scholarly journals Dephosphorization Behavior of High-Phosphorus Oolitic Hematite-Solid Waste Containing Carbon Briquettes during the Process of Direct Reduction-Magnetic Separation

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 897 ◽  
Author(s):  
Yunye Cao ◽  
Yiran Zhang ◽  
Tichang Sun
Keyword(s):  
Blast Furnace ◽  
Solid Waste ◽  
Magnetic Separation ◽  
Direct Reduction ◽  
Gangue Mineral ◽  
X Ray Diffraction ◽  
X Ray ◽  
Blast Furnace Dust ◽  
High Phosphorus ◽  
Coal Slime

In this paper, the process of direct reduction roasting using magnetic separation to produce direct reduction iron (DRI) from high-phosphorus oolitic hematite, using coal slime and blast furnace dust as reductant, is investigated. The possible use of slime coal and blast furnace dust as reductant and the dephosphorization behavior during the process of direct reduction was studied. Experimental results showed that both blast furnace dust and coal slime can be used as reductant under certain conditions in the process. The dephosphorization mechanism of blast furnace dust and coal slime were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM)-energy dispersive X-ray spectroscopy (EDS). A DRI with 91.88 wt. % iron grade, 88.38% iron recovery and 0.072 wt. % P can be obtained with 30 wt. % blast furnace dust as reductant. The program not only used blast furnace dust but also recovered iron from blast furnace dust and high-phosphorus oolitic hematite. The analysis results revealed that phosphorus is distributed in gangue mineral and fluorapatite when blast furnace dust is used as reductant. Phosphorus-bearing minerals were not reduced to phosphorus element when the blast furnace dust was the reductant, but part of the fluorapatite reduced to phosphorus which smelt into metallic iron with coal slime as reductant. This led to a high phosphorus content of DRI. This research could provide support to the idea concept for recycling of carbon-containing solid waste and to assist the effective recovery of refractory iron ore by direct reduction–magnetic separation.

Reaction Mechanism of Siderite Lump in Coal-Based Direct Reduction

2016 ◽  
Vol 35 (2) ◽  
pp. 185-194 ◽  
Author(s):  
Deqing Zhu ◽  
Yanhong Luo ◽  
Jian Pan ◽  
Xianlin Zhou
Keyword(s):  
Reaction Mechanism ◽  
Magnetic Separation ◽  
Iron Ore ◽  
Direct Reduction ◽  
Reduction Rate ◽  
Reduction Process ◽  
X Ray Diffraction ◽  
Transfer Resistance ◽  
X Ray ◽  
Rate Controlling Step

AbstractSiderite is one of the significant iron ore resources in China and yet is difficult to upgrade by traditional beneficiation processes. A process of coal-based direct reduction–magnetic separation was successfully developed for the beneficiation of siderite. However, few studies have thoroughly investigated the mechanism of the direct reduction of siderite. In order to reveal the reaction mechanism of coal-based direct reduction of siderite lump, thermodynamics of direct reduction was investigated with coal as the reductant. The thermodynamics results indicate that coal-based direct reduction process of siderite lump at 1,050°C follows the steps as FeCO3→ Fe3O4→ FeO → Fe, which is verified by chemical titration analysis, X-ray diffraction and scanning electron microscope. The microstructure of siderite sample varies with different reduction stages and some 45% porosity induced by thermal decomposition of siderite is conductive to subsequent reduction. The conversion of FeO to Fe is the main reduction rate-controlling step. The reduced product with the metallic iron size over 30 μm can be effectively beneficiated by wet magnetic separation after grinding. The obvious layered structure of reduced product is due to different heat transfer resistance, CO and CO2 concentration.

