IMPROVING THE QUALITY OF SILICON METAL BY THE METHOD OF X-RAY RADIOMETRIC SEPARATION OF RAW MATERIAL AND FINISHED PRODUCTS Текст научной статьи по специальности «Технологии материалов»

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Original article / Оригинальная статья DOI: http://dx.doi.org/10.21285/1814-3520-2020-5-1137-1149

Improving the quality of silicon metal by the method of x-ray radiometric separation of raw material and finished products

Nikolay N. Zobnin*,**, Sergey V. Korobko**, Dmitry L. Vetkovsky*, Andrey A. Moiseev*, Aleksandr O. Aganin*, Asylbek Kh. Nurumgaliev*, Irina A. Pikalova*

*Karaganda State Industrial University, Department of Metallurgy and Materials Science, Temirtau, Kazakhstan

**Tau-KenTemir LLP, Karaganda, Kazakhstan

Abstract: In this research, we investigate the process of X-ray radiometric separation of both raw materials (quartz, carbonaceous reducing agent) used for silicon smelting in ore-smelting furnaces and the resulting smelting products. The research objects were quartz from the Aktas field (Kazakhstan), coal from the Shubarkol field and silicon metal of various grades smelted at the Tau-Ken Temir LLP (Karaganda, Kazakhstan). X-ray diffraction analysis was performed using a Philips powder diffractometer. To determine the SiO2 and Fe2O3 content, an ARL PERFORM'X X-ray fluorescence spectrometer was used. To remove impurities, a CPF1-150М single-strand radiometric separator was used. We found that the radiometric separation of original quartz samples with the Fe2O3 content of ~ 0.1-0.15% produces pure quartz with the Fe2O3 content of < 0.05% and a yield of 65-70%. Provided that the Fe2O3 content in the original quartz sample does not exceed 0.5%, concentrates with the Fe2O3 content of 0.05% and a yield of 35-55% can be obtained. The yield of pure quartz with the Fe2O3 content of 0.01% does not exceed 15 -20%. The use of radiometric separation is established to reduce the amount of phosphorus in the final product by 2-3 times. This method is effective for obtaining coal concentrates of varying ash content (2.0, 4.1 and 7.3%); the resulting concentrated product obtained with a yield of 25% contains 1.5% of ash. Separation of silicon metal (with the initial iron content of 1.2-1.5%) yields a product matching silicon grade 773 (product yield ~ 50%), 553 (~ 35%) or 441 (20%). It is concluded that radiometric separation allows the content of impurities in quartz, silicon metal and coal ash to be reduced, thus facilitating the production of higher-grade silicon.

Keywords: quartz, coal, silicon metal, X-ray radiometric separation, impurity removal

Acknowledgements: The authors express their deep gratitude to the top managers of JSC Tau-Ken Samruk National Mining Company, the parent company of Tau-Ken Temir LLP. We appreciate the help of R.A. Akberdin, the Chief Production Officer of the JSC Tau-Ken Samruk National Mining Company, who supported the funding of this research within the contract no. 472/РРС-18 as of November 19, 2018 "Investigation of the possibility of separating lump technical silicon from a slag dump of silicon production and improving the quality of coal based on the technology of X-ray radiometric separation". We thank all the operators and employees of Tau-Ken Temir LLP, employees of Irgiredmet JSC (Irkutsk, Russia), who showed patience and understanding in carrying out this work and we hope to continue mutually beneficial cooperation.

Information about the article: Received August 10, 2020; revised September 22, 2020; accepted for publication on October 30, 2020

For citation: Zobnin NN, Korobko SV, Vetkovsky DL, Moiseev AA, Aganin AO, Nurumgaliev AKh, Pikalova IA. I mproving the quality of silicon metal by the method of x-ray radiometric separation of raw material and finished products. Vestnik Irkutskogo gosudarstvennogo tehnicheskogo universiteta = Proceedings of Irkutsk State Technical University. 2020;24(5): 1137-1149. https://doi.org/10.21285/1814-3520-2020-5-1137-1149

