ◽  
Roasting Time

This paper is devoted to studying the desulfurization and structural transformation behavior of lead sulfate in alkaline medium. The effects of roasting temperature, roasting time, and raw material ratio on the desulfurization and phase transition behavior of lead sulfate in sodium hydroxide molten salt was systematically investigated through a series of experiments and analyses. The results show that lead sulfate is gradually transformed to Pb5O4SO4, α-PbO, β-PbO, and finally to Pb3O4during roasting in sodium hydroxide molten salt at temperatures of 250°C to 550°C. At the conditions of roasting temperature 450°C, roasting time 40 minutes, molar ratio of lead sulfate to sodium hydroxide 1 : 2.6, lead sulfate can be completely converted to near-pure phase β-PbO powder. This paper provides a simple and efficient method for the recycling of waste lead acid battery, which consists mainly of lead sulfate.

Extraction of Aluminum from High Iron Bauxite by Carbothermal Reduction-Ammonium Sulfate Roasting

2014 ◽  
Vol 624 ◽  
pp. 3-7 ◽  
Author(s):  
Jing Yun Jin ◽  
Zai Yuan Li ◽  
Yan Wu
Keyword(s):  
Ammonium Sulfate ◽  
Carbothermal Reduction ◽  
Mass Ratio ◽  
High Iron ◽  
Roasting Temperature ◽  
Roasting Time

A new preparation of alumina from high iron bauxite, which has not been being made reasonably use of yet, has been studied. Iron in high iron bauxite was removed by carbothermal reduction and aluminum-rich slag could be obtained. Then aluminum was extracted from aluminum-rich slag by ammonium sulfate roasting. After leaching, Al2(SO4)3 was obtained, which can be used for preparation of alumina. The effects of roasting temperature, roasting time, ammonium sulfate/aluminum-rich slag mass ratio were investigated. Optimum roasting conditions from aluminum-rich slag by ammonium sulfate were found as roasting temperature:400°C;roasting time:120min;ammonium sulfate/aluminum-rich slag mass ratio:6. Approximately 98% of aluminum was effectively extracted.

scholarly journals Application of a cashew-based oxime in extracting Ni, Mn and Co from aqueous solution

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Chi M. Phan ◽  
Son A. Hoang ◽  
Son H. Vu ◽  
Hoang M. Nguyen ◽  
Cuong V. Nguyen ◽  
...  
Keyword(s):  
Organic Phase ◽  
Extraction Efficiency ◽  
Acidic Solution ◽  
Lithium Ion ◽  
Metal Extraction ◽  
Economic Potential ◽  
Cashew Nut ◽  
Valuable Metals ◽  
Loaded Organic Phase ◽  
Cashew Nut Shell

Abstract Background Cashew nut shell is a by-product of cashew (Anacardium occidentale) production, which is abundant in many developing countries. Cashew nut shell liquor (CNSL) contains a functional chemical, cardanol, which can be converted into a hydroxyoxime. The hydroxyoximes are expensive reagents for metal extraction. Methods CNSL-based oxime was synthesized and used to extract Ni, Co, and Mn from aqueous solutions. The extraction potential was compared against a commercial extractant (LIX 860N). Results All metals were successfully extracted with pH0.5 between 4 and 6. The loaded organic phase was subsequently stripped with an acidic solution. The extraction efficiency and pH0.5 of the CNSL-based extractant were similar to a commercial phenol-oxime extractant. The metals were stripped from the loaded organic phase with a recovery rate of 95% at a pH of 1. Conclusions Cashew-based cardanol can be used to economically produce an oxime in a simple process. The naturally-based oxime has the economic potential to sustainably recover valuable metals from spent lithium-ion batteries. Graphic abstract

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 CHEMICAL INVESTIGATIONS ON THE ACTIVE PRINCIPLES OF THE PHENOMENON OF LOCAL SKIN REACTIVITY TO BACTERIAL FILTRATES

1938 ◽  
Vol 67 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Gregory Shwartzman ◽  
S. A. Morell
Keyword(s):  
Particle Size ◽  
Physicochemical Properties ◽  
Ammonium Sulfate ◽  
Culture Filtrate ◽  
Active Materials ◽  
Local Skin ◽  
Skin Reactivity ◽  
Average Porosity ◽  
Active Substances ◽  
Capillary Analysis

Several physicochemical properties of the active principles of the phenomenon of local skin reactivity to bacterial filtrates have been investigated. Ultrafiltration through Zsigmondy filters of graded porosities has shown that the active substances are retained by membranes finer than 100 to 120 seconds, whereas coarser ones readily permit their passage. The average porosity of this filtration end-point represents a particle size of about 50 to 100 mµ. When fractionally precipitated with ammonium sulfate, most of the activity of a culture filtrate was concentrated in the two-thirds saturated portion. Isoelectric properties were studied by means of capillary analysis and cataphoresis. At pH 3.0 and below, the substances suspended in the culture filtrates migrated to the cathode; activity in this chamber, however, could not be demonstrated. At pH 4.0 and above, reversal to the anode occurred, as the active materials became negatively charged and readily migrated to this chamber. The isoelectric point, therefore, was considered to be between pH 3.0 and 4.0. Preliminary experiments on adsorption, extraction, and pH stability have been described.

Effect of the Synthesis Method on the Properties of Ultrafine YAG Powder

2018 ◽  
Vol 281 ◽  
pp. 40-45
Author(s):  
Jie Guang Song ◽  
Lin Chen ◽  
Cai Liang Pang ◽  
Jia Zhang ◽  
Xian Zhong Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Hydrothermal Reaction ◽  
Synthesis Method ◽  
Particle Morphology ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Synthesis Process ◽  
Powder Materials ◽  
Co Precipitation

YAG materials has a number of unique properties, the application is very extensive. In this paper, the superfine YAG powder materials were prepared by co-precipitation method and hydrothermal precipitation method. The influence of synthesis process on the morphology of the powder was investigated. The results showed that the precursor powder prepared via the co-precipitation method is mainly from amorphous to crystalline transition with the increasing calcination temperature, the precursor agglomeration is more serious, In the process of increasing the calcination temperature, the dispersibility of the roasted powder is greatly improved, which is favorable for the growth of the crystal grains, so that the particle size of the powder is gradually increased, the YAG precursor prepared by the co-precipitation method is transformed into YAG crystals, the phase transition occurs mainly between 900 and 1100°C. When the molar ratio of salt to alkali is Y3+: OH-=1: 8 via the hydrothermal reaction, the YAG particles with homogeneous morphology can be obtained. When the molar ratio of salt and alkali is increased continuously, the morphology of YAG particles is not obviously changed. The co-precipitation method is easy to control the particle size, the hydrothermal method is easy to control the particle morphology.

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