【作者】 何宾宾；

【导师】 皮振邦； 田熙科；

【作者基本信息】 中国地质大学 ， 应用化学， 2011， 硕士

【摘要】 硫酸渣是焙烧硫铁矿生产硫酸时产生的废渣,是一种工业固体污染物,但其一般含铁30-50%,是一种重要的二次铁资源。我国较早就对硫酸渣分选铁精粉进行了试验研究,一般采用磁选、重选、浮选或磁选-重选等联合流程。但是硫铁矿烧渣结构复杂,有异于天然铁矿物,这些方法获得的效果都不是很理想,烧渣中铁的回收率很低,且其中的硫和磷往往难以达到炼铁标准。为了开发与合理利用这种再生铁矿资源,本文以湖南湘西化工厂的硫铁矿烧渣为原料,采用三种新型的分选硫铁矿烧渣的方法,在原料铁品位仅有38%,硫含量高达8%的情况下,获得了铁品位较高,硫含量较低的铁精粉。主要内容和创新点如下：(1)采用熔融-酸浸法对硫铁矿烧渣进行了处理,该工艺分为熔融和酸浸两个阶段。熔融是将烧渣与氢氧化钠溶液相混合,经过高温熔融处理使硅酸盐、铝酸盐等矿物转变为可溶性化合物,然后再以水洗脱；而酸浸过程以低浓度王水为药剂,溶解大部分非铁物质,在这个过程中含铁矿物几乎不溶解,从而显著提高铁含量和降低硫含量。在试验中对每个工艺条件进行优化,确定了最佳工艺流程,并用XRD、SEM等手段对产物结构与形貌进行了表征,初步探讨了工艺的反应机理。经处理后的铁精粉中铁含量为65.01%,硫含量低于0.1%,整个工艺铁的回收率为82.12%。该法所用设备简单,工艺流程短,回收的铁精粉铁含量高,硫含量低,可以直接用于炼铁原料,值得推广应用。(2)通过水热-酸浸法对湘西化工厂的硫铁矿烧渣进行了处理,水热处理烧渣是利用水热加速了碱液和烧渣中硅酸盐矿物等之间的反应,该法提供一个在常压条件下无法得到的物理化学反应环境。试验中讨论了水热和酸浸的各种因素的试验条件,并采用XRD、SEM等手段对处理后的烧渣产品进行表征。经处理后的铁精粉的铁含量为61.19%,硫含量为0.10%,整个工艺的回收率为86.34%。(3)使用球磨-酸浸法处理硫酸渣,实现了常温常压下分选高铁低硫铁精粉的可能。球磨作用过程可用机械球磨的破碎、界面反应和扩散反应三个机理来解释。试验中讨论了球磨和酸浸的各种因素的试验条件。并采用XRD、SEM等手段对烧渣产品进行表征。通过实验获得了铁品位为57.25%,S含量为0.17%的铁精矿,回收率高达90.98%。球磨-酸浸法在常温常压条件下进行,具有生产成本低、工艺流程简单、具有易实现工业化生产等优点。(4)为了实现硫酸渣综合利用,本实验采用碱浸后的滤液为原料合成4A沸石,并采用XRD等检测手段对合成出的产品的形貌与结构进行了表征,以及通过测量白度和钙交换量对其性能进行了分析。结果表明,老化温度控制在60℃,时间为12h；晶化温度控制在90℃左右,时间为24h,可生产出指标合格的4A沸石,其Ca2+指数>295mg/g,达到了商品4A沸石一级品的要求。更多还原

【Abstract】 Pyrite cinder is the production of sulfuric acid sludge produced by roasting pyrite, it is a solid industrial pollutant. However, the content of iron is generally 30～50%, it is an important secondary resource. It has a study on producing iron with pyrite cinder many years ago in our country, In general, we treat pyrite cinder with reelection, magnetic separation, flotation or the joint of magnetic separation and reelection and so on to achieve the purpose of advancing the content of iron and reducing the content of sulfur. But the structure of pyrite cinder is complex, so the recovery rate of iron is very low and it is difficult to remove sulfur, which impact on the comprehensive utilization of pyrite slag. To develope and utilize such renewable mineral resource rationally, the pyrite cinder is provided by the chemical plant in Xiang Xi, Hunan province in this experiment. The content of iron of the pyrite cinder is only 38%, and the content of sulfur is no less than 8%. Under this situation, we adopt three kinds of ways to deal with it, and gain iron concentrate with high-content iron and low-content sulfur. The main content and innovations are as follows:(1) With fusion-acid leaching treat the pyrite cinder, this technics divide into two part—the melting and acid leaching process. Fusion is a process that mixed slag and lye, treat the impurities such as silicate turns into soluble compounds at high temperature, and then elute with water. The acid leaching process mainly rich the grade of iron and reduce the content of sulfur. We optimize the conditions of technics in trial and establish the best qualification. The appearance and structure of samples are characterized by SEM and XRD. After separation, the grade of iron concentrate can attain 65.01%, the content of sulfur can be reduced below 0.1% and the recovery is 82.12%.(2) With hydrothermal-acid leaching technics treat the pyrite cinder, which content of iron is only 38%. Hydrothermal can accelerate the reaction between lye and silicate ion. We discuss several factors about hydrothermal and acid leaching in these experiments, and characterize the treated-slag with XRD and SEM. After separation, the content of iron can attain 61.19%, the content of sulfur can be reduced 0.10% and the recovery is 86.34%.(3) With ball grinder-acid leaching technics treats pyrite cinder, this way carries out the possible treating slag under room temperature. Ball grinder can be explained with the theoretics of mechanical milling, interface reaction and diffusion-reaction. We discuss every factor about ball grinder and acid leaching processes in this experiment, and characterize the treated-slag with SEM and XRD. After separation, the content of iron can attain 57.25%, the content of sulfur can be reduced 0.17% and the recovery is about 90.98%.(4) To achieve the comprehensive utilization of pyrite cinder, zeolite 4A is synthesized using the alkali leaching filtrate, and the product structures are characterized by SEM, XRD, and their performance are analyzed by measuring the whiteness and calcium exchange capacity. The results show that the aging process is controlled at 60℃for 12h; the crystallization process is controlled at 90℃for 24h, it can produce qualified 4A zeolite, the Ca2+ index>295mg/g, which reaches a requirements with commodity 4A Zeolite-level product.更多还原