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1、镁制耐火材料相关文献翻译Characterization, microstructure andcorrosion behavior of magnesia refractories produced from recycled refractory aggregatesAbstractThis paper aims to report the results of some investigations carried out in I ran i an steel industries to reuse the spent magnesia graphi te refractory bri
2、cks in the forms of the new shaped and unshaped magnesia refractories. Economical aspects of recycling and minimizing the environmental effects of spent refractories landfills were the basic goals of this research. The spent MgO - C refractory bricks from electric arc (EAF) and ladle (LF) furnaces w
3、ere analyzed in terms of microstructural and chemical properties. Di fferent samples were prepared from natural sintered magnesia and 10 - 30 wt. % of recycled aggregates in the forms of magnesia refractory brick and ramming mix and their physical and mechanical properties were evaluated Also the sl
4、ag corrosion behavior and microstructural properties of corroded samples were investigated. The results showed that the addition of up to 30 wt. % of recycled aggregates had no negative effects on the properties of magnesia refractories. Keywords： Industrial minerals; Crushing; Particle size; Enviro
5、nmental; Recycling1. IntroductionRefractories are ceramic materials that are designed to withstand the variety of severe service condi tions, high temperatures, corrosive 1iquids and gases, abrasion, mechanical and thermal induced stresses (Othman and Nour, 2005 and Bennet et al., 1995). Refractorie
6、s are used by a variety of industries, including metal, ceramic, cement and glass manufacturers. When refractory materials have reached to end of their service 1ife they are replaced with new refractories that have to be manufactured from natural raw materials and the spent refractories are typicall
7、y disposed of in a landfill wasting valuable natural resources (Fang et al. , 1999, Smith et al. , 1999 and Bennet and Kwong, 1997). It is understood that recycling refers to use of a waste material in a manner similar to its original app1ication. In contrast a wastematerial is typically defined as
8、reused when it is used differently than the original product (Bennett et al., 2001 and Conejo et aL, 2006).This paper aims to report the results of investigations carried out in Iranian Khuzestan Steel Complex (KSCo.) by refractory research division of Iran University of Science and Technology (IUST
9、) to reuse the spent magnesia graphite refractory bricks. The goals of this research were characterizingspent refractories, establishing new way for minimizing wastes and spent refractories recycling, developing an applicable recyc1ing technique and comparing the properties of the recycled products
10、with those made from virgin material.2 Experimental procedure2.1. Spent refractories characterizationTable 1 shows the chemical analysis of intact and spent magnesia graphite refractory bricks which used at ladle slag line (LF & B-LF) and EAF hot spot (EAF & BHEAF) regions. The chemical analyses of
11、spent bricks were measured by X-ray fluorescence method (XRF) from hot face to 5 cm depth and the average was reported. As the results show, the analyses of spent bricks have no significant differences with original bricks.Table 1. Chemical analysis of bricks, raw materials and slag. SampleCarbon (g
12、raphite)Si02 A1203 CaO MgO Fc203 MnO L. 0. I Max MaxEAF12.70. 50. 51. 2 Max90. 50. 5B-EAF B-LFIranian 91% sinteredmagnesia Ball clay (SQ, UK) Microsilica (Iran53.8 30.7 93.6 1.320. 10.310. 5 4.51.03.5910. 215. 3 9.31.70.5 0.71. 20. 5Max84.70. 5 MaxMaxMax MaxLF9.33. 56 86. 1 4.7 6. 179. 35 1.833. 76
13、5. 10. 49 0. 97 0. 87SampleFerrosilicon Co.)Slag Carbon (graphite) Si02 A1203 CaO MgO Fe2O3 MnO L. 0. I - 28 13 35 6 9 9 At first the penetrated layers (3-5 cm from hot face) were cut and removed and then the none-reacted regions were crushed and screened. The recycled aggregates from 1 ad1e were mi
14、xed with aggregates obtained from EAF in equal weight percent. After crushing, the aggregates were screened in different particle size portions. In order to eliminate the residual graphite from recycled magnesia aggregates, they were heated in a rotary laboratory scale furnace at 1400 C for 2 h.2.3.
15、 Application of spent bricks in shaped refractoriesIn order to evaluate the using of the recycled aggregates for the production of magnesia refractory bricks, the recycled aggregates were added in various percents into a magnesia brick composition as additive. Table 2 shows the particle size distrib
16、ution and composition of designed magnesia bricks prepared from natural Iranian sintered magnesia (91% MgO and chemical properties according to Table 1) and recycled aggregates. A1 so i t should be noted that just the range of 1 - 4 mm (coarse grai ns) of recycled aggregates were used in the samples. The reason for selecting this fraction of particles was based on the fact that the im
