【作者】 罗春华；

【导师】 胡岳华； 孙伟；

【作者基本信息】 中南大学 ， 矿物加工工程， 2008， 硕士

【摘要】 本论文以河南低品位铝土矿为研究对象,考察了矿石嵌布特性和不同磨矿条件对铝土矿磨矿的影响;研究了不同药剂对铝土矿助磨和选择性磨矿的影响。并通过动电位、红外光谱等检测手段对助磨机理进行了探讨。由矿石嵌布特性可知,一水硬铝石晶体结构致密,与高岭石、伊利石等含硅脉石矿物的嵌布关系密切。一水硬铝石的嵌布特性,决定了磨矿的细度。同时,矿物的硬度、解理及岩矿的结构缺陷等均影响铝土矿的破碎行为,也影响矿物的选择性磨矿。通过磨矿条件和助磨剂添加试验发现:钢球介质尺寸和配比、磨矿时间以及磨矿浓度等条件对铝土矿磨矿有较大的影响;无水碳酸钠、六偏磷酸钠、RC对铝土矿-0.075mm粒级有较好的助磨作用,当磨矿浓度为80%时,与不加药剂相比,磨矿细度分别提高了9.23%、11.47%、9.74%。铝硅比分析表明,添加药剂后铝土矿磨矿产品中粗粒级铝硅比均有所提高,可见,所用药剂对铝土矿选择性磨矿均有一定的强化作用。助磨剂作用机理研究表明:无水碳酸钠、六偏磷酸钠和RC通过改变矿物表面电位绝对值,改变了矿浆的流变学特性,提高了磨矿效率;同时流变性的增强,弱化了软硬矿物之间的“屏蔽”和“催化”作用,强化了铝土矿的选择性磨矿。由于一水硬铝石矿物与铝硅酸盐矿物之间的结构差异,当药剂在矿物表面存在物理或化学吸附时,裂纹多的铝硅酸盐矿物较一水硬铝石更容易破碎,强化了其选择性磨矿。通过扫描电镜发现,六偏磷酸钠改变了铝土矿物颗粒表面粗糙度,有利于改变矿浆的流动性;同时颗粒表面没有明显空隙和裂缝存在,说明六偏磷酸钠在矿物表面的吸附降低了矿物颗粒的表面能,促进了缺陷裂缝的断裂。通过XRD分析发现,尿素可能通过插层作用加速了高岭石等层状结构硅酸盐矿物的破碎速度,强化了铝土矿的选择性磨矿。更多还原

【Abstract】 The dissemination characteristic and effects of different grinding conditions on grinding of Henan low grade bauxite was studied in this thesis. The effects of different reagents on promoting effect and selective grinding were studied. The mechanisms of grinding aids have been studied by measurements of Zeta potential, FTIR et al.As known from the dissemination characteristic, the crystal structure of diaspore is compact, and it possess the close relationship with the dissemination of silicon gangue minerals such as kaolinite、illite. The dissemination characteristic of diaspore determined the grinding granularity. Meanwhile, the crushing behavior and selective grinding are also impacted by the rigidity、liberation and the structure defect of the ore.The grinding condition and grinding aids addition experiments show that the steel ball size and size ratio、grinding time and grinding concentration et al. has great impaction on grinding of bauxite; Sodium carbonate、calgon and RC have better promoting effect on grinding of bauxite. Compared with no addition of reagent, when the grinding concentration is 80%, the contents of -0.075mm particles respectively increased 9.23%、11.47%、9.74%. The A/S analysis indicated that the A/S of the coarse size fraction in the grinding product improved when adding the reagents. So, the enhancing effect of the used reagents is obvious in selective grinding.The study on the mechanisms of grinding aids indicated that the surface Zeta potential was changed by adding sodium carbonate、calgon and RC, and thus lead to the modification of the pulp rheology characteristic and the improvement of grinding efficiency. At the same time, the improvement of pulp rheology characteristic decreased the screen and catalyzes effects between soft and hard minerals, strengthen the selective grinding of the bauxite. For the difference of the crystal structure between diaspore and aluminum-silicon minerals, reagent absorbed on the mineral surface, which lead to the cracked aluminum-silicon minerals are easier crush, and strengthened the selective grinding. The SEM result showed that surface roughness of bauxite mineral were changed through the addition of calgon, which are in favor of the pulp rheology characteristic alteration; and the particle surface did not exist obvious crack and interspace, which indicate the adsorption of calgon on mineral surface reduced the surface energey, and promote the flaw crack break. XRD analysis showed that the addition of urea may accelerate crushing through intercalation, thus strengthen the selective grinding of bauxite.更多还原