Experiment Research on Purifying Metallurgical Grade Silicon and Crystal Growth in Directional Solidification

2009 ◽  
Vol 79-82 ◽  
pp. 1213-1216 ◽  
Author(s):  
Xiang Yang Mei ◽  
Wen Hui Ma ◽  
Kui Xian Wei ◽  
Yong Nian Dai
Keyword(s):  
Crystal Growth ◽  
Directional Solidification ◽  
Crystalline Silicon ◽  
Acid Leaching ◽  
Raw Material ◽  
Metallurgical Grade Silicon ◽  
Silicon Ingot ◽  
Metal Impurities ◽  
Segregation Effect ◽  
Grade Silicon

The main raw material of solar energy is multi-crystalline silicon. Directional solidification technique is one important technological process of metallurgy purification technology for multi-crystalline silicon. It can purify metallurgical grade silicon by removing metal impurities and control crystal growth at the same time. In experiment, metallurgical grade silicon by acid leaching pre-treatment, was purified by our self-assembled directional solidification furnace. The sample was analyzed by electron-prode micro analysis (EPMA). According to the results, the removal efficiency of Fe and Al is 96.3% and 96.7%, respectively. The removing mechanism of metal impurities and the difference between theory value and experiment value were also discussed. The segregation effect in directional solidification is the reason of removing Fe, but analgesic effects of the segregation effect combined with vacuum volatilization are that of removing Al. When the silicon ingot was cooled down, lengthways section of silicon ingot was cut and etched, crystal growth was studied. The results indicate that columnar crystal growth shows diverging tendency from the bottom to the top of silicon ingots, and solidification interface shape is convex. The reasons may be the nucleation of new crystals on crucible sidewall is very serious and the pulling rate is too high.

The Influence of Cooling Water Flow to Purify the Metallurgical Grade Silicon by Directional Solidification

2013 ◽  
Vol 712-715 ◽  
pp. 784-787
Author(s):  
Tao Lin ◽  
Da Jun Zhang ◽  
Chun Yan Duan ◽  
Dong Liang Lu
Keyword(s):  
Directional Solidification ◽  
Water Flow ◽  
Removal Efficiency ◽  
Cooling Water ◽  
Experimental Results ◽  
Metallurgical Grade Silicon ◽  
Density Of Dislocations ◽  
Silicon Ingot ◽  
Metal Impurities ◽  
Grade Silicon

Directional solidification is one of the most important processes to purify the impurities in the metallurgical grade silicon. A lot of factors could influence the result of directional solidification. In this paper, we researched cooling water flow which could influence the result of directional solidification. We have studied three data of cooling water flow which influenced the results of the removal efficiency of the impurities. Experimental results showed that cooling water flow can influence the density of dislocations and twins in the ingot. The metal impurities of Al, Fe and Ca were concentrated in the middle of the silicon ingot mostly. It was inferred that the bigger cooling water flow was better to the efficiency of the purification in the experiment.

scholarly journals Pengaruh Waktu Pelindian pada Proses Pemurnian Silikon Tingkat Metalurgi Menggunakan Larutan HCl[Effect of Leaching Time on Purification Process of Metallurgical Grade Silicon by Using Acid Solution]

Metalurgi ◽  
2016 ◽  
Vol 27 (1) ◽  
pp. 1
Author(s):  
Bintang Adjiantoro ◽  
Efendi Mabruri
Keyword(s):  
Acid Solution ◽  
Extraction Efficiency ◽  
Acid Leaching ◽  
Purification Process ◽  
Metallurgical Grade Silicon ◽  
Mechanical Stirring ◽  
Metal Impurities ◽  
Grade Silicon ◽  
Impurity Elements ◽  
Leaching Efficiency

IntisariPENGARUH WAKTU PELINDIAN PADA PROSES PEMURNIAN SILIKON TINGKAT METALURGI MENGGUNAKAN LARUTAN HCl. Proses pemurnian silikon tingkat metalurgi (MG-Si)dengan menggunakan metoda pelindian asam pada konsentrasi 2,45mol/L HCl telah dilakukan dengan memvariasikan waktu pelindian pada temperatur didih (±100 °C) dan gerakan pengadukan mekanik. Hasil penelitian menunjukkan bahwa proses pelindian MG-Si dengan HCl dapat digunakan untuk menghilangkan unsur pengotor logam. Persentase hasil efisiensi ekstraksi dari unsur pengotor yang terkandung di dalam MG-Si dengan pelarutan HCl masing-masing mencapai 99,996 % untuk Al, 98,247 % untuk Ti dan 98,491 % untuk Fe pada waktu pelindian 120 jam. Sedangkan efisiensi larutan HCl terhadap unsur pengotor dengan gerakan pengadukan mekanik mencapai 99,04 %.Kata kunci : Silikon tingkat metalurgi, Pemurnian dengan proses kimia, Pelindian asam, PengotorAbstractEFFECT OF LEACHING TIME ON PURIFICATION PROCESS OF METALLURGICAL GRADE SILICON BY USING ACID SOLUTION. The purification process of metallurgical grade silicon (MG-Si) using acid leaching method at a concentration of 2.45 mol/L HCl was performed by varying the leaching time atboiling temperature ( ±100 °C) and with mechanical stirring. The results showed that the leaching process of MG-Si with HCl can be used to eliminate the element of metal impurities. The extraction efficiency of impurity elements contained in the MG-Si by HCl dissolution is 99.996 % for Al, 98.247 % for Ti and 98.491 % for Fe at leaching time of 120 hours. Whereas the leaching efficiency of HCl solution on the impurities using mechanical stirring is 99.04 %.Keywords : Metallurgical grade silicon, Chemical purification, Acid leaching, Impurities

