Effect of melt structure property on Al2O3 activity in CaO-SiO2-Al2O3-MgO system for blast furnace slag with different Al2O3 content

With the shortage of high-quality iron ore resources, more and more attention has been paid to the blast furnace (BF) smelting of Al2O3-rich iron ore in recent years. Thus, investigation on the thermodynamics property of Al2O3-rich blast furnace slag was inevitable in order to produce high quality hot metal with low cost. In this paper, based on the determination of Al2O3 activity by reference slag method at 1873 K in previous study, the effect of the mechanism of slag structure property on Al2O3 activity in CaO-SiO2-MgO-Al2O3 system was discussed by Raman spectra analysis. It was found that the [AlO4] structure was polymerized and [SiO4] structure was depolymerized with the Al2O3 content increasing from 10 wt.% to 18 wt.%, which caused the Al2O3 activity increased.

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Proper MgO/Al2O3 Ratio in Blast-Furnace Slag: Analysis of Proper MgO/Al2O3 Ratio Based on Observed Data

Metals ◽

10.3390/met10060784 ◽

2020 ◽

Vol 10 (6) ◽

pp. 784

Author(s):

Fengman Shen ◽

Xinguang Hu ◽

Haiyan Zheng ◽

Xin Jiang ◽

Qiangjian Gao ◽

...

Keyword(s):

Phase Diagram ◽

Blast Furnace ◽

Blast Furnace Slag ◽

Iron Ore ◽

Social Benefits ◽

Blast Furnaces ◽

High Quality ◽

Diagram Analysis ◽

Furnace Slag

With the gradual depletion of high-quality iron-ore resources, ironmaking blast furnaces have gradually shifted to using high-content Al2O3 iron ore. Under this condition, the addition of MgO in the slag is adopted to alleviate operation problems caused by the high content of Al2O3. However, the proper value of the MgO/Al2O3 ratio for blast-furnace slag systems (Al2O3 = 8–25%) is not systematically studied. In this paper, we discuss the proper MgO/Al2O3 ratio on the basis of blast-furnace slag systems under different Al2O3 contents. On the basis of thermodynamics and phase-diagram analysis, it could be concluded that: (1) the MgO/Al2O3 ratio is not limited when Al2O3 in slag is less than 14%, (2) the MgO/Al2O3 ratio is required to be in the range of 0.40–0.50 when Al2O3 in the slag is 15–17%, and (3) the MgO/Al2O3 ratio should be 0.45–0.55 when Al2O3 in the slag is larger than 18%. The proper MgO/Al2O3 ratio value has been established in various industries, and it has achieved significant economic and social benefits.

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Desulfurization Ability of Blast Furnace Slag Containing High Al2O3 at 1773 K

Crystals ◽

10.3390/cryst11080910 ◽

2021 ◽

Vol 11 (8) ◽

pp. 910

Author(s):

Yongchun Guo ◽

Fengman Shen ◽

Haiyan Zheng ◽

Shuo Wang ◽

Xin Jiang ◽

...

Keyword(s):

Blast Furnace ◽

Blast Furnace Slag ◽

Iron Ore ◽

Al2o3 Content ◽

High Alumina ◽

Free Oxygen ◽

Oxygen Ions ◽

Slag Structure ◽

Ft Ir ◽

Furnace Slag

With the consumption of high-quality iron ore resources, the grade of iron ore raw used in the iron making process has gradually decreased. The high aluminum raw materials has led to an increase in the Al2O3 content in the blast furnace slag, which has affected the normal operation of the blast furnace. The activity of the components involved in the desulfurization reaction is an important factor affecting the desulfurization process. In this paper, the effects of B(w(CaO)/w(SiO2)) and w(MgO)/w(Al2O3) on the desulfurization ability of a CaO-SiO2-MgO-Al2O3 quaternary blast furnace slag system were studied by using a double-layer graphite crucible to simulate the process of molten iron dropping through the slag at 1773 K. The desulfurization reaction mechanism of high alumina blast furnace slag is explained from the aspects of slag structure and component activity, which provides a theoretical basis for the reasonable selection of a slag making system under the condition of a high alumina content. The effects of different B and w(MgO)/w(Al2O3) on the slag structure 2343 analyzed by Fourier transform infrared spectroscopy (FT-IR). The results show that when w(MgO)/w(Al2O3) = 0.50 and w(Al2O3) = 20%, the desulfurization ability and MgO activity of slag increased with the increase of B; when w(Al2O3) = 20% and B = 1.30, the desulfurization ability and MgO activity of the slag increased with the increase of w(MgO)/w(Al2O3). The FT-IR analysis showed that with the increase of B or w(MgO)/w(Al2O3), the dissociated free oxygen ions (O2-) in the slag increased, and the dissociated free oxygen ions (O2-) interacted with the bridging oxygen (O0) of silicate, which made the complex Si-O structure in the slag gradually depolymerize and increase the desulfurization ability.