ВЕСТНИК ИРКУТСКОГО ГОСУДАРСТВЕННОГО ТЕХНИЧЕСКОГО УНИВЕРСИТЕТА 2020;24( 5):1137-1149

УДК 669.782

Повышение качества металлического кремния методом рентгеновского радиометрического разделения сырьевых

и готовых продуктов

© Н.Н. Зобнин***, С.В. Коробко**, Д.Л. Ветковский*, А.А. Моисеев*, А.О. Аганин*, А.Х. Нурумгалиев*, И.А. Пикалова*

*Карагандинский государственный индустриальный университет, г. Темиртау, Казахстан **ТОО «Tau-Ken Temir», г. Караганда, Казахстан

Резюме: Цель - исследовать процесс рентгенорадиометрического разделения сырьевых материалов (кварца, углеродистого восстановителя), используемых для выплавки кремния в руднотермических печах, и самого продукта плавки. Объектами исследования явились кварц месторождения Актас (Казахстан), уголь Шубаркульского месторождения и металлический кремний различных марок, выплавленный в ТОО « Tau-Ken Temir» (г. Караганда, Казахстан). Рентгенофазовый анализ проводили с помощью порошкового дифрактометра фирмы « Philips». Для определения содержания SiO2 и Fe2O3 использовали рентгенофлюоресцентный спектрометр ARL PER-FORM'X. Для удаления примесей применяли одноручьевой рентгенорадиометрический сепаратор типа СРФ1 -150М. Установлено, что при радиометрическом разделении образца исходного кварца с содержанием Fe 2O3 ~ 0,10-0,15% обеспечивается получение чистого кварца с содержанием Fe 2O3 менее 0,05% при выходе продукта 65-70%. При содержании в исходном кварце Fe2O3 до 0,5% также возможно получение концентратов с содержанием Fe2O3 0,05% при выходе чистого продукта 35-55%. Чистый кварц с содержанием Fe2O3 0,01% возможно получить с выходом лишь 15-20%. Показано, что при использовании радиометрического метода разделения достигается уменьшение фосфора в кварце в 2-3 раза. Уголь с различной зольностью (2,0, 4,1 и 7,3%) эффективно обогащается предложенным методом с получением концентрата, содержащего 1,5% золы, при выходе 25%. При обогащении металлического кремния (с исходным содержанием железа 1,2-1,5%) может быть получен продукт, соответствующий сорту кремния 773 (с выходом продукта ~ 50%), сорту 553 (с выходом ~ 35%) или сорту 441 (с выходом 20%). Радиометрический метод обогащения материалов позволяет снизить содержание основных примесей в кварце, металлическом кремнии и золе угля, что способствует получению кремния высших марок.

Ключевые слова: кварц, уголь, металлический кремний, рентгено-радиометрическое разделение, удаление примесей

Благодарности: Авторы выражают огромную благодарность руководству АО «Национальная горнорудная компания «Тау-Кен Самрук», которая является материнской компанией ТОО «Tau-Ken Temir». Особую благодарность выражаем генеральному директору по производству АО «НГК Тау-Кен Самрук» Акбердину Р.А., который поддержал финансирование исследований в рамках исполнения контракта № 472 / РРС-18 от 19 ноября 2018 г. по теме: «Исследование возможности разделения кускового технического кремния из шлакоотвала кремниевого производства и повышения качества углей на основе технологии рентгенорадиометрической сепарации». Благодарим всех операторов и сотрудников ТОО «Tau-Ken Temir», сотрудников АО «Иргиредмет» (г. Иркутск, Россия), проявившим терпение и понимание при проведении данной работы, и надеемся на продолжение взаимовыгодного сотрудничества.

Информация о статье: поступила в редакцию 10 августа 2020 г.; поступила после рецензирования и доработки 22 сентября 2020 г.; принята к публикации 30 октября 2020 г.