The Effects of Preparation Conditions And Chemical Composition On CMAS Glass Ceramics With One Step Process

2021 ◽  
Author(s):  
Yuliang Guo ◽  
Huixin Jin ◽  
Yuandan Xiao ◽  
Huahao Song ◽  
Shangjiefu Wang
Keyword(s):  
Solid Waste ◽  
Theoretical Basis ◽  
Chromium Content ◽  
Glass Ceramics ◽  
X Ray Diffraction ◽  
Crystallization Activation Energy ◽  
X Ray ◽  
Preparation Conditions ◽  
Treatment Conditions ◽  
One Step

Abstract Based on the composition of Cr-doped solid waste, other oxides were added to adjust the composition to prepare glass-ceramics with on step composition, and the effect of heat treatment system (including temperature and holding time), chromium content, MnO and Fe2O3 doped on the crystallization and physical properties of glass-ceramics was studied. The samples were characterized by X-ray diffraction, differential thermal analysis and scanning electron microscopy. The results show that the best treatment conditions are 1090 ℃ for 4h, and the amount of dissolved chromium reaches 5%. The main crystallization phase is diopside and anorthite. The hardness and chemical stability of the material were measured. The doping of MnO and Fe2O3 increases the crystallization activation energy of glass ceramics, and makes the crystal phase more uniform as the SEM results. This experiment provides a theoretical basis for the preparation of CMAS glass ceramics from chromium containing solid waste.

scholarly journals Effect of Sintering Temperature on Property of Low-Density Ceramic Proppant Adding Coal Gangue

2019 ◽  
Vol 26 (1) ◽  
pp. 94-98
Author(s):  
Jianying HAO ◽  
Huilan HAO ◽  
Yunfeng GAO ◽  
Xianjun LI ◽  
Mei QIN ◽  
...  
Keyword(s):  
Solid Waste ◽  
Bulk Density ◽  
Apparent Density ◽  
Sintering Temperature ◽  
Coal Gangue ◽  
Low Density ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sintering Method ◽  
Waste Coal

Calcined flint clay (45.6 wt.% Al2O3) and solid waste coal gangue were used to prepare low-density ceramic proppant by solid state sintering method. The density and breakage ratio of the ceramic proppant were systematically investigated as a function of sintering temperature. The morphology and phase composition of the ceramic proppant were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that the ceramic proppant is composed of rod-like mullite and granular cristobalite. Bulk density and apparent density of the proppant first rise and then slightly decrease with increasing the sintering temperature, while breakage ratios under 35 MPa and 52 MPa pressure gradually decrease and then increase. As the sintering temperature increases up to 1400 °C, the ceramic proppant shows denser microstructure. The proppant sintered at 1400 °C have the best performance with 1.27 g/cm3 of bulk density, 2.79 g/cm3 of apparent density, 3.27 % of breakage ratio under 35 MPa closed pressure and 8.36 % of breakage ratio under 52 MPa closed pressure, which conform to the requirement of low-density ceramic proppant. The addition of solid waste can greatly reduce the preparation cost of the ceramic proppant.

scholarly journals The Effects of Temperature on the Hydrothermal Synthesis of Hydroxyapatite-Zeolite Using Blast Furnace Slag

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2131 ◽  
Author(s):  
G.U. Ryu ◽  
G.M. Kim ◽  
Hammad R. Khalid ◽  
H.K. Lee
Keyword(s):  
Blast Furnace ◽  
Hydrothermal Synthesis ◽  
Blast Furnace Slag ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Type Zeolite ◽  
Effects Of Temperature ◽  
Furnace Slag

Blast furnace slag, an industrial by-product, is emerging as a potential raw material to synthesize hydroxyapatite and zeolite. In this study, the effects of temperature on the hydrothermal synthesis of hydroxyapatite-zeolite from blast furnace slag were investigated. Specimens were synthesized at different temperatures (room temperature, 50, 90, 120, or 150 °C). The synthesized specimens were analyzed qualitatively and quantitatively via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), BET/BJH, and scanning electron microscopy/energy dispersive using X-ray analysis (SEM/EDX). It was found that the hydroxyapatite phase was synthesized at all the reaction temperatures, while faujasite type zeolite appeared in the specimens synthesized at 90 and 120 °C. Moreover, faujasite was replaced by hydroxysodalite in the specimens synthesized at 150 °C. Additionally, the crystals of the hydroxyapatite tended to become larger and total crystallinity increased as the reaction temperature increased.

