共查询到17条相似文献,搜索用时 265 毫秒
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电子级多晶硅生产工艺的热力学分析 总被引:1,自引:0,他引:1
基于Gibbs自由能最小原理,对SiHCl3法生产电子级多晶硅闭环工艺的3个反应子系统分别进行了化学反应平衡计算,重点对SiHCl3还原反应子系统进行了热力学分析. 对于SiHCl3还原反应子系统,适宜的操作温度为1323~1473 K,压力为0.1 MPa;温度高于1323 K,H2/SiHCl3比大于6.6,低压下有利于SiHCl3还原生产多晶硅. 针对传统的SiHCl3还原需要高温下电加热给过程操作带来的诸多不便,提出了用Cl2部分氧化使SiHCl3还原反应体系实现能量耦合的新工艺,即反应过程不需外部加热就可完成,从而节约电耗,同时还发现平衡时体系中加入的Cl2能反应完全,不会影响后序工艺的进行. 对于SiCl4转化反应子系统,高压、低H2/SiCl4比有利于生成SiHCl3. 相似文献
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随着世界和国内PV市场的快速发展,低成本、高效率的多晶硅生产方法重新受到产业界人士的关注,其中Zn还原SiCl4法因其投资成本低、转换效率高、能耗低、对环境影响小且能满足PV高纯硅的要求等优点成为研究的重点。本文从Zn还原SiCl4制取太阳能级多晶硅的原理、工艺技术以及与其他方法的比较分析可以得出Zn还原SiCl4将是今后低成本生产太阳能级多晶硅的重点发展方向。 相似文献
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单硅烷(SiH4)作为一种提供硅组分的气体源,可用于制造多种高纯度晶体硅、非晶硅、氮化硅、氧化硅及金属硅化物,详细介绍了硅化镁法和还原法制备SiH4的工艺。硅化镁法的优点是工艺简单、成熟,原料易得;其缺点是分离和回收液氨时能耗大,SiH4收率相对较低。还原法的优点是可实现连续化生产、反应易于控制。 相似文献
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太阳能级多晶硅生产技术研究现状及展望 总被引:1,自引:0,他引:1
论述了目前太阳能级多晶硅的主要生产技术研究现状,并对一些具有代表性的新工艺进行介绍.太阳能级多晶硅的生产方法主要包括改良西门子法、硅烷法、流化床法、冶金法及锌还原法.指出硅烷法和流化床法是未来多晶硅生产技术发展的趋势和方向,冶金法和锌还原法的工艺尚不够成熟,但具有潜力. 相似文献
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Production of polysilicon by chemical vapor deposition of SiHCl3 with a fluidized bed reactor is a competitive technology. As equilibrium conversion can be approached in a fluidized bed reactor, a reliable thermodynamic analysis is very important. However, inconsistent thermodynamic analysis results have been reported in the lit-erature. The present work studied the effects of thermodynamic data and species selection, and recommended that JANAF was the best Cp data source and the minimum set of species included the following eight species:H2, HCl, SiCl4, SiCl2, SiHCl3, SiH2Cl2, SiH3Cl and Si. Then, the influence of operating conditions on the equilibrium was studied. For the SiHCl3–H2 system, both the yield of silicon and selectivity to silicon reached their maximum at (up to 1100 °C), and low pressure and high H2 feed ratio were of benefit for silicon production. For the SiHCl3–SiCl4–H2 system, silicon could be produced only at 900–1400 °C, and reducing pressure and increasing H2 feed ratio enhanced the yield of silicon. Meanwhile, the operation map for zero net by-production of SiCl4 by directly recycling the produced SiCl4 was determined. 相似文献
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Yanqing Hou Zhifeng Nie Gang Xie Rongxing Li Xiaohua Yu Plant A. Ramachandran 《中国化学工程学报》2015,23(3):552-558
