Identification of Carbonaceous Materials in Blast Furnace Dust by Micro-Raman Spectroscopy

抄録

Carbonaceous materials (CMs) in blast furnace dust (BFD) contain abundant information about evolution behavior and utilization efficiency of metallurgical coke and injected pulverized coal. A novel method for determination of origin and content of BFD by micro-Raman spectroscopy was proposed in this paper. Ten randomly areas was selected and each one covers an area of 120×120 µm in the surface of briquetting demineralization-BFD sample. Average area was multi-point scanning measured by micro-Raman spectrometer for 140 test points with the same step length. Then, contrasted CM including evolutive coke, coal char and precipitated carbon from deposition of carbon process were prepared in laboratory simulated the process of fuels under gradually heating up condition of blast furnaces (BFs) and tested by micro-Raman spectroscopy. Meanwhile, the raceway coke was also sampled and tested for compared with coke at high temperature. Typical feature of spectrogram of these CMs can be well correspond to the BFD results. Therefore, CMs in BFD could be attributable to different sources, and its content can be counted by statistics of spectrogram. By comparing the identification results of petrography method, this method can measure the small particle size such as soot derived from very fine pulverized coal and volatiles which is hard to measure by the latter. For the investigated BF, unconsumed char escape from raceway and powdery coke in stack contributed the main source of CMs in BFD, while content of overflowing coke powder from high-temperature region of BF and precipitated carbon by deposition carbon reaction is very low.