Papers by Keyword: Iron Ore

Abstract: The use of biomass as an alternative fuel to reduce the use of fossil fuels continues to increase, one of which is palm kernel shell (PKS) waste. This study investigated the pyrolysis reactivity of biomass samples (PKS) through thermogravimetric analysis. In addition, the pyrolysis mechanism is approached through the activation energy determined from the model used. This study utilized palm kernel shells as biomass with the addition of iron ore as a catalyst. The TGA test was carried out with variations in the catalyst composition (0, 10, and 15% of total mass) and heating rates (5, 10, and 15 °C/min) of the pyrolysis process. The kinetic parameter, E, was estimated using the independent model method, namely FWO (Flynn Wall Ozawa) and KAS (Kissinger Akahira Sunose). The study showed that the concentration effect on the conversion rate was almost the same for all concentrations in heating rate of 10 °C/men. The heating rate of 15 °C/min provided the highest conversion rate compared to the other two heating rates. Furthermore, the activation energy values fluctuated in the kinetic analysis using the FWO and KAS methods. Besides, the best fit is obtained from the conversion of 0.2-04 and 0.8-0.9.

Abstract: Metallurgical coke is the main source of fuel and reducing agent for iron and steel industry. Empty fruit bunch (EFB) biomass which is abundantly available in Malaysia could be utilized as a source of energy as well as reducing agent in iron making process. This research presents carbon infiltration within low-grade iron ore via chemical vapor infiltration (CVI) method from EFB pyrolysis vapor. Low-grade iron ore was first heated to remove the combined water (CW) that consequently created pore network within the iron ore. These pores would act as sites for carbon infiltration in the iron ore. The EFB treatment on iron ore has been carried out at different temperatures and the effect of pyrolysis temperature on the carbon infiltration has been investigated. The Brunauer−Emmet−Teller (BET) and Barrett−Joyner−Halenda (BJH) methods have been performed to analyze pore surface and pore volumes of the iron ore. Pore surface and pore volume decreased as the temperature increased indicated that more carbon has been deposited. Using X-ray diffraction (XRD) analysis, it was shown that the low-grade iron ore has been transformed into iron (Fe). The infiltrated carbon from the EFB pyrolysis vapor in the pore surface iron ore is proven to be able to be utilized as source of energy and reducing agent to partially replace metallurgical coke in the blast furnace in order to reduce emission of harmful gas.

Abstract: Using bio oil derived from biomass pyrolysis as an alternative fuel continues to be encouraged in order to decrease the utilization of fossil fuels. On the other hand, application of iron ore as a catalyst in the biomass pyrolysis process provides an advantage where there is a mutual effect on the reduction process of iron ore. The objective of the study is to probe the influence of temperature and catalyst concentration to the pyrolysis yields, the characterization of bio-oil gained, and additionally, phase and composition change of the iron ore. This research utilized palm kernel shells as biomass and raw iron ore as catalyst. The experiment was performed at different temperatures (450, 500, and 550oC) and different catalyst concentrations (0, 10, and 15 % of mass). The biomass was located in the lower part of the reactor and the catalyst was positioned on the upper side of the biomass being separated by using a thick layer of glass wool. The pyrolysis process was implemented by drawing off N₂ gas to avert the oxygen existence in the reactor. The results exhibited that the highest bio-oil yield, 43.63%, was obtained from the sample of 550oC with non-catalyst, but the highest tar yield was generated from sample of 550°C with 15% of catalyst concentration. GC-MS results showed that catalyst concentration of 15% mass induced opposite effect to composition of phenolic-aromatic compound and acetic acids content compared to the one of 10% mass. Eventually, pyrolysis conditions are able to encourage the reduction process occurred in the iron ore catalyst.

Abstract: Iron ore sintering is a predominant process for fine iron ore and its concentrate to be applied in the blast furnace process. However, sintering produces a negative impact on the environment. One of the effective ways to reduce greenhouse gas emissions from iron ore sintering is to use CO₂-neutral biomaterials for the fuel needs of this technology. Walnut shells (WNS) are a promising raw material for such fuel substitute. Herein, the effect of the raw and the pyrolyzed WNS with a constant fineness of 3-0 mm on the sintering process and the sinter properties were studied. The proportion of WNS in the fuel composition was set to 25 wt.%. It has been established that the use of WNS pyrolyzed up to 873 K is optimal. Additionally, the difference in the reactivity of WNS and coke breeze has provoked the studies on the influence of the pyrolyzed WNS size on the sintering process. WNS size was set to 1-0, 3-0, 5-0, and 7-0 mm. It has been found that the most optimal both for the iron ore sintering process and the sinter quality is the use of WNS with a particle size of 3-0 mm, subjected to preliminary pyrolysis up to 873 K.

