Kusin Faradiella Mohd, Hasan Sharifah Nur Munirah Syed, Molahid Verma Loretta M, Yusuff Ferdaus Mohamat, Jusop Shamsuddin
Department of Environment, Faculty of Forestry and Environment, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
Institute of Tropical Forestry and Forest Products (INTROP), Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
Environ Sci Pollut Res Int. 2023 Feb;30(9):22188-22210. doi: 10.1007/s11356-022-23677-3. Epub 2022 Oct 25.
Mining waste that is rich in iron-, calcium- and magnesium-bearing minerals can be a potential feedstock for sequestering CO by mineral carbonation. This study highlights the utilization of iron ore mining waste in sequestering CO under low-reaction condition of a mineral carbonation process. Alkaline iron mining waste was used as feedstock for aqueous mineral carbonation and was subjected to mineralogical, chemical, and thermal analyses. A carbonation experiment was performed at ambient CO pressure, temperature of 80 °C at 1-h exposure time under the influence of pH (8-12) and particle size (< 38-75 µm). The mine waste contains Fe-oxides of magnetite and hematite, Ca-silicates of anorthite and wollastonite and Ca-Mg-silicates of diopside, which corresponds to 72.62% (FeO), 5.82% (CaO), and 2.74% (MgO). Fe and Ca carbonation efficiencies were increased when particle size was reduced to < 38 µm and pH increased to 12. Multi-stage mineral transformation was observed from thermogravimetric analysis between temperature of 30 and 1000 °C. Derivative mass losses of carbonated products were assigned to four stages between 30-150 °C (dehydration), 150-350 °C (iron dehydroxylation), 350-700 °C (Fe carbonate decomposition), and 700-1000 °C (Ca carbonate decomposition). Peaks of mass losses were attributed to ferric iron reduction to magnetite between 662 and 670 °C, siderite decarbonization between 485 and 513 °C, aragonite decarbonization between 753 and 767 °C, and calcite decarbonization between 798 and 943 °C. A 48% higher carbonation rate was observed in carbonated products compared to raw sample. Production of carbonates was evidenced from XRD analysis showing the presence of siderite, aragonite, calcite, and traces of Fe carbonates, and about 33.13-49.81 g CO/kg of waste has been sequestered from the process. Therefore, it has been shown that iron mining waste can be a feasible feedstock for mineral carbonation in view of waste restoration and CO emission reduction.
富含含铁、钙和镁矿物的采矿废料可成为通过矿物碳酸化固定二氧化碳的潜在原料。本研究着重于在矿物碳酸化过程的低反应条件下，利用铁矿石开采废料固定二氧化碳。碱性铁矿石废料被用作水相矿物碳酸化的原料，并进行了矿物学、化学和热分析。在环境二氧化碳压力、80°C温度、1小时暴露时间、pH值为8至12以及粒径小于38至75微米的影响下，进行了碳酸化实验。该矿山废料含有磁铁矿和赤铁矿的铁氧化物、钙长石和硅灰石的钙硅酸盐以及透辉石的钙镁硅酸盐，其中氧化亚铁含量为72.62%、氧化钙含量为5.82%、氧化镁含量为2.74%。当粒径减小至小于38微米且pH值升至12时，铁和钙的碳酸化效率提高。在30至1000°C温度范围内通过热重分析观察到多级矿物转变。碳酸化产物的导数质量损失被分为四个阶段：30至150°C（脱水）、150至350°C（铁脱羟基）、350至700°C（碳酸铁分解）以及700至1000°C（碳酸钙分解）。质量损失峰值归因于662至670°C之间三价铁还原为磁铁矿、485至513°C之间菱铁矿脱碳、753至767°C之间文石脱碳以及798至943°C之间方解石脱碳。与原始样品相比，碳酸化产物的碳酸化速率高出48%。X射线衍射分析证明了碳酸盐的生成，显示存在菱铁矿、文石、方解石以及微量的碳酸铁，并且该过程已固定了约33.13至49.81克二氧化碳/千克废料。因此，鉴于废料修复和二氧化碳减排，已表明铁矿石废料可成为矿物碳酸化的可行原料。
