高品位氧化锌矿氨法溶蚀浸出试验研究及机理初探

发布时间：2018-06-11 11:29

本文选题：高品位氧化锌矿 + 氨溶蚀浸出　；参考：《昆明理工大学》2015年硕士论文

【摘要】：本论文主要是针对复杂氨浸体系下高品位氧化锌矿的浸出行为及其机理进行初步研究。依托导师承担的国家自然科学基金项目,前期已经完成对低品位难处理氧化锌矿的氨溶蚀浸出-浸渣浮选试验及相关机理研究,取得了相关成果。但在前期的研究过程中,时常会遇到含一定量硫化锌矿的中高品位氧化锌矿,为了探索该类矿的氨浸行为及其机理,同时也是作为对前期研究的有益补充,以较为全面的了解各品位段氧化锌矿的氨浸行为及机理。本论文主要研究对象是含锌40.61%、氧化率为78.72%的兰坪氧化锌矿,单从品位而言,该类矿可选择的加工处理方法是比较多的,但从机理的探索而言,本论文具有一定的理论价值,可在一定程度上丰富氧化锌矿氨溶蚀浸出的理论。在对高品位氧化锌矿进行氨溶蚀浸出试验的基础上,对不同氨浸体系的浸出效果进行了研究。首先分别进行了低总氨浓度浸出和高总氨浓度浸出的试验,选择了其中浸出效果相对较好的三种不同的氨溶蚀浸出体系,即单一氨水浸出体系、氨水-氟化铵浸出体系和氨水-硫酸铵浸出体系。研究结果表明三种浸出体系的氨溶蚀浸出指标的走势规律大体一致,但浸出效果却差异较大,与之前所述及的低品位氧化锌矿的氨溶蚀浸出规律不尽相同。浸出效果最好的是单一氨水浸出体系,其对原矿锌浸出率为39.42%,对可浸出相的锌浸出率为73.47%；氨水-氟化铵浸出体系效果次之,高总氨浓度时与单一氨浸体系效果接近,对原矿锌浸出率为39.33%,对可浸出相的锌浸出率为73.29%；氨水-硫酸铵效果最差,对原矿锌浸出率为30.88%,对可浸出相的锌浸出率为57.55%。此外,通过对浸出体系的液固比、氨铵比、搅拌速度、浸出时间、浸出温度、磨矿细度等因素的研究,得出对浸出效果影响最为显著的是液固比和浸出温度。通过采用XRD、SEM-EDS、XPS等分析测试手段,对不同浸出体系的浸出机理进行了探讨。XRD分析结果表明原矿及浸渣中的硅锌矿和锌铁尖晶石均以无稳定的晶体结构的形式存在。在原矿的浸出过程中,硅酸锌可与浸出剂反应生成无定形二氧化硅,这种物质在浸出体系中的存在形式十分复杂,对锌的浸出效果有着显著的影响。当浸出体系为弱碱性时,无定形二氧化硅以不溶物形式存在,当浸出体系为强碱性时,无定形二氧化硅以多核的稳定物形式存在于浸出液中。由于原矿中锌金属含量高,推测无定形二氧化硅被溶解后浸渣表面电荷可能失衡,从而使已被溶出的硅重新变为无定形二氧化硅附着于矿粒表面并继续与铵根离子及羟基反应而被溶解,形成循环,阻碍矿石中锌的浸出。同时发现对单一氨水浸出体系,浸渣表面氨浸溶蚀痕迹明显,出现定向排列的裂痕,呈现出光滑平整的晶面,推断浸出是沿着某些晶面进行；XPS分析结果表明原矿及浸渣表面的硅元素及碳元素的原子密度变化有一定规律性,铁元素及硫元素的变化规律不明确,各元素的分峰拟合图谱也显示硅元素及锌元素在进出前后其结合能变化不大。研究得出无定形二氧化硅是浸出过程中的重要影响因素。溶液中总硅浓度([Si]T)浓度会随着总氨浓度的增加而增加,且除H4SiO4的浓度不变之外,其余形态离子的浓度都将随之增加,存在优势比较明显的硅化合物离子可能是Si3O5(OH)53-、H3SiO4-、Si2O3(OH)42-。最后,论文对硅锌矿及菱锌矿在氨溶蚀浸出过程中的配位情况进行了研究。菱锌矿与硅锌矿经浸出处理后,体系中Zn2+的配合物主要存在的pH值范围基本相同,只考虑对锌离子的浸出时,其浸出行为与矿物阴离子关系不大。其中,硅锌矿在中性或偏酸性条件下主要以Zn2+及Zn(NH3)32+形式存在,当pH升至9.246时,Zn2+主要以高配位锌配合物离子存在。由于试验所涉及的浸出体系总氨浓度较高,因此单一氨水浸出体系pH值高,根据热力学计算结果,体系中Zn2+生成高配位的Zn(OH)64-,而氨水-氟化铵浸出体系实际为缓冲溶液,体系pH值较低且稳定,Zn2+的配位反应可能由氨基或氨基与羟基共同主导。
[Abstract]:This paper mainly studies the leaching behavior and its mechanism of high grade Zinc Oxide ore under the complex ammonia leaching system. Based on the National Natural Science Foundation project undertaken by the tutor, the ammonia dissolution leaching leaching residue flotation test and related mechanism of low grade refractory Zinc Oxide ore have been completed in the earlier period, and some related achievements have been obtained. In the early research process, the medium and high grade Zinc Oxide ore containing a certain amount of zinc sulfide ore is often encountered. In order to explore the ammonia leaching behavior and its mechanism of this kind of ore, it is also a useful supplement to the previous research, so as to understand the ammonia leaching behavior and mechanism of each grade of Zinc Oxide ore in a more comprehensive way. Zinc 40.61% and the oxidation rate of 78.72% in Lanping Zinc Oxide mine, the choice of processing methods for this kind of ore is more than the grade, but from the exploration of mechanism, this paper has a certain theoretical value, which can enrich the theory of ammonia dissolution leaching of Zinc Oxide ore to a certain extent. The leaching of ammonia in high grade Zinc Oxide ore is carried out in high grade Zinc Oxide ore. On the basis of the experiment, the leaching effect of different ammonia leaching systems was studied. First, the experiments of low total ammonia concentration leaching and high total ammonia concentration leaching were carried out respectively. Three different leaching leaching systems of ammonia leaching were selected, that is, single ammonia leaching system, ammonia water ammonium fluoride leaching system and ammonia water sulphur. The results show that the trend of the ammonia dissolution leaching indexes of the three leaching systems is generally the same, but the leaching effect is different, and the law of the ammonia dissolution and leaching of the low grade Zinc Oxide ore is not the same. The best leaching effect is the single ammonia water leaching system, and the leaching rate of zinc is 39.42%. The leaching rate of the leachable phase is 73.47%, the effect of ammonia water ammonium fluoride leaching system is second, the high total ammonia