Huiqing Tang

• Doctor
• University of Science and Technology Beijing, Beijing, China

In this paper, the iron-ore coal composite briquette (ICCB) for blast furnace (BF) was prepared using high-silica ore fines and non-coking coal fines with a method of cold briquetting followed by heat treatment. The cold-crushing strength of the ICCB was 1870 N/briquette and the ICCB was bounded by the sintered matrix. Tests under BF simulation con...

Charge carbon composite briquette (CCB) is an effective method to reduce CO2 emissions and save energy in blast furnace (BF) ironmaking. Presently with the hydrogen-bearing gas being injected in the BF, the content of H2 and H2O in the BF gas is comparable to those of CO and CO2, and they could not be ignored in analyzing the CCB reaction behavior...

A long campaign life of the trough of the blast furnace (BF) is important for improving the BF operation efficiency, reducing the cost of blast furnace ironmaking, and bettering the working conditions of the casting yard. In this paper, a water cooling device was designed for the trough of a BF with a volume of 630 m³. The effect of water cooling o...

A combined experimental and numerical analysis was conducted in this research on charging biochar composite briquette (BCB) to blast furnace (BF). The BCB used in this study was constituted of 10.10 wt pct carbon, 72.21 wt pct magnetite, 11.25 wt pct wustite, and 0.77 wt pct metallic iron. The reaction kinetics of BCB was determined using isotherma...

Partial replacement of coal and coke by biomass/biochar in the blast furnace (BF) ironmaking is important role to reduce CO2 emissions. In this research, numerical investigations were conducted on blast furnace (BF) operation with biochar composite briquette (BCB) charging. The BCB was with 11.1 mass% carbon, 72.7 mass% magnetite, 11.25 mass% wusti...

In this study, the reaction behavior of biochar composite briquette (BCB) in an actual blast furnace (BF) was investigated by modeling. The prepared BCB contained 11.1 wt% carbon, 72.7 wt% magnetite, 11.25 wt% wustite, 0.77 wt% metallic iron, and 4.67 wt% gangue. A reaction model for single BCB in BF was developed and validated using the results of...

In the present research, charging carbon composite briquettes (CCB) in a blast furnace (BF) was investigated. The CCB used contained 29.70 wt.% Fe3O4, 39.70 wt.%, FeO, 1.57 wt.% iron, 8.73 wt.% gangue, and 20.30 wt.% carbon. Its reaction kinetics in BF was examined by nonisothermal tests and modeled. Thereafter, the influence of replacing 10% ore w...

In this research, using the carbon composite briquetteCarbon composite briquette (CCB) containing carbon: 20.30 wt%, Fe3O4: 29.70 wt%, FeO: 39.70 wt%, metallic iron: 1.57 wt%, and gangue: 8.73 wt%. the reaction behaviorReaction behavior of the CCB in BFBlast furnace and the influence of coal reactivityCoal reactivity was examined by the numerical i...

In this research, using iron-oxide fines (average size: 2.5 μm) and biochar fines (average size: 50.0 μm), the biochar composite briquette (BCB) for blast furnace (BF) application was prepared by cold briquetting followed by heat treatment. The preparing conditions were optimized regarding its cold crushing strength. Anti-pulverization capability,...

In this research, carbon composite briquette (CCB) for BF application was prepared and had a mineralogical composition of carbon: 20.30 wt%, Fe3O4: 29.70 wt%, FeO: 39.70 wt%, Fe: 1.57 wt% and gangue: 8.73 wt%. A reaction model of the CCB in BF was developed. Using the model, the CCB reaction behavior under simulated BF conditions was explained, and...

One approach to reduce CO2 emission in the steelmaking industry is to recycle scrap to the blast furnace/basic oxygen furnace (BF/BOF) production system. This paper performed a numerical investigation on the BF operation with scrap charging. The investigated BF was with an inner volume of 820 m³, producing 2950 tons of hot metal per day (tHM/d). Th...

In this research, Carbon composite briquette (CCB) was prepared using ultrafine iron-oxide fine (Size = 2.0 μm), and Biochar fines (Size = 45.0 μm) by cold briquetting followed by heat treatment. Anti-pulverization capacity and Reduction kinetics of the prepared Biochar composite briquette (BCB) under Blast Furnace (BF) (BF) conditions were investi...

Application of high-carbon metallic briquette (HCMB) in the blast furnace (BF) ironmaking for coke saving was previously proposed. This paper is focused on clarifying the in-furnace phenomena and demonstrating the advantages of applying the HCMB in BF ironmaking. A mathematical model has been formulated based on the gas-solid counterflow and its va...

