Preparation of Direct Reduction Sponge Iron (DRI) Using Pyrite Cinder Containing Nonferrous Metals

2017 ◽  
Vol 36 (10) ◽  
pp. 971-978
Author(s):  
Tiejun Chun ◽  
Hongming Long ◽  
Zhanxia Di ◽  
Qingmin Meng ◽  
Ping Wang
Keyword(s):  
Compressive Strength ◽  
Sulfuric Acid ◽  
Removal Rate ◽  
Direct Reduction ◽  
Reduction Process ◽  
Nonferrous Metals ◽  
Reduction Roasting ◽  
Pyrite Cinder ◽  
Direct Reduction Iron ◽  
Oxidized Pellets

AbstractPyrite cinder is a solid waste generated by the sulfuric acid industry and is considered environmentally hazardous. It contains abundant iron, such as Fe2O3 and Fe3O4, and nonferrous metals, such as zinc, lead and copper. In order to try and recycle this material as a source of Fe units, preparation of direct reduction iron (DRI) using pyrite cinder was investigated by coal-based grate rotary kiln process. This process includes chloridizing and reduction roasting. The results show that 97 % lead was removed after the chloridizing process. Copper was only detached in chloridizing process with the removal rate of 78.49 %. Furthermore, the removal of zinc was carried out in both chloridizing and reduction process, and the removal rate of 96.76 % was achieved after reduction roasting. The final product representing a metallization degree of 93.36 % with compressive strength of 1,198 N/pellet was obtained after the oxidized pellets were reduced at 1,050 °C for 80 min.

The Effects of Reduction Parameter to Composite Pelet of Iron Ore and Coal Using Single Conveyor Belt Hearth Furnace

2016 ◽  
Vol 842 ◽  
pp. 115-119
Author(s):  
Johny Wahyuadi Soedarsono ◽  
Andi Rustandi ◽  
Yudha Pratesa ◽  
Rianti Dewi Sulamet-Ariobimo ◽  
Bagus Hadi Prabowo ◽  
...  
Keyword(s):  
Iron Ore ◽  
Direct Reduction ◽  
Reduction Process ◽  
Conveyor Belt ◽  
Separation Process ◽  
Iron Ores ◽  
Hearth Furnace ◽  
Composite Pellet ◽  
Direct Reduction Iron ◽  
Composite Pellets

Iron ores should be separated from oxygen and impurities which are coming along during the mining process. The separation process is known as reduction. There are two types of reduction process, and the most common is direct reduction process (DRP). There are several parameters in DRP which will determine the quantities of the product known as direct reduction iron (DRI). This worked discussed the effect of reduction temperature and pellet heap to the quantities of DRI using single conveyer belt Hearth furnace. The worked was done in laboratory scale using composite pellets with 14 mm in diameter. The ratio of iron ore to coal in the composite pellet is 1 to 1. The reduction process temperatures are 500oC, 700oC and 900oC. The reduction time is 25 minutes. While the pellets heap are also varied to 1, 3, 5, 7, 8 and 9 layers. The results show that DRI was formed in 700OC and the quantities of DRI are in line with the reduction temperatures and layers of composite pellets heap.

scholarly journals Numerical Analysis of Radiative Heat Transfer and Direct Reduction of Three-Dimensional Multilayer Ellipsoidal Carbon-Containing Pellet Unit in the Rotary Hearth Furnace

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 994
Author(s):  
Nan Li ◽  
Feng Wang
Keyword(s):  
Heat Transfer ◽  
Removal Rate ◽  
Direct Reduction ◽  
Reduction Process ◽  
View Factor ◽  
Radiant Heat Transfer ◽  
Rotary Hearth Furnace ◽  
Reduction Degree ◽  
Hearth Furnace ◽  
Direct Reduction Process

It is very important for a multilayer pellet bed to have a proper description of the radiant heat transfer and direct reduction process in the rotary hearth furnace. Ellipsoidal pellets may also be used in industrial production. The research on this ellipsoidal pellet bed will provide comprehensive data support for the production process. Besides, the view factor is one of the important factors affecting the heat transfer of the multilayer pellet bed. It is of great significance to study its value and distribution. In this study, the effects of the gas field and the bottom of the furnace on the direct reduction of multilayer ellipsoidal pellets were considered. The local environmental viewing angle coefficient in the model was obtained through the mechanism calculation method, which is more accurate than the calculation through the radiation exchange network. Furthermore, the porosity variation in the pellet during the direct reduction process was also considered. According to the calculation, it was found that the higher initial temperature at the furnace bottom is beneficial to increase the degree of metallization (DOM) and zinc removal rate (ZRR) for all pellets, and is more advantageous to the lower pellets in the material bed. Nevertheless, the reduction degree of the lower pellets is still smaller than that of the upper pellets. The results also show that increasing the offset ξ has a greater effect on increasing the ambient view factor and each position reduction degree in the ellipsoidal pellets layer. Results can be applied for the optimization of pellets distribution in a rotary hearth furnace.

