Analysis of the Composition and Properties of the Silicon Production Wet Cleaning Sludge to Identify Sustainable Techniques for its Processing

2021 ◽  
Vol 316 ◽  
pp. 649-654
Author(s):  
Andrey A. Tyutrin ◽  
Andrey S. Vologin
Keyword(s):  
Grain Size ◽  
Test Sample ◽  
Raw Material ◽  
Metallurgical Grade Silicon ◽  
Cleaning Product ◽  
Silicon Production ◽  
X Ray ◽  
Grade Silicon ◽  
Processing Techniques ◽  
Silicon Based

The paper is devoted to the urgent issue of processing the dust waste of metallurgical-grade silicon production, i.e. wet cleaning sludge, which contains a significant amount of valuable silica. The paper analyzes the formation of finely dispersed techno-genic materials that are generated in significant quantities (up to 120 t/d) at the Kremniy JSC. The composition and properties of the silicon production wet cleaning product have been studied. In analytical studies of the wet cleaning sludge samples, the modern certified analysis techniques have been used: laser diffraction, X-ray diffraction, and X-ray fluorescence. According to the analysis, the L:S ratio of liquid sludge is 2.1:1; after dehydration, the sludge cake has a grain size of 150 μm, with the prevailing (90 %) grain size of 59.65 μm in the test sample. The chemical composition of the sludge is 95.86 % SiO2; therefore, the wet cleaning sludge is a valuable raw material to produce metallurgical-grade silicon. Based on the analysis of the composition and properties of the silicon production wet cleaning sludge sample, we have developed a program for its processing. Sustainable sludge processing techniques are aimed at obtaining a briquetted charge, which can be used as an additive to the main raw material.

scholarly journals Research into the chemical composition of refinery slag from silicon production for its efficient recycling

2021 ◽  
Vol 25 (2) ◽  
pp. 252-263
Author(s):  
N. V. Nemchinova ◽  
V. V. Hoang ◽  
I. I. Aponchuk
Keyword(s):  
Chemical Composition ◽  
Crystalline Silicon ◽  
Raw Material ◽  
Smelting Process ◽  
Elemental Silicon ◽  
Silicon Production ◽  
X Ray ◽  
Industrial Material ◽  
Furnace Slag ◽  
Oxidation Refining

The aim was to investigate the chemical composition of refinery slag obtained during silicon production in order to identify approaches to its further recycling. Research samples were collected from the slag remained after oxidation refining at the JSC Silicon (AO Kremny), RUSAL (Shelekhov, Irkutsk Oblast). The methods of X-ray phase, X-ray fluorescence, metallographic and scanning electron microscopy were employed to investigate the chemical composition of the samples. It was found that the refinery slag under study includes such basic components as elemental silicon, its carbide and oxide, as well as elemental carbon. It was shown that silicon carbide is the product of incomplete reduction, resulting from melting silica-containing ores in a smelting furnace. According to the conducted X-ray fluorescent analysis, the samples also contain (wt %): Ca - 7.40; Al - 3.80; Fe - 0.30; Ba - 0.19; K - 0.14; Na - 0.09; Sr - 0.09; Mg - 0.08; Ti - 0.05; S - 0.02. Calcium and aluminium are present in the slag mostly in the form of oxides. Complex oxides of an anor-thite type were also found: CaO Al2O3 2SiO2. The refinery slag under study also features insignificant amounts of other metal oxides, which are released from the furnace slag forming during the smelting process. The slag produced by oxidation refining during crystalline silicon production is a technogenic raw material containing valuable components. Due to the significant content of silicon in the refinery slag (from 42% to 65%), the existing methods applied to recycle such an industrial material were analysed in terms of additional silicon extraction or production of commercial silicon-containing products, which are in demand in various industries.