Для цитирования: Зобнин Н.Н., Коробко С.В., Ветковский Д.Л., Моисеев А.А., Аганин А.О., Нурумгалиев А.Х., Пикалова И.А. Повышение качества металлического кремния методом рентгеновского радиометрического разделения сырьевых и готовых продуктов. Вестник Иркутского государственного технического университета. 2020. Т. 24. № 5. С. 1137-1149. https://doi.org/10.21285/1814-3520-2020-5-1137-1149

INTRODUCTION

Silicon is widely used for various industrial purposes, e.g. as an agent for casting alloys, silicon bronzes, steel and cast iron or as a basis for obtaining organosilicon compounds, poly-crystalline silicon and materials for 3D technolo-

gies [1-6]. The production of metal silicon in ore-smelting furnaces is steadily increasing globally, thus stimulating research into the development of novel smelting technologies based on the use alternative raw materials for improving the quality of smelted silicon and solving as-

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sociated environmental problems [7-13].

Iron impurities in silicon metal present a challenging industrial problem. When the quartz components are reduced, the entire amount of iron passes into the liquid silicon phase. Oxida-tive refining cannot be used for removing iron, since the affinity of silicon for oxygen is higher than that of iron. Coal and its coking products are another source of iron. Tab. 1 presents the material balance calculated during the process of smelting silicon metal under the conditions of Tau-Ken Temir LLP (Karaganda, Kazakhstan) in January 2018.

It can be seen that the vast amount of iron is transferred in silicon metal from quartz and, to some extent, from coal and its thermal treatment products. In order to improve the quality of silicon metal, iron should be removed from these starting materials. In addition, the contamination of silicon metal with iron can occur while transferring the product from the furnace into the casting ladle using steel instruments. Therefore, it is also necessary to purify the finished product after its crushing and sifting into commercial fractions. A method for separating quartz from iron using magnetic and electrostatic separation was described in [14, 15]. Its disadvantage consists in the need to provide a high level of quartz grinding, which cannot be used for smelting silicon metal in a furnace with a submerged electric arc. Quartz can also be purified by flotation [16,

17], a combination of magnetic separation and acid leaching [18, 19], as well as by gravity separation [20, 21]. However, both these methods require the use of water and aqueous solutions, which complicates the process in winter and involves additional expenses for chemical reagents. The most effective method is likely to be X-ray radiometric separation, which requires neither grinding of the raw materials, nor use of aqueous media and chemical reagents [22].

EXPERIMENTAL

To study the process of removing impurities, quartz of Aktas deposits (Kazakhstan) was used. At the moment, the process of mining of quartz does not exclude impurity rock. We can distinguish 5 groups of pollution (impurity rocks): "black" quartz - fig. 1, "ferruginous" quartz - fig. 2, granite - fig. 3, "ruby" quartz - fig. 5, "burgundy" quartz - fig. 6. The chemical impurity of rocks is given in tab. 2, in the same place the composition of the main mass of quartz, in fig. 4.

The X-ray radiometric properties of samples were studied using X-ray diffraction analyzers with CuKa radiation (40 kV, 30 mA) in the range 20) = 10-70o at a goniometer rate of 20 = 2 o/min. The content of SiO2 and Fe2O3 in quartz was examined by, XRF (X-ray Fluorescence) spectrometry using an ARL PERFORM'X instrument.

Raw material

Material Expendi pendi-tu re rate, t/t Ash, % Fe2O3 in ash, % Fe2O3 in the material, % Fe, % Go Fe into

t %

Quartz 3.20 - - 0.17 0.12 3.96 63.29

Charcoal 0.64 2.04 2.90 0.05 0.04 0.26 4.23

Coal 0.93 4.10 4.41 0.18 0.12 1.17 18.79

Semicoke 0.35 7.40 4.41 0.32 0.22 0.79 12.76

Graphite electrode 0.11 0.10 19.00 0.02 0.01 0.01 0.23

Wood chips 0.84 0.25 2.90 0.00725 0.005 0.04 0.68

Total 6.07 6.26 100.00

Finished products

Products Expenditure rate, t/t Fe2O3 in the material, % Fe, % Go Fe out

t %

Silicon metal 1.0000 - 0.5836 5.8360 93.1644

Slag 0.0885 0.4168 0.2918 0.2582 4.1228

Microsilica 1.2138 0.0200 0.0140 0.1699 2.7126

Total - - - 6.2641 100.0000

Table 1. Material balance of iron in the process of smelting silicon metal at the LLP Tau-Ken Temir in January 2018 Таблица 1. Материальный баланс железа в процессе выплавки кремния металла ТОО «Tau-Ken Temir», январь 2018 года