Effect of Thermal Charging of Iron Ore Pellets on the Reduction Rate and Compressive Strength in Gas-Based Reduction Process

2012 ◽  
Vol 532-533 ◽  
pp. 262-266 ◽  
Author(s):  
Zhu Cheng Huang ◽  
Dao Guang Yang ◽  
Ling Yun Yi
Keyword(s):  
Compressive Strength ◽  
Iron Ore ◽  
Inner Core ◽  
Direct Reduction ◽  
Reduction Rate ◽  
Reduction Process ◽  
Optical Microscope ◽  
Ore Pellets ◽  
Iron Crystal ◽  
Reduced Pellets

Burden in gas-based direct reduction process is iron ore oxide pellet, which has experienced oxide roasting and cooling before reduction. However, it would be heated again in the reduction process. This may cause much energy waste and adverse effects on reduction process. In this paper, roasted pellets with and without cooling were charged for gas-based reduction respectively. The reduction rate and compressive strength during reduction were studied to reveal the effects of charging methods. Results showed that there is little difference on reduction rate between the two. However, the compressive strength of reduced pellets via thermal charging improves obviously. And nucleation and growth mechanisms of iron crystal grain in gas-based reduction were investigated by optical microscope (Leica DMRXP). The iron crystal nucleuses firstly form at the interface of grains and edge of wustite, and then gradually grow from surface layer to inner core as reduction proceeds. Thermal charging can promote the migration and accumulation of iron crystal grain effectively.

scholarly journals Effects of High Proportion Unground Sea Sand Ore on the Preparation Process and Reduction Performance of Oxidized Pellets

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 87 ◽  
Author(s):  
Gong-jin Cheng ◽  
Zhen-xing Xing ◽  
He Yang ◽  
Xiang-xin Xue
Keyword(s):  
Compressive Strength ◽  
New Zealand ◽  
Reduction Process ◽  
Spherical Particles ◽  
Detection Methods ◽  
Preparation Process ◽  
Reduction Degree ◽  
Sea Sand ◽  
Oxidized Pellets ◽  
Reduction Swelling

The New Zealand sea sand ore is a kind of vanadia–titania magnetite formed by erosion in the coastal zone. Because of its coarse particle size, smooth spherical particles, complex chemical composition, it has been added to sinter as an auxiliary material. Based on the principle of optimizing ore blending to strengthen advantages and weaken disadvantages, this paper used New Zealand sea sand raw ore that has not undergone any pretreatment as the main material and prepared it into oxidized pellets using a disc pelletizer and explored the influence of high-proportion unground sea sand ore on the preparation process and reduction performance of oxidized pellets. The influence of unground sea sand ore on the falling strength, compressive strength, reduction swelling index, and reduction degree of pellets was analyzed by the ICPAES, XRF, XRD, SEM-EDS, and other detection methods, and the change laws and influencing factors of oxidized pellets were analyzed. With the increase of the amount of unground sea sand ore used, the falling strength and compressive strength of the green pellets first decreased and then gradually increased, while the compressive strength of the oxidized pellets first increased and then decreased. At the same time, as the amount of sea sand ore used increased, the reduction process of pellets was restricted. The reduction swelling index and the reduction degree index generally show a downward trend. However, the compressive strength of the pellets gradually increased after reduction. Through the research on the pellet-forming performance and reduction properties of unground sea sand ore, it is shown that when the amount of unground sea sand ore used was 40%, it can still be used as raw material for blast furnace ironmaking. Thus, this research provided specific data support for iron and steel enterprises to improve the ratio of unground sea sand ore and reduce production cost.

scholarly journals Effect of Incremental Utilization of Unground Sea Sand Ore on the Consolidation and Reduction Behavior of Vanadia–Titania Magnetite Pellets

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 269
Author(s):  
Zhenxing Xing ◽  
Gongjin Cheng ◽  
Zixian Gao ◽  
He Yang ◽  
Xiangxin Xue
Keyword(s):  
Compressive Strength ◽  
New Zealand ◽  
Reduction Rate ◽  
Reduction Process ◽  
Production Costs ◽  
Raw Material ◽  
Iron And Steel ◽  
Sea Sand ◽  
Oxidized Pellets ◽  
Magnetite Pellets

