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

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.

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Role of sodium citrate in leaching of low-grade and multiphase zinc oxide ore in ammonia–ammonium sulfate solution

Hydrometallurgy ◽

10.1016/j.hydromet.2017.03.013 ◽

2017 ◽

Vol 169 ◽

pp. 534-541 ◽

Cited By ~ 11

Author(s):

Kun Yang ◽

Libo Zhang ◽

Chao Lv ◽

Jinhui Peng ◽

Shiwei Li ◽

...

Keyword(s):

Zinc Oxide ◽

Ammonium Sulfate ◽

Sodium Citrate ◽

Sulfate Solution ◽

Low Grade ◽

Ammonium Sulfate Solution

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Alkaline Leaching of Low Grade Complex Zinc Oxide Ore

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.158.12 ◽

2010 ◽

Vol 158 ◽

pp. 12-17 ◽

Cited By ~ 5

Author(s):

Shao Jian Ma ◽

Jin Lin Yang ◽

Gui Fang Wang ◽

Wei Mo ◽

Xiu Juan Su

Keyword(s):

Zinc Oxide ◽

Metal Oxide ◽

Ammonium Chloride ◽

Ammonium Carbonate ◽

Preliminary Investigation ◽

Low Grade ◽

Leaching Rate ◽

Alkaline Leaching ◽

Solid Ratio ◽

Zn Content

Alkaline leaching is an important way for treating low grade metal oxide ore, which has some advantages such as low corrosion and low pollution compared to acidic leaching. In order to recover the zinc from a low grade complex zinc oxide ore in which the grade of Zn and Fe are 13 wt.% and 40.2 wt.%, respectively, and 52.8% of Zn is contained in siderite, 34.63% in limonite and 11.55% in smithsonite, this paper presents a preliminary investigation of this type of ore by alkaline leaching method. In this study, ammonia-ammonium chloride and ammonia-ammonium carbonate were used as the leaching reagents. The effects of alkaline concentration, leaching time, leaching temperature and liquid to solid ratio (L/S) were studied, respectively. The results show that 43.15% of initial Zn content was extracted adopting ammonia-ammonium chloride as the leaching reagent in 4.5M at 30°C for 3h with a liquid to solid ratio of 4:1, while 43.07% of Zn recovery was achieved employing ammonia-ammonium carbonate as the leaching reagent at 5M, 30°C and 4:1(L/S). The low leaching rate of Zn is probably attributed to that the zinc contained in siderite was not extracted completely because Zn and Fe exist as isomorphism in siderite.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.616-618.1051 ◽

2012 ◽

Vol 616-618 ◽

pp. 1051-1054 ◽

Cited By ~ 1

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.

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A Study on Leaching of Zinc Oxide Ore in Ammonium Sulfate Solution

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.522-524.1463 ◽

2014 ◽

Vol 522-524 ◽

pp. 1463-1466

Author(s):

Dan Dan Wu ◽

Shu Ming Wen ◽

Jing Yang ◽

Yi Jie Wang ◽

Chao Lv

Keyword(s):

Particle Size ◽

Zinc Oxide ◽

Ammonium Sulfate ◽

Average Particle Size ◽

Sulfate Solution ◽

Solution Temperature ◽

Average Particle ◽

Leaching Rate ◽

Ammonium Sulfate Solution ◽

Effects Of Temperature

In this paper, the leaching effect of zinc oxide ore was investigated using ammonium sulfate solution as leaching agent. The effects of temperature, concentration of ammonium sulfate, average particle size and stirring speed on the leaching of zinc oxide ore were studied. The leaching rate increased with increasing solution temperature, concentration, and stirring speed as well as with decreasing average particle size. Ammonium sulfate solution can therefore be used as an effective leaching agent for zinc extraction from zinc oxide ore.

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Fungicidal and Bactericidal Activity of the Alkyl-Substituted Guanidine-Containing Oligomers

Mikrobiolohichnyi Zhurnal ◽

10.15407/microbiolj82.06.054 ◽

2020 ◽

Vol 82 (6) ◽

pp. 54-63

Author(s):

M.Ya. Vortman ◽

◽

Yu.B. Pysmenna ◽

A.I. Chuenko ◽

D.R. Abdulina ◽

...

Keyword(s):

Heterotrophic Bacteria ◽

Trichoderma Viride ◽

Rhodococcus Erythropolis ◽

Biological Action ◽

Molar Ratio ◽

Diffusion Method ◽

Klebsiella Pneumonia ◽

Alkyl Bromides ◽

Base Form ◽

Two Stages

Biocides are widely used in medicine and various industries to protect against a number of harmful microorganisms. Organic quaternary ammonium and guanidine-containing compounds, the biological action of which is based on membrane-toxic properties, are used as bactericidal preparations. The aim of this work was to study the bactericidal and fungicidal activities of the synthesized oligomeric alkylsubstituted guanidinium bromides with different radicals -C3H7, -C7H15, -C10H21, against different isolates of heterotrophic bacteria and microscopic fungi. Methods. The synthesis of alkyl-substituted guanidiniumcontaining oligomers was performed in two stages. In the first stage, alkyl-substituted guanidine was obtained by the reaction of guanidine, previously converted by alkali from the salt form to the base form by the base and alkyl bromides (Alk=-C3H7 (propyl), -C7H15 (heptyl), -C10H21 (decyl)) in methanol at a temperature of 50°C and a molar ratio of 1:1. The second carried out the reaction between aromatic oligoepoxide DER-331 and alkyl-substituted guanidine in methanol at a temperature of 50°C for 2–3 hours and a molar ratio of 1:2. Bacteria were grown on meat-peptone agar for 48 hours at a temperature of 28±2°С. Test cultures of micromycetes were cultured on agar beer wort (6°B), incubated for 14 days in a thermostat at a temperature of 28±2°C. Antimicrobial activity of newly synthesized alkyl-substituted guanidinium-containing oligomers was determined by standard disco-diffusion method (method of disks on agar) and fungicidal activity was determined by the method of holes in agar. Results. Oligomeric alkylsubstituted guanidinium bromides with different radicals composed -C3H7, -C7H15, -C10H21- synthesized by the reaction of guanidine alkyl bromides with aromatic oligoepoxydes. It was found that alkyl-substituted guanidinium-containing oligomers at a concentration of 1–3% inhibited the growth of Escherichia coli 475, Pseudomonas aeruginosa 465, Klebsiella pneumonia 479, Pseudomonas pseudoalcaligenes 109, Staphylococcus aureus 451, E. faecalis 422, Rhodococcus erythropolis 102, Bacillus subtilis 138 and most of the studied micromycetes – Aureobasidium pullulans F-41430, Paecilomyces variotii F-41432, Penicillium funiculosum F-41435, Penicillium ochrochloron F-41431, Scopulariopsis brevicaulis F-41434, Trichoderma viride F-41437, Candida albicans F-41441, Aspergillus flavus F-41442, Aspergillus niger F-41448, Penicillium sp. F-41447. Conclusions. Antimicrobial and fungicidal properties significantly depend on the length of the alkyl radical, with increasing of its length the diameter of the zone of bacterial and micromycetes growth retardation increases.10.15407/microbiolj82.06.054

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

Green Processing and Synthesis ◽

10.1515/gps-2021-0008 ◽

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.

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

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2017-0055 ◽

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.

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