石墨种类对超低碳MgO-CaO-C砖性能的影响

Influence of graphite type on properties of ultra-low carbon MgO-CaO-C brick

以电熔镁钙砂（粒度为5-3、3-1和≤1 mm）为骨料,电熔镁砂（≤0.074 mm）为基质,分别加入3%（w）的大鳞片石墨（≤0.149 mm）、细鳞片石墨（≤0.044 mm）、微孔化石墨（≤0.074 mm）制备了3种超低碳MgO-CaO-C砖试样,并对比了其高温强度、抗氧化性、抗热震性和抗渣侵蚀性。结果表明：（1）石墨种类对超低碳MgO-CaO-C砖的物理性能影响不大。（2）大鳞片石墨制备的超低碳MgO-CaO-C砖的抗氧化性和抗渣侵蚀性较好,而微孔化石墨制备的试样抗热震性最好;考虑到整体性能,碳源以1.5%（w）大鳞片石墨与1.5%（w）微孔化石墨的复合形式加入最佳。

Three different ultra-low carbon MgO-CaO-C brick specimens were prepared with fused doloma（grain size：5-3,3-1,≤1 mm） as aggregate and fused magnesia powder（≤0.074 mm） as matrix,adding 3 wt% coarse flake graphite（≤0.149 mm）,fine flake graphite（≤0.044 mm） and microporous graphite（≤0.074 mm）,respectively.Hot strength,oxidation resistance,thermal shock resistance and slag corrosion resistance of the bricks were compared.The results show that：（1）graphite type has no obvious influence on physical properties of ultra-low carbon MgO-CaO-C bricks;（2）ultra-low carbon MgO-CaO-C brick prepared with coarse flake graphite shows better oxidation resistance and slag corrosion resistance,but specimens prepared with microporous graphite possesses the best thermal shock resistance.General thinking,the optimum carbon introduction method is 1.5 wt% coarse flake graphite and 1.5 wt% microporous graphite by the present studies.