【摘要】：目前,全球化石能源日益枯竭,能源危機已迫在眉睫,太陽能作為一種分布廣泛、安全、清潔的可再生新能源得到了快速的發(fā)展,已成為21世紀(jì)最重要的新能源。硅材料作為太陽能級電池基礎(chǔ)原料供不應(yīng)求,但多晶硅的傳統(tǒng)制備工藝改良西門子法成本較高,且核心技術(shù)被國外壟斷。冶金法制取太陽能級多晶硅與傳統(tǒng)工藝相比具有成本低、環(huán)境友好、能耗低等優(yōu)點。研究擁有自主知識產(chǎn)權(quán)的冶金法制備多晶硅技術(shù)對發(fā)展我國光伏產(chǎn)業(yè)有著重要的戰(zhàn)略意義。本文研究了用凈化原料結(jié)合電熱冶金法制備高品質(zhì)硅的工藝,為電熱冶金法制備太陽能級多晶硅奠定基礎(chǔ)。由于原料石油焦和硅石中的雜質(zhì)都可能隨著冶煉過程進入產(chǎn)物硅中,所以本實驗首次對兩種原料分別進行除雜,控制其中金屬及P、B含量。主要內(nèi)容包括：(1)石油焦超聲酸浸除雜工藝的研究。得到優(yōu)化條件為：石油焦粒徑在75μm以下,酸浸時間0.5 h,液固比10：1,鹽酸濃度12 wt%,酸浸溫度50℃,超聲功率270W,超聲頻率45 kHz,在此優(yōu)化條件下,Fe元素的去除率達99.15%,P元素的去除率達到94.42%。超聲酸浸對雜質(zhì)的去除效果十分明顯。(2)硅石酸浸除雜工藝的研究。通過單因素實驗分別得到了超聲酸浸與常規(guī)攪拌酸浸工藝的優(yōu)化條件,兩種優(yōu)化條件下的提純效果對比表明,超聲酸浸在提純效果和提純速率上都具有明顯優(yōu)勢。同時得到超聲酸浸優(yōu)化條件：硅石粒徑在75 μm以下、鹽酸濃度12 wt%、反應(yīng)溫度40℃、超聲功率300 W、超聲頻率45 kHz,反應(yīng)至20 min時即達到最佳浸出效果,鐵的去除率達到98.97%。(3)提凈化原料電熱冶金法制備高品質(zhì)硅可行性的探究。本文共進行兩次熔煉實驗：第一次選用未經(jīng)凈化處理的硅石和石油焦為原料；第二次選用分別經(jīng)優(yōu)化酸浸條件提純的硅石和石油焦為原料,得到產(chǎn)物硅含量為99.74%,純度遠高于第一次開爐產(chǎn)物的98.02%,已超過國家A級工業(yè)硅標(biāo)準(zhǔn),Fe、Al、Ca金屬雜質(zhì)含量均低于現(xiàn)有國家A級工業(yè)硅標(biāo)準(zhǔn),P、B含量分別為10 ppm和6 ppm,均低于現(xiàn)有工業(yè)硅中磷和硼的含量。研究表明,通過對原料凈化提純來制備高品質(zhì)硅的工藝是完全可行的。
[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，

本文編號：2299463