Developments in blast furnace (BF) ironmaking have long focused on low-coke operation. In this study, high-carbon metallic briquettes (HCMB) were prepared using ultrafine iron oxide powders and coal fines for BF application. The preparation conditions were optimized, and the binding mechanism of the briquette was analyzed. The gasification behavior...

Iron ore-carbon briquette is often used as the feed material in the production of sponge iron via coal-based direct reduction processes. In this article, an experimental and simulation study on the reduction behavior of a briquette that is made by hematite and devolatilized biochar fines under CO–CO2 atmosphere was carried out. The reaction model w...

To reduce coke consumption in blast furnace ironmaking, this study proposed a new method of applying iron-coke briquette prepared using hematite powder and pulverized coal to protect coke in BF iron making. Results showed that, with a ratio of hematite to coal of 2.0, the iron-coke briquette could obtain a satisfying compressive strength of more th...

The top gas recycling oxygen blast furnace (TGR-OBF) is a new ironmaking process which can significantly reduce the coke ratio and emissions of carbon dioxide. To better understand the coal combustion characteristics in the TGR-OBF, a three dimensional model was developed to simulate the lance–blowpipe–tuyere–raceway of a TGR-OBF. The combustion ch...

The FASTMELT® process was developed as an alternative to blast furnace ironmaking; in this process, high-quality molten iron is produced using direct reduction followed by high-temperature slag/metal separation. In this study, iron recovery and phosphorus removal from oolitic high-phosphorus haematite using the FASTMELT® process was investigated. T...

The inner shape of a blast furnace is of fundamental importance for blast furnace ironmaking to achieve goals of high yield, high quality, low fuel rate and long campaign life. Therefore, it is worthwhile to design better furnace inner shapes. This paper conducted numerical simulations of performance for the blast furnaces with conventional and mod...

A two-dimensional gas-solid model has been developed for examination of the blast furnace (BF) performance under hot charge operation. Simulation conditions were obtained from the actual operation conditions of the BF with inner volume of 2500 m3 and molten iron output of 6250 ton hot metal (THM) per day. The simulation results indicate that hot ch...

A new method of utilizing high-silica hematite to produce low-silicon molten iron was proposed. In this method, FASTMELT, which comprised direct reduction and melt separation processes, was applied, with highly reactive biochar as the reductant in the direct reduction stage. The proposed method was experimentally investigated and the results show t...

To efficiently utilize high-phosphorus oolitic hematite resources, a method using direct reduction followed by melting separation was proposed. In this study, direct reduction behavior of the ore–char briquette and the melting separation behavior of the reduced briquette were investigated. Direct reduction test results show that under investigated...

Grain sticking often occurs in the fluidized bed reduction of fine iron ore, which is closely related to the precipitation morphology of metallic iron on the surface of ore particles. In this work, simulating the gas-solid reduction process of iron ore, in situ observations were carried out to investigate effects of doping mineral oxides on the pre...

Phosphorus removal from oolitic high-phosphorus hematite using direct reduction followed by melting separation was investigated. At the direct reduction stage, highly volatile wood char was prepared by carbonizing jujube wood at 673 K for 2 h and was used as reducing agent. The results of the direct reduction tests show that at a temperature of 137...

Improvement of the coke quality for blast furnace (BF) iron making by hydrothermal oxidation treatment on coke quality was investigated. Results show that, under subcritical condition, sulfur removal rate is 15% and the weight loss is 3%; under supercritical condition, both sulfur removal rate and mass loss rate increase with the increase of H2O2 c...

Grain sticking often occurs in the fluidized bed reduction of fine iron ore, which is closely related to the precipitation morphology of metallic iron on the surface of ore particles. In this work, simulating the gas-solid reduction process of iron ore, in situ observations were carried out to investigate effects of doping mineral oxides on the pre...

Improvement of the coke quality for blast furnace (BF) iron making by hydrothermal oxidation treatment on coke quality was investigated. Results show that, under subcritical condition, sulfur removal rate is 15% and the weight loss is 3%; under supercritical condition, both sulfur removal rate and mass loss rate increase with the increase of H2O2 c...

Based on the operation conditions of the iron making blast furnace of 580 m3 in the industrial base of MCC Company, a three-dimensional mathematical model for analyzing combustion behavior of gas, pulverized coal and coke bed in the tuyere-raceway-dripping zone of blast furnace has been developed in the present research. The gas was modeled with st...

