scholarly journals Preparation of NaA Zeolite from High Iron and Quartz Contents Coal Gangue by Acid Leaching—Alkali Melting Activation and Hydrothermal Synthesis

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1198
Author(s):  
Deshun Kong ◽  
Rongli Jiang
Keyword(s):  
Hydrothermal Synthesis ◽  
Mass Fraction ◽  
Acid Leaching ◽  
Coal Gangue ◽  
Raw Material ◽  
Iron Ions ◽  
Optimum Conditions ◽  
High Iron ◽  
Solid Ratio ◽  
Naa Zeolite

In this study, NaA zeolite was successfully synthesized from coal gangue with high contents of iron and quartz as the main raw material. The results show that most iron ions can be removed from coal gangue after calcination at 700 °C for 2 h, leaching in hydrochloric acid with a mass fraction of 20% for 7 h and a liquid-solid ratio of 3.5:1. When m (acid leached residue of calcined gangue):m (Na2CO3) = 1.1 and melting at 750 °C for 2 h, the quartz and other aluminosilicates turn into nepheline, which dissolve in water. Finally, the optimum conditions of synthesis NaA zeolite are as follows: n(SiO2)/n(Al2O3) = 2.0, n(Na2O)/n(SiO2) = 2.1, n(H2O)/n(Na2O) = 55, aging at 60 °C for 2 h, and crystallization at 94 °C for 4 h. This shows that the high iron and quartz contents coal gangue can be used for the synthesis of NaA zeolite.

Study on Leaching Zinc Calcine with High Iron

2013 ◽  
Vol 826 ◽  
pp. 118-121
Author(s):  
Jin Lin Yang ◽  
Hong Mei Zhang ◽  
Xiu Juan Su ◽  
Shao Jian Ma
Keyword(s):  
Sulfuric Acid ◽  
Acid Concentration ◽  
Great Influence ◽  
Sulfuric Acid Concentration ◽  
Acid Leaching ◽  
Leaching Rate ◽  
Iron Extraction ◽  
High Iron ◽  
Solid Ratio ◽  
Leaching Efficiency

In recent years, recovering zinc from zinc calcine with high iron has been a matter of discussion. In this paper, sulfuric acid leaching was carried out to assess the effect of several parameters on zinc and iron extraction in zinc calcine with high iron in which the grade of zinc and iron is 53.90% and 19.38%, respectively. Parameters, such as stirring speed, sulfuric acid concentration, liquid to solid ratio and leaching time, were investigated. The results show that leaching time has done nothing to the leaching rate, but has great influence on leaching efficiency. Liquid to solid ratio and sulfuric acid concentration have significant influence on leaching results, and stirring rate has not obvious influence on leaching results. Under the condition of 120g/L sulfuric acid, 6:1 liquid to solid ratio, 55°C leaching temperature and 120min leaching time, the recovery of zinc and iron is 82.24% and 9.64%, respectively. It is obvious that ZnO in zinc calcine is easy to dissolve in acidity solution, which shown in two aspects: high leaching rate and high leaching speed. ZnO can be dissolved entirely in sufficient sulfuric acid in 10min.

scholarly journals A New Process of Extracting Titanium from Vanadium–Titanium Magnetite

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 327
Author(s):  
Yandong Li ◽  
Shuangyin Chen ◽  
Huamei Duan
Keyword(s):  
Recovery Rate ◽  
Acid Leaching ◽  
Leaching Rate ◽  
Optimum Conditions ◽  
Solid Ratio ◽  
New Process ◽  
Leaching Experiments ◽  
Panxi Area ◽  
Vanadium Titanium ◽  
Titanium Magnetite

A new process of extracting titanium from vanadium–titanium magnetite (VTM) in the Panxi area in Sichuan, China is introduced in this work. Various experiments, including reduction–magnetic separation, leaching and hydrolyzing experiments, are carried out. The results show that the optimum conditions for leaching experiments are an acid/slag ratio of 4:1, a leaching temperature of 60 °C, a leaching time of 80 min, and a liquid/solid ratio of 3.2:1. The leaching rate of titanium in Ti-bearing slag is 92.41%. The optimum conditions for hydrolyzing experiments are an H+ concentration of 0.75 g·L−1, hydrolyzing temperature of 100 °C, and hydrolyzing time of 180 min, and the hydrolyzing rate of titanium in acid leaching liquor is 96.80%. After the leaching and hydrolyzing experiments, the recovery rate of titanium from the Ti-bearing slag is 89.45%.

scholarly journals Extraction of REEs (Ce, Tb, Y, Eu) from Phosphors Waste by a Combined Alkali Roasting–Acid Leaching Process

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 437
Author(s):  
Bing-Xuan He ◽  
Yong Liang ◽  
Lue-Wei Xu ◽  
Long-Bin Shao ◽  
De-Gang Liu ◽  
...  
Keyword(s):  
Rare Earth ◽  
Oxygen Concentration ◽  
Acid Leaching ◽  
Solution Concentration ◽  
Mass Ratio ◽  
Optimum Conditions ◽  
Solid Ratio ◽  
Roasting Temperature ◽  
Leaching Efficiency ◽  
Hcl Solution

