利用磷尾矿制备泡沫混凝土的研究

发布时间：2018-04-20 03:34

本文选题：磷尾矿 + 泡沫混凝土　；参考：《武汉工程大学》2015年硕士论文

【摘要】：磷矿是一种重要的化工矿物原料,可以用于制备磷肥、黄磷、磷酸、磷化物等人们不可缺少的产品。而在磷矿的开采利用过程当中,部分磷矿由于品位太低,很难被利用,只能作为工业废弃物处理,这些磷矿被称之为磷矿尾矿,简称磷尾矿。每生产1吨磷精矿,同时将产生0.44吨的磷尾矿。我国近年来的磷尾矿年产量都在近千万吨。大量的磷尾矿建库堆放,带来一系列的问题如:占用大量的土地,存在安全隐患,尾矿库建设和维护费用高等。目前,关于磷尾矿应用的研究有很多,如制备微晶玻璃、免烧砖等。但用于制备泡沫混凝土的研究尚少,本研究就是用磷尾矿为原料来制备GB 11968-2006 A3.5 B05级泡沫混凝土。泡沫混凝土是指对混凝土浆料采用物理、机械或化学发泡方法,然后再经过注浆成型,养护、烘干而形成的一种具有大量封闭气孔的新型轻质保温材料。近年来,随着节能成为社会的热门话题之一,泡沫混凝土以其轻质、保温、隔音、抗冲击、防火等优点而倍受人们的青睐。本课题旨在抗压强度能够达到GB 11968-2006 A3.5 B05级泡沫混凝土要求的前提下,尽可能多的掺入磷尾矿,从而进一步减小磷尾矿对环境保护的压力。本研究通过大量前期试验研究发现,容重、导热系数、线性收缩等各项指标均易达标,唯独抗压强度不易达标。故系统研究了水泥、硅灰、减水剂、硬脂酸钙、水灰比、成型温度、养护制度、磷尾矿掺量对泡沫混凝土抗压强度的影响。并得出在满足抗压强度要求的前提下,磷尾矿最多掺量为6.9wt%。当将磷尾矿进行高温煅烧后,其中的白云石相会分解生成游离的氧化钙和氧化镁,可以与二氧化硅反应从而具有一定的活性,可以作为活性集料使用。通过设计混料试验,得出在抗压强度达标的前提下,磷尾矿作为活性集料的使用量比磷尾矿直接作为惰性集料多用了8.6wt%。本文用Micro Capture对泡沫混凝土试块拍截面进行摄照片,然后结合IPP(Image Pro Plus)图像分析处理软件,通过比较几种不同的截面处理方法对孔结构参数的影响,最终确定通过用真密度、容重计算得出孔隙率;对截面用马克笔涂黑然后拍照结合IPP统计平均形状因子;在马克笔涂黑的基础上再用碳酸钙粉末将气孔填平,然后拍照结合IPP统计其平均孔径。再在此基础上,研究泡沫混凝土的孔隙率、平均孔径及平均形状因子相互间的关系及他们对抗压强度的影响和孔隙率对导热系数的影响,并拟合出数学表达式。
[Abstract]:Phosphate ore is an important chemical mineral raw material, which can be used in the preparation of phosphate, yellow phosphorus, phosphoric acid and phosphide. In the process of exploitation and utilization of phosphate ore, some phosphate ores are very difficult to be used because of low grade and can only be used as industrial wastes. These phosphate ores are called phosphate mines, for short, phosphorus tailings. 1 tons of phosphorus concentrate will be produced and 0.44 tons of phosphorous tailings will be produced at the same time. The annual output of phosphorus tailings in China is nearly ten million tons in recent years. A large number of phosphorus tailings are stacked and stacked, which brings a series of problems, such as a large number of land, hidden dangers, high construction and maintenance costs of tailings. The preparation of microcrystalline glass, no burning brick and so on. But the research on the preparation of foamed concrete is few. This study is to prepare GB 11968-2006 A3.5 B05 foam concrete with phosphorous tailings. The foam concrete is formed by the use of physical, mechanical or chemical foaming method for concrete slurry, then after grouting, curing and drying. A new type of lightweight thermal insulation material with a large number of closed holes. In recent years, as one of the hot topics in the society, foam concrete is favored by people for its advantages of light quality, insulation, sound insulation, shock resistance and fire protection. This subject is aimed at the ability to reach the requirements of the GB 11968-2006 A3.5 B05 foam concrete. As much as possible, the phosphorus tailings are added to the tailings as much as possible to further reduce the pressure on the environmental protection of the phosphorous tailings. Through a large number of previous experiments, we found that the bulk density, thermal conductivity, linear shrinkage and other indexes are easy to reach the standard, only the compressive strength is not easy to reach the standard. The effect of type temperature, curing system and the amount of phosphorous tailings on the compressive strength of the foam concrete is obtained. The maximum amount of phosphorous tailings is 6.9wt%., when the phosphorus tailings are calcined at high temperature, the dolomite phase will decompose and produce free calcium oxide and Magnesium Oxide. It has certain activity and can be used as active aggregate. Through the design of the mixture test, it is concluded that the use of phosphorus tailings as the active aggregate is more used than the phosphorous tailings as the inert aggregate on the premise of the compressive strength to meet the standard. 8.6wt%. Micro Capture is used in this paper to photograph the cross section of the foam concrete test block, and then combined with IPP (Image). Pro Plus) image analysis and processing software, by comparing the influence of several different cross section processing methods on the pore structure parameters, it is concluded that the porosity is calculated by using true density and the bulk density is calculated. The cross section is blackened with Mark pen then taking photos with IPP to statistic the average shape factor, and then using the calcium carbonate powder on the basis of the Mark pen to black the pores. The average pore size of the foam concrete, the relationship between the porosity, the average pore size and the average shape factor and their influence on the compressive strength and the effect of porosity on the thermal conductivity are studied on the basis of IPP, and the mathematical form is fitted.

【学位授予单位】：武汉工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD926.4;TU528.2

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