添加半成品废砖的再生镁碳砖研究

Effect of semi-finished rejected brick addition on properties of reproduced MgO-C brick

为了回收利用镁碳砖生产过程中产生的半成品废砖,将半成品废砖经拣选、破碎、筛分后制成3～1、≤1和≤0.088 mm三种粒度的再生料,然后在镁碳砖常规配方中添加20%(w)的再生料制成再生镁碳砖试样,研究了试样的颗粒级配(粗颗粒、中颗粒、细粉的质量分数分别为44%～56%、14%～26%、24%～36%),再生料加入方式(分级后分别与相同粒度的其他料混合后加入或不分级直接与电熔镁砂颗粒料混合后加入),树脂添加量(外加质量分数分别为3.8%、4.0%、4.2%、4.4%)对再生镁碳砖试样性能的影响,并与未添加再生料的镁碳砖试样进行了对比。结果表明:1)适当增加中颗粒料的量,减少细粉的量,可以提高再生镁碳砖试样的致密度和抗氧化性能,但对强度影响不大。2)再生镁碳砖试样中树脂的最佳外加量(w)为4.0%。3)与不分级直接加入相比,再生料分级加入可以有效提高再生镁碳砖试样的致密度和强度。4)通过工艺优化,添加20%(w)再生料的再生镁碳砖试样的性能可以达到YB 4074—91中镁碳砖MT14A的技术要求。

Regenerated MgO-C mix was prepared by sorting,crushing and screening semi-finished rejected MgO-C bricks in order to recycle semi-finished rejected MgO-C bricks generated during production. Reproduced MgO-C bricks with 20% （in mass,the same hereinafter） regenerated mix （3-1 mm,1-0 mm and ≤0.088 mm） were produced. The influences of grain size compositions （coarse grains：44%-56%, middle grains ： 14%-26%, fine powder.24%-36% ）, batching method of regenerated mix （the screened regenerated MgO-C particles premix with the same size of other materials respectively,or all regenerated mix before screening together mix with magnesia particles）,and extra resin addition （3.8% ,4.0% ,4.2% and 4.4% ） on properties of reproduced MgO-C bricks were investigated. The results show that. （1）in- creasing middle grain content or decreasing fine powder content properly can enhance the density and oxidation resistance of specimens but do not improve the cold crushing strength significantly; （2）the opti- mum addition of resin is 4.0% ;（3）adding the screened regenerated MgO-C mix can improve the density and strength of reproduced MgO-C brick more effectively than adding the unscreened regenerated MgO- C mix; （4）through process optimization,the properties of MgO-C bricks with 20% regenerated MgO-C mix can reach the specifications of MT-14A bricks in YB 4074-91.