Publications

Efficient separation of lead and antimony metals from the Pb-Sb alloy by super-gravity technology

The Pb-Sb alloy was obtained during the pyrometallurgical processing of jamesonite (Pb4FeSb6S14). To effectively separate lead and antimony metals from the Pb-Sb alloy, an innovative approach of super-gravity technology was introduced in the current study. The super-gravity technology plays a significant role in enhancing mass transfer and phase migration of heterogeneous phases as the interfacial tension between different phases will become insignificant. The theoretical calculation of separating efficiencies based on the lever principle of Pb-Sb phase diagram was investigated. The effect of the super-gravity field on Pb-Sb alloys and the corresponding mechanism of filtrating were discussed. With the help of scanning electron microscopy-energy dispersive spectroscopy, metallographic microscopy and X-ray diffraction methods, it demonstrated that the lead phase migrated to the bottom of the sample along the super-gravity direction, whereas almost all of the antimony-rich phase accumulated along the opposite direction. As a step further, the Pb-Sb alloy was separated effectively by the filter in the super-gravity field, and the separating efficiency increased with the increasing of the gravity coefficient (G) within the range of G ≥ 50. With an optimized separation condition T = 533K (260 °C), G = 450, d pore  = 48 μm and t = 210 s, the mass fraction of Pb in the filtrated lead phase reached 85 wt%, which was close to the theoretical separation value 88.8 wt% based on the phase diagram of the Pb-Sb alloy, and the mass fraction of Sb in the residue antimony-rich phase exceeded 91 wt%.

Efficient and comprehensive extraction of multiple heavy metals from high-arsenic copper dross via stepwise phase transformation and supergravity separation

CSD 2141999: Experimental Crystal Structure Determination

An entry from the Inorganic Crystal Structure Database, the world’s repository for inorganic crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the joint CCDC and FIZ Karlsruhe Access Structures service and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Competitive crystallization of B, Si, and Mg and two-stage separation of olivine and suanite from boron-bearing slag in supergravity field

Boron-bearing slag is a typical secondary resource of boron (B) and magnesium (Mg). However, the boron dispersed in the amorphous phase, which is difficult to recover from the boron-bearing slag. This study investigated the effect of supergravity field on the competitive crystallization behavior of B, Si, and Mg in boron-bearing slag, and developed an efficient method for two-stage separation of olivine (Mg2SiO4) and suanite (Mg2B2O5) from the slag. In stage 1, the M g 2 + was preferentially crystallized into olivine with the S i O 4 4 - rather than B 2 O 5 4 - at 1623 K to 1473 K, and the olivine crystals were efficiently separated from the boron-bearing slag melt under the supergravity field. Due to the separation of olivine in the stage 1, the S i O 4 4 - was depleted and a favorable condition for single crystallization of suanite was created in the remaining boron-rich slag. Thus in stage 2, the B 2 O 5 4 - and M g 2 + were adequately crystallized into suanite at 1473 K to 1323 K, and the suanite crystals were recovered further from the separated boron-rich slag melt in the supergravity field. Moreover, the high purity and high crystallinity of the suanite and olivine separated from the boron-bearing slag confirmed the enhancement of supergravity field on the solid-liquidseparation in a complex slag system.

A green method for solidification and recovery of soluble sodium in red mud via super-gravity

Red mud produced in the Bayer process is an ultrafine solid waste containing various metallic elements, which is hazardous to the environment because of its high alkalinity caused by the soluble sodium (Na). In this study, a green method for efficiently solidification and recovery of soluble sodium to eliminate high alkalinity of red mud via super-gravity was developed. Iron-slag melting separation from red mud was firstly conducted at 1523 K, where the Fe was fully recovered into metallic iron and almost all the Na was enriched into the Na-rich slag. Subsequently, the Na was selectively solidified into a stable phase of anorthite at 1373–1323 K, all of which were efficiently separated from the Na-rich slag at 1323 K via super-gravity, where the recovery ratio of Na in anorthite was up to 97.09%. Compared to the red mud, the leaching rates of Na+ in the anorthite and residue were significantly decreased to 0.01% and 0.05%, and the pH of both products was decreased to 8.1–8.4. It was confirmed that the high soluble sodium in red mud was efficiently solidified and recovered into a stable phase of anorthite, and the high alkalinity was fully eliminated in both products which are environmentally friendly.