Abstract: The use of biomass as fuel might solve several technological and environmental issues and overcome certain challenges of sinter production. In particular, as revealed by comprehensive analyses, biomass can be used as fuel for iron ore sintering. In this study, we investigate the use of some raw and pyrolysis-processed biomass pellet types, namely wood, sunflower husks (SFH), and straw, for iron ore sintering. In the experiments, the pyrolysis temperature was set to 673, 873, 1073, and 1273 K, and the proportion of biomass in the fuel composition was set to 25%. It was established that the addition of biofuels to the sintering blend leads to an increase in the gas permeability of the sintered layer. The analysis of the complex characteristics of the sintering process and the sinter strength showed the high potential of wood and sunflower husk pellets pyrolyzed at 1073 and 873 K, respectively, for iron ore sintering. The analysis of the macrostructure of the sinter samples obtained using biomaterials revealed that with higher pyrolysis temperatures; the materials tend to have greater sizes and higher amounts of pores and cracks. The composition analyses of the resultant sinters revealed that with higher temperature, the FeO content of the sinters tends to increase.

Abstract: The provision of carbon reducing agents for the direct reduction process of iron ore is carried out by immersing the iron ore in a tar solution and then proceeding with the pyrolysis/ carbonization process to obtain carbon deposits on the surface of the iron ore. The purpose of this study is to investigate the characterization and reduction behavior of Fe compounds resulting from impregnation and carbonization processes. In this study, iron ore is immersed in the pine flower tar with immersion time varying from 0 - 12 hours and a fixed ratio of tar / ore 1: 1. The soaking mixture is then carbonized in a vertical tube reactor covered by furnace with N₂ gas flowed during the carbonization/pyrolysis process. The carbonization runs with a temperature variation of 450-550°C, for 1 hour, and a heating rate of 10°C/min. From SEM-EDX-Mapping result shows that the immersion method in tar followed by carbonization caused the carbon content in iron ore to increase by 86.68% in a 1: 1 tar/ore ratio, the impregnating time of 6 hours, and a pyrolysis temperature of 450°C. Effect of impregnation duration evidence that immersion times of 6 and 12 hours are sufficient to produce the magnetite phase after the carbonization process. Furthermore, the 6 hours’ duration provides a more optimal peak intensity. Meanwhile, the effect of temperature on the carbonization process shows that 450°C is the optimal temperature to obtain the magnetite phase in the carbonized ore.

Abstract: The research assesses the possibilities of using local minerals to create foundry alloys that are used in conditions of low temperature. The mineral-geochemical composition of iron ore from Verkhnyaya Amga ore occurrences in the Aldan region of the Sakha Republic (Yakutia) was studied in detail. The expedience of using iron ores from this ore occurrence to develop new cold-resistant and high-strength steels was analyzed. The chemical composition and microstructure of the cast alloys were studied. The ore contains oxides of alkaline earth metals: MgO; CaO; Sr0 and BaO, the total content of which is 4.2%, that contributes to the process of deoxidation of the melt during its cooling, and the deoxidation product in the form of oxides and other chemical compounds based on Ca, Sr and Ba floats into slag. During crystallization, the melt is cleaned of detrimental impurities, non-metallic inclusions, gases, pores, etc. Alloy is smelted from enriched ore, samples for static tension and toughness are made in order to study the physicomechanical properties. Microstructure of the obtained alloy and structural steel subjected to static tension at an external load of 0.8 yield strength (σ = 0,8 σ_т) was investigated. Mechanical properties and dynamic characteristics were measured. Analogues for comparing the strength and plastic properties were given.

Abstract: In the presentation, previous archaeological achievements as well as analytical studies conducted on ironwork sites in Chungju are reviewed. In addition, the early iron production technology in the area can be characterized based on various evidences. Extensive ironworks were conducted at various sites concentrated especially in Chungju. Direct smelting was still the main technology until rather later on. Substantial amounts of tap slag and their analytical features support this idea. In addition, comprehensive studies as to the structure of furnaces and tuyeres used to do ironwork and their technical relationships also need to be discussed. Furthermore, smithing processes, which were mostly conducted at the smelting sites, were also described in detail so that the general ironworking process could be identified.

Abstract: The main aspects of effective dephosphorization of steel under conditions of induction melting are presented. Regularities of scale growth on the surface of iron, as well as the conditions of its catastrophic oxidation, are considered. An industrial experiment was conducted to remove phosphorus from steel intended for brake discs.

Abstract: Indonesia has abundant resources or raw materials, especially the iron sand raw materials. But, the iron sand processing in Indonesia is still low. Even though, the steel demand in Indonesia is still high. So, the iron sand processing product as raw materials in steelmaking is the solution of it. In this research, the study was conducted by using the variation of briquette dimension of mixture of iron sand and iron ore in Direct Reduction process. The aim of this research is to study the effect of briquette dimension on Fe content and degree of metallization of the Direct Reduced Iron (DRI). First, the iron sand and iron ore were crushed and shieved until pass the 50 mesh standar size. Then, iron sand and iron ore were mixed and briquetted based on the variation of dimension. There are three variations of briquette dimension. Then, the briquettes was reduced at 1250°C for 12 hours. The reduced briquettes then were analyzed using XRD, XRF and degree metallization calculation. The result showed that the dimension of briquette affect the Fe content and the degree metallization of DRI. The dimension of briquette will affect the reductor gas flow in the crucible, so the rate and direction of reduction process of iron oxide will be affected too. The best briquette is Briquette B (7.9 cm for inside diameter, 15.1 cm for outer diameter and 19.5 cm for the height), with 75.02% for Fe total content and 66.52% for degree of metallization. This was due to The briquette B has the most evenly diffused dimension either vertically and horizontally.