电热冶金法制备高品质硅的原料净化研究及炼硅初探
发布时间：2018-10-30 08:21
【摘要】：目前,全球化石能源日益枯竭,能源危机已迫在眉睫,太阳能作为一种分布广泛、安全、清洁的可再生新能源得到了快速的发展,已成为21世纪最重要的新能源。硅材料作为太阳能级电池基础原料供不应求,但多晶硅的传统制备工艺改良西门子法成本较高,且核心技术被国外垄断。冶金法制取太阳能级多晶硅与传统工艺相比具有成本低、环境友好、能耗低等优点。研究拥有自主知识产权的冶金法制备多晶硅技术对发展我国光伏产业有着重要的战略意义。本文研究了用净化原料结合电热冶金法制备高品质硅的工艺,为电热冶金法制备太阳能级多晶硅奠定基础。由于原料石油焦和硅石中的杂质都可能随着冶炼过程进入产物硅中,所以本实验首次对两种原料分别进行除杂,控制其中金属及P、B含量。主要内容包括：(1)石油焦超声酸浸除杂工艺的研究。得到优化条件为：石油焦粒径在75μm以下,酸浸时间0.5 h,液固比10：1,盐酸浓度12 wt%,酸浸温度50℃,超声功率270W,超声频率45 kHz,在此优化条件下,Fe元素的去除率达99.15%,P元素的去除率达到94.42%。超声酸浸对杂质的去除效果十分明显。(2)硅石酸浸除杂工艺的研究。通过单因素实验分别得到了超声酸浸与常规搅拌酸浸工艺的优化条件,两种优化条件下的提纯效果对比表明,超声酸浸在提纯效果和提纯速率上都具有明显优势。同时得到超声酸浸优化条件：硅石粒径在75 μm以下、盐酸浓度12 wt%、反应温度40℃、超声功率300 W、超声频率45 kHz,反应至20 min时即达到最佳浸出效果,铁的去除率达到98.97%。(3)提净化原料电热冶金法制备高品质硅可行性的探究。本文共进行两次熔炼实验：第一次选用未经净化处理的硅石和石油焦为原料；第二次选用分别经优化酸浸条件提纯的硅石和石油焦为原料,得到产物硅含量为99.74%,纯度远高于第一次开炉产物的98.02%,已超过国家A级工业硅标准,Fe、Al、Ca金属杂质含量均低于现有国家A级工业硅标准,P、B含量分别为10 ppm和6 ppm,均低于现有工业硅中磷和硼的含量。研究表明,通过对原料净化提纯来制备高品质硅的工艺是完全可行的。
[Abstract]:At present, the global fossil energy is increasingly depleted, energy crisis is imminent, solar energy as a widely distributed, safe, clean renewable energy has been rapid development, has become the most important new energy in the 21st century. As the basic raw material of solar cell, silicon material is in short supply, but the traditional preparation process of polysilicon is expensive to improve Siemens method, and the core technology is monopolized by foreign countries. Compared with the traditional technology, the preparation of solar polysilicon by metallurgical process has the advantages of low cost, environmental friendliness and low energy consumption. It is of great strategic significance to study the preparation technology of polysilicon by metallurgical process with independent intellectual property rights for the development of photovoltaic industry in China. In this paper, the preparation process of high quality silicon with purified raw materials combined with electrothermal metallurgy is studied, which lays a foundation for the preparation of solar grade polysilicon by electrothermal metallurgy. Since the impurities in petroleum coke and silica may enter into the product silicon with the smelting process, the content of metal and Pu B is controlled by removing impurity from the two raw materials for the first time in this experiment. The main contents are as follows: (1) study on ultrasonic acid leaching technology of petroleum coke. The optimized conditions are as follows: the diameter of petroleum coke is below 75 渭 m, the acid leaching time is 0.5 h, the ratio of liquid to solid is 10: 1, the concentration of hydrochloric acid is 12 wt%, the temperature of acid leaching is 50 鈩，
本文编号：2299463
[Abstract]:At present, the global fossil energy is increasingly depleted, energy crisis is imminent, solar energy as a widely distributed, safe, clean renewable energy has been rapid development, has become the most important new energy in the 21st century. As the basic raw material of solar cell, silicon material is in short supply, but the traditional preparation process of polysilicon is expensive to improve Siemens method, and the core technology is monopolized by foreign countries. Compared with the traditional technology, the preparation of solar polysilicon by metallurgical process has the advantages of low cost, environmental friendliness and low energy consumption. It is of great strategic significance to study the preparation technology of polysilicon by metallurgical process with independent intellectual property rights for the development of photovoltaic industry in China. In this paper, the preparation process of high quality silicon with purified raw materials combined with electrothermal metallurgy is studied, which lays a foundation for the preparation of solar grade polysilicon by electrothermal metallurgy. Since the impurities in petroleum coke and silica may enter into the product silicon with the smelting process, the content of metal and Pu B is controlled by removing impurity from the two raw materials for the first time in this experiment. The main contents are as follows: (1) study on ultrasonic acid leaching technology of petroleum coke. The optimized conditions are as follows: the diameter of petroleum coke is below 75 渭 m, the acid leaching time is 0.5 h, the ratio of liquid to solid is 10: 1, the concentration of hydrochloric acid is 12 wt%, the temperature of acid leaching is 50 鈩，
本文编号：2299463
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