浮选尾煤中矿物质及镓元素富集规律的研究

发布时间：2019-05-18 05:34

【摘要】：随着细粒煤产量的提高,选煤厂浮选尾煤与日俱增,已经成为最大的工业固体废弃物之一。常规对浮选尾煤的处理利用多集中在混煤燃烧、型煤和建筑材料等方面,对尾煤中具有提纯价值的矿物质和微量元素的综合利用较少。开发浮选尾煤高效利用技术,实现浮选尾煤的高附加值利用,不仅能变废为宝,节能减排,还可以提高企业经济效益。同时也为防止环境污染,缓解我国经济快速发展带来的资源紧缺等问题具有促进作用,对我国经济、环境的可持续发展战略具有重要意义。本文以浮选尾煤为研究对象,在分析原煤中矿物质在浮选过程的迁移规律的基础上,建立了矿物质与灰分的一般数学关系;开展了以回收浮选尾煤中含量最高的高岭石为目的的试验研究,通过沉降和浮选的方法,对尾煤中高岭石进行提纯,确定最佳药剂制度和实验方案,并对浮选机理进行初步探索;在此基础上,对提纯后的高岭石精矿进行镓元素的分布和迁移规律研究,考察不同分级条件下镓元素的迁移特征,并且考察了不同煅烧-酸浸条件下镓的溶出特性,为浮选尾煤中矿物质高岭石和镓元素的提纯提供理论依据。结果如下:(1)原煤中矿物质在浮选过程的迁移规律显示,高岭石的含量y与尾煤灰分x满足二次函数y=-0.0053x2+0.9x+6.87关系,石英的含量与尾煤灰分x满足一次函数y=0.32x-1.3752,方解石的含量与尾煤灰分无明确的数学关系。随密度级增大,尾煤中矿物质含量逐渐升高;随粒度的增大,方解石含量逐渐升高,石英和高岭石含量逐渐降低。(2)浮选尾煤中高岭石的沉降和浮选提纯试验结果表明,沉降法提纯高岭石的回收率不超过35%;浮选法提纯试验中,捕收剂单独作用下,CTAB对高岭石的浮选回收率达到91.25%,精矿高岭石品位由尾煤中35.72%提高至65.19%,在六种捕收剂中达到最高。通过金属离子对阴离子捕收剂MAP-K的活化试验可知,当Fe3+用量为3×10-4mol/L时,精矿高岭石的回收率由56.69%上升至83.86%。CTAB与MAP-K混合使用条件下,高岭石的最高回收率为80%。捕收剂单独作用下的捕收能力大小顺序为:CTABDDAMAP-K油酸钠辛烷基二甲基叔胺SDBS;不同浮选体系中,高岭石浮选的回收率的效果为:CTAB(单独作用)MAP-K(Fe3+配合使用)CTAB与MAP-K混合。(3)物料性质及试验条件对高岭石浮选精矿中镓的分布的影响试验结果显示,随着样品粒度级的降低、密度级的升高,镓的含量不断提高,-0.045mm样品中镓的含量达到30.59μg/g,+1.8kg/L密度级样品中镓的含量为30.03μg/g,均达到工业利用标准;而且高岭石品位与镓的含量满足线性递增关系。对高岭石精矿进行煅烧-酸浸结果显示,在700oC下煅烧130min,并采用6mol/L的盐酸作为浸出液,在60oC浸取温度下镓溶出率为91.86%,溶出效果最佳。
[Abstract]:With the increase of fine coal output, floatation tail coal in coal preparation plant is increasing day by day, and has become one of the largest industrial solid wastes. The conventional treatment and utilization of flotation tail coal is mainly focused on mixed coal combustion, briquette and building materials, but the comprehensive utilization of minerals and trace elements with purification value in tail coal is less. The development of high efficiency utilization technology of flotation tail coal and the realization of high added value utilization of flotation tail coal can not only turn waste into treasure, save energy and reduce emissions, but also improve the economic benefit of enterprises. At the same time, it also plays an important role in preventing environmental pollution and alleviating the shortage of resources caused by the rapid economic development of our country, which is of great significance to the sustainable development strategy of our economy and environment. In this paper, the flotation tail coal is taken as the research object, and the general mathematical relationship between minerals and ash is established on the basis of analyzing the migration law of minerals in raw coal in flotation process. An experimental study was carried out for the purpose of recovering the highest content of Kaolinite in the tail coal of flotation. The method of sedimentation and flotation was used to purify the kaolinite from the tailings coal, and the optimum reagent system and experimental scheme were determined. The flotation mechanism is also explored. On this basis, the distribution and migration of gallium elements in purified Kaolinite concentrate were studied, the migration characteristics of gallium elements under different classification conditions were investigated, and the dissolution characteristics of gallium under different calcination and acid leaching conditions were investigated. It provides a theoretical basis for the purification of kaolinite and gallium elements in flotation tail coal. The results are as follows: (1) the migration law of minerals in raw coal during flotation shows that the content y of kaolinite and the content x of tail coal ash satisfy the quadratic function y=-0.0053x2 0.9x 6.87. The content of quartz and the content of tail coal ash satisfy the first order function y 鈮，

本文编号：2479726