Direct Concentration of Iron, Slag and Britholite-(Ce,La,Pr,Nd) at 1473 K in a Super Gravitational Field

The investigations of concentrating iron, slag and britholite-(Ce,La,Pr,Nd) from gaseous reduced Bayan Obo ore were conducted at 1473 K in a super gravitational field. The results showed that iron grains concentrated at the bottom area along super gravitational direction, whereas the gangue formed the slag in the upper area along the opposite direction, as well as the REEs enriched into britholite-(Ce,La,Pr,Nd) with a typical hexagonal structure and concentrated in the bottom slag. Moreover, the effects of gravity coefficient on both iron-slag separation and the concentration of REEs precipitates were investigated further.

CSD 2218851: Experimental Crystal Structure Determination

An entry from the Inorganic Crystal Structure Database, the world’s repository for inorganic crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the joint CCDC and FIZ Karlsruhe Access Structures service and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Effect of super gravity on successive precipitation and separation behaviors of rare earths in multi-components rare-earth system

Re-concentrate is a complex multi-components Re-system consisting of Ce, La, Pr and Nd, which brings great difficulties for investigating the transformation and separation behaviors of REEs. The effect of super-gravity field on the mass transfer and phase separation behaviors of REEs was investigated in this paper, and the phenomenon of successive precipitation and separation of REEs was discovered. The Re3+ was firstly precipitated into Re-oxyfluoride phase with OF3-, which overcame the interface tension to be evidently separated into the bottom layer under the action of super gravity. Subsequently, the Re3+ were successively precipitated with FeO3 3-, SiO4 4- and PO4 3- into Re-ferrate phase and britholite phase, which were separated further into the middle and top layers along the super gravity direction. Moreover, various REEs were efficiently recovered into the different Re-phases, respectively. The theoretical and experimental results verified the significant enhancement of super gravity on the mass transfer and phase separation of REEs, and its efficient application in REEs recovery from multi-component Re-system.

Selective Crystallization and Separation of Ti in Ti-Bearing Slag

It reports the selective crystallization and separation of Ti in Ti-bearing slag. The selective crystallization of Ti into perovskite, the phase transformation of Ti into rutile, the crystallization behavior of Ti into anosovite, and the carbothermal reduction of Ti into TiC in Ti-bearing slag are reported in Sects. 2.1, 2.2, 2.3, and 2.4, respectively. The study on selective separation of various Ti–rich phases of perovskite, rutile, anosovite, and TiC powders in molten Ti-bearing slag is included in the Sects. 2.1, 2.2, 2.3, and 2.4, respectively. The amplification study for selective separation of Ti in Ti-bearing slag is reported in Sect. 2.5.

CSD 2218771: Experimental Crystal Structure Determination

An entry from the Inorganic Crystal Structure Database, the world’s repository for inorganic crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the joint CCDC and FIZ Karlsruhe Access Structures service and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Evaluation of Mass Transfer Coefficient during Scrap Melting

Mass transfer is a critical scrap melting step. Herein, mass transfer coefficients (k) during scrap melting were calculated using laboratory-scale experiments. Correlation analysis and the entropy weight method were used to determine the effect of variables on k. The evaluation model under natural and forced convection was established. It was consistent with the experimental results. Under forced convection, at 1573 and 1673 K, when the rotation speed was increased from 141 to 423 r/min, k increased from 7.50 × 10−5 to 1.54 × 10−4 m/s and from 8.42 × 10−5 to 1.72 × 10−4 m/s, respectively. Furthermore, as the bath temperature was increased from 1573 to 1723 K, the k value of a stationary specimen increased from 3.14 × 10−5 to 5.31 × 10−5 m/s, respectively. Correlation analysis and the entropy weight method indicated that the effects of variables on k decreased as follows: molten pool stirring rate > bath temperature > scrap type. Moreover, the explicit functional relationships between k and the factors affecting k under natural and forced convection conditions were established, and the results were consistent with the experimental data. Our results can be used to determine the quantitative relationships between k and the factors affecting k.

Chemical Structure of Si–O in Silica Fume from Ferrosilicon Production and Its Reactivity in Alkali Dissolution

As an environmentally hazardous waste, silica fume was considered as a potential alternative for cement and SiO2 production. The structure of Si–O was highly relevant to the reactivity of Si conversion for efficient utilization. In this study, the characteristic and chemical structure of Si–O in silica fume were characterized by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR). Deconvolution of XPS and FTIR spectra into elementary profiles was carried out to analyze the structural components. As a result, the valence state, bonding structure and elementary unit in the Si–O network of silica fume were determined. Then, the reactivity silica fume with alkali solution was studied involving the effects of NaOH concentration and temperature. The staged kinetics behavior was associated with the structure of Si–O bonds, and the activation energies were determined. The results thus provided fundamental information for the utilization of silica fume for SiO2 production and geopolymer.

