Study on Utilization Technology of Vanadium Titanium Magnetite Based on the Rotary Hearth Furnace Direct Reduction Process

2012 ◽  
Vol 217-219 ◽  
pp. 441-444 ◽  
Author(s):  
Gong Guo Liu
Keyword(s):  
Recovery Rate ◽  
Large Scale ◽  
Direct Reduction ◽  
Reduction Rate ◽  
Reduction Process ◽  
Direct Reduction Process ◽  
Metallization Rate ◽  
Study Results ◽  
Vanadium Titanium ◽  
Titanium Magnetite

Through carrying out large scale of experiments, the process of ‘rotary harth furnace direct reduction—deep reduction electric arc furnace—extracting vanadium from vanadium bearing slag—extracting titanium from titanium bearing slag gets through and the recovery of Fe, V and Ti reached 90.77%, 43.82% and 72.65% respectively. With the study on the laboratory experiments and industrial tests, the bottlenecks of this technology such as low metallization rate of vanadium-titanium magnetite in direct reduction process, low reduction rate of vanadium in EAF, vanadium-recovery of hot metal with high silicon content, titanium-recovery of high –Mg &Al slag with titanium, and so on, have been solved. Based on this, the metallization rate of vanadium-titanium magnetite in direct reduction process is more than 90%, reduction rate of vanadium in EAF deep reduction process is more than 80%, vanadium-recovery rate in slag is more than 65%, and titanium-recovery rate in slag is more than 75%. That means good study results have been gotten. Furthermore, low-carbon pig iron with good quality in EAF steelmaking are gotten. Otherwise, V2O5 sheet and titanium products can meet the requirements of GB3283-87 and PTA121, respectively.

scholarly journals Effect of catalyst on tail gas during reduction of vanadium-titanium magnetite carbon-containing pellet

2021 ◽  
Vol 267 ◽  
pp. 02046
Author(s):  
Bo Wang ◽  
Xueyong Ding ◽  
Xiaofei Zhang ◽  
Tianhua Ju ◽  
Shigang Li
Keyword(s):  
Rotary Kiln ◽  
Flue Gas ◽  
Reduction Process ◽  
Reduction Mechanism ◽  
Gas Analyzer ◽  
Metallization Rate ◽  
Vanadium Titanium ◽  
Reduction Effect ◽  
Calcium Catalysts ◽  
Titanium Magnetite

Catalyst can enhance the reduction effect and promote the reduction of vanadium titanomagnetite. In this paper, the carbon-containing pellets of vanadium titanomagnetite were prepared by using highly volatile coal as the reducing agent under the background of a novel process of pre-reduction in the rotary kiln. The effects of CaO, CaCO3, B2O3 and borax (Na2B4O7·10H2O) on the tail gas characteristics of carbon-containing pellets in the prereduction process were studied by using a simulated rotary kiln and flue gas analyzer. The results showed that the enhanced reduction effect of boron catalysts was slightly stronger than that of calcium catalysts, among which CaO catalyzed the least and borax the best. With the increase of metallization rate, the CO utilization in the tail gas is generally reduced, while when using CaCO3 as the catalyst, the CO utilization is significantly increased. Due to different reduction mechanism, the boron catalysts have little effect on the tail gas, and the calcium catalysts have a great effect on the tail gas. Based on the experimental results and the characteristics of the tail gas from the reduction process, we put forward the idea of using CaCO3 as the best catalyst and using CaO to absorb CO2 in the tail gas to form CaCO3.

scholarly journals Experimental Study on Strengthening Carbothermic Reduction of Vanadium-Titanium-Magnetite by Adding CaF2

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 219 ◽  
Author(s):  
Xiangdong Xing ◽  
Yueli Du ◽  
Jianlu Zheng ◽  
Yunfei Chen ◽  
Shan Ren ◽  
...  
Keyword(s):  
Carbothermic Reduction ◽  
Reduction Rate ◽  
Reduction Process ◽  
Complex Compounds ◽  
Carbon Gasification ◽  
Promotive Effect ◽  
Mass Fractions ◽  
Vanadium Titanium ◽  
Gasification Reaction ◽  
Titanium Magnetite