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Table 2. The chemical composition of varieties of quartz Таблица 2. Химический состав разновидностей кварца

Name Chemical composition, %

Fe2O3 Al2O3 CaO TiO2 SiO2

The bulk of quartz 0.02 0.14 0.003 0.003 99.83

Granite 0.62 5.46 0.108 0.026 93.79

"Ferrous" quartz 1.23 0.16 0.011 0.005 98.60

"Black" quartz 5.92 3.83 0.129 0.146 89.98

"Ruby"quartz 0.28 0.08 0.003 0.004 99.64

"Burgundy"quartz 24.01 0.19 0.028 0.017 75.75

Fig. 1. "Black" quartz Рис. 1. «Черный» кварц

Fig. 2. "Ferrous" quartz Рис. 2. «Железистый» кварц

Fig. 3. Granite Рис. 3. Гранит

Fig. 4. The bulk of quartz Рис. 4. Основная масса кварца

Fig. 5. "Ruby" quartz Рис. 5. «Рубиновый» кварц

Fig. 6. "Burgundy" quartz Рис. 6 «Бордовый» кварц

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To remove impurity rocks, a single-strand X-ray radiometric separator of the SRF1-150M type was used. This is a new generation of Angara-type separators (developed by the Irgired-met JSC and the Tekhnosort LLC) equipped by a highly sensitive measuring system with semiconductor detectors of reflected X-ray radiation. Fig. 7 and 8 present the signal flow and circuit operation diagrams, as well as the appearance of this equipment. The removal of impurities proceeds as follows. The feeding mechanism provides dosed continuous unloading of raw materials to the tray design, which forms the flow of raw materials with a discrete feed to the zone of measurement and sorting in the free fall mode.

The detector unit makes an assessment of the material composition of the raw material by the X-ray fluorescence method on the basis of the secondary X-ray spectrum recorded from the bulk sample, comparing the measurement result with the threshold and issuing a control signal to the pusher actuation.

When quality requirements are not met, an electromagnetic or electropneumatic slide type pusher changes the falling trajectory of the sample. Samples of quality raw materials fall without deviating their trajectory. The control signal for duration and impact force is proportional to the linear size of the sorted sample. To create a control signal, spectral ratios for iron, calcium and strontium were used:

Pea = Nca/ Ns; PFe = NFe/ Ns; Psr = Nsr/ Ns; (1)

where: NCa, NFe, NSr are the number of pulses of characteristic X-ray radiation of the elements Ca (3.7 keV), Fe (6.4 keV) and Sr (14.2 keV) reflected from a freely falling sample of raw material; NS is the secondary scattered X-ray radiation recorded from a sample of raw material together with the characteristic radiation of the elements contained there in.

Initially, the samples were estimated according to the statistical distribution of the intensity of reflected characteristic X-radiation. This assessment was carried out on such a generalized mass of samples that the statistical distribution did not change its character within a statistical error of 5%. The obtained mass was established

as the limit of its representativeness from the volume of the studied sample. The validity of checking this limit was verified in static and dynamic conditions. Next, an analysis was made of the statistical distribution of the magnitude of the spectral ratio within the variation range in order to identify the threshold separation value. As a criterion that determined the values of the threshold spectral ratio, the yield of concentrates and tailings was used. The yield was estimated based on a histogram of statistical distribution. In addition, the value of X-ray reflected radiation most pronounced the obtained statistical distribution was determined. On the basis of this analysis, the element contained in the material under study by which the division should be made was determined, as well as the separation principle. After that, control enrichment of a representative sample was performed. The resulting separation products were averaged, reduced and subjected to chemical analysis. In cases where the result was unsatisfactory, the yield of the separation products was changed by varying the threshold spectral ratio, the element used for the separation and the separation principle. When splitting into two products, a one-step scheme was used with a single value of the separation criterion. When splitting into three products, a two-stage scheme was used, etc. These studies were conducted on different size classes, because the size of raw materials also affects the separation rate.