In the iron and steel industry, improving the usage amount of New Zealand sea sand ore as a raw material for ironmaking can reduce the production costs of iron and steel enterprises to a certain extent. In this paper, New Zealand sea sand ore without any grinding pretreatment was used as a raw material, oxidized pellets were prepared by using a disc pelletizer, and the effect of sea sand ore on the performance of green pellets and the metallurgical properties of oxidized pellets was investigated. The effects of sea sand ore on the compressive strength, falling strength, compressive strength of oxidized pellets, and reduction performance were mainly investigated. X-Ray Diffraction (XRD) patterns and Scanning Electron Microscope (SEM) analysis methods were used to discuss the influence of sea sand ore on the microstructure of the pellets’ oxidation and reduction process. As the amount of sea sand ore used increased, the compressive strength of green pellets was gradually decreased, and the falling strength of green pellets and the compressive strength of oxidized pellets were gradually increased. When the amount of sea sand ore used was 40%, the reduction swelling index of pellets was 16.31%. The increase of sea sand ore used made the reduction of pellets suppressed and the reduction rate decreased. When the amount of sea sand ore used increased to 40%, the reduction degree of sea sand ore pellets was only 60.06%. The experimental results in this paper provide specific experimental data for the large-scale application of New Zealand sea sand ore in the blast furnace ironmaking process.

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.

Direct Reduction of Heavy Nonferrous Metals from Sulfide Compounds

2020 ◽  
Vol 61 (6) ◽  
pp. 601-607
Author(s):  
V. S. Chekushin ◽  
N. V. Oleynikova ◽  
S. P. Baksheev ◽  
A. V. Dontsov
Keyword(s):  
Direct Reduction ◽  
Nonferrous Metals ◽  
Heavy Nonferrous Metals

scholarly journals Stormwater Runoff Treatment Using Pervious Concrete Modified with Various Nanomaterials: A Comprehensive Review

2021 ◽  
Vol 13 (15) ◽  
pp. 8552
Author(s):  
Vahid Alimohammadi ◽  
Mehdi Maghfouri ◽  
Delaram Nourmohammadi ◽  
Pejman Azarsa ◽  
Rishi Gupta ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Compressive Strength ◽  
Adsorption Capacity ◽  
Removal Rate ◽  
Stormwater Runoff ◽  
Infiltration Rate ◽  
Stormwater Treatment ◽  
Adsorption Mechanisms ◽  
Wide Range ◽  
Adsorption Processes

Clean water is a vital need for all living creatures during their lifespan. However, contaminated stormwater is a major issue around the globe. A wide range of contaminants, including heavy metals, organic and inorganic impurities, has been discovered in stormwater. Some commonly utilized methods, such as biological, physical and chemical procedures, have been considered to overcome these issues. However, these current approaches result in moderate to low contaminant removal efficiencies for certain classes of contaminants. Of late, filtration and adsorption processes have become more featured in permeable concretes (PCs) for the treatment of stormwater. As nanoparticles have vast potential and unique characterizations, such as a higher surface area to cure polluted stormwater, employing them to improve permeable concretes’ capabilities in stormwater treatment systems is an effective way to increase filtration and adsorption mechanisms. The present study reviews the removal rate of different stormwater contaminants such as heavy metals, organic and other pollutants using nanoparticle-improved PC. The application of different kinds of nanomaterials in PC as porous media to investigate their influences on the properties of PC, including the permeability rate, compressive strength, adsorption capacity and mix design of such concrete, was also studied. The findings of this review show that different types of nanomaterials improve the removal efficiency, compressive strength and adsorption capacity and decrease the infiltration rate of PC during the stormwater treatment process. With regard to the lack of comprehensive investigation concerning the use of nanomaterials in PC to treat polluted stormwater runoff, this study reviews 242 published articles on the removal rate of different stormwater contaminants by using PC improved with nanoparticles.

Metallographic Estimation of the Number of Forming Metallic Particles Obtained during Direct and Indirect Reduction of Metals from Complex Oxides

2019 ◽  
Vol 946 ◽  
pp. 523-527
Author(s):  
Arman S. Bilgenov ◽  
P.A. Gamov ◽  
V.E. Roshchin
Keyword(s):  
Metal Forming ◽  
Solid Phase ◽  
Quantitative Estimation ◽  
Direct Reduction ◽  
Reduction Process ◽  
Complex Oxide ◽  
Experimental Results ◽  
Solid Carbon ◽  
Indirect Reduction ◽  
Co Gas

The direct reduction of metals from a complex oxide with low iron content by solid carbon and indirect reduction by CO gas were studied in a vertical laboratory resistance furnace at 1300 °C for an hour reduction time. The experimental results were described from the point of view of the electrochemical nature of the metal reduction process, that involves the interaction of ions and electrons in the oxide lattice. The technique was developed by using the two different software programs for the quantitative estimation of the areas, average size and number of the metal forming in a complex oxide with extensive fields of vision. The obtained results of the quantitative characteristics of the metal forming during solid-phase carbo-thermal reduction were presented. The processes of reduction by solid carbon and CO gas based on the areas occupied by metal particles were quantitatively compared. The experimental results and the prospects for further experimental work were assessed and outlined.

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