scholarly journals Efficient Separation of Silicon and Vanadium by Sodium Roasting-Water Leaching from Vanadium Slag and CaV2O6 Preparation

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 255
Author(s):  
Changqing Li ◽  
Haichao Zhang ◽  
Ma Tao ◽  
Xufeng Wang ◽  
Hang Li ◽  
...  
Keyword(s):  
New Product ◽  
Molar Ratio ◽  
Migration Behavior ◽  
Vanadium Slag ◽  
Water Leaching ◽  
Solid Ratio ◽  
Leaching Solution ◽  
Micro Morphology ◽  
Precipitation Ratio ◽  
Separation Behavior

Calcium vanadate (CaV2O6), a new product of vanadium precipitation, was obtained from vanadium slag by sodium roasting-water leaching and calcium precipitation. The separation behavior of vanadium and silicon in vanadium slag during sodium roasting and water leaching was systematically studied, and micro-morphology and valence migration behavior of vanadium and Fe in vanadium slag, roasting slag, and residue were revealed. The Na2CO3 was added to the vanadium slag at 20% mass fraction, roasted at 790 ℃, and kept for 120 min, the roasted sample was added to the deionized aqueous solution with a liquid-solid ratio of (L/S) 5mL/g, and then heated at 90 ℃ for 60 min, 89.54% vanadium and 1.96% chromium were extracted. Sodium carbonate tends to combine with vanadium to form sodium vanadate, while silicon is easy to combine with Fe and Na to form acmite (NaFeSi2O6). When the molar ratio of N (Ca/V) is 0.6 and CaO, is added to adjust the pH of vanadium leaching solution to 6.7 ± 0.1 and precipitate 90 min at 90 ℃, vanadium is precipitated in the form of CaV2O6 with a purity of 95.69%, under these conditions, the precipitation ratio is 95.03%.

scholarly journals Preparation of Calcium Stannate from Lead Refining Dross by Roast–Leach–Precipitation Process

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 283 ◽  
Author(s):  
Dixiu Wu ◽  
Junwei Han ◽  
Wei Liu ◽  
Fen Jiao ◽  
Wenqing Qin
Keyword(s):  
Precipitation Process ◽  
Lead Smelter ◽  
Solid Ratio ◽  
Lead Refining ◽  
Average Grain Size ◽  
Naoh Solution ◽  
Leaching Solution ◽  
Leaching Parameters ◽  
Optimized Conditions ◽  
Calcium Stannate

Lead refining dross containing plenty of tin and other heavy metals, such as lead and antimony, is considered a hazardous waste generated in large quantities in lead smelter plants. In this study, calcium stannate was synthesized from lead refining dross using sodium carbonate roasting and alkaline leaching followed by precipitation with CaO. The effect of roasting and leaching parameters on the extraction efficiency of tin was investigated. The leaching efficiency of tin reached 94% under the optimized conditions: roasting with 60% Na2CO3 at 1000 °C for 45 min, and leaching using 2 mol/L NaOH solution for 90 min at 85 °C and 8 cm3/g liquid/solid ratio. Furthermore, more than 99% of tin in the leaching solution was precipitated using CaO. Finally, XRD, SEM, and ICP-OES analyses indicated that the final CaSnO3 product had a purity of 95.75% and its average grain size was smaller than 5 μm. The results indicated that the developed method is feasible to produce calcium stannate from lead refining dross.

Porous Poly(1-naphthylamine) Synthesized by Interfacial Polymerization

2014 ◽  
Vol 809-810 ◽  
pp. 319-322
Author(s):  
Zhen Zhong Hou ◽  
Qing Hao Yang
Keyword(s):  
Interfacial Polymerization ◽  
Amorphous Polymer ◽  
Molar Ratio ◽  
Polymerization Temperature ◽  
Main Mode ◽  
Reaction Conditions ◽  
Ft Ir ◽  
Micro Morphology ◽  
Polymerization Method ◽  
Porous Poly

Porous poly (1-naphthylamine) were synthesized by interfacial polymerization method. The effects of several reaction conditions including oxidant/monomer molar ratio, polymerization temperature and reaction time on the polymerization yield have been investigated. The highest yield of poly (1-naphthylamine) was up to 73% at oxidant/monomer molar ratio of 3 and polymerization temperature of 25 °C for over 20h. Using FT-IR and XRD to analyze the structure of the obtained polymer, the results show that the main mode of connection for 1-naphthylamine units was linking N to para-C and it formed amorphous polymer with some ordered strutures. The micro-morphology of the polymer observed by SEM was found to have irregular porous structure with pore size less than 5μm, which may be related to the “self-emulsion effect” during polymerization.

