scholarly journals Effect of Cooling Methods on the Strength of Silico-ferrite of Calcium and Aluminum of Iron Ore Sinter during the Cooling Process

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 402
Author(s):  
Xu Zhang ◽  
Hao Bai ◽  
Xin Lu ◽  
Tian He ◽  
Jian Zhang ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Iron Ore ◽  
Cooling Process ◽  
Slow Cooling ◽  
Iron Ore Sinter ◽  
Mass Fractions ◽  
Mechanical Strengths ◽  
Biot Numbers ◽  
Cooling Methods

In the iron making process, a high mechanical strength is favorable for iron ore sinters in the blast furnace, and the bonding phase is regarded as one of the key components that determines the quality of the iron ore sinter, in which the silico-ferrite of calcium and aluminum (SFCA) is one of the typical phases. In this study, synthesized samples with different SFCA mass fractions were prepared to study the effect of different cooling methods on the strengths of the SFCA samples. The results showed that the strength of a sample could be improved by increasing the SFCA content during a temperature change. Further, the test results for the compressive strength suggested that the SFCA had a positive effect on the strength of the iron ore sinter during cooling, with slow cooling being significantly effective at preventing the generation of thermal stress. Moreover, the Biot number was introduced to normalize all of the cooling methods. The results showed that higher mechanical strengths for iron ore sinters will be obtained with higher SFCA content and lower Biot numbers, which will guide the evaluation of mechanical strength of iron ore sinter after the cooling process in industry.

scholarly journals Iron-Ore Sintering Process Optimization / Optymalizacja Procesu Aglomeracji Rudy Żelaza

2015 ◽  
Vol 60 (4) ◽  
pp. 2895-2900 ◽  
Author(s):  
M. Fröhlichová ◽  
D. Ivanišin ◽  
A. Mašlejová ◽  
R. Findorák ◽  
J. Legemza
Keyword(s):  
Iron Content ◽  
Iron Ore ◽  
Raw Materials ◽  
Size Composition ◽  
Sintering Process ◽  
Iron Ore Sintering ◽  
Iron Ore Sinter ◽  
A Charge ◽  
Iron Ore Concentrate

The work deals with examination of the influence of the ratio between iron ore concentrate and iron ore on quality of produced iron ore sinter. One of the possibilities to increase iron content in sinter is the modification of raw materials ratio, when iron ore materials are added into sintering mixture. If the ratio is in favor of iron ore sinter, iron content in resulting sintering mixture will be lower. If the ratio is in favor of iron ore concentrate and recycled materials, which is more finegrained, a proportion of a fraction under 0.5 mm will increase, charge permeability property will be reduced, sintering band performance will decrease and an occurrence of solid particulate matter in product of sintering process will rise. The sintering mixture permeability can be optimized by increase of fuel content in charge or increase of sinter charge moisture. A change in ratio between concentrate and iron ore has been experimentally studied. An influence of sintering mixture grain size composition, a charge grains shape on quality and phase composition on quality of the produced iron sinter has been studied.

Quality Estimation for the Iron Ore Sinter Obtained via Separate Blend Preparation

2020 ◽  
Vol 844 ◽  
pp. 114-123
Author(s):  
Volodymyr Bochka ◽  
Artem Sova ◽  
Lina Kieush ◽  
Oleksandr Hryshyn ◽  
Alisa Dvoiehlazova
Keyword(s):  
Iron Ore ◽  
Mineralogical Composition ◽  
Equivalent Diameter ◽  
Sintering Process ◽  
Iron Ore Sintering ◽  
Positive Effects ◽  
Iron Ore Sinter ◽  
Iron Ore Sintering Process ◽  
Ore Sintering

This paper reveals that obtaining high-quality sinter, improved or stabilized by its size and strength, is a challenge to be solved by embracing both the formation of sinter with the strong structure and the optimal mineralogical composition of its bonds during the preparation of the sintering blend. The existing technological schemes of iron ore sintering do not allow producing the sinter where the amounts of fines with 0-0.5 mm of fraction would be less than the typical amounts of 8.1-20.4%. Therefore, the study to establish how the blend preparation with the preliminary made composites affects the parameters of iron ore sintering process and the quality of the resulting sinter has been carried out. It has determined that the use of separate pre-granulation has commonly positive effects on the process of blend preparation, namely it significantly decreases the amount of non-granulated fraction of 0-1 mm and increases the equivalent diameter of the granules, reduces the standard deviation and variation coefficient, indicating the more homogeneous granulometric composition of raw granules.

Effects of Different Cooling Methods on Postharvest Physiology of Yali Pears during Ice Temperature Storage

2012 ◽  
Vol 554-556 ◽  
pp. 1072-1075
Author(s):  
Li Ya Liang ◽  
Zhao Jin ◽  
Li Ping Hao ◽  
Shi Jie Yan
Keyword(s):  
Respiration Rate ◽  
Ethylene Production ◽  
Physiological Disorder ◽  
Slow Cooling ◽  
Rapid Cooling ◽  
Postharvest Physiology ◽  
C Storage ◽  
Cooling Methods ◽  
Temperature Storage

The effects of slow and rapid cooling methods on the postharvest physiology of Yali pears during ice temperature (-0.5°C) storage were investigated. Respiration rate, ethylene production, browning index and polyphenol oxidase(PPO) activity were used to evaluate the quality of Yali pears. The results showed that the slow cooling treatment decreased the levels of respiration rate，ethylene production，and PPO activity of Yali pears, and delayed the occurrence of the respiration, ethylene, and PPO activity peak compared to the rapid cooling treatment. The browning indexes of Yali pears with slow cooling treatment were lower than that of rapid cooling treatment. The results indicate that the cooling method may be an important factor affecting the storage quality of Yali pears. The slow cooling can delay the occurrence of physiological disorder during ice temperature storage.

