Ti-bearing electric furnace smelting slag produced from direct reduction and electric furnace smelting process of vanadium titanomagnetite ore, contains a high TiO2 content of 40–55 wt%. While a mass of Mg, Al, Ca and Si are closely mixed with Ti in the slag, which greatly limits the recovery of Ti resource from the slag. In this work, the replacement behavior of Ti and Mg in MgxTi3-xO5 was studied, and selective separation of various MgxTi3-xO5 phases from Ti-bearing electric furnace smelting slag was conducted via super-gravity. It was found that Mg could replace Ti in Ti3O5 and form the MgxTi3-xO5, and increasing of cooling rate greatly limited the doping of Mg into MgxTi3-xO5, the MgxTi3-xO5 was transformed from (MgTi2)O5 to (Mg0.9Ti2.1)O5, (Mg0.75Ti2.25)O5 and (Mg0.6Ti2.4)O5 respectively. On this basis, various MgxTi3-xO5 (x = 1, 0.9, 0.75, 0.6) phases were selectively separated from the smelting slag via super-gravity, where the mass fraction of TiO2 was increased from 78.69 to 90.32 wt% while that of MgO was decreased from 13.56 to 6.98 wt% with the increase of Ti/Mg ratio in MgxTi3-xO5. Moreover, the replacement mechanism of Mg and Ti was confirmed from characterization of crystal structure and lattice parameter of various separated high-purity MgxTi3-xO5 crystals.
A process with acid leaching followed by hydrogen-based fluidized reduction and melt separation is presented for recovering DRI (direct reduced iron) from high-phosphorus oolitic hematite in this study, and the aim of this study is to provide theoretical and technical basis for economical and rational use of high phosphorus oolitic iron ores. The reducibility of the ore can be improved by acid leaching, which is caused by the formation of voids in the ore particles after acid leaching and enhancing the internal gas diffusion. The phosphorus content in the DRI is still relative high even though there is no carbon in DRI, and it can be decreased to 0.087 wt% (raw ore 1.2 wt%) with the optimum condition in this study. It is proved that P exists in the DRI recovered from melt separation in the form of P2O5 inclusions or FexP as solid solutions, while not in the form of Ca3(PO4)2 inclusions. Finally, a combined flowsheet for the treatment of high phosphorus oolitic iron ore is designed in this study.
A novel method of effectively recovering rare earthsRare earths (REEs) from rare-earth concentrateRare-earth Concentrate under super-gravity was proposed in this paper. The reconstructions of rare-earth phases in normal gravity and the separation behaviours of REEs...
High-purity rutile (TiO2) possessing favorable dielectric properties was sustainably recovered from Ti-bearing blast furnace slag through phase transformation and super-gravity separation in this study. Firstly, the phase transformation behavior of Ti was studied, the favorable conditions for transformation from perovskite to rutile were determined, and the Ti elements were efficiently enriched into rutile in the Ti-bearing blast furnace slag. Subsequently, the condition for solid and liquid phases of rutile and slag in coexistence was acquired by high-temperature CSLM, the rutile was effectively recovered from the Ti-bearing blast furnace slag through super-gravity separation, and its high purity was verified by the results of XRD, SEM-EDS, XRF, EPMA and Raman. Moreover, the rutile ceramic was prepared, and its dielectric properties were investigated, the dielectric constant was up to around 200, and the dielectric loss was as low as 0.0047 at about 900 Hz. The excellent frequency stability, high dielectric constant and low dielectric loss of the rutile recovered from Ti-bearing blast furnace slag reflect its favorable energy storage capability for dielectric material.
As the tailings of complex paigeite ore through the multistep magnetic separation process, the boron-bearing iron concentrate is mainly used in the ironmaking process for the recovery of iron, while the boron is hard to be recovered. In this study, a novel method was proposed for efficient recovery of boron from boron-bearing iron concentrate through mineral phase transformation and low-temperature separation via super-gravity. The mineral phase transformation of boron-bearing iron concentrate in the reduction process as a function of the temperature mainly included three stages, Stage I: The iron minerals were fully reduced to metallic iron at 1373–1423 K, Stage II: The boron was mainly transformed from suanite (Mg2B2O5) into the boron-rich slag with a high concentration at 1473–1523 K, Stage III: The forsterite (Mg2SiO4) was further melted into slag and some boron was also reduced and entered into liquid iron which caused a significant decrease in boron concentration in the slag at 1573–1623 K. Thus, low-temperature separation of boron-rich slag from the iron phase was conducted at 1523 K via super-gravity. The boron was efficiently recovered into the boron-rich slag with a high recovery of 98.24 % and a high mass fraction of B2O3 of 39.27 wt%, and almost all boron was enriched into a form of suanite. Low-temperature separation greatly improves the recovery of boron in boron-rich slag and prevents boron from entering metallic iron, and also improves the activity of boron-rich slag for sustainable utilization.
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.
