铜渣提铁综合利用试验研究

发布时间：2017-12-27 04:08

本文关键词：铜渣提铁综合利用试验研究　出处：《西安建筑科技大学》2016年硕士论文　论文类型：学位论文

【摘要】：目前我国铜产量的90%以上均为火法冶炼生产,火法冶炼生产1t精铜将产出2.2t左右渣。2015年底我国精炼铜产能为1056万吨,按这个产能计算,我国2015年就产出2300万吨的冶炼铜渣,这些铜渣不仅占用大量的土地,铜渣中含有的各种碱性重金属还污染土地和当地环境。通过对甘肃某厂提供的铜渣进行化学分析,发现铜渣中含有多种有价金属,特别是铁元素含量可达40%,高于我国很多矿石品位。如果可以有效的回收利用铜渣中的铁,仅2015年所产铜渣就可以回收近1000万吨铁。由此可见,回收利用铜渣中的铁可以减轻当地铜渣堆存占地和环境污染问题。本课题以此铜渣为原料,对铜渣进行理化分析和矿相分析,探讨相关因素对铜渣直接还原和熔融还原提铁的影响,以获得实验室条件下铜渣提铁的最优影响参数,为后续的半工业化和工业化生产提供理论指导和基本的实验数据。现有铜渣中的铁的赋存形式主要是铁橄榄石(Fe2SiO4),铁橄榄石稳定性高且还原性能差,如果直接进行提铁实验,铜渣碱度仅为0.4,铜渣中FeO活度较低,阻碍还原反应的进行,在此碱度条件下的还原开始温度可达1042.2K,加大了还原成本,因此在铜渣提铁前需要对试样进行改质处理,调整铜渣的碱度。实验中发现,向铜渣中添加一定量的CaO,可以使铜渣中的铁橄榄石中稳定的SiO2被替换,降低了还原反应的开始温度,且随着CaO的加入,熔池碱度增加,FeO活度随之增加。但过量的CaO会使渣黏度增加,阻碍反应的进行;此外,利用动力学知识对影响熔融还原反应的因素进行分析,发现随着温度的增加,渣的黏度会随之降低,从分子理论讲,渣黏度降低,反应的动力学条件得到改善,铁的还原率上升,但无限升高温度并不能无限提高反应速率,当温度超过一定范围,还原反应达到平衡,此时继续升高温度对反应影响不大。因此,实验中对温度和碱度对提铁反应的影响进行了优化实验研究。此外,因铜渣改质需要调整碱度添加CaO和还原剂煤粉,所以需要对其造球工艺进行研究,判断改质后铜渣的成球性能及生球性能。经过对铜渣造球工艺包括加水加料方法和造球机的控制方法的改善,对利用铜渣生产的生球进行测试,发现通过向铜渣中添加2%的膨润土可以增加生球的强度,且在碱度为1.0、1.2时,生球性能包括落地强度、抗压强度和爆裂温度、干燥后生球的抗压强度均可以满足生产要求。利用球团继续冶炼试验,利用控制变量的方法对试验结果进行分析,发现每100g铜渣配28.08gCaO即铜渣碱度达到1.2时,添加13.3g的煤进行还原,还原温度1450℃并保温50min的条件下,铁还原率最高,渣铁分离效果最好。在此条件下进行半工业化实验,可得到铁还原率80.9%的效果,达到实验目的。
[Abstract]:At present, more than 90% of the copper production in China is produced by fire smelting, and the production of 1t fine copper by fire smelting will produce about 2.2t slag. At the end of 2015, the capacity of China's refined copper was 10 million 560 thousand tons. According to this capacity calculation, China produced 23 million tons of smelting slag in 2015. These copper slag not only occupied a lot of land, but also all kinds of alkaline heavy metals contained in copper slag, which also pollute the land and the local environment. Through chemical analysis of copper slag from a factory in Gansu, it is found that copper slag contains a variety of valuable metals, especially iron content, up to 40%, which is much higher than that of many ore grades in China. If iron can be recovered and utilized effectively in copper slag, nearly 10 million tons of iron can be recovered in 2015 only. Thus, the recycling of copper slag in iron copper slag can reduce the local storage area and the problem of environmental pollution. This topic this copper slag as raw material, chemical analysis and mineral phase analysis of copper slag, and explore the related factors of copper slag reduction and smelting reduction iron extraction effect, in order to obtain the optimal laboratory conditions of copper slag iron parameters, to provide theoretical guidance and experimental data for the semi industrialization and industrialized production subsequent. The existing forms of iron existing in copper slag is mainly iron olivine (Fe2SiO4), fayalite high stability and reduction of poor performance, if the direct iron extraction experiment, copper slag basicity is 0.4, copper slag in FeO activity is low, hindering the reduction reaction, start the temperature up to 1042.2K under the condition of reduction in alkalinity increase the cost reduction, therefore, need to put in copper slag samples modified iron, copper slag alkalinity adjustment. It was found in experiment that adding a certain amount of CaO to copper slag can make the stable SiO2 in iron slag of copper slag be replaced, and reduce the starting temperature of reduction reaction. With the addition of CaO, the basicity of molten pool increases, and the activity of FeO increases. But excessive CaO may make the slag viscosity increase, which hindered the progress of the reaction; in addition, the factors influencing on the reduction reaction of melt using the dynamic analysis of knowledge, it is found that with increasing temperature, the viscosity of slag decreases from the molecular theory, the slag viscosity decreased, the dynamic reaction conditions are improved, the reduction rate of iron rise, but infinite temperature does not infinitely increase the rate of reaction, when the temperature exceeds a certain range, balanced reduction reaction, this continues to increase in temperature has little effect on the reaction. Therefore, the effect of temperature and alkalinity on the reaction of iron extraction was studied in the experiment. In addition, copper slag needs to adjust the alkalinity and increase CaO and reductant powder. Therefore, it is necessary to study its pelletizing process and determine the pelletizing property and pellet property of copper slag after modification. After the copper slag pelletizing process control method comprises water feeding method and balling machine improved, tested using copper slag production ball, found by adding 2% to the copper slag in bentonite can increase the green ball strength, and the basicity is 1 and 1.2, the compressive strength of green ball the performance including landing strength, compressive strength and burst temperature, after drying the ball can meet the production requirements. The pellet to smelting test, the test results were analyzed by the method of controlling variables, found that each 100g 28.08gCaO copper copper slag with basicity of slag reached 1.2, adding 13.3g coal reduction, reduction temperature of 1450 DEG C and the insulation of 50min, iron reduction rate is the highest, the best slag iron separation effect. Under the conditions of semi industrialization under this condition, the effect of iron reduction rate of 80.9% can be obtained, and the experimental purpose is achieved.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X758;TF56

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