利用蛇紋石進行二氧化碳礦化封存研究

A Study on Mineralization of Serpentine on CO2 Sequestration

陳姵如(Pei-Ru Chen)

指導教授 ： 鄭大偉

國立臺北科技大學/工程學院/資源工程研究所/碩士(2012年)

摘要

在各種CO2封存技術中,礦物封存具有:礦物蘊藏量豐富、產物不會造成環境二次污染並且產物可再利用、反應過程為自發反應等優點。蛇紋石為一種富含鎂鐵之矽酸鹽礦物，其氧化鎂含量約為36%，屬於變質岩類。是為台灣地區最重要之自產礦產之一，礦物資源估計總儲存量約為35.5億公噸，其主要產地集中在東部地區。主要利用於肥料、鍊鋼助熔劑、建築石材以及其他化學工業。
本研究旨利用蛇紋石製成鹼式碳酸鎂，探討二氧化碳封存之可能性。研究係先將蛇紋石進行焙燒破壞其結構，再以鹽酸進行萃取。探討在不同條件下鎂離子之萃取率和pH變化與氧化鎂純度之關係。再將氧化鎂溶液進行二氧化碳之吸收，討論不同溫度下之產物。
研究結果顯示，蛇紋石在700℃處理後，以1 M的鹽酸萃取，鎂萃取率能達90%。而當固液比在1:6.7以上時，萃取液之pH會由酸性轉變近中性(pH=6.5)，在此條件下產生之氧化鎂純度可達98%。而將氧化鎂之水溶液進行碳酸化，於30℃條件下可直接生成鹼式碳酸鎂沉澱物，若將反應溫度提高，生成速率亦隨之增加。

關鍵字

蛇紋石 ； 二氧化碳封存 ； 鹼式碳酸鎂

並列摘要

Among various technologies of CO2 sequestration, the advantages of mineral sequestration are abundant mineral quantities in ores, the products could be reused and no environmental secondary pollution, the reaction process as a spontaneous reaction, etc... Serpentine is a type of hydrated magnesium silicate formed mineral.It contents about 36% Magnesium oxide (MgO), and is a type of metamorphic rocks. (metamorphic rocks). Serpentine is an important mineral found in Taiwan, and is mainly distributed in the eastern Taiwan. The total estimated storage resources of Serpentine is about 3.55 billion tons.The major applications for serpentine are fertilizer, flux material for iron making, dimension stone for building decoration, and other chemical engineering usages.
The objective is to evaluate the possibility of CO2 sequestration by producing basic magnesium carbonate from serpentine. The method is first to decompose the structures of the serpentine by calcining and then to extract magnesium by leaching with hydrochloric acid(HCl). In this study, the magnesium extract rate under various conditions and the relativities of magnesium oxide(MgO) purity in pH value changes have been investigated. And then discuss the production rate of processing magnesium oxide(MgO) solution for CO2 absorption under different temperatures.
The result shows that the serpentine at 700 ℃ after extraction with 1 M hydrochloric acid(HCl), magnesium extraction rate is 90%. When the solid-liquid ratio 1:6.7 above, the pH of the extract solution is changed from the acid to nearly neutral (pH = 6.5), magnesia purity of 98% under this conditions. The processing of magnesium oxide(MgO) solution carbonated at 30 ℃, basic magnesium carbonate precipitates is generated directly; the generation rate is increased, when the reaction temperature increased.

並列關鍵字

serpentine ； Carbon dioxide ； Hydromagnesite

參考文獻

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