Challenging Issues of Silicon Manufacturing Technology in Bangladesh

2020 ◽  
Vol 1 (1) ◽  
pp. 22-30
Author(s):  
Kifaet Kamal ◽  
◽  
Ashifa Akber ◽  
Md. Aminul Islam ◽  
Md. Abdus Satter ◽  
...  
Keyword(s):  
High Tech ◽  
Metallurgical Grade Silicon ◽  
Silicon Production ◽  
Carbon Reduction ◽  
Industrial Grade ◽  
Primary Element ◽  
Grade Silicon ◽  
Quality Material ◽  
High Quartz

The knowledge related to available high-quality sand deposits, Si manufacturing process and different challenging issues in manufacturing is essential for developing the silicon industry in Bangladesh, which is addressed in this article. For high-tech applications, the primary element silica needs to be 98% pure, at least. A case study in Bangladesh shows that Bipinganj sand, with the high quartz percentages, low moisture content, is suitable for the industrial-grade silicon production. No trace of Boron content has been found in the sand of Shameshwari river near Bipinganj locality. Some other potential sand deposits in Bangladesh which contain a high amount of silica are Balijuri of Sherpur district, Moulvibazar, Dakshin zangal of Hathhazari Upazila in Chittagong district, Chauddagram of Comilla district and Shajibazar of Habiganj district etc. Metallurgical grade silicon (MG-Si) is the precursor for the solar grade (SoG) and electronic-grade silicon. In photovoltaic and electronic applications, an electric arc furnace is used for the growth of MGS. Some parameters, such as furnace temperature and heat loss, need to be considered for good quality material production. MG-Si can be produced through both carbon reduction and magnesium reduction processes. Mg reduction is comparatively expensive. Silicon production from waste glasses can be a potential technology for MG-Si production in respective to Bangladesh.

Impact of Impurities in Metallurgical Grade Silicon on Removal Efficiency of Vacuum Evaporation

2011 ◽  
Vol 287-290 ◽  
pp. 1521-1525
Author(s):  
Kui Xian Wei ◽  
Wen Hui Ma ◽  
Yang Zhou ◽  
Ke Qiang Xie ◽  
Bin Yang ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Raw Materials ◽  
Vacuum Evaporation ◽  
Raw Material ◽  
Vacuum Furnace ◽  
Metallurgical Grade Silicon ◽  
Quality Product ◽  
Grade Silicon ◽  
And Performance ◽  
Volatile Impurities

Vacuum evaporation is usually utilized to remove volatile impurities in metallurgical grade silicon to prepare solar grade silicon by metallurgical routes. Especially phosphorus needs to be removed by vacuum evaporation. And the removal efficiency of impurities strongly influenced the quality and performance of products. In this paper, the removal efficiency of impurities is studied by using different raw material. The results indicated that the content of impurities in raw material had deep effect on the removal efficiency of vacuum evaporation. The high quality product can be obtained by vacuum evaporation only once from raw materials with the lower content of impurities whereas it is not for high content of impurities in raw material. This is due to the vapor-liquid equilibrium in the vacuum furnace. The impurities can be removed effectively by vacuum evaporation many times.

Removal of Iron from Metallurgical Grade Silicon with Pressure Leaching

2011 ◽  
Vol 675-677 ◽  
pp. 873-876 ◽  
Author(s):  
Ke Qiang Xie ◽  
Zhan Liang Yu ◽  
Wen Hui Ma ◽  
Yang Zhou ◽  
Yong Nian Dai
Keyword(s):  
Particle Size ◽  
Reaction Time ◽  
Removal Efficiency ◽  
Acid Concentration ◽  
Operating Conditions ◽  
Raw Material ◽  
Optimum Operating ◽  
Pressure Leaching ◽  
Metallurgical Grade Silicon ◽  
Grade Silicon

In this paper, removal of iron from metallurgical grade silicon with pressure leaching is carried out. We investigated the factors such as the concentration of hydrochloric, particle size of raw material ground, temperature, pressure and reaction time, which influenced on the removal of iron. The results show that the optimum operating conditions for pressure leaching in hydrochloride are: acid concentration 4 mol/L, diameter for raw material less than 50 μm, leaching temperature 160 0C，leaching pressure 2.0 MPa, leaching time 2.0 h. The content of iron residual in MG-Si powder was reduced to about 200 ppmw. The removal efficiency of iron is up to 90.90 %.