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Phosphorus retention capacity of iron-ore and blast furnace slag in subsurface flow constructed wetlands

Water Science & Technology ◽

10.2166/wst.2001.0811 ◽

2001 ◽

Vol 44 (11-12) ◽

pp. 69-75 ◽

Cited By ~ 29

Author(s):

B. Grüneberg ◽

J. Kern

Keyword(s):

Blast Furnace ◽

Constructed Wetlands ◽

Blast Furnace Slag ◽

Iron Ore ◽

Subsurface Flow ◽

Phosphorus Retention ◽

Anaerobic Conditions ◽

Retention Capacity ◽

Aerobic Conditions ◽

Furnace Slag

The suitability of iron-ore and blast furnace slag for subsurface flow (SSF) constructed wetlands was studied over a period of four months. Dairy farm wastewater (TP 45 mg l-1) was percolated through buckets planted with reed (volume 9.1 l; hydraulic load 15 l m-2d-1). One group of buckets was kept under aerobic conditions and the other group under anaerobic conditions, monitored by continuous redox potential measurements. Even at high mass loading rates of 0.65 g P m-1d-1 the slag provided 98% removal efficiency and showed no decrease in performance with time. However, phosphorus fractionation data indicate that the high phosphorus retention capacity under aerobic conditions is to a great extent attributable to unstable sorption onto calcium compounds (NH4Cl-P). Phosphorus sorption of both the slag (200 μg P g-1) and the iron-ore (140 μg P g-1) was promoted by predominantly anaerobic conditions due to continuous formation of amorphous ferrous hydroxides. None of the substrates had adverse affects on reed growth.

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The effect of Ground Granulated Blast Furnace Slag (GGBFS) on Portland cement type II to compressive strength of high quality concrete

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/830/2/022068 ◽

2020 ◽

Vol 830 ◽

pp. 022068

Author(s):

N Puspita ◽

A I Hani’a ◽

M Fauzi

Keyword(s):

Compressive Strength ◽

Blast Furnace ◽

Portland Cement ◽

Blast Furnace Slag ◽

Type Ii ◽

Cement Type ◽

High Quality ◽

Granulated Blast Furnace Slag ◽

Furnace Slag

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Geopolymer Bricks Using Iron Ore Tailings, Slag Sand, Ground Granular Blast Furnace Slag and Fly Ash

Geopolymers and Other Geosynthetics ◽

10.5772/intechopen.81748 ◽

2020 ◽

Author(s):

Raghunandan Kumar ◽

Pranab Das ◽

M. Beulah ◽

H.R. Arjun

Keyword(s):

Blast Furnace ◽

Fly Ash ◽

Blast Furnace Slag ◽

Iron Ore ◽

Iron Ore Tailings ◽

Furnace Slag

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Probing of Iron Ore “Plus Calcium Oxide Grade"

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.160-162.1253 ◽

2010 ◽

Vol 160-162 ◽

pp. 1253-1256

Author(s):

Zhi Xia Zhang ◽

Hai Sheng Yin

Keyword(s):

Blast Furnace ◽

Calcium Oxide ◽

Blast Furnace Slag ◽

Iron Ore ◽

Mass Percentage ◽

Iron Concentrate ◽

Oxide Addition ◽

Furnace Slag

A new concept, “Plus Calcium Oxide Grade”, was put forward, which is the very mass percentage of iron element when Calcium Oxide addition fulfills the need of the basicity of the blast furnace slag. The “Plus Calcium Oxide Grade” and “Minus Calcium Oxide Grade” of iron ore, iron concentrate, sinter and pellet was calculated, analyzed and also compared. The results showed that: the Plus Calcium Oxide Grade can reflect the smelting value more objectively and reasonably, while the basic grade and “Minus Calcium Oxide Grade” can not. So it is suggested that the concept of “Plus Calcium Oxide Grade” can be brought into the iron ore dealing and using, and also into the area of iron concentrate, sinter, pellet and furnace mixture.