Improving the Purity of Multicrystalline Silicon by Using Directional Solidification Method

2018 ◽  
Vol 911 ◽  
pp. 51-55
Author(s):  
Peng Ting Li ◽  
Shi Qiang Ren ◽  
Zi Long Wang ◽  
Yi Tan
Keyword(s):  
Crystal Growth ◽  
Temperature Gradient ◽  
Directional Solidification ◽  
Removal Rate ◽  
Large Temperature ◽  
Metal Impurity ◽  
Silicon Ingot ◽  
Fast Speed ◽  
Metal Impurities ◽  
Large Temperature Gradient

Large temperature gradient was introduced to improve the removal rate of metal impurity in silicon ingot during direction solidification. The concentration of metal impurities in the silicon ingot with a large temperature gradient is 0.96 ppmw. The solidification time is reduced by 20% due to the fast speed of crystal growth improved; meanwhile the purity is increased by 64%.

Effect of Defects on Electrical Property of Multi-Crystalline Silicon

2011 ◽  
Vol 148-149 ◽  
pp. 947-950
Author(s):  
Yi Tan ◽  
Ya Qiong Li ◽  
Qiang Xu ◽  
Yan Jiao Liu ◽  
Gen Xiong Hu ◽  
...  
Keyword(s):  
Carrier Lifetime ◽  
Minority Carrier ◽  
Crystalline Silicon ◽  
Raw Materials ◽  
Minority Carrier Lifetime ◽  
Metallurgical Grade Silicon ◽  
Crystalline Defects ◽  
Silicon Ingot ◽  
Grade Silicon ◽  
Influence Of Impurities

Multi-crystalline silicon ingot was prepared by directional solidification method using metallurgical grade silicon as raw materials. The influence of impurities and crystalline defects in mc-Si on the minority carrier lifetime and resistivity was investigated. The results indicate that both grain boundary and impurities play important roles in the deterioration of the minority carrier lifetime.

Comparison between slag refining processes for B removal with metallurgical grade silicon and Si–Sn alloy

2018 ◽  
Vol 115 (3) ◽  
pp. 312 ◽  
Author(s):  
Rowaid Al-khazraji ◽  
Yaqiong Li ◽  
Lifeng Zhang
Keyword(s):  
Removal Efficiency ◽  
Acid Leaching ◽  
Experimental Results ◽  
Mass Ratio ◽  
Metallurgical Grade Silicon ◽  
Clear Effect ◽  
Slag Refining ◽  
Before And After ◽  
Grade Silicon ◽  
Refining Processes

Boron (B) removal by slag refining using CaO–SiO2–CaCl2 was investigated in metallurgical-grade silicon (MG-Si) and 75 wt% Si–Sn alloy. Experiments were conducted at 1500 °C for 15 min. The microstructure was characterized before and after refining. The effects of acid leaching, basicity, and slag/Si mass ratio on B removal were investigated. Experimental results showed that acid leaching had no effect on B removal from MG-Si but had a clear effect on the refined Si–Sn alloy after slag refining. The final B concentration was highly affected by the CaO/SiO2 mass ratio with minimum value, where the content of B was reduced from 18.36 ppmw to 5.5 ppmw at the CaO/SiO2 = 1.2 for MG-Si slag refining and from 18.36 ppmw to 3.7 ppmw at CaO/SiO2 = 1.5 for 75 wt% Si–Sn alloy. Increasing the slag mass ratio by 2:1 mass ratio also increased B removal efficiency by approximately 15–20% more than an increase by 1:1.

Purification of Metallurgical-Grade Silicon by Acid Leaching

Silicon ◽  
2018 ◽  
Vol 11 (4) ◽  
pp. 1979-1987 ◽  
Author(s):  
Farzad Ebrahimfar ◽  
Mahdi Ahmadian
Keyword(s):  
Acid Leaching ◽  
Metallurgical Grade Silicon ◽  
Grade Silicon

Purification of metallurgical-grade silicon via acid leaching, calcination and quenching before boron complexation

2013 ◽  
Vol 139 ◽  
pp. 64-72 ◽  
Author(s):  
Yan-Hui Sun ◽  
Qi-Hui Ye ◽  
Chang-Juan Guo ◽  
Hong-Yu Chen ◽  
Xu Lang ◽  
...  
Keyword(s):  
Acid Leaching ◽  
Metallurgical Grade Silicon ◽  
Grade Silicon
Sign in / Sign up

Export Citation Format

Share Document