Pulverized coal injection (PCI) into blast furnace tuyere using two novel oxygen-coal lances has been designed by MCC Company. In this paper, a three-dimensional multi-phase model with Discrete Particle Model (DPM) approach has been developed to examine the performance of the novel oxygen-coal lance for PCI operation. Simulation conditions and prop...

Coating MgO can inhibit sticking effectively during iron ore reduction in a fluidized bed, in order to explore the functional mechanism of coating,different MgO coating methods (briquetting-sintering method, high temperature injection method, powder method, slurry-sintering method) were tried in this experiment.

In this study, an energy-saving and environmentally friendly method to produce low-phosphorus molten iron from high-phosphorus oolitic hematite was experimentally investigated and theoretically analyzed. The results indicate that biomass char is a suitable reducing agent for the proposed method. In the direct reduction stage, the ore–char briquette...

The vanadium titano-magnetite (VTM) iron ore fines of 110–150 μm in diameter were reduced in a transparent quartz fluidized bed by 70%CO-30%H2 (volume fraction) mixtures. MgO powders served as coating agent to solve sticking problem. Two coating methods were introduced in this experiment: high temperature injection method and briquetting→oxidizing...

A new method to process the oolitic high phosphorus iron ore for phosphorus removal has been proposed in this research. It is an integration of direct reduction and melting separation with carbon-containing pellets prepared using biomass char. Experiments of direct reduction were preceded using a tubular furnace and three parameters were investigat...

Introduction Description of PCI Process Mathematical Model Results and Discussion Conclusions Acknowledgements

A three-dimensional multi-phase model with Discrete Particle Model (DPM) approach has been developed to examine the performance of the twin oxygen-coal lances for PCI operation. Simulation conditions and properties of the PC were obtained from the real operation conditions of the blast furnace of 580 m3 with molten iron output of 1775 t/d. The simu...

Abstract A new method to process the oolitic high phosphorus iron ore for phosphorus removal has been proposed in this research. It is an integration of direct reduction and melting separation with carbon-containing pellets prepared using biomass char. Experiments of direct reduction were preceded using a tubular furnace and three parameters were i...

Slag/metal separation process of the highly reduced oolitic high-phosphorus iron ore fines was investigated. Samples were prepared using the reduced ore fines (metallization rate: 88%) and powder additives of CaO and Na2CO3. Slag/metal separation behavior tests were conducted using a quenching method and the obtained metal parts were subjected to d...

Influence of microwave treatment on the previously proposed phosphorus removal process of oolitic high phosphorus iron ore (gaseous reduction followed by melting separation) has been studied. Microwave treatment was carried out using a high-temperature microwave reactor (Model: MS-WH). Untreated ore fines and microwaved ore fines were then characte...

A method of phosphorus removal was proposed to process oolitic high-phosphorus iron ore. It is an integration of direct reduction and melting separation with carbon-containing pellets prepared with high-reactivity biomass char. Direct reduction experiments were performed in a tubular furnace, and three parameters were investigated, i.e., reduction...

Influence of microwave radiation on newly proposed phosphorus removal process (gaseous reduction and slag/metal separation) is studied. Microwave radiation on the ore fines is carried out using MW-HS multi-function high temperature microwave reactor. The treated ore fines are subjected to examinations of SEM, EDS and TG. TG tests are conducted usin...

Influence of microwave radiation on the newly proposed phosphorus removal process (gaseous reduction followed by melting separation) has been studied. Microwave radiation on the ore fines was carried out using MW-HS multi-function high temperature microwave reactor. The treated ore fines were subjected to the examinations of SEM, EDS and TGA. TGA t...

In this study, a simple process has been developed for zinc oxide recovery from RHF (rotary hearth furnace) secondary dust. The results have shown that a high dissolution efficiency of soluble zinc was achieved with water leach at ambient temperature with a liquid/solid ratio of 10/1 in 30min while 20% of the dust was left as solid residue. The rat...

In the current study, a new method for the purification of metallurgical grade silicon (MG-Si), fractional melting process, was proposed and discussed. The proposed method combines the phosphorus segregation behavior between solid silicon and Al-Si melt to removal phosphorus. The segregation coefficient of phosphorus between solid silicon and Al-Si...

This paper reports the phosphorus removal of high phosphorus oolitic iron ore by acid leaching and its influence factors. The experimental ore is Exi high phosphorus oolitic iron ore with 0.5% phosphorus, 51.7% iron and 0.34% sulphur. After acid leaching, the P content decreases to about 0.07%, the iron loss during acid leaching is about 0.18%, and...