Analysis of Physical and Chemical Features of Sintering Dust and Study of Recycling Treatment

2015 ◽  
Vol 768 ◽  
pp. 350-362
Author(s):  
Bin Pei ◽  
Guang Zhan ◽  
Zhan Cheng Guo ◽  
Jin Tao Gao
Keyword(s):  
Calcium Carbonate ◽  
Potassium Chloride ◽  
Sodium Carbonate ◽  
Calcium Sulfate ◽  
Sodium Carbonate Solution ◽  
Potassium Sulfate ◽  
Water Leaching ◽  
Leaching Experiment ◽  
Leaching Solution ◽  
Physical And Chemical

Several physical and chemical detection methods were used to study the basic properties of sintering dust collected from Baogang Steel Corporation. The result shows that the major constituents of the electrostatic precipitator dust (ESP dust) were KCl, NaCl, Fe2O3 and Fe3O4. Water leaching experiment on the sintering dust had shown that the KCl in the ESP dust could be separated and recovered by water leaching and fractional crystallization. Component analysis of leaching solution showed that the massive calcium sulfate in the leaching solution should be removed first in order to obtain the pure potassium salt. In order to provide theoretical guidance to inhibit the dissolution of calcium ions from the sintering dust, the water leaching experiment of ESP dust and the dissolution behavior of CaSO4 in the potassium chloride, sodium chloride, potassium sulfate and their mixed salt solution were studied. Result showed that, a lower liquid-solid ratio should be chosen in the leaching process to inhibit the dissolution of calcium sulfate dehydrate. Using sodium carbonate solution as a precipitating agent, the influences of the concentration of sodium carbonate solution, reaction temperature, stirring speed on the preparation of the spherical calcium carbonate were studied. Spherical calcium carbonate with good dispersing performance and grain size distribution in nanometer range of less than 10μm was obtained. The production technology of potassium sulfate by double decomposition was sutdied, the results showed that over 80% and 12.76% of the recovery rate of potassium sulfate and potassium chloride ammonium compound fertilizer could be obtained. Furthermore, a potassium recovery process with joint production of spherical calcium carbonate and potassium sulfate was designed. This process is technically viable and considerable in economic benefit.

scholarly journals One-Part Alkali-Activated Pastes and Mortars Prepared with Metakaolin and Biomass Ash

2020 ◽  
Vol 10 (16) ◽  
pp. 5610
Author(s):  
Alessandra Mobili ◽  
Francesca Tittarelli ◽  
Hubert Rahier
Keyword(s):  
Compressive Strength ◽  
Reaction Kinetics ◽  
Isothermal Calorimetry ◽  
Molar Ratio ◽  
Alkaline Solutions ◽  
Strength Increase ◽  
Biomass Ash ◽  
Solid Ratio ◽  
User Friendly ◽  
Alkali Activated

Common alkali-activated materials (AAMs) are usually manufactured with highly alkaline solutions. However, alkaline solutions are dangerous for workers who must wear gloves, masks, and glasses when handling them. This issue makes common (or two-part) AAMs not user-friendly and problematic for bulk production if no safety procedures are followed. In this paper, the possibility of manufacturing alkali-activated pastes and mortars without alkaline solution is investigated. These innovative one-part AAMs have been prepared with metakaolin as the aluminosilicate precursor, potassium-rich biomass ash as the alkaline activator, and water. AAMs have been prepared by varying the K/Al molar ratio: pastes have been studied in terms of reaction kinetics, through isothermal calorimetry, and mortars have been tested in terms of mechanical compressive strength. Results show that the K/Al molar ratio governs both the reaction kinetics and the mechanical strength of these innovative materials. The highest compressive strength is obtained when the K/Al ratio is equal to 2.5 and the water/solid ratio is equal to 0.49. If biomass ash is heated at 700 °C to decompose the calcium carbonate, its reactivity and the final compressive strength increase.

Study on the Synthesis of LiCoO2 from Spent Li-Ion Batteries

2012 ◽  
Vol 630 ◽  
pp. 93-98 ◽  
Author(s):  
Yan Gao ◽  
Jin Hui Li
Keyword(s):  
Reaction Time ◽  
Cycling Performance ◽  
Molar Ratio ◽  
Li Ion Batteries ◽  
Iron Precipitation ◽  
Structure And Morphology ◽  
Leaching Solution ◽  
Li Ion ◽  
Precipitation Ph ◽  
Charge Discharge

A new LiCoO2 recovery technology from leaching solution of spent Li-ion batteries was studied in this paper. Leaching solution contained many metals, such as Cu, Co and Fe. Copper was removed through replacement by iron powder followed by iron precipitation in goethite method. The experimental results show that Cu can be removed 99% at least through replacement by Fe powder, and the removal of Fe can achieve 99% by goethite method. The optimum Cu removal conditions are that temperature is 50 °C, Femol/Cumol=1.5,reaction time is 30 min. The optimum Fe removal conditions are that terminal precipitation pH is 4, temperature is 90 °C, reaction time is 6 h. The remainder Co can be mixed with Li2CO3,LiOH•H2O and LiAc•2H2O to adjust the Li/Co molar ratio to 1.00. The new LiCoO2 was obtained by calcining the mixture at 850°C for 12 h in the air. Structure and morphology of the recycled powders and resulted sample were observed by XRD and SEM technique, respectively. The layered structure of the LiCoO2 synthesized by adding Li2CO3 is best, and it is found to have the best characteristics as cathode material in terms of charge–discharge capacity and cycling performance.

