膨润土提纯制备铸造型砂粘结剂试验研究

发布时间：2019-03-16 13:54

【摘要】：膨润土作为一种重要的工业矿物,广泛应用于钻井、冶金、铸造等工业领域,其中铸造用膨润土全球消耗量逐年递增。辽宁朝阳地区膨润土资源丰富,主要以生产加工铸造用土而闻名,但随着开采,地表可采的高指标原土的质量逐渐下降,目前生产铸造土的企业都面临原土指标降低与生产工艺需要改进的问题。针对上述问题,论文选取朝阳地区两种原土,利用水力旋流器提纯技术,探究每种提纯土单独钠化效果、不同配比的提纯土钠化效果,同时对比其与挤压钠化法的实验结果,通过层电荷测定分析两种土的属型。得到如下结果：通过XRD.SEM分析原矿A、B土样,对原矿进行基本性能测定,采用水力旋流器对原矿进行提纯处理,对A、B原矿进行单因素条件试验、混配、多因素正交试验等研究,确定最佳的配比方案及钠化条件并测定改型土的铸造工艺性能,分析水分、阳离子种类等因素对铸造用膨润土粘结剂的影响作用机理,测定化学成分,计算层电荷并确定A、B两种矿物属型。通过各项分析、试验过程,结果表明：XRD分析确定A、B均为典型的钙基膨润土(001)面d值分别为dA=15.0035A,dB=14.76708A；SEM分析结果显示,同样放大倍数条件下,B矿片层状更多,并且粒度比A矿更细；在最佳的提纯条件下,A、B两矿均能使蒙脱石含量达到90%以上；条件试验结果表明：A1最佳加碱量为5%,加水量为35%,陈化时间为6d；B1最佳加碱量为4%,加水量为35%,陈化时间为5d；正交试验结果表明：采用3#混配土,提纯土A1：B1=1：2的配比,进行混配,并以加碱量4%,加水量35%,陈化时间6d作为最佳的钠化条件可以制备出符合国标一级品要求的铸造用膨润土：吸蓝量40g/100g、膨胀倍23m1/2g、胶质价100m1/15g,常态湿压强度105Kp,热湿拉强度3.0Kp,复用性62.5%；两土样层电荷分析试验结果表明：A矿层电荷为1.22,属于切托型蒙脱石,B矿层电荷为0.50,属于典型的怀俄明型蒙脱石。
[Abstract]:Bentonite, as an important industrial mineral, is widely used in drilling, metallurgy, casting and other industrial fields, in which the global consumption of bentonite for casting is increasing year by year. Liaoning Chaoyang area is rich in bentonite resources, mainly known for its production and processing of foundry soil, but with mining, the quality of high-index raw soil, which can be mined on the surface of the earth, is gradually declining. At present, the enterprises producing cast soil are faced with the problems of reducing the index of raw soil and improving the production process. In order to solve the above problems, two kinds of raw soil in Chaoyang area were selected in this paper. Using hydrocyclone purification technology, the sodium effect of each kind of purified soil was investigated, and the effect of sodium purification in different proportion was studied. At the same time, the experimental results were compared with that of extruded sodium method. The types of the two soils were analyzed by layer charge measurement. The results are as follows: by means of XRD.SEM analysis of raw ore A and B soil samples, the basic properties of the original ore are determined, the original ore is purified by hydrocyclone, the single factor condition test of A and B raw ore is carried out, and the mixed match is carried out. Multi-factor orthogonal experiment was carried out to determine the optimum proportion scheme and sodium condition, to determine the casting process properties of the modified soil, to analyze the influence mechanism of moisture and cation types on bentonite binder for casting, and to determine the chemical composition of bentonite binder. The layer charges are calculated and two types of minerals A and B are determined. Through the analysis and the test process, the results show that both A and B are typical Ca-based bentonite (001) surface d value is dA=15.0035A,dB=14.76708A;, respectively. The XRD analysis confirms that A, B are typical calcium-based bentonite (001) surface d value. The results of SEM analysis show that under the same magnification, B ore sheet has more layers and finer grain size than that of A ore, and under the optimum purification conditions, both A and B ore can make the content of montmorillonite more than 90%. The results of condition test showed that the optimum dosage of Al _ 1 was 5%, the amount of water was 35%, the aging time was 6 d and B _ 1 was 4%, 35%, and the aging time was 5 days, and the optimum dosage of alkali was 5%, the amount of water was 35%, and the aging time was 5 days. The results of orthogonal test showed that the mixture of 3 # mixed soil and purified soil A1:B1=1:2 was mixed and mixed with 4% alkali and 35% water. When the aging time is 6 days, the bentonite for casting can be prepared according to the requirements of the first grade of the national standard: the amount of blue absorption is 40g / 100g, the expansion time is 23m1g / 2g, the colloid price is 100m1 / 15g, the normal wet compressive strength is 105Kp, the hot and wet tensile strength is 3.0Kp. Reusability 62.5%; The results of charge analysis of the two soil samples show that the charge of ore layer A is 1.22, which belongs to Ceto type montmorillonite, and the charge of ore bed B is 0.50, which belongs to the typical Wyoming type of montmorillonite.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD985

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