Rare Earth (RE) phosphors waste contains valuable rare Earth elements (REEs), such as cerium, terbium, yttrium, and europium. In industry, the process of NaOH roasting followed by acid leaching is usually used to extract the REEs from the waste in China. Using this process, the leaching efficiencies of cerium and terbium are clearly lower than those of other REEs, which results in uneven extraction of REEs in the waste and low total REE leaching efficiency. The key reason is that the trivalent cerium and terbium in the waste are oxidized into RE oxides during NaOH roasting, which are difficult to dissolve in acid solution. To solve this problem, an optimized process of controlling the oxygen concentration during NaOH roasting is proposed in this paper. The influences of the oxygen concentration, roasting temperature, roasting time, mass ratio of waste phosphor to NaOH, HCl solution concentration, acid leaching temperature, acid leaching time, and liquid–solid ratio on the REE leaching efficiency were investigated. Under the optimum conditions, the leaching efficiencies of cerium and terbium increased dramatically and the total REE leaching efficiency is 99.11%.

Treatment of Pyrite Cinders for Arsenic Removal Using Acid Leaching Process

2013 ◽  
Vol 634-638 ◽  
pp. 3541-3544
Author(s):  
Shao Jun Bai ◽  
Shu Ming Wen ◽  
He Fei Zhao ◽  
Qin Bo Cao ◽  
Hai Ying Shen ◽  
...  
Keyword(s):  
Steel Industry ◽  
Arsenic Removal ◽  
Acid Leaching ◽  
Raw Material ◽  
Pyrite Cinder ◽  
Iron Concentrate ◽  
Solid Ratio ◽  
Leaching Process ◽  
Chinese Steel Industry ◽  
Sulphuric Acid Concentration

A craft of concentrated acid-heating reinforced leaching process is investigated for the treatment of a high arsenic pyrite cinder, a common by-product in vitriol industry. The pyrite cinder, containing 57.37% Fe, and 2.78% As, was conducted for the acid leaching process. The results demonstrated that iron concentrate with 60.57% Fe, 0.28% As and 96.23% of iron recovery was obtained under the optimal acid leaching conditions(Sulphuric acid concentration is a mass ratio of 20%, a leaching temperature of 60°C, a liquid-solid ratio of 2:1 and a leaching time of 120 min).This craft can be used to utilize pyrite cinder and produce qualified concentrate as iron-bearing feed for steel industry, which will help to solve the pollution of sulfuric acid residue and extend raw material sourcing for Chinese steel industry.

scholarly journals Alkali Activation of Waste Clay Bricks: Influence of The Silica Modulus, SiO2/Na2O, H2O/Na2O Molar Ratio, and Liquid/Solid Ratio

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 383 ◽  
Author(s):  
R. A. Gado ◽  
Marek Hebda ◽  
Michal Łach ◽  
Janusz Mikuła
Keyword(s):  
Compressive Strength ◽  
Raw Material ◽  
Molar Ratio ◽  
Alkali Activation ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Solid Ratio ◽  
Clay Bricks

This study was conducted to investigate the influence of various reaction conditions, namely the silica modulus SiO2/Na2O, H2O/Na2O molar ratio, and liquid/solid ratio on the geopolymerization reaction of the waste fired clay bricks (Grog). The starting raw material and the generated geopolymer specimens produced by different geopolymerization reaction conditions have been characterized using different techniques: X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and thermal analysis. Furthermore, physico–mechanical characterization has been carried out through the determination of bulk density, porosity, water absorption, and compressive strength for each sample at interval curing times of up to 28 days. The results indicated that the geopolymerization system of the waste fired clay bricks is influenced by the investigated reaction conditions at room temperature. The compressive strength of the geopolymer sample produced at optimum conditions increased significantly by up to 37.5 MPa, in comparison with 4.5 MPa for other conditions. Finally, an optimum recommendation and useful conclusions concerning the recycling and utilization of this waste material through the geopolymerization process are made for compatibility with construction applications.

Research on the Extract Al2O3 from Coal Gangue

2012 ◽  
Vol 524-527 ◽  
pp. 1947-1950 ◽  
Author(s):  
Lei Zhang ◽  
Hao Wang ◽  
Yu Li
Keyword(s):  
Hydrochloric Acid ◽  
Aluminum Oxide ◽  
Acid Concentration ◽  
Acid Leaching ◽  
Coal Gangue ◽  
Hydrochloric Acid Concentration ◽  
Leaching Rate ◽  
Mass Ratio ◽  
Sample Mass ◽  
Solid Ratio

