煤矸石提铝渣制备白炭黑工艺优化及工程化设计

发布时间：2018-03-04 04:06

  本文选题：煤矸石提铅渣　切入点：硅酸钠　出处：《山西大学》2015年硕士论文　论文类型：学位论文

【摘要】：煤矸石是我国产量最大的工业固体废弃物之一,大量的煤矸石露天堆存,对生态环境造成了严重的破坏。目前煤矸石的主要利用方式以煤矸石发电、回填、生产建工、建材为主,煤矸石的利用方式粗放、利用率较低。煤矸石中含有大量A1203. Si02,从煤矸石中提取氧化铝是其高值化利用的重要途径之一,但是到目前煤矸石提铝技术大都存在过程物耗能耗高、废液废渣排放量大、二次污染严重以及产品附加值低等问题,难以实现工业化。考虑到煤矸石提铝渣中的主要成分为Si02(60～90wt.%),因此,以煤矸石提铝废渣为原料制备硅系高附加值产品成为降低煤矸石提铝工艺的废物排放、减少二次污染、实现煤矸石高值化综合利用的重要研究方向之一课题组前期研究了煤矸石提铝废渣与碳酸钠低温共熔结合高压水溶技术制备高纯度硅酸钠的新方法,在实验室制备出了高纯度、高溶解度的硅酸钠产品,探讨了废渣中氧化硅与碳酸钠低温共熔机制以及氧化铝对共熔温度、产品纯度和溶解度的影响。在此基础上,本文分析了新工艺工程化可能遇到问题,如固态熔融反应过程中硅酸钠出料难、白炭黑质量不稳定等。对以煤矸石提铝渣制备白炭黑的工艺进行了优化研究,并进行了年产3000吨白炭黑项目的设计。主要研究内容与结果如下：(1)针对工程化可能遇到的问题,提出了解决方案,优化了工艺条件：①硅酸钠在790-850℃下粘度大,静态固相反应过程中,易附着于反应器内壁,难以出料,采取回转窑动态固相反应,解决了硅酸钠的出料问题,且连续生产相较于间歇式生产存在操作方便、能耗低等优点；②煤矸石提铝渣中杂质A1203的含量,对Si02的溶出率及水玻璃质量存在着一定影响,且不同产地、批次的煤矸石组成以及铝的提取率差异显著,为了得到质量稳定的白炭黑,采取添加石英砂控制提铝渣中A1203含量的方法来保证整个工艺路线的稳定,石英砂的添加量按A1203总含量占混合物料总质量的5%计算；③采取喷雾离心干燥的方式提高白炭黑产品质量,进料固含量20%,喷雾干燥进口温度300℃、出口温度110℃。(2)进行了年产3000吨白炭黑项目的设计。首先确定了工艺流程,在此基础上对各单元操作进行了物料衡算,对主要设备进行了物料衡算,汇总得出物料平衡总表,经计算,生产1吨白炭黑可消纳煤矸石提铝渣0.68吨、消耗石英砂0.68吨、纯碱0.99吨,同时产生制砖废渣0.34吨。根据物料衡算、能量衡算的结果进行了主要设备的选型与设计,确定了主要设备的规格与型号,并绘制了工艺流程图。
[Abstract]:Coal gangue is one of the most productive industrial solid wastes in China. A large amount of coal gangue is stored in open air, which has caused serious damage to the ecological environment. At present, the main ways of utilization of coal gangue are coal gangue power generation, backfill, production and construction. The coal gangue contains a large amount of A1203.Si02.The extraction of alumina from coal gangue is one of the important ways of its high value utilization. However, at present, most of the technologies of extracting aluminum from coal gangue have many problems, such as high consumption of energy, large amount of waste residue, serious secondary pollution and low added value of products, etc. It is difficult to achieve industrialization. Considering that the main component in the aluminum extraction slag from coal gangue is Si02A6090wt., therefore, the preparation of high value-added products of silicon series from coal gangue aluminum extraction residue as raw material will reduce the waste discharge and reduce secondary pollution in the aluminum extraction process of coal gangue, One of the important research directions of realizing high value comprehensive utilization of coal gangue, a new method for the preparation of high purity sodium silicate by low temperature eutectic and high pressure water solution of waste aluminum residue and sodium carbonate from coal gangue has been studied in this paper, and a high purity of sodium silicate has been prepared in laboratory. The low temperature eutectic mechanism of silica and sodium carbonate in waste residue and the effect of alumina on eutectic temperature, product purity and solubility are discussed. For example, it is difficult to discharge sodium silicate and the quality of silica is unstable in the process of solid melt reaction. The process of preparing silica from aluminum residue from coal gangue has been optimized. The main research contents and results are as follows: (1) in view of the problems that may be encountered in engineering, the solution is put forward, and the technological conditions are optimized. The viscosity of sodium silicate is high at 790-850 鈩，

本文编号：1564037