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Metal lead was first prepared from waste lead paste by direct electrochemical reduction in NH3-NH4Cl solution. Cyclic voltammetry of waste lead paste powders indicated that waste lead paste could be directly electrochemically reduced to metal lead. After constant cell voltage electrolysis for 3 h, waste lead paste pellets were almost completely converted into metal containing 98.3% lead, and the current...
The mixer settler is widely employed in the extraction and recycling of battery materials. The improvement of the separation efficiency is one of the most important issues. In order to investigate the effect of agitating speed on the flow characteristics and settling performance, both computational fluid dynamics coupled population balance model simulations and experiments with particle image velocimetry...
Ferrotitanium is used as a deoxidizer, a degassing agent and an alloying element additive in the steel industry. The thermite method, as a way of preparing ferrotitanium, has the advantages of abundant raw material resources, low energy consumption, and low production costs. However, Al and O impurities in ferrotitanium prepared by this method change greatly with its Ti content. The distribution of...
To develop a more benign materials production route and encourage reuse of bauxite residue produced in the Bayer process, this study aimed to recover the alkali and alumina fractions from bauxite residue by using a novel calcification–carbonization (C–C) method. The obtained dealkalized and dealuminized residue (C–C residue) was then remediated for reclamation to consume all secondary tailings. The...
In terms of secondary resource recovery and environmental impact, fly ash is attracting a great deal of attention in China. This study aimed to investigate the carbochlorination process of titanium oxide to recover titanium. The extraction kinetics mechanism of titanium oxide from fly ash was investigated at temperatures ranging from 850°C to 1050°C. The effect of various experimental parameters was...
In the metal extraction process, recovery of valuable elements from fly ash can have economic benefits and maximize its utilization. Extraction of Mg and Ca from fly ash by the carbochlorination method was studied as a function of carbochlorination temperature, time, carbon content, pellet diameter, and chlorine gas flow rate. The kinetic regime of the carbochlorination of Mg- and Ca-bearing compounds...
Sodium aluminosilicate hydrate is the main equilibrium solid phase of Bayer red mud. Owing to the alkaline insoluble phase, the saltpetering of Bayer red mud tends to occur over time, even after washing procedures. This prevents the large-scale utilization of Bayer red mud for the production of cement, brick, subgrade materials, etc. In this study, a new type of red mud (C-C residue), structured through...
The pyrolysis reactions within a self-made jet pyrolysis reactor were simulated using FLUENT software. The effects of process parameters and reactor structural parameters on the pyrolysis reaction efficiency were studied. Within certain ranges, the CeO2 yield can be improved by reducing the inlet fuel flow rate or by increasing the CeCl3 concentration. To ensure two-phase mixing homogeneity and reaction...
Mixer-settlers have been widely employed in the rare earth element separation industry. Presently, reducing the loss of reagents and occupied areas and achieving a highly efficient separation in the settler are challenging issues. In this work, we report numerical simulations of the liquid–liquid flow in a stirring settler and thereafter describe the experimental validation. A computational fluid...
A new electrotransformation process based on bubbling CO2 into the electrolyte in an electrolytic process to cause precipitation of aluminum salt is proposed herein to solve problems such as the high energy consumption in the process of alumina extraction by acid leaching. The effects of different additives in this electrotransformation process applied to aluminum chloride solution and the resulting...
During CeO2 preparation via jet-flow pyrolysis, the standard spherical particles typically assumed in numerical simulations do not match the actual particle morphologies. In the present work, an extension factor α, fullness factor k, and shrinkage ratio β were introduced to characterize the distributions of several specific types of irregular spherical CeO2 particles inside a jet-flow pyrolysis reactor...
With the aim of developing a novel aluminothermic reduction method for preparation of low-oxygen low-aluminum ferrotitanium by multistage deep reduction we studied the effects of the ratio of reductant Al on the occurrence and distribution of Al and O residuals. The results indicated that Al residual was present in the form of Ti3Al and Al2O3 inclusions. O residual in ferrotitanium with Ti content...
The solvent extraction and separation process of Sc(III) and Fe(III) from a strongly acidic and highly concentrated ferric solution using mixtures of di(2-ethylhexyl) phosphate (D2EHPA) and tri-n-butyl phosphate (TBP) in sulfonated kerosene was studied. The effects of various parameters, including D2EHPA concentration, dosage of TBP, and phase ratio, were investigated for the extraction process. The...
The carbochlorination kinetics of high-alumina fly ash was investigated. The influence of reaction temperature, time, carbon content, pellet diameter, and Cl2 flow rate on the reaction was analyzed. The morphological changes of the samples during the reaction showed that different sizes of spherical particles disappeared entirely after the carbochlorination process. For carbochlorination of alumina,...
To enable use of copper slag and extract the maximum value from the contained copper, an innovative method of reducing moderately diluted slag to smelt copper-containing antibacterial stainless steel is proposed. This work focused on moderate dilution of copper slag using natural gas. The thermodynamics of copper slag dilution and ternary phase diagrams of the slag system were calculated. The effects...
We present a novel methodology for preparing as-cast Ti-Al-V alloy directly from titanium-rich material through a thermite reduction. The new method is shown to be feasible through a thermodynamics and dynamics analysis. The as-cast Ti-Al-V alloys synthesized from titanium dioxide, rutile, and high-titanium slag were analyzed by an x-ray diffractometer, a scanning electron microscope, an inductively...
A novel process has been proposed for magnesium production, in which powder materials including dolomite, ferrosilicon, fluorite and binder are mixed to produce pellets. Kinetics of the silicothermic reduction using the pre-prepared dolomite pellets was investigated by a non-isothermal, flowing argon-protected gravimetric technique at a temperature range from 1323 K to 1673 K. The results suggest...
Electrical conductivity is one of the most important properties of molten slags. It has an important influence on process parameter selection of the electroslag remelting process. In the present work, a new model for estimating electrical conductivity of high-temperature slags has been proposed via calculating the conductivity by electrical conductivity of pure substances and interaction parameters...
The kinetics of extracting vanadium (V) from microwave-roasted (MR) vanadium slag (V-slag) with concentrated H2SO4 were investigated. The microwave irradiation experiments were performed in a modified microwave muffle furnace at temperatures ranging from 150°C to 750°C. The x-ray diffraction analysis indicated that the spinel phase of the V-slag is destroyed after 10 min of roasting. The phase composition...
The complex fluid flow in a large-scale tank stirred with multiple Ekato Intermig impellers used in the seed precipitation process was numerically analyzed by the computational fluid dynamics method. The flow field, liquid–solid mixing, and power consumption were simulated by adopting the Eulerian granular multiphase model and standard k–ε turbulence model. A steady multiple reference frame approach...
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