工业硅生产用碳质还原剂的研究与应用

发布时间：2018-05-05 05:17

本文选题：碳质还原剂 + 工业硅　；参考：《昆明理工大学》2017年博士论文

【摘要】：木炭因具有较高比电阻以及较高反应活性,是工业硅冶炼生产常用的碳质还原剂。木炭来源主要以砍伐大量的森林为代价,对生态环境具有严重的破坏性。石油焦较高的固定碳和较低的灰分,理论上是一种理想碳质还原剂,但因具有一定石墨化结构,尤其高温条件下极易发生石墨化,将导致其化学反应活性大幅度降低以及导电性大幅度提高,进而不利于工业硅冶炼生产。另一方面,石油焦较高的硫含量不仅对工业硅冶炼过程有重要的影响,而且高硫石油焦使用过程中会产生大量对环境有害的SO_2气体。因此,针对目前工业硅冶炼生产用碳质还原剂存在高成本、低性能以及工业硅冶炼过程高能耗等问题进行研究具有非常重要的意义。具体研究内容主要包括以下几点:(1)结合TGA和XRD分析石油焦的反应性能,研究石油焦添加剂(K_2CO_3)质量比为0.5、0.8、1.0和1.5%在CO_2气氛条件下的热反应行为,以及不同介质中(蒸馏水和无水乙醇两种具有代表性的介质)混合处理后对石油焦物理性能的影响,研究发现相同添加剂条件下,有机介质对石油焦的反应性能具有明显的改善效果,反应完成时间最大可以缩短67%。(2)真空强化高硫石油焦脱硫方法,从工艺角度系统研究了石油焦样品颗粒:350~450μm,300~350μm,180~300μm,150~180μm,125~150μm和~125μm;料层厚度:0~30mm,30~60mm和60~90mm;温度:600-1500℃(间隔为100℃);保温时间:0.5h,1.0h,1.5h,2.0h,2.5h和3.0h;真空度:10~(-2) Pa,1Pa,和100 Pa对石油焦脱硫效果,对比发现同等条件下真空条件下脱硫效果比常压下提高了约20%。结合XRD分析方法探讨了真空条件下石油焦的脱硫机理是一个石油焦中有机硫即C-S键的断裂和C-C键重新组合的一个过程。(3)通过TGA分析几种典型生物质原料反应性能,并通过研究生物质原料和石油焦混合物料比分别为:0:100,20:80,40:60,60:40,80:20和100:0的反应特性,引用了催化指数对不同生物质原料对石油焦协同反应效果进行了评估。研究结果显示同种生物质原料和石油焦不同质量比混合反应,随着生物质原料的质量比增加,混合物料化学活化能降低最大幅度达50%。通过理论计算值和实验值对比发现生物质和石油焦混合反应不仅仅是单独原料的反应加和,而他们之间发生了协同作用,其作用的机制主要是生物质原料中碱金属/碱土金属对原料中碳成分产生了催化效果。(4)通过连续生产3个多月的实验数据,系统分析了工业硅冶炼过程45%能量来源于电能。并将有效能或收益能和支付能或总能的比值既?效率来评估工业硅生产过程,表示如下:分析显示工业硅冶炼过程的?效率仅仅为30%,而其余的70%的能量通过烟气、冷却水、炉渣、炉子的辐射或热交换损失。(5)等高线方法分析了工业硅冶炼过程原料带入的主要杂质Fe_2O_3、Al_2O_3,Ca O以及微量杂质氧化物对工业硅冶炼过程电耗的影响,结果显示了主要氧化物对电耗的影响强弱顺序为:Ca OFe_2O_3Al_2O_3,微量氧化物杂质含量对工业硅冶炼过程电耗的影响强弱顺序为:Ti O_2Cr_2O_3Mg OK_2O,揭示各种杂质氧化物的熔点和对过程电耗的影响基本一致。(6)采用统计学分析方法分析了碳质还原剂工业成分对工业硅过程电耗和?效率的影响,并通过等高线分析方法分析了不同碳质还原剂组合条件下工业成分两两相互作用对工业硅冶炼过程电耗以及?效率的影响。结果显示了工业成分对电耗和?效率的影响情况:固定碳挥发分水分。另外通过人工神经网络模型预测了碳质还原剂不同工业成分对工业硅电耗值和实际电耗值之间均方根R~2=0.9393,?效率预测值和实际值之间均方根R~2=0.8723,可以看出模型可以成功应用于碳质还原剂工业成分对电耗和?效率影响的预测。(7)在明确不同碳质还原剂以及碳质还原剂中化学成分以及工业成分对工业硅生产的影响情况下。通过优化原料配比以及还原剂成分,实验制备球团碳质复合还原剂,进行物理化学性能测试分析。将其用于工业硅冶炼生产,综合分析结果显示吨硅生产成本降低50~150元,具有相对可观的经济价值。
[Abstract]:Charcoal is a common carbonaceous reducing agent in industrial silicon smelting because of its high specific resistance and high reactive activity. The source of charcoal is mainly deforestation at the cost of a large number of forests, and has serious destructiveness to the ecological environment. The high fixed carbon and low ash content of petroleum coke are ideal carbon reducing agent in theory, but it is one of the ideal carbonaceous reducing agents. Graphitization, especially at high temperature, will lead to a large reduction in chemical reaction activity and a large increase in electrical conductivity, which is not conducive to industrial silicon smelting. On the other hand, the high sulfur content of petroleum coke not only has an important influence on the process of industrial silicon smelting, but also the process of using high sulfur petroleum coke. A large number of SO_2 gases which are harmful to the environment will be produced. Therefore, it is of great significance to study the high cost, low performance and high energy consumption of the industrial silicon smelting process for the current industrial silicon smelting production. The main contents of this study include the following points: (1) the analysis of the inverse of petroleum coke with the combination of TGA and XRD. The thermal reaction behavior of petroleum coke additive (K_2CO_3) with the mass ratio of 0.5,0.8,1.0 and 1.5% in CO_2 atmosphere and the effect of mixed treatment on the physical properties of petroleum coke in different media (distilled and anhydrous ethanol two kinds of representative medium) were investigated. The reaction performance of the coke has obvious improvement effect. The maximum reaction time can shorten the 67%. (2) vacuum enhanced high sulfur petroleum coke desulfurization method. From the process point of view, the sample particles of petroleum coke are systematically studied: 350~450 mu m, 300~350 mu m, 180~300 mu m, 150~180 u m, 125~150, m and ~125 muon; temperature: 600-1500 0.5h, 1.0h, 1.5h, 2.0h, 2.5h and 3.0h, vacuum degree: 10~ (-2) Pa, 1Pa, and 100 Pa on the desulfurization of petroleum coke. The comparison of the desulfurization effect under the same conditions under the same condition was found under the same