Reaction Mechanism and Kinetics of Boron Removal from Metallurgical-Grade Silicon Based on Li2O-SiO2 Slags

JOM ◽  
2015 ◽  
Vol 68 (9) ◽  
pp. 2371-2380 ◽  
Author(s):  
Huixian Lai ◽  
Liuqing Huang ◽  
Chenghao Lu ◽  
Ming Fang ◽  
Wenhui Ma ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Boron Removal ◽  
Metallurgical Grade Silicon ◽  
Mechanism And Kinetics ◽  
Grade Silicon ◽  
Silicon Based ◽  
Kinetics Of

Research on Removal of Boron from Metallurgical Grade Silicon by Si-Al Alloying

2010 ◽  
Vol 156-157 ◽  
pp. 1037-1040
Author(s):  
Yu Liu ◽  
Dong Liang Lu ◽  
Yu Yan Hu ◽  
Tao Lin ◽  
Yan Hui Sun ◽  
...  
Keyword(s):  
Removal Rate ◽  
Low Cost ◽  
Atomic Emission ◽  
Metallographic Analysis ◽  
Separation Procedure ◽  
Plasma Atomic Emission ◽  
Spectroscopy Analysis ◽  
Metallurgical Grade Silicon ◽  
X Ray ◽  
Grade Silicon

A low-cost process for removing boron from metallurgical grade silicon was developed by Si-Al alloying, and the separation procedure of silicon grains from Si-Al melt by solidification was investigated in this paper. The microstructure and purity of silicon were characterized and detected by metallographic analysis, energy dispersive X-ray spectrometers analysis and inductive coupled plasma atomic emission spectroscopy analysis. The results showed that the content of boron in the purified silicon decreased from 128.00 ppmw to 27.62 ppmw. In addition, the process of purification with Si-Al alloying combined with the treatment of hydrofluoric acid could remove boron to a low content of 13.81 ppmw, the removal rate of which is 89.21 %. The results indicated that the removal of boron from metallurgical grade silicon by Si-Al alloying is an efficient and prospective method.

Approaches to the development of environmentally friendly and resource-saving technology for solar-grade silicon production

MRS Advances ◽  
2019 ◽  
Vol 4 (35) ◽  
pp. 1937-1947
Author(s):  
Sergey M. Karabanov ◽  
Dmitriy V. Suvorov ◽  
Dmitry Y. Tarabrin ◽  
Evgeniy V. Slivkin ◽  
Andrey S. Karabanov ◽  
...  
Keyword(s):  
Solar Cells ◽  
Environmental Safety ◽  
Solar Grade Silicon ◽  
Resource Saving ◽  
Silicon Production ◽  
Environmentally Safe ◽  
Energy Consuming ◽  
Solar Silicon ◽  
Grade Silicon ◽  
Silicon Based

ABSTRACTCurrently, the main material for the production of solar cells is still silicon. More than 70% of the global production of solar cells are silicon based. For solar-grade silicon production the technologies based on the reduction of silicon from organosilicon compounds are mainly used. These technologies are energy-consuming, highly explosive and unsustainable.The present paper studies the technology of purification of metallurgical-grade silicon by vacuum-thermal and plasma-chemical treatment of silicon melt under electromagnetic stirring using numerical simulation and compares this technology with the existing ones (silane technologies and Elkem Solar silicon (ESS) production process) in terms of energy consumption, environmental safety and the process scalability.It is shown that the proposed technology is environmentally safe, scalable and has low power consumption. The final product of this technology is multicrystalline silicon, ready for silicon wafer production.

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.

Sign in / Sign up

Export Citation Format

Share Document