The effects and reduction mechanisms of carbothermic reduction of vanadium–titanium–magnetite were studied by adding various mass fractions of CaF2 ranging from 0%, 1%, 3%, 5% to 7%. The results showed that the proper CaF2 addition could strengthen the carbothermic reduction of vanadium–titanium–magnetite while the excessive amounts will weaken the promotive effect, hence the appropriate dosage was determined to be 3 mass%. The CaF2 was favorable for the carbon gasification reaction, where it increased the partial pressure of CO inside briquette and caused the lattice distortion of vanadium–titanium–magnetite. The reaction improved the reduction process and accelerated the reduction rate. The appearance of 3CaO·2SiO2·CaF2 and other complex compounds with low melting point facilitated the aggregation and growth of the slag and the iron, which increased the concentration of iron grains and the aggregation level of the slag.

scholarly journals The effect of composite reducing agent on the reduction process and the tail gas of carbon-containing pellets

2021 ◽  
Vol 267 ◽  
pp. 02040
Author(s):  
Bo Wang ◽  
Xueyong Ding ◽  
Xiaofei Zhang ◽  
Tianhua Ju ◽  
Shigang Li
Keyword(s):  
Rotary Kiln ◽  
Bituminous Coal ◽  
Reduction Process ◽  
Reducing Agent ◽  
Process Conditions ◽  
Metallization Rate ◽  
New Type ◽  
Vanadium Titanium ◽  
Ironmaking Process ◽  
Titanium Magnetite

In order to explore a reasonable way for the efficient utilization of coal resources in the ironmaking process. In this paper, lignite and bituminous coal are used as reducing agents, and two types of vanadium-titanium magnetite composite reducing agent pellets are prepared for different content ratios and mixed forms of the two coal powders. Under the simulated rotary kiln pre-reduction conditions, the influence of the ratio and mixing of pulverized coal on the metallization rate and tail gas composition of the reduction process was explored. The results show that increasing the proportion of high volatile lignite is beneficial to the reduction of pellets and can obtain pellets with a higher metallization rate. Under the new pre-reduction process conditions of the rotary kiln, the vanadium-titanium magnetite double-layer pellet with 75wt% lignite inside and 25wt% bituminous coal outside has the highest metallization rate of about 76%. At the same time, this new type of composite reducing agent pellets reduced gas emissions. This pellet is of great significance to the coal-based ironmaking process.

Effect of B2O3 on the carbothermal reduction of vanadium titanium magnetite

2019 ◽  
Vol 116 (6) ◽  
pp. 630 ◽  
Author(s):  
Xing Xiangdong ◽  
Wang Sha ◽  
Pang Zhuogang ◽  
Zhang Qiuli
Keyword(s):  
Melting Point ◽  
Carbothermal Reduction ◽  
Three Dimensional ◽  
Reduction Rate ◽  
Reduction Process ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Vanadium Titanium ◽  
First Order Chemical Reaction ◽  
Titanium Magnetite

The effect of B2O3 on the carbothermal reduction of vanadium titanium magnetite was investigated under different temperatures by isothermal experiments. XRD analysis, SEM analysis and kinetic analysis were used to reveal the mechanism of B2O3 in the reduction process. The results showed that B2O3 could accelerate the reduction rate of vanadium titanium magnetite, and the suitable addition amount was 3%. B2O3 was easy to melt during carbothermal reduction, B3+ diffused into the crystal lattice of ferrotitanium compound, resulting in a decrease in binding energy and an increase in lattice parameters. B2O3 had also an erosion effect on the surface of the iron ore, and the contact area between reducing agent CO and vanadium titanium magnetite increased, thereby promoting the reduction. Low melting point compound CaO ∙ B2O3 formed after adding B2O3, which could improve the fluidity of the system and change the melting point of non-ferrous phase to further promote the growth and aggregation of iron particles. The reduction process was firstly limited by the first-order chemical reaction, then it was controlled by three-dimensional diffusion of reactants. The activation energy calculated by the best model was smaller than that of without adding B2O3.

Impact on the Reduction Process of Carbon Containing Pellets with Biomass Replacing Traditional Reducing Agent

2015 ◽  
Vol 1120-1121 ◽  
pp. 1302-1307
Author(s):  
Peng Yuan ◽  
Hong Liang Han ◽  
Dong Ping Duan
Keyword(s):  
Compressive Strength ◽  
Direct Reduction ◽  
Reduction Process ◽  
Reducing Agents ◽  
Reducing Agent ◽  
Volumetric Shrinkage ◽  
Bamboo Charcoal ◽  
Direct Reduction Process ◽  
Metallization Rate ◽  
The Impact