The experiments selected Wang Taipu gangue as raw materials and adopted single factor experimental method to study the leaching of aluminum oxide from gangue by using hydrochloric acid as leaching medium. The experiments studied solvent/sample mass ratio, hydrochloric acid/sample, liquid-solid ratio, hydrochloric acid concentration, leaching time and leaching temperature on Al2O3 leaching rate of coal gangue. Through the parallel experiment of the above factors, we can found that optimization conditions of hydrochloric acid leaching of alumina were: solvent /sample mass ratio: 0.20, solvent: NaF, liquid-solid ratio: 1:10, hydrochloric acid concentration: 6mol/L, leaching time: 150min, leaching temperature:110°C. In this case, the aluminum oxide of optimal leaching rate was 79.33%.

scholarly journals Regeneration of LiFePO4 from spent lithium-ion battery by a facile closed-loop process featuring acid leaching and hydrothermal synthesis

2021 ◽  
Author(s):  
Yifan Song ◽  
Boyi Xie ◽  
Shuya Lei ◽  
Shaole Song ◽  
Wei Sun ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Lithium Ion Battery ◽  
Closed Loop ◽  
Acid Leaching ◽  
Lithium Ion ◽  
Power Battery

As a widely used power battery, the scrapping boom of LiFePO4 (LFP) battery is coming. Both pyrometallurgical repair and hydrometallurgical processes have been applied in the recycling of spent LFP...

Recovery Technology of Zinc from Hydrometallurgical Zinc Residues

2011 ◽  
Vol 396-398 ◽  
pp. 620-623
Author(s):  
Ya Li Zhang ◽  
Xian Jin Yu ◽  
Xiao Na Guo ◽  
Xiao Bin Li
Keyword(s):  
Acid Leaching ◽  
Optimum Conditions ◽  
Water Leaching ◽  
Zn Content

In this work, it was aimed to select and propose a feasible as well as an applicable method, or series of methods for the extraction of zinc. After determination of the components of the residue, water leaching, acid leaching and roasting-leaching were performed to reclaim Zn. Roasting-leaching was found to be effectively for Zn extraction by controlling acid mass, roasting duration and temperature as parameters. At the optimum conditions, 0.7 times the amount of H2SO4 at 250 °C for 150 min in roasting, 82.05% of initial Zn content was extracted.

scholarly journals Effect of Acid Leaching Pre-Treatment on Gold Extraction from Printed Circuit Boards of Spent Mobile Phones

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 362
Author(s):  
Nicolò Maria Ippolito ◽  
Franco Medici ◽  
Loris Pietrelli ◽  
Luigi Piga
Keyword(s):  
Mobile Phones ◽  
Printed Circuit Boards ◽  
Acid Leaching ◽  
Economic Feasibility ◽  
Circuit Boards ◽  
Gold Extraction ◽  
Printed Circuit ◽  
Solid Ratio ◽  
Thiourea Complex ◽  
Pre Treatment

The effect of a preliminary acid leaching for the recovery of gold by thiourea from printed circuit boards (PCBs) of spent mobile phones, was investigated. Preliminary leaching is aimed to recover copper in the leachate that would compete with gold in the successive leaching of the residue with thiourea, thus preventing the formation of the gold-thiourea complex. Two hydrometallurgical routes were tested for the recovery of copper first, and gold after. The first one was based on a two-step leaching that utilizes sulfuric acid and hydrogen peroxide in the preliminary leaching and then thiourea for the recovery of gold in the successive leaching: A copper and gold recovery of 81% and 79% were obtained, respectively. In the second route, nitric acid was used: 100% of copper was recovered in the leachate and 85% of gold in the thiourea successive leaching. The main operative parameters, namely thiourea and ferric sulphate concentrations, leach time, liquid-solid ratio, and temperature were studied according to a factorial plan strategy. A flowsheet of the processes was proposed, and a mass balance of both routes was obtained. Finally, qualitative considerations on the technical and economic feasibility of the different routes were made.

Fine Silver Powders Production

2021 ◽  
Vol 410 ◽  
pp. 411-417
Author(s):  
Anastasia A. Zvereva ◽  
Vladimir A. Shunin ◽  
Roman S. Voinkov ◽  
Konstantin L. Timofeev
Keyword(s):  
Silver Powder ◽  
Raw Material ◽  
Solution Temperature ◽  
Production Environment ◽  
Optimum Conditions ◽  
Mixing Rate ◽  
Silver Recovery ◽  
Variable Parameters ◽  
Ph Level ◽  
Tapped Density

The article lays out the findings aimed to develop the fine silver powder production technique for electronics industry by selecting the variable parameters whereby a number of powder grades can be produced in the existing production environment (JSC “Uralelektromed”, Russia). The tests for significance of the parameters of silver recovery by ascorbic acid such as pH level of nitrate silver solution, dispersant flow rate, initial concentration of silver, mixing rate and solution temperature made it possible to choose optimum conditions to produce powders of 0.8-6.3 μm in particle size, of 3.0-4.2 g/cm3 in tapped density and with the specific surface area of 2300-4300 cm2/g. Crystalline silver of 99.98 % purity served as a raw material for obtaining silver powders.

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