煅烧温度对用B_4C水选废料制备B_4C材料性能的影响

Effect of calcining temperature on properties of B_4C materials prepared by boron carbide water separation wastes

为了节约资源,实现废料回收利用,以化学组成(w):B_4C 88.20%、B_2O_32.80%、Fe_2O_30.27%、游离B1.95%、游离C 2.91%、其他3.87%的碳化硼水选废料为原料,添加烧结助剂Al粉,并在活性炭固体渗碳作用下实现无压低温烧结制备碳化硼耐火材料。研究了煅烧温度1 000、1 100、1 200、1 300及1 400℃保温30 min时对试样性能的影响。采用国家标准检测烧后试样的体积密度、显气孔率和耐压强度;采用X射线衍射仪进行物相分析;采用FESEM观察试样的显微形貌。结果表明:提高温度和活性炭的渗碳作用都有助于提高煅烧试样的致密化程度。本试验较优的煅烧温度为1 400℃,在此温度下制备的碳化硼耐火材料的耐压强度为231.27MPa,显气孔率为22.43%,体积密度为1.72 g·cm-3。

For resource conservation and waste recycling,boron carbide refractories were fabricated via pressureless low temperature sintering with boron carbide water separation wastes（B4C 88. 20%,B2O32. 80%,Fe2O30. 27%,free B 1. 95%,free C 2. 91% and the others 3. 87%,by mass） as the raw materials,Al powder as the sintering additive,activated carbon as the carburizer. Effects of calcining temperatures（1 000,1 100,1 200,1 300 and 1 400 ℃,respectively） for 30 min on properties of the specimens were researched. The bulk density,apparent porosity and compressive strength of the specimens were tested according to Chinese standards; the phases were analyzed with an X-ray diffractometer; the microstructure was observed with FESEM. The results show that elevated temperature and carburizing can improve the densification of the specimens. The optimum calcining temperature is 1 400 ℃,at which,the compressive strength,apparent porosity,and bulk density are 231. 27 MPa,22. 43% and 1. 72 g ·cm^-3,respectively.