The modified Siemens process, which is the major process of producing polycrystal ine silicon through current technologies, is a high temperature, slow, semi-batch process and the product is expensive primarily due to the large energy consumption. Therefore, the zinc reduction process, which can produce solar-grade silicon in a cost effective manner, should be redeveloped for these conditions. The SiCl2 generation ratio, which stands for the degree of the side reactions, can be decomposed to SiCl4 and ZnCl2 in gas phase zinc atmosphere in the exit where the temperature is very low. Therefore, the lower SiCl2 generation ratio is profitable with lower power consumption. Based on the thermodynamic data for the related pure substances, the relations of the SiCl2 generation ratio and pressure, temperature and the feed molar ratio nZn=nSiCl4 ? ? are investigated and the graphs thereof are plotted. And the diagrams of KpΘ–T at standard atmosphere pressure have been plotted to account for the influence of temperature on the SiCl2 generation ratio. Furthermore, the diagram of KpΘ–T at dif-ferent pressures have also been plotted to give an interpretation of the influence of pressure on the SiCl2 gener-ation ratio. The results show that SiCl2 generation ratio increases with increasing temperature, and the higher pressure and excess gas phase zinc can restrict SiCl2 generation ratio. Finally, suitable operational conditions in the practical process of polycrystalline silicon manufacture by gas phase zinc reduction of SiCl4 have been established with 1200 K, 0.2 MPa and the feed molar ratio nZn=nSiCl4 ? ? of 4 at the entrance. Under these conditions, SiCl2 generation ratio is very low, which indicates that the side reactions can be restricted and the energy consumption is reasonable. 相似文献
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影响多晶硅质量的因素 总被引:1,自引:0,他引:1
在三氯氢硅加氢还原生产多晶硅过程中,影响产品品质的因素有:三氯氢硅提纯、三氯氢硅加氢还原和外来杂质等.多晶硅分析要求精度高而分析方法中存在不足,建议从整个多晶硅生产工艺来分析和判断多晶硅杂质产生的原因. 相似文献
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太阳能级多晶硅的制备工艺分为物理法和化学法两大类。物理法包括造渣提纯硅法、利用热交换定向凝固提纯、利用电磁感应等离子技术提纯、CP法等,其中CP法生产的太阳能级多晶硅的纯度接近于化学法。但要生产纯度大于6N的多晶硅,仍需要采用化学法。目前常用的化学法有三氯氢硅氢还原法、硅烷热分解法、四氯化硅氢还原法等。三氯氢硅氢还原法又称改良西门子法,是化学法制备太阳能级多晶硅的主流工艺,不足之处是耗能大、污染严重、运行成本较高。 相似文献
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四氯化硅的合成与精制 总被引:1,自引:0,他引:1
重点介绍了四氯化硅的制备及精制工艺。四氯化硅的工业制备方法主要有硅铁氯化法、废触体氯化法、硅氢氯化法、二氧化硅氯化法等,并分别介绍了各方法的特点。其精制方法主要有吸附法、反应法、精馏法以及这些方法的组合。通过采用2级精馏方法可得到光纤级高纯四氯化硅,同时介绍了高纯四氯化硅的充装和质量标准。此外,还简要介绍了四氯化硅的应用、经济概况及展望。 相似文献
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介绍了山东铁雄冶金科技集团有限公司硫膏和脱硫废液原有处理工艺状况及存在问题。技术改造后采用富氧燃烧高温裂解及二转二吸干法制酸工艺,将硫膏和脱硫废液制成硫酸产品。该30 kt/a硫膏和脱硫废液制酸装置包括预处理、净化、干吸、转化、尾气处理等工序,装置投产后运行稳定,SO2总转化率大于99.85%,制酸尾气流量7800~8000 m3/h,外排尾气ρ(SO2)<200 mg/m3,硫酸雾(ρ)小于5 mg/m3。净化副产w(H2SO4)2%~4%稀酸2.2~2.6 t/h,在硫铵工序全部回收利用。硫膏和脱硫废液制酸既无害化处理了焦化副产硫膏和脱硫废液,又回收了硫资源,具有良好的经济效益和社会效益。 相似文献