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氨基酸促进钙长石中元素浸出机理
Mechanism of amino acid promoting element leaching in anorthite
【摘要】 钙长石中的钙、镁等元素浸出速率是制约固碳过程的关键因素。相比于传统的物理和化学手段,利用微生物代谢产物促进矿物溶解具有低污染、低能耗、低成本的优势。本文采用密度泛函理论(DFT)计算与浸矿实验相结合的方式,研究了氨基酸促进钙长石中元素浸出的微观机理并比较了不同种类氨基酸对浸矿效果的影响。氨基酸分子吸附在钙长石表面后,氨基(—NH2)上的H原子通过氢键与矿物表面相互作用;羧基(—COOH)上的羟基发生断裂导致矿物表面羟基化,表面Al原子倾向于与羧基中的羰基O结合并发生电荷转移和轨道杂化。3种氨基酸浸矿效果从强至弱顺序依次为天冬氨酸、赖氨酸、甘氨酸,即酸性氨基酸、碱性氨基酸、中性氨基酸。研究结果表明:氨基酸的氢键作用和络合作用共同促进元素浸出并使得化学键发生伸缩振动,导致硅(铝)氧四面体骨架松散,加速了钙长石的溶解。
【Abstract】 The leaching rate of Ca, Mg and other elements in anorthite is a key factor restricting the carbon fixation process. Compared with traditional physical and chemical methods, the use of microbial metabolites to promote mineral dissolution has the advantages of low pollution, low energy consumption and low cost. In this paper, density functional theory(DFT) calculations and leaching experiments were used to study the microscopic mechanism of amino acid promoting element leaching in anorthite and to compare the influence of different types of amino acid on the leaching effect. After the amino acid molecules are adsorbed on the surface of anorthite, the H atoms on the amino groups interact with the mineral surface through hydrogen bonds. The hydroxyl groups on the carboxyl groups break, resulting in hydroxylation of the mineral surface. The surface Al atoms tend to combine with the carbonyl O in the carboxyl groups, and charge transfers and orbital hybridization occurs. The order of leaching effect of the three amino acids from strong to weak is aspartic acid, lysine, glycine, that is, acidic amino acid, alkaline amino acid, neutral amino acid. The results show that the hydrogen bonding and complexation of amino acid jointly promote the leaching of elements and the stretching vibration of the chemical bonds, resulting in the loosening of silicon(aluminum) oxygen tetrahedron skeleton and accelerating the dissolution of anorthite.
【Key words】 amino acid; anorthite; DFT; adsorption; leaching mechanism;
- 【文献出处】 中南大学学报(自然科学版) ,Journal of Central South University(Science and Technology) , 编辑部邮箱 ,2025年09期
- 【分类号】TD985;X701
- 【下载频次】24