Oxygen Pressure Acid Leaching of Vanadium Slag

2011 ◽  
Vol 79 ◽  
pp. 242-247 ◽  
Author(s):  
Wang Zhong Mu ◽  
Ting An Zhang ◽  
Zhi He Dou ◽  
Guo Zhi Lü ◽  
Lan Hu ◽  
...  
Keyword(s):  
Oxygen Pressure ◽  
Acid Leaching ◽  
Leaching Rate ◽  
Vanadium Slag ◽  
Solid Ratio ◽  
Leaching Process ◽  
Oxygen Pressure Acid Leaching ◽  
Effects Of Temperature ◽  
Pressure Acid Leaching ◽  
Single Factor Experiment

Oxygen pressure acid leaching process was used to extract vanadium from vanadium slag (Panzhihua steelmaking plant of China). The single factor experiment was finished and the effects of temperature, leaching time, liquid to solid ratio, stirring speed, initial concentration of sulfuric acid, and were investigated on the leaching rate of vanadium, titanium and iron. The leachate and residue were characterized by ICP, XRF, XRD, SEM and EDX. The experiment results indicate when temperature is 140 °C, leaching time is 120 min, liquid to solid ratio is 20:1(ml:g), stirring speed is 500 rpm, initial acid concentration is 200 g/L, oxygen partial pressure is 0.5 MPa, and particle size is -0.075~+0.055 mm, leaching rate of vanadium is 97.89% and the content of vanadium in the residue is 0.586%. Leaching rate of titanium and iron is 12.78% and 94.45% respectively. Vanadium could be extracted effectively through the oxygen pressure acid leaching process.

Effective Extraction of Vanadium and Chromium from High Chromium Content Vanadium Slag by Sodium Roasting and Water Leaching

2016 ◽  
Vol 863 ◽  
pp. 144-148 ◽  
Author(s):  
Ming Li ◽  
Liang Xiao ◽  
Jing Jing Liu ◽  
Zhi Xin Shi ◽  
Zi Bi Fu ◽  
...  
Keyword(s):  
Chromium Content ◽  
Leaching Rate ◽  
Vanadium Slag ◽  
Water Leaching ◽  
Sodium Salts ◽  
High Chromium ◽  
Effective Factor ◽  
Roasting Process ◽  
Roasting Temperature ◽  
Roasting Time

The extraction of vanadium and chromium from high chromium content vanadium slag by salt roasting and water leaching process has been investigated, which uses mixed sodium salts (Na2CO3 and NaOH) as additive agent in roasting process. The mineralogical morphology was prospected by TG-DSC, XRD, SEM and EDS. The oxidation of slag and transversion of V/Cr-containing phase and sodium salts have been discussed. It has been demonstrated that the presence of NaOH contributes to decompose spinel and olivine phases, which is beneficial to reduce the roasting temperature and elevate V, Cr leaching ratio. The roasting parameters have been studied as a function of roasting temperature, roasting time and ratio of alkali, in which the roasting temperature is the most effective factor on the leaching rate of vanadium and chromium. Under the optimum condition, the leaching rates of V and Cr reached 95.8% and 97.6%, respectively.

scholarly journals Studying of possibility for breakdown of ilmenite concentrate with ammonium sulphate

2020 ◽  
Vol 4 (312) ◽  
pp. 22-30
Author(s):  
G. F. Krysenko ◽  
◽  
D. G. Epov ◽  
M. A. Medkov ◽  
E. B. Merkulov ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Ammonium Sulfate ◽  
X Ray Diffraction ◽  
Iron Compounds ◽  
Water Leaching ◽  
Ilmenite Concentrate ◽  
Double Salts ◽  
Leaching Solution ◽  
Double Sulfates ◽  
Main Components

The data on investigation of the possibility of breakdown of ilmenite concentrate of the Ariadnensky deposit in Primorsky Krai with ammonium sulfate are presented in the article. For study the ilmenite concentrate and ammonium sulfate interaction, the concentrate and (NH4)2SO4 were mixed based on the formation of sulfates of the main components of the concentrate and then double sulfates of the components of the concentrate and ammonium. The interaction was carried out in glassy carbon crucibles, which were placed in a muffle furnace controller company Nabertherm GmbH (Germany). The weight of sample was 10–40 g. Thermogravimetry, X-ray diffraction and atomic absorption analyses were used in the study. It was found that when the temperature of thermal decomposition of (NH4)2SO4 (3000С) is reached, the interaction of the main components of the concentrate with (NH4)2SO4 begins and proceeds in the temperature range of 300-3600С with the formation of a mixture of double salts well soluble in water - ammonium sulfate and iron compounds (NH4)2Fe2(SO4)3 and NH4Fe(SO4)2 and ammonium sulfate and titanyl of the composition (NH4)2TiO(SO4)2. The interaction at a temperature above 3600С leads to thermal decomposition of the formed double sulfates of ammonium and titanyl and ammonium and iron to sulfates and then oxides. It was shown that water leaching of the product of the interaction of ilmenite concentrate with (NH4)2SO4 at 3600С allows to extract practically all titanium and the bulk of iron to water in the form of well soluble double salts. The conditions for the titanium dioxide separation in the form of anatase from the water leaching solution were found.

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