Growth process of iron whiskers and mechanism of CaO influence on precipitation morphology of metallic iron at the gas-solid interfaces was studied. Analytical reagents of Fe(NO3)3 and Ca(NO3)2 aqueous solution were used to prepare sheet film sample of Fe2O3-CaO by thermal decomposition at high temperature. In-situ observation was conducted using a...

Influence of magnesium and calcium oxide on control of agglomeration and defluidization during Fe2O3 reduction was investigated in a visual fluidized bed reactor. Added MgO and CaO extended the defluidization time and thus inhibited agglomeration significantly. According to the controlled defluidization tests, the particle cohesiveness and agglomer...

Gaseous reduction kinetics of the high phosphorus iron ore fines from Hubei in China and effect of microwave pretreatment on the gaseous reduction behavior were studied. Gaseous reduction kinetics were investigated by TG (Thermogravimetric) methods using LINSEIS STA PT 1600 thermal analysis equipment. Microwave pretreatments to the ore fines with f...

To develop a new method of refining silicon for use in solar cell materials, liquation refining with Al-Si alloying was proposed for purification of metallurgical grade silicon (MG-Si). The morphologies of impurities, especially for phosphorus and iron, before and after purification were analyzed. By alloying MG-Si with Al, phosphorus in MG-Si form...

The sticking during reduction of iron ore fines under different atmosphere conditions was studied by using a thermal state visible fluidized bed from 973 to 1173 K. It is found that when defluidization occurs the influences of temperature and reducing atmosphere on the metallization rate of iron ore fines are limited if the superficial gas velocity...

A new method has been developed for determination of kinetic parameters for gaseous reduction of iron ore fines. The new method was based on conducting TG experiments and employing an optimization tool, the genetic algorithm (GA). TG experiments were performed using LINSEIS STA PT 1600 thermal analysis instrument (LINSEIS Co. Germany). The obtained...

A new 2D computational fluid dynamic (CFD) model was developed for the gaseous reduction of iron ore fines in an innovative reactor- multilayer moving-fluidized bed. The solution of the proposed model was performed by integration of FLUENT and PHOENICS. Numerical results of cold state were compared with the experimental data and the agreement betwe...

Ultrafine precipitated silica was obtained from Na2SiO3 solutions and simulative lime kiln gas by carbonization process. The surface modification of ultrafine precipitated silica using 3-methacryloxypropyltrmethoxysilane (KH570) at the rear stage of carbonization process was investigated. The optimum synthesis condition of precipitated silica was o...

To process optimization and improve the degree of reduction, a two-step experiment was designed. The experiment was carried out in the micro-fluidized bed. The reactor in the micro-fluidized bed is operated as a differential reactor to ensure an equal temperature and residence time with the reactor volume. The experiment used Brazilian iron ore and...

The effect of coating MgO with different methods on sticking behavior during the reduction of iron ore fines was investigated, at 1073 K with 70%CO–30%H2 gas mixture in a visualization fluidized bed. It was found that coating MgO on particle surface could extend fluidization time from 12 min to more than 80 min, and improve the degree of metallizat...

A two-dimensional CFD model was developed for pre-reduction of iron ore fines using a Z-path movingfluidized bed. The proposed model was solved using an integration of PHOENICS and FLUENT. Simulation results of cold state including pressure drop per perforated plate, gas flow patterns and solid flow patterns were compared to experimental results an...

Dephosphorization process of high phosphorus oolitic iron ore by acid leaching and leaching kinetics were investigated in the paper. The high phosphorus ore samples (51%T.Fe, 0.52%P) used in this work were analysed by SEM-EDS and XRD, which showed their oolitic structure and mineral phases. Among the three kinds of acids (H2SO4, HCl and HNO3), sulf...

To optimize the process and improve the degree of reduction, a two-stage experiment was designed. It was carried out in a micro-fluidized bed. It is operated as a differential reactor to ensure every particle in the micro-fluidized bed is at equal temperature, concentration and residence time. The experiment used iron ore powder from Yangdi. The re...

The combustion reaction mechanism and kinetic characteristics of pulverized anthracite coal in two phase flow were studied by micro fluidized bed kinetic analyzer, and compared with those by thermogravimetry method. The results show that the combustion reaction mechanism of pulverized coal and the composition of combustion gas product change when t...

A comprehensive mathematical model of full oxygen blast furnace with top recycle gas heated by gasifier was established. The model consists of the calculation equations for gas composition of four zones (hearth, belly, lower shaft, top) in the blast furnace, the thermo-chemical balance model of blast furnace, the energy balance model of hot stand-b...