Considering the rotary hearth furnaces (RHF) direct reduction process, using bamboo char, charcoal and straw fiber as reducing agents added into the carbon containing pellets, the experimental study on the impact of reduction effect has been conducted from metallization rate, compressive strength and volumetric shrinkage. Test results showed that biomass reducing agents can replace traditional reducing agents used in the RHF direct reduction process. Compared with traditional reducing agents, biomass has less of effect on metallization rate, but different biomass reducing agents have large impact on strength and volumetric shrinkage of pellets. The compressive strength of pellet with straw fiber is relatively higher, and the compressive strength of pellets with charcoal or bamboo charcoal is low, for reaching the production requirement, which will be improved at higher temperature (1300°C). Using bamboo charcoal as reducing agent will lead to the swell of pellets in the beginning stage, and this situation will make the volumetric shrinkage at high temperature lower, finally, all of these will affect the strength of pellets and the heat-transfer between different material layers, thus it should be used accompanying with other reducing agent.

Separation of aluminium and preparation of powdered DRI from lateritic iron ore based on direct reduction process

2016 ◽  
Vol 55 (3) ◽  
pp. 345-355 ◽  
Author(s):  
T. Jiang ◽  
L. Yang ◽  
G. Li ◽  
J. Luo ◽  
J. Zeng ◽  
...  
Keyword(s):  
Iron Ore ◽  
Direct Reduction ◽  
Reduction Process ◽  
Direct Reduction Process

BF Charge Reduction with Gases of Different H2 Ratio in High Temperature Zone

2011 ◽  
Vol 284-286 ◽  
pp. 1152-1157
Author(s):  
Guo Zhang Tang ◽  
Zhen Gao ◽  
Yan Chang Kong ◽  
Kun Ouyang ◽  
Fu Min Li
Keyword(s):  
Loss Rate ◽  
Direct Reduction ◽  
Mass Loss Rate ◽  
Reduction Rate ◽  
Reduction Kinetics ◽  
Reduction Degree ◽  
Charge Reduction ◽  
Temperature Zone ◽  
Metallization Rate ◽  
Direct Reduction Degree

The reduction of different basicity BF charge with gases of different H2 ratio has been determined to simulate different BF technology. The results reveal: reduction rate (R & r) and metallization rate of charge increase with the H2 ratio increasing, and the temperature increasing while the reducing time becomes longer simultaneously. The direct reduction degree of charge in Hydrogen-enrichment BF is very low, thus the energy consumption of Ironmaking could be reduced. There is certain difference between metallization rate and reduction degree due to reduction kinetics. The mass loss rate of coke increases sharply with the H2 ratio increasing, the H2 ratio of gas should be selected an appropriate value.

Numerical analysis of the carbon containing pellets direct reduction process

2021 ◽  
Vol 118 (2) ◽  
pp. 209
Author(s):  
Nan Li ◽  
Feng Wang ◽  
Wei Zhang
Keyword(s):  
Direct Reduction ◽  
Reduction Process ◽  
Operating Conditions ◽  
Utilization Efficiency ◽  
Heat Absorption ◽  
Furnace Temperature ◽  
Chemical Reaction Kinetics ◽  
Direct Reduction Process ◽  
Pellet Surface ◽  
Composite Pellets

In view of the carbon-containing composite pellets direct reduction process in rotary hearth furnace, a mathematical model coupling heterogeneous chemical reaction kinetics, heat and mass transfer of this process was established. The effects of furnace temperature (from 1273.15 K to 1673.15 K) and pellet radius (from 6 mm to 16 mm) on the direct reduction of carbon-containing composite pellets were studied by adopting computational fluid dynamics software. The pellet temperature and composition changes under different operating conditions were analyzed. CO and CO2 fluxes, heat fluxes on the pellet surface were especially studied. Total heat absorption by the pellet, CO and CO2 overflow from the pellet surface together with pellet degree of metallization (DOM) and zinc removal rate (ZRR) were calculated. Results show that with the increasing of furnace temperature or the decreasing of the pellet radius, the temperature difference between pellet surface and its center and the final DOM, ZRR increased. The larger the pellet radius, the smaller the heat absorption, also the smaller CO and CO2 overflow. But heat absorption and CO overflow per unit volume are higher. There is an optimal pellet radius with high CO utilization efficiency. Pellet porosity decreases at first and then increases with reducing time. It is also found that effective thermal conductivity is a major factor limiting the pellets temperature increasing. The reduction sequence of the pellets is Fe2O3→Fe3O4→FeO→Fe.

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