红柱石的浮选分离技术及机理研究

【作者】 周灵初；

【导师】 张一敏；

【作者基本信息】 武汉科技大学 ， 化学工艺， 2010， 博士

【摘要】 红柱石是一种无水铝硅酸盐矿物。它与蓝晶石,硅线石的化学组成相同,但结构相异,属蓝晶石族矿物。它是一种新型的高级耐火材料,也是优良的硅铝合金原料和技术陶瓷原料。在我国它属正在开发利用的非金属矿种,而浮选是细粒红柱石的主要选矿方法之一。论文以红柱石与其伴生矿物(主要为石英和黑云母)的晶体结构差异为基础,通过晶体结构分析、量子化学计算、结合矿物表面Zeta电位测定、光电子能谱分析、红外光谱分析、药剂吸附量测定以及浮选试验等各种方法,系统地研究了红柱石及其伴生矿物的晶体结构、表面性质和浮选行为三者之间的关系,研究了不同类型浮选药剂体系中红柱石及其伴生矿物的浮选行为,以及浮选药剂在红柱石及其伴生矿物表面的作用机理。研究内容与结果如下:1.红柱石及其伴生矿物晶体结构和表面性质主要存在以下差异当矿物破碎后,红柱石表面主要区别于石英和黑云母的地方是在红柱石晶体表面上有为数较多的未被补偿的铝离子,这种情况使得有可能利用阴离子捕收剂进行红柱石选择性浮选。2.采用阴离子捕收剂浮选体系十二烷基磺酸钠易与铝离子发生受电荷控制的化学作用,不易与矿物表面的硅离子发生作用。因而十二烷基磺酸钠易于吸附于红柱石表面,不易吸附于石英和黑云母表面。研究提出了红柱石矿酸法浮选工艺。该工艺采用石油磺酸钠为捕收剂,淀粉为抑制剂,在酸性矿浆条件下﹙pH=3～4﹚,通过三次粗选三次精选的开路浮选流程,并对浮选精矿进行强磁选,最终可获得产率为20.31%,Al2O3品位为56.53%,红柱石品位为93.79%,红柱石回收率为65.73%的合格红柱石精矿。研究表明,采用十二烷基磺酸钠作捕收剂,用淀粉作抑制剂,在酸性条件下,淀粉对被金属离子活化了的石英和黑云母有较强抑制效果,淀粉的基本作用是去活作用,其去活的原因是取代和与金属离子生成化合物之故。3.采用阳离子捕收剂浮选体系在阳离子捕收剂浮选体系中,矿物表面荷电机理的不同是导致红柱石与其伴生矿物石英和黑云母可浮性差异的主要原因。以十二胺为捕收剂,在矿浆自然pH值﹙7左右﹚条件下,采用一次粗选,五次扫选的开路反浮选工艺流程,最终获得产率为36.20%,Al2O3品位为48.33%,红柱石品位为73.48%,红柱石回收率为61.50%的红柱石精矿,精矿质量达不到Ⅱ级品标准。4.捕收剂与矿物表面作用机理研究结果本文采用量子化学计算方法从微观角度深入研究了十二烷基磺酸钠与红柱石的作用机理,得出结论:十二烷基磺酸根离子与红柱石表面不同位置的Al原子结合后,体系的总能量均会降低,十二烷基磺酸根离子在红柱石表面可以发生化学吸附,电子从红柱石表面的Al原子流向十二烷基磺酸根离子上的O原子。采用表面电性测定,浮选解吸试验及红外光谱等手段对十二烷基磺酸钠与红柱石及其伴生矿物的相互作用机理进行了系统的试验研究,通过研究得出以下结论:对于红柱石矿阴离子捕收剂浮选体系,十二烷基磺酸钠在pH值3～4之间主要为十二烷基磺酸根离子以离子键相互作用形式吸附在矿物表面,存在十二烷基磺酸根离子直接与铝离子以离子键相互作用的化学吸附,磺酸盐类捕收剂在红柱石表面上的固着是物理和化学两种吸附共存;磺酸盐在石英上和黑云母表面上的吸着,则是借助于库仑力和碳氧基的缔合作用的物理吸附;磺酸盐捕收剂在红柱石伴生矿物上的物理吸附强度低决定了精选作业的效率会很高。总结量子化学计算结果和吸附产物测试结果,可以得出:十二烷基磺酸钠在pH值3～4之间主要以十二烷基磺酸根离子形式吸附在红柱石矿物表面,存在十二烷基磺酸根离子直接与铝离子以离子键相互作用的化学吸附。另外,表面吸附点的多少决定了红柱石、石英和黑云母三种矿物的可浮性差异。更多还原