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Study on the Modification of Blast Furnace Smelt Slag and Crystallization Behavior in the Solidification Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1094.352 ◽

2015 ◽

Vol 1094 ◽

pp. 352-359 ◽

Cited By ~ 1

Author(s):

Jie Li ◽

Kai Zhao ◽

Yu Zhu Zhang ◽

Wei Xing Liu ◽

Ai Min Yang

Keyword(s):

Blast Furnace ◽

Fly Ash ◽

Blast Furnace Slag ◽

Iron Ore ◽

Crystallization Behavior ◽

Vitreous Body ◽

Solidification Process ◽

Waste Rock ◽

Furnace Slag ◽

Air Hole

The direct fibrillation of blast furnace slag can solve these problems, such as having not been recycled of sensible heat, the consumption of water resources, environmental pollution and the low additional value of product, which are caused by the traditional water quenching method. The modification is the key problem of fiber forming. The thesis mainly aims at the study of viscosity of slag, the ability of crystallization and mineral phase structure after the modified process of blast furnace slag and confined the relevance of the three to optimize the appropriate texturizer and adding ratio. The results are as following: Iron ore waste rock, fly-ash and compounded texturizer can improve the high temperature viscosity of the slag respectively, while it has different effect on landing gradient of viscosity and temperature (Fly-ash occupies first place, compounded texturizer comes second and iron ore and waste rock comes the minimum). By analyzing the crystallization behavior of the slag in the solidification process, when the proportion of iron ore waste rock is more than 9%, the fly-ash is equal or greater than 8% and the compounded texturizer is more than 9%, the solidification slag will appear amorphous. The mineral composition of the slag transforms gradually from melilite to vitreous body, which will make the air hole of the vitreous body increased and aperture decreased. When the iron ore waste rock is added, the homogeneity of the air hole will deteriorate, while adding the fly-ash and compounded texturizer will strengthen the homogeneity of the air hole and make the mineral structure intensive gradually.

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Metal reduction from landfill leachate by using blast furnace slag and pine bark - discussion about the parameters significant for metal removal

Linnaeus Eco-Tech ◽

10.15626/eco-tech.2005.028 ◽

2019 ◽

pp. 277-286

Author(s):

Emma Nehrenheim

Keyword(s):

Blast Furnace ◽

Landfill Leachate ◽

Blast Furnace Slag ◽

Metal Removal ◽

Low Cost ◽

Paper Industry ◽

Filter Material ◽

Pine Bark ◽

Cost Treatment ◽

Furnace Slag

In Sweden there are many old landfills of which the content is more or less unknown, Theleachates from these are of varying quality, mirroring the waste deposited in the landfills,Metals commonly occurring in leachates are i,e, zink (Zn), lead (Pb), cupper (Cu) and nickel(Ni), Ni is of particular interest due to the un-predictable mobility of the metal, For small,weak leachates a passive low-cost treatment system can be suitable, Reactive filter technologyis one alternative and by using by-products from national and global industries theenvironmental benefit could be further increased, Pine bark (from pulp and paper industry)and blast furnace slag (from steel manufacturing) are examples of such materials, Designingfilters for removal of metals from leachate includes taking a series of parameters into accountAt the landfill site in Eskilstuna, Sweden, a facility was designed as a pilot study, Fourcolumns were filled with filter material, The materials were sand, amorphous and crystallineblast furnace slag and pine bark, The aim was to investigate parameters significant for metaluptake from landfill leachate, A screening of the metals, physio-chemical parameters andsome organic pollutants was conducted for a period of five months, A part from this, a batchexperiment was conducted, Contact time, initial concentration, other leachate components andpH are examples of parameters that have a significant influence on the metal removingcapacity of a filter,

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Preparation of a New Unburned Brick from Ti-Bearing Blast Furnace Slag and PVA Modified by Epikote

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.785-786.328 ◽

2013 ◽

Vol 785-786 ◽

pp. 328-331 ◽

Cited By ~ 3

Author(s):

Xiang Wen Kong ◽

Li Li Ren ◽

Xia Ai ◽

Jing Zhang

Keyword(s):

Blast Furnace ◽

Blast Furnace Slag ◽

Low Cost ◽

Mixing Time ◽

Cementitious Materials ◽

Test Method ◽

Process Conditions ◽

Curing Time ◽

Orthogonal Test Method ◽

Furnace Slag

A new unburned brick was prepared from the Ti-bearing blast furnace slag as an aggregate and PVA modified by epikote as cementitious materials. The effects of modified PVA and auxiliaries on compressive strength of unburned brick were studied by the orthogonal test method. The results show that samples have better properties and low cost when the samples have a composition of slag dosage 72 %, modified PVA dosage 6%, auxiliary 1 dosage 6%, auxiliary 2 dosage 10%, water 6% and the process conditions of preparing the brick sample were mixing time 1 h, forming time 10 min, forming pressure 40 MPa, and curing time 7 d. The study reveals that the samples properties can meet the standard requirements of excellent grade products (MU20) in GB11945-1999.

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