1、 外文资料翻译 Reuse and Reproduction of Used Refractories The paper analyzed the recycle condition and developing trend of used refractories in China and other countries, including research achievement of recycles of used refractories such as MgO-C bricks, Al2O3-MgO-C bricks, Al2O3-SiC-C castable and MgO-
2、Cr2O3 bricks. Recycled refractory exhibit the same or even better properties compared with the original. In addition, prospects for recycle of used refractories are also discussed. 1 Introduction About 9 millions tons of refractories are consumed in China annually owing to the rapid development of t
3、he metallurgical industry,from which more than 4 million tons of used refract ories are inevitably generated.Most of used refractories are obsolescence, and only aminority is recycled as rawmaterials for refractory products. Discard of used refracto ries not only is lavish the natural resources but
4、also is harmful to the environment Pollution of used refractories include following as pects of: 1) dust; 2) an thraco silicosis caused by crystalline silica dust; 3) radioactivity of zirconia rawmaterial; 4) carcinogenity of Cr+ 6; 5) carcinogenicity of refractory fiber and asbestos; 6) pollutant f
5、rom volatile and the rmal decomposed substance of pitch and resin. Used refractories can be even processed into rawmaterials with high price, performing as highquality second resources. Not only saving mineral resources and energy and reducing the environmental pollution, but also saving the cost of
6、 refractory and steelmaking, recycle of used refractories becomes an important cause to refractory enter prises. 2 Circum stances for used refractories in China Baosteel pays great attention to reuse and reproduction of used refractories. Combine reuse and reproduction of used refractories with cutt
7、ing down cost and increasing benefit, protecting environment and advancing enter prise level. Accelerate research and development on used refractories. The research results are reported as follows: Used MgO-C bricks for BOF and LF lining are selected to remove sundries such as dirt, slag and iron sc
8、raps, which decrease seriously the quality of reproduced refractories. Properties of MgO-C brick reproduced are shown in table 1. Tab.1 Properties of MgO-C brick reproduced at R&D Bao steel MgO 80 76 80 77 C 12 14 11 14 Cold rush Strength /M Pa 60 52 60 52 Bulk Density/ (g cm- 3) 3.04 3.01 3.08 3.04
9、 Apparent Porosity/% 3 2 3 2 Hot Modulus Of Rupture /M Pa 13 12 13 12 Added ratio of used MgO-C brick /% 97 97 80 80 The MgO-C brick reproduced was used slag line of 300t ladle and service life reaches 82 heats that contains 20 heats ladle furnace Maxi mum wear speed at slag line is 1128mm /heat, an
10、d original MgO-C brick is 1140mm /heat Therefore, the performance of the reproduced MgO-C brick reaches level of original MgO-C brick . Tab2 Properties of magnesia-chrome bricks reproduced MgO 60 Cr 2O3 18 180 , 24h Bulk density/ ( g cm- 3) 3.12 Apparent porosity/% 13 Cold crush strength /M Pa 64.3
11、1750 , 3h Bulk density/ ( g cm- 3) 3.14 Apparent porosity/% 17.7 Cold crush strength /M Pa 48.7 Added ratio of magnesia-chrome brick used /% 70 Baosteel developed used magnesia-chrome brick for RH before 10 years, 20% used magnesia2 chrome brick was added into gunning mix for RH, and achieved favora
12、ble service result. Reproducing magne-sia- chrome brick is researched recently. Experimental result is shown in table 2. We have studied on AMC brick and ASC castable with AMC brick used for ladle and ASC castable used for iron runner system. 3 Prospect Used refractories can reduce the cost of raw m
13、aterial for refractories and metallurgy auxiliary material. The reuse ratio on of used refractories is very low in Bao steel at present; but R&D has been carried out. Pattern of reuse and repoducing on used refractories is diversification, i. e. consumer uses directly, refractories plant reclaimes,
14、building professional plant reclaiming used refractories and they unite. The key t o success is developing and researching high technology on reuse and reproduction of used refractories. Reuse and reproduction of used refractories is also a contribution on environment protection, and so, reuse and r
15、eproduction of used refractories increases rapidly. Trend of zero discard has been indicated. 用后耐火材料的再生利用 综述了国内外对用后耐火材料的再利用情况和发展趋势,报导了宝钢对用后镁碳砖、铝镁碳砖、铁沟料和镁铬砖等的再利用研究成果。再生耐火材料的性能接近或达到新产品的水平,甚至有些能达到优质耐火材料的水平。扼要介绍了用后耐火材料再生利用的设想。 1 简介 大约九百万吨的耐火材料消耗在中国每年快速发展的冶金行业,而不可避免的产生大约四百万吨的废旧耐火材料,而只有一少部分是作为耐火材料的原材料循环利用
16、的。用后耐火材料的摒弃不仅是国家自然资源的巨大浪费 ,而且也是对环境的污染 ,不能用的耐火材料危害包括以下的几种: 1)垃圾; 2)产生的二氧化硅粉尘引起尘肺病; 3)产生放射性的氧化锆原料; 4)产生毒害性的铬离子;5)耐火纤维制品、石棉致癌性物质; 6)从已分解的沥青树脂产生挥发性和热能的污染。用后的耐火材料能被加工成原材料,或者制成新的耐火资源,这样不但能节约能源、矿产资源 和降低环境污染,而且节约耐火材料和炼钢的成本,这是镁钙系耐火材料循环使用的重要原因。 2 用后耐火材料在中国的现状 宝钢注重用后耐火材料的循环再生利用,他们使用用后的耐火材料,这样可以降低成本、提高效益、保护环境和推
17、进事业水平。因此必须加快研发用后耐火材料的生产技术,研究的结果如下: 使用 MgO-C 砖时必须清除 BOF 和 LF 炉内的夹杂物,如灰尘、夹渣、钢铁残渣,因为这些物质会大大降低镁钙系耐火材料的质量。 MgO-C 砖的再生性能如表 1。 表 1 宝钢研发的再生 MgO-C 砖的性能 MgO 80 76 80 77 C 12 14 11 14 抗冷冲的强度 /M Pa 60 52 60 52 体积密度 / (g cm- 3) 3.04 3.01 3.08 3.04 显气孔率 /% 3 2 3 2 热震稳定性 /M Pa 13 12 13 12 加用后镁碳砖的比例 /% 97 97 80 80 使用再生的镁碳砖的三百吨的钢包渣线的寿命从二十炉延长到八十二炉,原