RESULTS AND DISCUSSION

Fig. 9 shows the ratio between the number of pulses of reflected X-ray radiation from the sample under examination over the measurement period and the frequency, keV. As can be seen from the graph, there is a good agreement between the magnitude of the peak in the region of the characteristic X-ray frequency of iron and its content in quartz. The maximum peak of 1350 pulses was observed from "black" quartz with an iron content of 5.92%. The minimum peak of 150 pulses corresponds to "ruby" quartz with an iron content of 0.28%. Based on this relationship, the spectral ratio PFe was chosen as the sorting criterion during separation of the investigated material. Tab. 3 presents the results of separation obtained by the method described above.

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Fig. 7. Schematic diagram of signal movement in an SRF1-150M X-ray radiometric separator: BXR - Brake X-ray; CXR - Characteristic X-ray; DXR - Diffuse X-ray Рис. 7. Принципиальная схема движения сигналов в рентгенорадиометрическом сепараторе СРФ1-150М: BXR - тормозной рентгеновский снимок; CXR - характеристический рентгеновский снимок;

DXR - диффузный рентгеновский снимок

Fig. 8. Schematic diagram of the operation and appearance of an SRF1-150M X-ray radiometric separator Рис. 8. Принципиальная схема работы и внешний вид рентгенорадиометрического сепаратора СРФ1-150М

As can be seen from the results presented in tab. 3, quartz with a Fe2O3 content of less than 0.05% with a yield of 65-70% was obtained from quartz with the initial Fe2O3 content of 0.10-0.15%. Provided that the initial quartz contains up to 0/5% of Fe2O3 the yield of pure product reaches 35-55%. Pure quartz with a Fe2O3 content of 0.01% can be obtained with a yield of 15-20%. The process enables removal of such impurities -aluminium and calcium oxides, phosphorus. In comparison with the initial concentration, a two- or three-fold decrease in the

amount of phosphorus can be achieved. It should be noted that the best enrichment conditions are achieved when separating the feedstock into fractions of 20-40 and 40-80 mm. With the enrichment of the quartz fraction of 20 -80 mm, the yield of a suitable product decreases from 70 to 50%.

When separating coal from the Shubarkul deposit (Kazakhstan), similar results were obtained (tab. 4). This coal is also used in the production of silicon metal at the Tau-Ken Temir LLP.

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Ж

Fig. 9. Dependence of the number of pulses of reflected X-ray radiation over the measurement period on frequency, ke V: 1 - "Black" quartz; 2 - "Ferrous" quartz; 3 - Granite; 4 - "Ruby" quartz Рис. 9. Зависимость количества импульсов отраженного рентгеновского излучения за период измерения от частоты: 1 - «черный» кварц; 2 - «железистый» кварц; 3 - гранит; 4 - «рубиновый» кварц

The studies were carried out using the separation of spectral ratios by iron and strontium as a criterion. High-quality ash removal was achieved when using the spectral ratio for iron as a criterion for the separation. As can be seen from tab. 4, coal can be effectively enriched by the X-ray radiometric separation. Regardless of the initial concentration (2.0, 4.1, 7.3%), coal concentrate can be obtained from the content of 1.5% and yield of 25%.

Using a similar technique, separation of silicon metal was carried out. The respective results and separation curves (lines of Henri Poin-care) are presented in fig. 10-12. As can be seen from fig. 10-12, silicon metal with the initial iron content of 1.2-1.5% can be obtained as separation products corresponding to 773 metal silicon grade and a yield of 50%, 553 metal silicon grade with a yield of 35% or 441 metal silicon grade with a 20% yield. This depends on the demand for and cost of a particular metal silicon grade. Silicon metal of the grade 553 with a yield about 20% can be produced from silicon metal of the grade 773 (initial iron content of 0.6%). Silicon metal of the grade 4403 can be obtained from silicon metal of the grade 3301 with a yield of about 60%. Moreover, the lower the initial content of harmful impurities in silicon metal, the lower the purifying effect that can be achieved as a result of X-ray radiometric sepa-

ration. This method is most effective when purifying ferrous silicon with ferrous inclusions obtained in the process of release from the furnace using steel tools.