Speciation of Zn in Blast Furnace Sludge from Former Sedimentation Ponds Using Synchrotron X-ray Diffraction, Fluorescence, and Absorption Spectroscopy

2012 ◽  
Vol 46 (22) ◽  
pp. 12381-12390 ◽  
Author(s):  
Ruben Kretzschmar ◽  
Tim Mansfeldt ◽  
Petar N. Mandaliev ◽  
Kurt Barmettler ◽  
Matthew A. Marcus ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Absorption Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Blast Furnace Sludge

XRD (X-Ray Diffraction) Analysis of the Stabilized Ash

2013 ◽  
Vol 459 ◽  
pp. 7-10
Author(s):  
Hai Ying Zhang ◽  
Shu Zhen Li
Keyword(s):  
Heavy Metals ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Waste Incineration ◽  
Municipal Solid Waste Incineration ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Leaching Toxicity ◽  
Mineralogical Compositions

MSWI (municipal solid waste incineration) fly ash, generated in incineration process of municipal solid waste, contains lots of heavy metals, which will do harm do the environment if extracted. In this work, the ash is stabilized by cement to reduce leaching toxicity of heavy metals. Besides, mineralogical compositions of the product of different cement / ash ratios after conservation for different period were analyzed by means of XRD (X-ray diffraction). It was found that major mineralogical compositions CaCO3, Ca (0H)2 and C-H-S hydration products. Content of Ca (0H)2 and C-H-S rises with increase of conservation period and cement / ash ratio.

Study on Sulfur Existing Form in Sinter

2011 ◽  
Vol 284-286 ◽  
pp. 1279-1283
Author(s):  
Yu Zhu Zhang ◽  
Su Ju Hao ◽  
Wu Feng Jiang ◽  
Yue Long
Keyword(s):  
Blast Furnace ◽  
Sulfur Content ◽  
Raw Materials ◽  
Value Added ◽  
X Ray Diffraction ◽  
Mineralogical Analysis ◽  
Metallurgical Production ◽  
X Ray ◽  
Calcium Sulphide ◽  
Existing Form

Lower sulfur content is absolutely necessary for high value-added quality steel, so it is required to reduce sulfur content of product in each link of metallurgical production. Sintering is one of important links to provide blast furnace raw materials. Study on Sulfur existing form in Sinter can provide significant theoretical guide on sulfur distribution in metallurgical production. In this paper, small sintering experiments were carried out and sinter samples with different alkalinities were prepared. The samples were characterized by mineralogical analysis and X-ray diffraction. The results show that Sulfur existing form in Sinter is calcium sulphide (CaS). CaS can not be oxidized and melted down in the following process of blast furnace iron-making and can directly enters into slag for discharge outside the furnace.

Development and Characterization of Cementing Composites with Blast Furnace Slag Replacement

2014 ◽  
Vol 976 ◽  
pp. 246-250
Author(s):  
Reyna Sánchez-Ramírez ◽  
Manuela Diaz-Cruz ◽  
Sebastían Díaz de La Torre ◽  
Enrique Rocha-Rangel
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Bending Strength ◽  
Isothermal Calorimetry ◽  
Oil Wells ◽  
X Ray Diffraction ◽  
Hydration Kinetics ◽  
X Ray ◽  
Furnace Slag

In this work, they were produced and characterized cementing composites made with blast furnace slag replacement, for their use in the construction of oil wells. To this, slurries were prepared with a replacement of 20 and 30% slag, as well as a slurry with 100 % slag and a slurry with 100% H-cement were prepared. Starting materials were characterized by chemical analysis, X-ray diffraction and Fourier Transformed Infra Red. Slurries also were activated with sodium silicate in order to study theirs hydration kinetics, driving by isothermal calorimetry. These studies were complemented by the preparation of specimens of 4 X 4 X 16 cm to which they determine its compressive and bending strength during 2 and 28 days of curing. From the results it can be concluded that it was obtained a product that can be effectively used in the construction of oil wells.

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