condition. The desulfurization mechanism of petroleum coke under vacuum conditions was discussed in a petroleum coke under vacuum conditions. Organic sulfur is a process of breaking the C-S bond and recombining the C-C bond. (3) the reaction properties of several typical biomass materials were analyzed by TGA, and the catalytic index was used for the petroleum coke of different biomass raw materials by studying the reaction characteristics of biomass raw materials and petroleum coke mixture ratio: 0:100,20:80,40:60,60:40,80:20 and 100:0 respectively. The results of the synergistic reaction were evaluated. The results showed that the mass ratio of the same biomass and petroleum coke was higher than that of the mixture. With the increase of the mass ratio of biomass, the maximum reduction of chemical activation energy of the mixture was 50%. and the comparison between the theoretical calculation value and the experimental value showed that the mixture of biomass and petroleum coke was not only single. The reaction of the single raw material is added, and the synergistic effect occurs between them. The main mechanism is that the alkali metal / alkaline earth metal has a catalytic effect on the carbon composition in the raw material. (4) through the continuous production of the experimental data for more than 3 months, the 45% energy of the industrial silicon smelting process is derived from the energy. The ratio of income energy and payout or total energy not only the efficiency to evaluate the industrial silicon production process, which is as follows: the analysis shows that the efficiency of the industrial silicon smelting process is only 30%, while the rest of the 70% energy passes through the flue gas, cooling water, slag, radiation or heat exchange loss of the furnace. (5) the method of contour analysis of the industrial silicon smelting process raw material into the process. The effect of the main impurities, Fe_2O_3, Al_2O_3, Ca O and trace impurity oxides on the electrical consumption of industrial silicon smelting process, shows that the order of the influence of the main oxides on the power consumption is Ca OFe_2O_3Al_2O_3, the order of the influence of the content of trace oxide impurities on the electrical consumption of industrial silicon smelting process is Ti O_2Cr_2O_3Mg OK_2O. The melting point of the kind of impurity oxide is basically the same as the influence on the process power consumption. (6) the effects of the industrial composition of the carbonaceous reducing agent on the electrical consumption and the efficiency of the industrial silicon process are analyzed by statistical analysis. The industrial composition 22 interaction under different carbonaceous reductant combination strips is analyzed by the method of contour analysis. The effects of the power consumption and efficiency of the process. The results show the effects of the industrial composition on the power consumption and efficiency: the fixed carbon volatilization water. In addition, the artificial neural network model is used to predict the R~2=0.9393, the efficiency and the actual value of the industrial silicon electricity consumption value and the actual electricity consumption value. The mean square root R~2=0.8723 can be seen that the model can be successfully applied to the prediction of the effects of the industrial components of a carbonaceous reducing agent on the power consumption and efficiency. (7) under the influence of the chemical composition and the industrial composition of different carbonaceous reductants and carbonaceous reductants on industrial silicon production, the composition of the raw materials and the reductant components are optimized. The pellet carbonaceous compound reductant is tested and analyzed in physical and chemical properties. It is used in industrial silicon smelting. The comprehensive analysis results show that the production cost of tons silicon is reduced by 50~150 yuan, which has relatively considerable economic value.

【学位授予单位】：昆明理工大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TQ127.2

【参考文献】