臺灣博碩士論文加值系統

本論文進行氧化鋅廢觸媒加碳酸鈣碳熱還原以回收鋅之反應動力學探討。我們以感應耦合電漿質譜儀、元素分析儀、Ｘ光繞射儀、原子吸收光譜儀、表面積測定儀及掃描式電子顯微鏡來測定反應過程中固體樣品的組成變化及物性變化，藉以探討氧化鋅廢觸媒加碳酸鈣之碳熱還原反應。
分析結果指出廢觸媒中含87.5wt%的ZnO及3.1wt%的ZnS。另外，實驗結果顯示鋅碳酸鈣先分解成氧化鈣和二氧化碳，廢觸媒中的氧化鋅與硫化鋅會還原成鋅氣體和一氧化碳逸出，硫的成份則以CaS的形態留在固體中。小孔表面積、小孔體積及小孔直徑會隨時間先上升，達到一最高點，然後下降。若反應時間固定為6,300秒時，樣品的小孔表面積、小孔體積及小孔直徑則隨溫度的上升而下降。我們提出一個反應機構來說明整體化學反應。
由原子吸收光譜儀的分析，可以繪出鋅回收率與反應時間的關係。我們發現提高固體樣品高度、反應溫度或固體樣品初始密度會提高鋅初始回收速率與最終回收率。另外，降低氬氣流量、Zntotal/C莫耳比、Zntotal/CaCO3莫耳比、廢觸媒粉粒大小、碳粉凝聚團大小或碳酸鈣凝聚團大小都會提高鋅初始回收速率與最終回收率。
根據所得到的實驗數據，我們可以迴歸出鋅初始回收速率式與鋅最終回收率方程式。

The kinetics of zinc recovery from the spent zinc oxide catalyst by carbon in the presence of calcium carbonate was studied using inductively coupled plasma mass spectrometer, elemental analyzer, X-ray diffractometer, atomic absorption spectrometer, surface area meter and scanning electron microscope. The spent zinc oxide catalyst was found to be composed of 87.5wt% zinc oxide and 3.1wt% zinc sulfide. Results of X-ray diffractometer indicated that calcium carbonate decomposed to calcium oxide and carbon dioxide while zinc oxide and zinc sulfide were reduced to zinc vapor and carbon monoxide evolving from solid sample and sulfur was scavenged as calcium sulfide remained in the solid. Results of surface area measurement indicated that the surface area of the solid sample increased with reaction time, reached a maximum and then decreased. The surface area of the reacted sample was found to decrease with reaction temperature. The variations of pore volume and average pore diameter were observed to be similar to that of surface area. A mechanism was proposed to explain the reaction. Experimental results of atomic absorption spectrometer indicated that the initial rate of zinc recovery and final zinc recovery can be increased by increasing sample height, reaction temperature or initial bulk density. Furthermore, they were found to increase with decrease in argon flow rate, molar ratio of Zntotal/C, molar ratio of Zntotal/CaCO3, grain size of the spent catalyst, agglomerate size of carbon or agglomerate size of calcium carbonate. Initial rate of zinc recovery and final zinc recovery were determined finally.

目 錄
中文摘要 Ι
英文摘要 Ⅲ
誌謝 Ⅴ
目錄 Ⅵ
圖表索引 Ⅹ
第一章緒論1
第二章文獻回顧3
2-1氧化鋅碳熱還原反應3
2-1-1文獻整理3
2-1-2反應機構5
2-1-3變數對反應速率的影響5
2-1-4回收速率式7
2-2 硫化鋅加碳酸鈣碳熱還原反應8
2-2-1文獻整理8
2-2-2反應機構8
2-2-3變數對反應速率的影響10
2-2-4回收速率式12
2-3碳酸鈣的角色12
2-4量測化學反應的儀器13
第三章實驗部分15
3-1氣體與藥品15
3-1-1氣體15
3-1-2藥品15
3-2實驗設備與儀器16
3-2-1熱重分析儀16
3-2-2產物分析設備21
3-2-3其他儀器與設備23
3-3實驗原理、條件及步驟24
3-3-1氧化鋅廢觸媒碳熱還原24
3-3-1-1固體樣品的製備步驟24
3-3-1-2碳熱還原反應的實驗步驟24
3-3-2原子吸收光譜儀的分析26
3-3-3 Ｘ光繞射儀的分析28
3-3-4元素分析儀的分析28
3-3-5感應耦合電漿質譜儀的分析30
3-3-6掃描式電子顯微鏡的步驟及原理31
3-3-7孔隙表面積測定儀的原理及步驟31
3-4實驗工作項目34
3-4-1反應變數對氧化鋅廢觸媒碳熱還原之影響 34
3-4-2固體試樣之化學成份分析及物理性質的測定36
第四章結果與討論38
4-1固體試樣之觀察與分析38
4-1-1固體試樣之觀察38
4-1-2感應耦合電漿質譜儀（ICP-MS）的分析結果40
4-1-3元素分析儀(EA)的分析結果40
4-1-4 X光繞射儀(XRD)的分析結果43
4-1-4-1廢觸媒、碳酸鈣及反應前固體樣品之分析結果43
4-1-4-2不同反應時間樣品之分析結果47
4-1-4-3不同反應溫度樣品之分析結果52
4-1-5小孔表面積、小孔體積及小孔直徑之測定結果55
4-1-5-1不同反應時間樣品之測定結果55
4-1-5-2不同反應溫度樣品之測定結果59
4-1-6電子顯微鏡照片63
4-2實驗變數對廢觸媒鋅回收率的影響67
4-2-1氬氣流量的影響 74
4-2-2固體樣品高度的影響76
4-2-3反應溫度的影響 78
4-2-4 Zntotal /C莫耳比的影響 82
4-2-5 Zntotal /CaCO3莫耳比的影響84
4-2-6物料粉粒大小的影響 86
4-2-7固體樣品初始密度的影響91
4-3起始回收速率及最終回收率之經驗式93
第五章 結論117
參考文獻119
附錄：實驗數據122
作者簡介133
授權書134
圖 表 索 引
Fig. 3-1Schematic diagram of experimental set-up.17