In gaseous reduction of iron ore fines, alkaline earth oxides have profound effects on the precipitation behavior of fresh metallic iron on the particle surface. In this work, in situ observation was performed to reveal the influence of alkaline earth oxides on the precipitation morphology and micro-structure variation of fresh metallic iron from m...

The high-temperature defluidization behavior of iron powder was investigated in different fluidizing gases (Ar, N-2, CO, H-2), especially in terms of the physical and chemical properties and change of the gas and solid phase at high temperatures. The agglomeration tendency, represented by the temperature required to reach defluidization, decreased...

The precipitation morphology of metallic iron and evolution process of mineralogical structure at gas-solid interface during reduction were studied by in situ observation and thermal analysis to identify the relationships between the precipitation morphology of metallic iron and micro-structure, sticking property. Results indicate that metallic iro...

A comprehensive mathematical model of full blast furnace with top gas recycling was established. The model consists of the calculation equations for gas composition of four zones (hearth, belly, lower shaft. top) in the blast furnace, the thermo-chemical balance model, the energy balance model of hot stand-by zone of the blast furnace and the shaft...

Influence of mixing MgO additive on fluidized bed reduction of iron ore fines using simulate COREX reducing gas was investigated. Experiments were conducted at 1073 K in a visualization fluidized bed. Mixing MgO additive was carried out using powder method and solution method. It was found that mixing MgO into ore fines using solution method could...

Performance of the Z-path moving-fluidized bed reactor for gaseous reduction of iron ore fines was numerically investigated. The proposed mathematical model was developed by analyzing the gas-solid transport phenomena and chemical reactions in the reactor. The model was solved by a new solving approach - integration of FLUENT package (V6.3) and PHO...

Micro-fluidized bed reactor is a new research method for the reduction of iron ore fines. The reactor is operated as a differential reactor to ensure a constant gas concentration and temperature within the reactor volume. In order to understand the dynamic process of the reduction reaction in micro-fluidized bed, a series of kinetic experiments wer...

V2O5 sintered pellets and graphite rods were employed as the cathode and the anode, respectively; a molten CaCl2-NaCl salt was used as the electrolyte. Then, V2O5 was directly reduced to metal vanadium by the Fray-Farthing-Chen (FFC) method at 873 K to realize low-temperature electrolysis. Two typical experimental conditions, electrolysis time and...

The investigation on purification of metallurgical grade silicon by solidification of hypereutectic Al-Si melt with super gravity as an intensified separation way was carried out. The results indicate that the refined silicon grains are successfully enriched at the bottom of the Al-Si alloy along the direction of super gravity. Then the refined sil...

The reduction of iron ores in a continuous stream of 100% CO was carried out in the micro fluidized bed. With minimized effects of external diffusion, the measurement in micro fluidized bed resulted in an activation energy of 26. 28kJ/mol and a pre-exponential factor of 0. 039 46 s -1. It is indicated that the reduction of iron ores was subject to...

Micro-fluidized bed reactor is a new research method for the reduction of iron ore fines. The reactor is operated as a differential reactor to ensure a constant gas concentration and temperature within the reactor volume. In order to understand the dynamic process of the reduction, Micro-fluidized bed was used to do a series of kinetic experiments....

The influence that temperature has on bed pressure drop, grain size and morphology of iron fines in a hot-state visualizable fluidized bed was investigated in this work. It was found that there are both a start sticking temperature (T s, 673 K-773 K) and a critical defluidization temperature (T c, 923 K-973 K) of the iron particles in the fluidized...

The influences of CaO on the formation and growth of iron whiskers and their mechanism in the reduction of iron oxide under CO atmosphere were studied. In situ observations on the development of iron whiskers were carried out using a stereo optical microscope and a hot stage under CO atmosphere. The reduced samples were analyzed by scanning electro...

By the use of thermal state visualized fluidized bed, sticking process during reduction of concentrate fines was investigated. The macrography view of fluidized bed and microcosmic changes of particles were described. It is found that different reductants lead to different swelling levels of batch layer. Swelling is about 40% in H 2-N 2 mixtures, b...

A new method (gas-based separation plus melt separation) has been proposed to remove phosphorus of the high phosphorus iron ore which was 1.25% of phosphorus content and 50.0% of iron content. HSC chemistry package and the coexistence theory of slag structure were adopted for theoretical analysis. The gas-based reduction was carried out using a lix...

The traditional methods of mineral and metallurgical processes are very difficult in treating the high-level phosphorus iron ore from west Hubei Province of China to meet the requirements of the iron and steel industry. A new technical route, gas-based reduction and electrical furnace melt separation, was proposed and demonstrated. Based on the min...