Competitive crystallization, <i>in situ</i> separation and solidification mechanism of Cr-spinel crystal from Cr-bearing slag

The competitive crystallization, in situ separation, and solidification mechanism of Cr-spinel crystals were studied and the occupancy of Cr in the Cr-spinel lattice remained constant with the substitution of Fe and Mn.

CSD 2218855: Experimental Crystal Structure Determination

An entry from the Inorganic Crystal Structure Database, the world’s repository for inorganic crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the joint CCDC and FIZ Karlsruhe Access Structures service and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Adsorption kinetic and equilibrium studies for maxilon blue GRL dye by cotton fiber in aqueous solutions

Abstract The adsorption interaction between cotton fibers and dye maxilon blue GRL was systematically investigated under varying contact times, initial dye concentrations, pH, agitation speeds and temperatures; and the adsorption capacity of dyes increases with the increase of those five parameters. The kinetic and isotherm results showed that the saturated adsorption capacity q m and adsorption capacity K F exhibited temperature-dependent enhancement; both the equilibrium adsorption amount q e and the apparent rate constant k 2 increase with elevated agitation speeds and temperatures. Thermodynamic analysis indicated a non-spontaneous endothermic process. The low activation energy and adsorption enthalpy change confirmed physical adsorption mechanisms. Understanding the interaction between fiber and dye is helpful for optimizing dye utilization in industrial processes and engineering modified cotton fibers for wastewater decolorization.

General Introduction

Reports the general introduction for super gravity high-temperature metallurgy. The principles, apparatus, and research methods for super gravity high-temperature metallurgy are introduced in Sect. 1.1. The characteristics for metallurgical slag produced from various complex ores are introduced, and a new method for selective crystallization and separation of valuable component in metallurgical slag by super gravity is proposed in Sect. 1.2.

Promoted acid leaching of Zn from hazardous zinc-containing metallurgical dusts: Focusing on transformation of Zn phases in selective reduction roasting

As hazardous wastes from metallurgical processes, high zinc dust (HZD) was considered as a potential alternative resource of Zn. The acid leaching of HZD was a principal step and therefore was highly relevant to efficient utilization. Unfortunately, zinc ferrite (ZnFe2O4) in HZD was difficult to be leached by hydrometallurgical methods. Therefore, in this study, to enhance the recovery of zinc, selective reduction roasting was used to decompose ZnFe2O4. The transformation of Zn phases during the reduction process was investigated by thermodynamic calculation, XRD analysis. The results showed that ZnFe2O4 was converted into acid-soluble ZnO in H2 at 600 °C, while the further reduction of ZnO to Zn(g) and the volatilization of ZnO was avoided. However, the soluble ZnSO4 in HZD was also reduced to acid-insoluble ZnS. Consequently, a novel method of reduction roasting combined with water leaching was proposed to pretreat HZD. In water leaching, the solid-liquid ratio was1:10 (g/mL). When H2SO4 concentration was 80 g/L, the leaching ratio of Zn was 94.24% after pretreatment, higher than that of direct leaching of HZD (87.76%). Therefore, acid leaching of Zn was promoted by water leaching and reduction roasting pretreatment, which will bring considerable benefits to the high zinc dust recycling enterprises.

A green method for selective crystallization and extraction of suanite (Mg2B2O5) crystals from boron bearing slag under super-gravity

A green method was proposed for selective crystallization and extraction of suanite crystals from boron bearing slag for ceramics reinforced phase under super-gravity. Through investigating crystallization behavior of boron bearing slag melt, olivine (Mg2SiO4) and suanite (Mg2B2O5) crystals were precipitated successively at various temperature ranges of 1623-1473 K and 1473-1323 K. Hence, selective crystallization conditions for the last precipitated suanitie crystals were investigated and two-step separation of suanite crystals from boron bearing slag was conducted in a super-gravity field. Firstly, the mixture of suanite and olivine crystals was separated from slag melt at crystallization temperature of suanite. Subsequently, the molten suanite phase was separated further from olivine crystals at melting temperature of suanite, which precipitated further into suanite crystals after cooling process. Accordingly, high-purity suanite crystals were efficiently attained from boron bearing slag, providing an essential ceramics reinforced phase for ceramic-metallic composite material and glass ceramic.