In addition, experiments were carried out on the X-ray radiometric separation of slag produced in the smelting of silicon metal. The separation of the enrichment products by X-ray spectra was qualitative. In addition to the elemental silicon, the oxide component is present in the concentrates. The enrichment wastes in the oxide base contain small (0-10 mm) particles of elemental silicon. Visually, the oxide part in the concentrate is represented by inclusions of un-reacted quartz rather than by slag. The spectrum of quartz is close to that silicon; therefore, it was not separated during purification. The presence of the initial quartz in the slag points to massive violations of the technological regime during smelting of silicon metal. Such violations are described in [23]. The methods described in this paper [23] can be used to avoid the possibility of contamination of slags with quartz and to obtain concentrates without oxide inclusions during X-ray radiometric separation. This product can already be defined as a silicon metal of a certain brand. In this regard, the authors plan to return to this work after the implementation of the above recommendations.

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Table 3. The results of X-ray radiometric separation of quartz from the "Aktas" deposit

Таблица 3. Результаты рентгенорадиометрической сепарации кварца месторождения «Актас»

Fraction of quartz, mm Experiment no. PFe Product name Weight, kg Product yield,% Chemical composition %

Fe203 Al203 CaO Ti02 P2O5 Si02

-80+40 1 0.030/0.038 Concentrate 16.4 25.1 0.03 0.09 0.02 0.0032 0.0027 99.76

Intermediate product 27.2 41.6 0.06 0.31 0.06 0.0105 0.0043 99.45

Waste 21.8 33.3 0.33 0.74 0.51 0.030 0.0112 98.27

Source quartz 65.4 100.0 0.142 0.398 0.200 0.015 0.006 99.135

2 0.030/0.042 Concentrate 31.5 63.0 0.02 0.12 0.02 0.0044 0.0027 99.74

Intermediate product 6.0 12.0 0.11 0.52 0.07 0.0210 0.0066 99.17

Waste 12.5 25.0 0.47 1.17 0.51 0.061 0.0231 97.67

Source quartz 50.0 100.0 0.143 0.431 0.149 0.021 0.008 99.154

3 0.040 Concentrate 22.6 58.9 0.04 0.19 0.03 0.0051 0.0034 99.63

Waste 15.8 41.1 0.18 0.69 0.05 0.025 0.0066 98.94

Source quartz 38.4 100.0 0.098 0.396 0.038 0.013 0.005 99.346

-40+20 4 0.040 Concentrate 18.9 52.1 0.05 0.21 0.03 0.0061 0.0046 99.60

Waste 17.4 47.9 0.17 0.72 0.13 0.0297 0.0119 98.82

Source quartz 36.3 100.0 0.107 0.454 0.078 0.017 0.008 99.226

5 0.045 Concentrate 14.1 42.9 0.04 0.28 0.02 0.0082 0.0021 99.55

Waste 18.8 57.1 0.46 0.91 0.52 0.0412 0.0174 97.96

Source quartz 32.9 100.0 0.280 0.640 0.306 0.027 0.011 98.642

6 0.028/0.038 Concentrate 16.2 39.2 0.02 0.17 0.05 0.0059 0.0040 99.65

Intermediate product 12.8 31.0 0,07 0.31 0.05 0.0127 0.0048 99.46

Waste 12.3 29.8 0.35 0.93 0.46 0.043 0.0184 98.09

Source quartz 41.3 100.0 0.134 0.440 0.172 0.019 0.009 99.126

-80+20 7 0.042 Concentrate 9.8 37.7 0.05 0.20 0.033 0.009 0.0001 99.62

Waste 16.2 62.3 0.61 0.53 0.172 0.028 0.0200 98.54

Source quartz 26.0 100.0 0.399 0.406 0.120 0.021 0.012 98.947

8 0.042 Concentrate 16.0 40.0 0.03 0.16 0.03 0.0058 0.0035 99.67

Waste 23.8 60.0 0.44 1.08 0.55 0.0490 0.0203 97.79

Source quartz 39.8 100.0 0.276 0.712 0.342 0.032 0.014 98.542

сп S

со сл 2 о

(0 N

0 О

w b

I i

с I 3"