Fig. 3-2Photographs of experimental set-up.18
Fig. 3-3Flow chart of sample preparation for carbothermal reduction.25
Fig. 3-4Flow chart of carbothermal reduction. 27
Fig. 3-5Calibration curve of zinc concentration determined by atomic absorption spectrometer.29
Fig. 4-1Photograph of specimen.39
Fig. 4-2X-ray diffraction pattern of spent catalyst.44
Fig. 4-3X-ray diffraction pattern of CaCO3.45
Fig. 4-4X-ray diffraction pattern of unreacted sample.46
Fig. 4-5X-ray diffraction patterns of partially reacted solids for various reaction times. Reaction temperature = 1,323K.51
Fig. 4-6X-ray diffraction patterns of partially reacted solids for various reaction temperatures. Reaction time = 6,300s. 54
Fig. 4-7Plot of total surface area of partially reacted solid sample against reaction time. Reaction temperature = 1,323K.56
Fig. 4-8Plot of pore volume of partially reacted solid sample against reaction time. Reaction temperature = 1,323K.57
Fig. 4-9Plot of average pore diameter of partially reacted solid sample against reaction time. Reaction temperature = 1,323K.58
Fig. 4-10Plot of total surface area of partially reacted solid sample against reaction temperature. Reaction time = 6,300s.60
Fig. 4-11Plot of pore volume of partially reacted solid sample against reaction temperature. Reaction time = 6,300s.61
Fig. 4-12Plot of average pore diameter of partially reacted solid sample against reaction temperature. Reaction time = 6,300s.62
Fig. 4-13Scanning electron micrographs of (a)spent catalyst, (b) carbon black and (c)calcium carbonate.64
Fig. 4-14Scanning electron micrographs of solid sample. Reaction temperature = 1,323 K. (a)unreacted, (b)450s, (c)900s, (d)1,800s, (e)2,200s and (f)2,700s.66
Fig. 4-15Scanning electron micrographs of solid sample. Reaction time = 6,300 s. (a)1,173K, (b)1,223K and(c)1,373K.68
Fig. 4-16Plot of zinc recovery against time showing reproducibility of experimental system.72
Fig. 4-17Plot of zinc recovery against time. Effect of Ar flow rate.75
Fig. 4-18Plot of zinc recovery against time. Effect of sample height.77
Fig. 4-19Plot of zinc recovery against time. Effect of reaction temperature.79
Fig. 4-20Arrhenius plot showing temperature dependence of initial rate.81
Fig.4-21Plot of zinc recovery against time. Effect of molar ratio of Zntotal/C.83
Fig.4-22Plot of zinc recovery against time. Effect of molar ratio of Zntotal/CaCO3.85
Fig. 4-23Plot of zinc recovery against time. Effect of grain size of spent catalyst.88
Fig. 4-24Plot of zinc recovery against time. Effect of agglomerate size of carbon.89
Fig. 4-25Plot of zinc recovery against time. Effect of agglomerate size of CaCO3.90
Fig. 4-26Plot of zinc recovery against time. Effect of initial bulk density. 92
Fig. 4-27Plot of ln (NtZno dYZn/ dt |t=0) against ln(dcato).97
Fig. 4-28Plot of ln (NtZno dYZn/ dt |t=0) against ln(dCaCO3o).98
Fig. 4-29Plot of ln (NtZno dYZn/ dt |t=0) against ln(dCo).99
Fig. 4-30Plot of ln (NtZno dYZn/ dt |t=0) against ln(ρo).100
Fig. 4-31Plot of ln (NtZno dYZnt/ dt |t=0) against lnR1o.101
Fig. 4-32Plot of ln (NtZno dYZn/ dt |t=0) against lnR2o.102
Fig. 4-33Plot of ln (NtZno dYZn/ dt |t=0) against ln(ho).103
Fig. 4-34Plot of ln (NtZno dYZn/ dt |t=0) against ln(fAro).104
Fig. 4-35Plot of ln (NtZno dYZn/ dt |t=0) against 1/T.105