concentration is close to that of the single ammonia leaching system, the leaching rate of zinc is 39.33%, the leaching rate of zinc in the leachable phase is 73.29%, the effect of ammonia water ammonium sulfate is the worst, the leaching rate of zinc is 30.88%, and the leaching rate of the leachable phase is obtained. In addition, through the study of the liquid to solid ratio of the leaching system, the ratio of ammonia to ammonium, the stirring speed, the leaching time, the leaching temperature and the grinding fineness, the most significant effect on the leaching effect is the liquid to solid ratio and the leaching temperature. The leaching mechanism of different leaching systems is explored by means of XRD, SEM-EDS, and XPS. The results of.XRD analysis show that both the zine zinc ore and the zinc iron spinel in the raw ore and the leaching residue are all in the form of unstable crystal structure. In the leaching process of the original ore, zinc silicate can react with the leaching agent to produce amorphous silica. The existence of this substance in the leaching system is very complex, and the leaching effect of zinc is significant. When the leaching system is weak alkali, amorphous silica exists in the form of insoluble substances. When the leaching system is strong alkaline, amorphous silica is found in the leach solution in the form of polynuclear stabilizers. Due to the high content of zinc metal in the original ore, it is presumed that the surface charge of the impregnated silica may be unbalance after the amorphous silica is dissolved. The dissolved silicon is reformed into amorphous silica on the surface of the ore particles and continues to be dissolved in the reaction with the ammonium ion and hydroxyl group. It forms a cycle and hinders the leaching of zinc in the ore. At the same time, a single ammonia leaching system has been found, and the surface of the leaching residue is marked with obvious corrosion marks on the surface of ammonia leaching, showing a smooth and smooth crystal. The results of XPS analysis show that the change of the atomic density of silicon and carbon elements on the surface of the raw ore and the surface of the leaching residue has a certain regularity. The change law of iron and sulfur elements is not clear. The peak fitting Atlas of each element also shows that the binding energy of the elements and the elements of the silicon and zinc have little change. It is found that amorphous silica is an important factor in the leaching process. The concentration of total silicon ([Si]T) in the solution will increase with the increase of the concentration of the total ammonia. Besides the constant concentration of H4SiO4, the concentration of the other forms of ions will increase, and the presence of silicon compounds with obvious advantages may be Si3O5 (OH) 53-, H3SiO 4-, Si2O3 (OH) 42-. finally, the coordination of znite and znzite in the process of ammonia dissolution leaching is studied. After the leaching treatment of znzite and zine, the main pH range of Zn2+ complexes in the system of Zn2+ is basically the same, only when the leaching of zinc ions is considered, the leaching behavior has little relation with the mineral anions. In the form of Zn2+ and Zn (NH3) 32+ under neutral or partial acidic conditions, when pH rises to 9.246, Zn2+ mainly exists with high coordination zinc complex ions. Because the concentration of total ammonia in the leaching system is high, the pH value of the single ammonia leaching system is high. According to the thermodynamic calculation, the high coordination level of Zn2+ is generated in the system. Zn (OH) 64-, while ammonia water ammonium fluoride leaching system is actually a buffer solution, the system pH value is low and stable. The coordination reaction of Zn2+ may be dominated by the amino or amino group and the hydroxyl group.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD952

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