摘要
选用废旧WC-8Co硬质合金为原料,采用氧化法研究了通氧速率、注水速率和炉体转速对其氧化行为的影响,通过Factsage热力学软件对硬质合金的氧化产物进行了预测,采用热重-差热(TG-DTA)分析确定了氧化温度范围,并用X衍射分析仪(XRD)和场发射电子扫描电镜(SEM)对氧化混合物的物相和形貌进行了表征。结果表明:WC-8Co废旧硬质合金在富氧、潮湿和旋转条件下能迅速氧化为WO_3和CoWO_4混合物,H_2-H_2O-O_2组成的氧化-还原体系与炉体转动产生的复杂应力协同促进氧化进程。当注水速率为1.2 ml·min^(-1),氧气速率为0.125m3·h^(-1),炉体转速为15 r·min^(-1)时,废旧硬质合金仅需在850℃下氧化1 h就能完全氧化,其氧化增重为16%,氧化物颗粒形貌多为近球形,分布均匀且粒径分布较窄,主要分布在0.26~2.86μm范围内,其平均粒径为0.93μm。
The waste WC-8Co hard alloy was chosen as raw material. Influence of injecting rate, oxygen flow rate and rotation rate on oxidation behavior was studied by oxidation method. Oxidation products were predicted by Factsage thermodynamic software. Oxidation temperature ranges were analyzed by thermal gravimetry-differential thermal analysis （TG-DTA） , and the phase and morphology of oxide mixtures were characterized by X-ray diffraction analysis （XRD） and field-emission scanning electron microscope （SEM）. The results showed that WC-8Co carbide scrap could rapidly oxidize to WO3 and CoWO4 mixtures in oxygen enriched, wetting and rotary conditions. The oxidation-reduction system composed of H2-H2O-O2 and the complex stress produced by the rotation of the furnace promoted the oxidation process. When injection rate of the water was 1.2 ml·min ^-1 , the oxygen flow rate was 0. 125 m3·h^-1 and the furnace body rotating rate was 15 r·min^-1, the waste hard alloy was oxidized completely at 850℃ for 1 h. The increase in weight was 16% due to the oxidation of the sample. Most of the oxide powder particles showed a near-spherical morphology, and the particles, which had a homogeneous and narrow size distribution with the average particle size of 0.93 μm, were mostly distributed between 0.26 - 2. 86 μm.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2016年第11期1138-1144,共7页
Chinese Journal of Rare Metals
基金
江西省自然科学基金(KJLD13041
GJJ14409
20142BAB216010
GJJ150688)
中国留学基金委项目(201508360122)
江西百人远航计划项目(2015082)资助
关键词
硬质合金
氧化行为
氧化-还原体系
复杂应力
hard alloy
oxidation behavior
oxidation-reduction system
complex stress