Stainless steel slag is classified as a hazardous waste owing to the presence of soluble poisonous Cr(VI), which is harmful to the surrounding environment and human health. In this study, an environmental-friendly process was proposed for efficient recovery of Cr resources and harmless utilization of stainless steel slag. Cr element was selectively enriched from molten slag into the Cr-spinel crystal with the decrease of temperature and efficiently immobilized into the Cr-spinel with a stable valence state of Cr(III) at the temperature of 1573 K in molten stainless steel slag. In addition, almost all Cr-spinel crystals were fully recovered from the molten slag under the supergravity field, where the recovery rate of Cr was up to 95.24 % and the mass fraction of Cr2O3 in Cr-spinel phase reached 19.96 wt%. Moreover, the total leaching amount of Cr in both Cr-spinel and residue phases is as low as 0.67 mg/L and 0.13 mg/L and both products were further recycled, which indicated that Cr elements were completely immobilized in both green and environmental-friendly products.
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.
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.
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.
To study the mechanical properties related to the typical functional failure modes of non-absorbable suture anchor in clinical use, and to support product design, development and verification.By retrieving the database of relevant adverse events, the typical functional failure modes of non-absorbable suture anchor were summarized, and the influencing factors of functional failure were further analyzed by studying the mechanical properties related to functional failure. The publicly available test data was retrieved for verification and provided reference for the researchers.The typical functional failure modes of non-absorbable suture anchor include anchor failure, suture failure, fix loosening, inserter failure, which are related to the mechanical properties of products, such as screw-in torque and break torque of screw-in anchors, insertion force of knock-in anchors, suture strength, pull-out force before and after system fatigue test and elongation of sutures after fatigue test.Enterprises should pay attention to improving the mechanical performance level of products through material, structural design and the suture weaving process to ensure the safety and effectiveness of products.
Boron-bearing iron concentrate, as the tailings of boron concentrate otained from ludwigite, still contains more than 5 wt.% of B2O3, which can hard to be utilized. In this study, low-temperature separation compared with high-temperature melting separation of boron and iron from boron-bearing iron concentrate, and the migration, transformation, separation and enrichment behaviors of boron in both processes were studied. High-temperature melting separation of iron and slag could be accomplished at 1823 K for 60 min, where the boron mainly distributed in a form of glass phase in the slag with a B2O3 content of 22.69 wt.%, while 0.35 wt.% of [B] was melted into the liquid iron. In contrast, iron and slag were efficiently separated at a low temperature of 1573 K for 10 min enhanced by supergravity, almost all of boron was enriched into suanite phase in the slag with a significantly higher B2O3 content of 35.61 wt.% and a high recovery ratio of 99.37%, and the content of B was decreased to 0.15 wt.% in the iron. Compared with high-temperature melting separation, low-temperature separation greatly improved the enrichment of boron in slag and avoided the melting of boron into iron.
The crystallization behavior, in situ separation, and crystal structure of V-spinel in vanadium slag were studied and the displacement mechanism of V and Ti in V-spinel was revealed.
According to the melting behavior of high phosphorous iron ore gaseous reduction product at 1473 K, the iron grains remain in solid state, and the other minerals have formed into slag phase, as well as the phosphorus mainly exist in the form of apatite coexisting with slag phase, while it is impossible to accomplish the iron-slag separation at that temperature under the conventional conditions. Hence, concentrating experiments of iron, slag and apatite phases from high phosphorous iron ore gaseous reduction product at 1473 K by super gravity were carried out in this study, and the results confirmed that it was a feasible and effective method. The layered structures appear significantly in the samples obtained by super gravity treatment, the iron grains and molten slag moved in opposite direction and concentrated at the bottom and upper of the sample, respectively, and the apatite crystals concentrated in the iron-slag interface. Moreover, increasing the gravity coefficient is definitely beneficial for the separating and concentrating of iron, slag and apatite phase. With the gravity coefficient of G=1200, the mass fraction of MFe in the iron rich phase is up to 90.50 wt%, and that of P is decreased to 0.061 wt% after removing the slag inclusion in iron rich phase.
Bayan Obo ore, located in Baotou China, is the second largest niobium (Nb) deposit in the world. However, mining of niobium from this ore has not yet been
In this study, Fe-bearing phase and P-bearing phase were successfully enriched from the steelmaking slag by super gravity. After centrifugal enrichment, there was significant stratification presenting in the sample, the upper part was loose and porous, while the lower was compact and tight. With the help of scanning electron microscope (SEM) and X-ray diffraction (XRD), it was found that large quantities of particles for P-bearing phase gathered in the upper part and gradiently distributed along the direction of the super gravity, while the Fe-bearing phase mainly enriched in the lower part, and the enrichment efficiency was proportional to the centrifugal time and gravity coefficient. Under the gravity coefficient G = 800, T = 1663 K and t = 40 min, the mass fraction of P2O5 in the P-bearing slag was up to 4.12%, and that of FetO in the Fe-bearing slag was 35.17%. The recovery ratio of P2O5 and FetO was up to 77.56 and 60.18%, respectively.
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.
