本文探討碳酸鋰與氧化鈣存在下的硫化鋅碳熱還原反應。本反應在熱重分析儀(TGA)中進行，另外我們將反應前及反應後的固體樣品進行X光繞射(XRD)分析、碳硫分析儀(CSD)分析、元素分析儀(EA)分析、原子吸收光譜儀(AAS)分析、掃瞄式電子顯微鏡觀察(SEM)、表面積儀(SAA)分析。
實驗結果發現，加了碳酸鋰以後，反應加快約四倍；TGA、AAS、CSD及EA的實驗結果相近；SEM的結果發現含鋅粒子、碳粒子及含鈣粒子會被覆一層碳酸鋰液膜。表面積儀的結果顯示，反應初期，固體樣品的小孔表面積及平均小孔直徑大幅下降，而小孔體積大幅上揚。反應時間增長後，小孔表面積與平均小孔直徑變化趨緩，而小孔體積則大幅下滑再維持穩定。反應溫度與反應時間對小孔表面積、小孔體積及平均小孔直徑變化的影響相若。
我們提出了一個機制及模式來說明本反應。
反應動力學的探討是根據TGA數據來進行的，實驗結果指出氬氣流量不會影響鋅的生成速率，而增加反應溫度、初始C/ZnS莫爾比、初始CaO/ZnS莫爾比及初始Li2CO3/ZnS莫爾比與減少樣品高度、碳黑凝聚團大小及樣品密度會使鋅的生成速率上升。除了初始Li2CO3/ZnS莫爾比的因素外其他因素對鋅生成率的影響在添加Li2CO3觸媒與未添加觸媒的碳熱還原反應中大致相同。

Carbothermic reduction of zinc sulfide in the presence of lithium carbonate and calcium oxide was carried out in a thermogravimetic analysis system (TGA). Solid sample before and after reaction were analyzed by an X-ray diffractometer (XRD), an atomic absorption spectrometer (AAS), a carbon and sulfur determinator (CSD), an elemental analyzer (EA), a scanning electron microscope (SEM) and a surface area analyzer (SAA).
Experimental results revealed that reaction rate was enhanced about four times in the Li2CO3 catalyzed system. The results of TGA, AAS, CSD and EA were found to be close to each other. The results of SEM indicated that zinc containing grains, carbon grains and the calcium containing grains were covered by a layer of liquid film of lithium carbonate. The results of SAA indicated that the pore surface area and average pore diameter of a solid sample reduced drastically and the pore volume increased rapidly in the initial stage. When the reaction time elapsed, the changes of the pore surface and average pore diameter become mild and the pore volume reduced drastically and then remain unchanged. The effects of reaction temperature on the variations of pore surface area, pore diameter and average pore diameter were similar to that of reaction times.
A mechanism and a model were proposed to interpret this reaction.
The study on the kinetics of the carbothermic reduction was based on the data of the TGA. Experimental results indicated that the reduction rate could not be changed by the variation of argon flow rate. However, it could be increased by the reaction temperature, the initial molar ratio of C/ZnS, the initial molar ratio of CaO/ZnS, or the initial molar ratio of Li2CO3/ZnS and decreasing the sample height, the size of carbon aggregate, or initial bulk density. The effects of the operating variables, excluding the initial molar ratio of Li2CO3/ZnS, on the reaction rate in Li2CO3 catalyzed system were found to be close to those of uncatalyzed system.

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