Fig. 4-36Plot of ln (Yf) against ln(dcato).107
Fig. 4-37Plot of ln (Yf) against ln(dCaCO3o).108
Fig. 4-38Plot of ln (Yf) against ln(dCo).109
Fig. 4-39Plot of ln (Yf) against ln(ρo).110
Fig. 4-40Plot of ln (Yf) against lnR1o.111
Fig. 4-41Plot of ln (Yf) against lnR2o.112
Fig. 4-42Plot of ln (Yf) against ln(ho).113
Fig. 4-43Plot of ln (Yf) against ln(fAro).114
Fig. 4-44Plot of ln (Yf) against 1/T.115
Table 2-1Literatures on carbothermal reduction of zinc oxide. 4
Table 2-2Literatures on carbothermal reduction of zinc sulfide. 9
Table 4-1Ingredient content of Zn, S, Al and As of spent catalyst.41
Table 4-2Content of carbon, hydrogen, nitrogen and sulfur of spent catalyst and samples reacted at 1,323K for various durations. 42
Table 4-3Values of experimental variables in carbothermal reduction experiments.70

Abramowitz, H. and Y. K. Rao, “Direct Reduction of Zinc Sulfide by Carbon and Lime”, Trans. Inst. Min. Metall. (Sec. C), 87, 180-188 (1978).
Froment G. F. and K. B. Bischoff, “Chemical Reactor Analysis and Design”, 2nd edition, 164, John Wiley & Sons Inc., New York (1990).
Chen, H. K., “A Study on the Carbothermic Reduction of Zinc Oxide”, Technical Report to National Science of Republic of China, NSC88-2214-E-146-002 (1999a).
Chen, H. K., “Effect of Additives on Carbothermic Reduction of Zinc Oxide”, Journal of Materials Science Letters, 18, 1,399-1,400 (1999b).
Guger, C. E. and F. S. Manning, “Kinetics of Zinc Oxide Reduction With Carbon Monoxide”, Metallurgical Transactions, 2(1), 3083-3090 (1971).
Gu, J. S. and C. I. Lin, “Sulfation of Magnesium Carbonate”, Journal of The Chin. I. Ch. E., 22(11), 181-187(1990).
Lopez, F. A., F. Medina, J. Medina and M. A. Palacios, “Process for Recovery of Non-Ferrous Metals from Steel Mill Dusts Involving Pelletizing and Carbothermic Reduction”, Ironmaking and Steelmaking, 18(4), 292-295 (1991).
Rao Y. K. and B. P. Jalan, “The Reduction of Zinc Oxide by Carbon: Non-Catalyzed Reaction”, Metallurgical Society of CIM, 1-5 (1977).
Rao, Y. K., “Catalysis in Extractive Metallurgy” Journal of Metals,. July, 46-50 (1983).
Satterfield C. N. and F. Feakes, “Kinetics of Thermal Decomposition of Calcium Carbonate”, A.I.Ch.E. J., 5(1), 115-122 (1959).
Skopov, G. V., G. P. Kharitidi, A. I. Tikhonov, “Reduction of Zinc from the Sulfide by Carbon in the Presence of Calcium Oxide or Calcium Carbonate”, Izv. Vyssh. Uchebn. Zaved., Tsvetn. Metall., 4, 33-37 (1976); Chem. Abstr., 85, 146312 (1976).
Szekely, J., J. W. Evans and H. Y. Sohn, “Gas-Solid Reactions”, Academic Press, New York, New York (1976).
Budavari, S. ed., “The Merck index”, 12th ed., Whitehouse Station, N.J. : Merck (1996).
Ueda, Y., T. Nakamuna and F. Noguchi, “Direct Reduction of Zinc Sulfide”, J. Min. Met. Japan, 99, 127-132 (1983).
Zhang, C., I. Asakura and O. Ogawa, “Direct Reduction of Zinc Sulfide Concenrtrate with Coal and Calcium Oxide”, J. Min. Met. Japan, 104, 469-474 (1988a).
Zhang, C., I. Asakura and O. Ogawa, “Direct Reduction of Zinc Sulfide Concenrtrate with Coal and Calcium Carbonate”, J. Min. Met. Japan, 104, 837-841 (1988b).
Zhang, C. F., S. Ryokichi, A. Iwazo, O. Osamu and R. Q. Peng, “Studies on the Rate Controlling Step for the Reduction of Zinciferous Coked Briquettes”, Metallurgical Review of MMIJ, 6(1), 38-45 (1989).
許樹恩及吳泰伯：X光繞射原理與材料結構分析，國科會精密儀器中心 (1992)。