【Abstract】 Andalusite is an anhydrous aluminum-silicate mineral. Although it has the same chemical composition with kyanite and sillimanite, however, andalusite has totally different structures from those and thus it has different physical properties. Andalusite is good for silicon-aluminum metal and technical-ceramic as well as the best refractory. It is a non-metallic mineral being developed in our country, while flotation is one of the most commonly used beneficiation methods for fine-grained andalusite.Based on the differences in the crystal structure of the andalusite and its associated minerals (mainly quartz and biotite), this dissertation presents an attempt of a systematic study of the relationship among crystal structure, surface properties and flotation behavior of the andalusite and its associated minerals by various methods of analyzing crystal structure, quantum chemical calculating, measuring Zeta potential of the mineral surface, photoelectron spectroscopy, infrared spectroscopy, pharmaceutical absorption and flotation tests, aiming to make a comparative study on the flotation behavior of andalusite and its associated minerals in different types of flotation agents and interaction mechanism in the surface of andalusite and its associated minerals. The research contents and results of the tests are summarized as the following:1. There exist some differences on crystal structures and surface properties of andalusite and its associated mineralsAfter the mineral is broken, surface of andalusite differentiates from that of quartz’s and biotite’s because there are a relatively larger number of non-compensated aluminum ions on the crystal surface of andalusite, which makes it possible to use anionic-collector to float andalusite selectively.2. Adopting the anionic-collector flotation systemSDS tends to interact chemically with aluminum ions, which are controlled by electric charge, rather than silicon ions, and thus SDS is easier to be absorbed on the surface of andlusite rather than that of quartz and biotite.This dissertation describes a new technique on acid floatation of andalusite. In the test, petroleum sodium sulphonate is used as the collector and starch as the depressant. By means of the open floatation circuit consisting of 3-stages of rougher followed by 3-stages of cleaner with pH value between 3 and 4 of the acid pulp and a magnetic separation of flotation concentrate, a qualified andalusite concentrate with mass recovery of 56.53%, grade of A12O3 93.79%, grade of andalusite 93.79%, andalusite recovery 65.73%, is finally obtained.The results have shown that the mechanism of the depression of quartz and biotite by starch is deactivation with SDS as collector under acid condition. Starch may react with the activating metal ions in the aqueous environment to prevent the ions from adsorbing and thus activate quartz or biotite surfaces. It may also react with the metal ions adsorbed on quartz or biotite surfaces by either stripping them from the surfaces or forming hydrophilic compounds on the surface.3. Adopting the cationic-collector flotation systemIn the cationic-collector flotation system, different charging mechanism on the mineral surface is the primary factor to determine different floatability for andalusite and its associated minerals: quartz and biotite. By way of the inverse flotation consisting of 1-stages of rougher followed by 5-stages of scavenging in natural pH (around 7) of the slurry, an andalusite concentrate with mass recovery of 36.2%, grade of A12O3 48.33%, grade of andalusite 73.48% and andalusite recovery 61.50%, is finally obtained, when dodecylamine is used as the collector, Thus, this concentrate cannot meet the specifications of Level II.4. Investigations from interaction mechanism of collector and the mineral surfaceThis thesis studied in details the interaction mechanism of SDS with andalusite by means of quantum chemical calculation method. The following conclusions can be made: when dodecyl sulfonic acid ion is combined with Al atoms on the surface at different locations of andalusite, the total energy of the system is decreased, and dodecyl sulfonic acid ion in andalusite surface can produce chemical adsorption, so electrons are transferred from Al atom of andalusite (electron donors) to O atoms of SDS(acceptor). Adopting surface electrical measurement, flotation desorption test and IR means to studied the interaction mechanism of SDS with andalusite and associated minerals in detail, the conclusions were gained in the following:In the anionic-collector flotation system, sodium dodecyl sulfate is absorbed on the surface of the mineral in form of ionic bond interaction with pH value between 3 and 4. Therefore, there exists chemical absorption in which SDS ions are directly interacted with aluminum ions in form of ionic bond. On the other hand, sulfonate collector fixing on the surface of andalusite is a combination of physical and chemical absorption; Sulfonate being absorbed on the surface of quartz and biotite is a physical adsorption with the aid of Coulomb force and oxygen-based associating interaction. The low intensity of physical adsorption of the sulfonate-collectors on the surface of the andalusite’s associated minerals determines the high efficiency of the cleaning operation.From quantum chemical calculation and the testing results of adsorption product, we can conclud that SDS is adsorbed on the surface of andalusite mainly in the form of dodecyl sulfonic acid ion under pH value between 3 ~ 4, and the interaction between dodecyl sulfonic acid ion with aluminum ion exists chemical adsorption directly. In addition, the surface adsorption point numbers determine the flotability.differences of the three minerals, such as andalusite, quartz and biotite.更多还原