scholarly journals Influence of Iron Ore Fines Feed Size on Microstructure, Productivity and Quality of Iron Ore Sinter

2011 ◽  
Vol 51 (6) ◽  
pp. 922-929 ◽  
Author(s):  
Tekkalakote Umadevi ◽  
Angalakuditi Brahmacharyulu ◽  
Ajay Kumar Roy ◽  
Pradipta Chandra Mahapatra ◽  
Manjunath Prabhu ◽  
...  
Keyword(s):  
Iron Ore ◽  
Iron Ore Sinter ◽  
Iron Ore Fines

scholarly journals Microstructure and Minerals Evolution of Iron Ore Sinter: Influence of SiO2 and Al2O3

Minerals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 449 ◽  
Author(s):  
Ji ◽  
Zhao ◽  
Gan ◽  
Fan ◽  
Chen ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Calcium Silicate ◽  
Iron Ore ◽  
Sio2 Content ◽  
Al2o3 Content ◽  
Sinter Quality ◽  
Iron Ore Sinter ◽  
Research Findings ◽  
Functional Mechanisms ◽  
Sintering Processes

SiO2 and Al2O3 are two important minerals that can affect the mechanical and metallurgical properties of sinter. This investigation systematically studied the influences of these minerals and revealed their functional mechanisms on sinter quality. Results showed that with an increasing Al2O3 content in sinter, the sintering indexes presented an improvement before the content exceeded 1.80%, while the quality decreased obviously after the content exceeded 1.80%. With an increasing SiO2 content, the sinter quality presented a decreasing tendency, especially when the content exceeded 4.80%. Consequently, the optimal content of Al2O3 was ≤1.80% and that of SiO2 was ≤4.80%. The evolution of the microstructure and minerals in sinter showed that enhancing the Al2O3 content increased the proportion of SFCA generated, which improved the sinter’s mechanical strength, while excessive Al2O3 led to the formation of sheet-like SFCA with weak mechanical strength. Increasing the content of SiO2 strained the formation of SFCA and promoted the formation of calcium silicate, the mechanical strength of which is lower than that of SFCA. The research findings will be useful in guiding practical sintering processes.

Predicting iron ore sinter strength through partial least square regression (PLSR) analysis of X-ray diffraction patterns

2017 ◽  
Vol 32 (S2) ◽  
pp. S66-S69
Author(s):  
Nathan A.S. Webster ◽  
Mark I. Pownceby ◽  
Natalie Ware ◽  
Rachel Pattel
Keyword(s):  
Process Control ◽  
Iron Ore ◽  
Partial Least Square ◽  
Least Square ◽  
Process Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sinter Strength ◽  
Iron Ore Sinter

The decrease in quality of Australian iron ore, coupled with the demand for more efficient energy use, means that closer monitoring and optimisation of process conditions for iron ore sinter production is required. Here, the suitability of using partial least-squares regression analysis of powder X-ray diffraction data, collected for iron ore sinter samples, for the prediction of iron ore sinter strength has been further assessed. In addition, a preliminary assessment of the effect of 2θ range on the quality of prediction has been made. For the purposes of process control, the level of correlation between predicted strength and actual sinter strength would inform an operator whether or not the process was operating within the acceptable limits, or whether there was a potential problem requiring further investigation or rapid intervention. Reducing the 2θ range was found to reduce the level of correlation between predicted and actual strength, to a point where the particular analysis may no longer be suitable for process control.

Assessing the quality of iron-ore sinter on the basis of its chemical composition

2009 ◽  
Vol 39 (10) ◽  
pp. 843-846 ◽  
Author(s):  
I. S. Bersenev ◽  
V. I. Klein ◽  
V. I. Matyukhin ◽  
Yu. G. Yaroshenko
Keyword(s):  
Chemical Composition ◽  
Iron Ore ◽  
Iron Ore Sinter

Metastable δ-Bi12SiO20 and its effect on the quality of grown single crystals of γ-Bi12SiO20

1996 ◽  
Vol 11 (10) ◽  
pp. 2575-2582 ◽  
Author(s):  
Senlin Fu ◽  
Hiroyuki Ozoe
Keyword(s):  
Single Crystals ◽  
Melting Temperature ◽  
Room Temperature ◽  
Lattice Distortion ◽  
Grown Crystal ◽  
Growth Parameters ◽  
Cooling Process ◽  
Slow Cooling ◽  
Large Lattice

Metastable δ-Bi12SiO20 may crystallize from the overheated Bi12SiO20 melt and transform into stable γ-Bi12SiO20 at about 569.5 °C during the subsequent slow cooling process. The transition δ-Bi12SiO20 → γ-Bi12SiO20 is irreversible and the γ-Bi12SiO20 is stable up to the melting temperature. By quenching the Bi12SiO20 melt, pure δ-Bi12SiO20 can be obtained at room temperature. The quenched δ-Bi12SiO20 crystal is nontransparent and has a space group of Fm3m (225) and a lattice constant of 55.417 Å at 20 °C. The quenched metastable δ-Bi12SiO20 can transform into pure γ-Bi12SiO20 at 382.5–386.1 °C with an exothermic heat of 31.68–32.38 J/g. The transition-produced δ-Bi12SiO20 crystal is still nontransparent and has a large lattice distortion. The transition δ-Bi12SiO20 → γ-Bi12SiO20 causes about 6% volume contraction, which may result in cracking of the grown crystal. By controlling the growth parameters, this transition can be effectively avoided.

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