利用硅切割废砂浆制备Si3N4结合SiC耐火材料

Preparation of Si_3N_4 bonded SiC refractories from waste slurry of cutting silicon

以光伏企业线切割硅产生的废砂浆(其w(SiC)=25%,w(Si)=60%)为主要原料,加入不同比例的SiC粉(废砂浆与SiC粉的质量比为65∶35～35∶65),加无水乙醇球磨、干燥、加PVA造粒后,以10 MPa压力(保压1 min)成型为55 mm×5 mm×5 mm的坯体,在1 450℃氮气气氛中烧结制备了Si3N4结合SiC耐火材料,然后检测其常温抗折强度、显气孔率、体积密度,并进行XRD分析。结果表明:烧后试样的常温抗折强度较高,最高达50.2 MPa,但致密度较低,显气孔率在31.20%～35.64%之间;烧后试样中只有SiC和Si3N4两相,单质Si已完全氮化生成了Si3N4。

Si3N4 bonded SiC refractories were prepared using waste slurry of cutting silicon of photovoltaic enterprise （w（SiC） =25% and w（Si） = 60% ） as main starting material,adding SiC powder with mass ratio of waste slurry to SiC varying from 65：35 to 35：65, ball milling with absolute ethanol ,drying, pelletizing with PVA,shaping into the specimens with dimensions of 65 mm ×5 mm ×5 mm under 10 MPa for 1 min,and firing at 1 450℃ in nitrogen atmosphere. The cold modulus of rupture, apparent porosity, and bulk density were determined ,and their phase compositions were analyzed by XRD. The results show that：the CMOR of the specimens is high, reaching the maximum of 50.2 MPa, the density is low, and the apparent porosity ranges from 31.20% to 35.64% ;the specimens only have SiC and Si3N4,and Si has completely been ni- tridized into Si3N4.