矿渣中碱土金属的溶解析出特性

论文总字数：32038字

摘 要

现如今，二氧化碳作为一种温室气体已经严重影响到了生态环境的平衡。随着经济的快速的发展，我国的二氧化碳的排放量已经跃居世界前列，因此建立适合国情实际的低成本、低环境风险、高收益的二氧化碳减排技术是目前解决我国二氧化碳排放问题的最有效的途径之一。固定封存二氧化碳有很多的方法，这众多的方法中，碳酸化固定二氧化碳是最适合我国解决二氧化碳的技术途径。利用含钙镁的矿石或含钙镁矿渣通过碳酸化反应固定二氧化碳不仅可以有效的吸收二氧化碳，同时可以将那些矿石残渣有效的利用达到资源的再利用，这对我国的可持续发展有重大的意义。钙镁矿石在以醋酸为媒介进行碳酸化的过程中受到了很多因素的影响，其中钙镁矿石在醋酸溶液中的溶解过程就是一个重要的控速步骤，本文主要研究了碱土金属的溶解特性，并开展了以下研究工作：

1. 基于XRF、XRD等实验分析矿石中的钙镁等碱土金属化学结构。
2. 考察粒径、温度、酸碱度、液固比以及加热方式等工况对矿石中碱土金属的溶解析出特性影响，利用ICP光谱法对样品在各反应条件下随着时间的浓度变化，获得各条件对矿渣中碱土金属的溶解析出特性曲线。

结果显示：矿渣中含有Ca、Mg、Fe、Cr、Ni等多种元素，其中碱土金属Mg的含量的最高。碱土金属的溶解析出浓度随着颗粒粒径的减小、液固比的减小、温度的升高、醋酸浓度的升高而迅速增加。相比于水浴加热，微波加热促使碱金属更快的溶解析出。对比分析可知，酸碱度、颗粒粒径对于碱土金属镁的析出影响最大，温度的影响次之，液固比的影响最小。

关键词：二氧化碳，碳酸化固定，碱土金属，溶解析出

DISSOLUTION CHARACTERISTICS OF ALKALINE EARTH METALS IN SLAG

ABSTRACT

Today, carbon dioxide as a greenhouse gas has seriously affected the balance of the ecological environment. With the rapid economic development, China’s carbon dioxide emissions have become the top of the world. Therefore, the establishment of a low-cost, low-environmental-risk, high-yield CO₂ emission reduction technology suited to actual conditions is one of the most effective solutions to mitigate carbon dioxide. There are many methods for the storage of carbon dioxide. Of these numerous methods, carbon dioxide fixation is the most suitable technology for solving carbon dioxide in China. The use of calcium or magnesium-containing ores or slag to fix carbon dioxide through carbonation can not only effectively absorb carbon dioxide, but also can effectively utilize those ore residues to achieve the reuse of resources, which is of great significance for the sustainable development of our country. Calcium-magnesia ore is influenced by many factors in the process of carbonation with acetic acid. The dissolution process of calcium or magnesium ore in acetic acid solution is an important rate-control step. This paper mainly studied the dissolution properties of alkaline earth metals under different conditions. The main research work included:

(1) XRF, XRD analysis and experiments to analyze the chemical composition of alkaline earth metals such as calcium and magnesium in ore.
(2) Studying the dissolution characteristics of alkaline earth metals in ores, conducting experiments under different conditions such as particle size, temperature, pH, liquid-solid ratio, and heating method, and analyzing the ions concentration over time by using ICP spectroscopy Concentration measurement.

The results showed that: slag contains Ca, Mg, Fe, Cr, Ni and other elements, in which the content of alkaline earth metal Mg is the highest. Alkaline-earth metal dissolution precipitation concentration with the particle size of the particle decreases, the liquid-solid ratio decreases, the temperature increases, acetic acid concentration increases rapidly. Microwave heating causes faster dissolution and dissolution of alkali metal than water bath heating. Comparative analysis showed that pH, particle size had the greatest effect on the precipitation of alkaline earth magnesium, followed by temperature, and liquid-solid ratio had the smallest effect.

KEY WORDS: CO₂, Carbonation fixation, rare earth metal, Dissolution

目录

摘要..............................................................................................................................Ⅰ

Abstract........................................................................................................................Ⅱ

1. 绪论..................................................................................................................1
   1. 研究背景..........................................................................................................1

1.1.1 我国温室气体CO₂排放现状................................................................1

1.1.2 CO₂的封存与固定..................................................................................1

1.2 研究现状..........................................................................................................2

1.2.1 矿物碳酸化定义....................................................................................2

1.2.2 矿物碳酸化固定CO₂反应原理............................................................2

1.2.3 矿物碳酸化固定CO₂工艺....................................................................3

1.2.4 醋酸媒介间接工艺................................................................................3

1.3 主要工作..........................................................................................................4

第二章 实验方法及原理..............................................................................................5

2.1 实验样品..........................................................................................................5

2.2 实验方法..........................................................................................................6

2.2.1 实验方法................................................................................................6

2.2.2 分析方法................................................................................................7

2.3 实验仪器..........................................................................................................7

2.3.1 X射线荧光光谱分析.............................................................................7

2.3.2 X射线衍射实验分析.............................................................................7

2.3.3 电感耦合等离子体发射光谱分析........................................................8

第三章 矿渣中碱土金属析出特性..............................................................................9

3.1 颗粒粒径的影响..............................................................................................9

3.2 温度的影响....................................................................................................11

3.3 溶液酸碱度的影响........................................................................................12

3.4 液固比的影响................................................................................................14

3.5 加热方式的影响............................................................................................16

3.6 其它元素的析出特性....................................................................................18

3.7 XRD实验结果分析........................................................................................20

第四章 结论与展望....................................................................................................22

4.1 结论................................................................................................................22

4.2 展望................................................................................................................23

致谢..............................................................................................................................24

参考文献......................................................................................................................25

1. 绪论

1.1研究背景

近年来温室效应已经成为全世界共同关注的话题，特别是在2009年哥本哈根气候变化大会之后，作为造成温室效应的罪魁祸首之一的CO₂逐渐引起了人们的重视。大气中的CO₂浓度大幅度的增加，直接导致了严重的温室效应。全球气候逐渐变暖对人类生产活动和生存环境都产生了很大影响：海平面上升、大量的农作物死亡、土地荒漠化、海洋酸化、河流干涸等等。这种种后果严重威胁到了人类的生命健康，因此气候变化无疑将成为全世界共同关注的问题。

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