О

c

0 r

■0 О

0 b

w k

к О

о со

О c

№ S

ф 3 f

к <

о s

m k

с y

к с p

й

О e

О

с

О 3 ■0

О

0 s

m ы 3 «Q

S

ф 3-

I ф

с -Q

ф С

а l

-с ф y

с О

3 m s

а

м 0 О

ф 3

3 а 3

с ф l

с

-с b

ф y

с S

к ^

о Ф

<\>

0 3

к Ф

ф м I » О d

с О

S

-

a

y

ш

Table 4. The results of X-ray radiometric separation of coal from the "Shubarkol" deposit

Таблица 4. Результаты рентгенорадиометрической сепарации угля месторождения «Шубарколь»

Initial coal quality Fraction of coal, mm Product name Sort indicators

PFe - 0,022/0,028 PSr - 0,026/0,030

Weight, kg Product yield, % Ash content, % Weight, kg Product yield, % Ash content, %

High -40+20 Concentrate 11.1 28.2 1.6 11.5 52.0 1.6

Intermediate product 25.0 63.6 2.0 5.1 23.1 1.8

Waste 3.2 8.1 2.9 5.5 24.9 1.9

Source coal 39.3 100.0 2.0 22.1 100.0 1.72

Average -40+20 Concentrate 10.2 56.7 2.8 5.0 28.2 2.2

Intermediate product 6.4 35.6 3.5 5.9 33.3 4.5

Waste 1.4 7.8 16.5 6.8 38.4 4.3

Source coal 18 100.0 4.1 17.7 100.0 3.77

Low -40+20 Concentrate 13.1 62.7 3.8 7.5 42.1 5.3

Intermediate product 5.9 28.2 7.1 5.6 31.5 4.6

Waste 1.9 9.0 32.1 4.7 26.4 4.5

Source coal 20.9 100.0 7.42 17.8 100.0 4.87

y b

so

%

oi it

П!

gi ie

o

c y

о. £

Fe Al Ca

sc

icc

Product yield, % by weight

Fig. 10. Ferric silicon enrichment line Рис. 10. Линия обогащения железистого кремния

y b

so

%

oi it

(б

o

c y

.

£

0,6 0,5 0,4 0,3 0,2 0,i c

Fe Al Ca

0 50 100

Product yield, % by weight

Fig. 11. Silicon Grade 773 Enrichment Line Рис. 11. Линия обогащения кремния 773

%

я

io

'Ü

rt th

S3 .Sí

ec ie

§ *

oc y

ir u а S

0,35 0,3 0,25 0,2 0,i5 0,i

0,05 0

Fe Al Ca

50

i00

0

0

Product yield, % by weight

Fig. 12. Silicon Grade 4403 Enrichment Line Рис. 12. Линия обогащения кремния 4403

ВЕСТНИК ИРКУТСКОГО ГОСУДАРСТВЕННОГО ТЕХНИЧЕСКОГО УНИВЕРСИТЕТА 2020;24( 5):1137-1149

CONCLUSIONS

The relationship between the number of reflected X-ray pulses over the measurement period and the frequency of quartz of different chemical composition was established. On the basis of this dependence, an X-ray radiometric separation technique for quartz, coal, metal silicon and silicon slag was developed and tested.

This technique solves the practical problem of improving the quality of silicon metal obtained by smelting. The possibility of reducing the concentration of such harmful impurities as iron, titanium and phosphorus in the resulting silicon metal was demonstrated. This can significantly reduce the cost of solar-grade silicon production.

References

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3. Ragulina RI, Emlin BI. Electrothermics of Silicon and Silumin. Moscow: Metallurgiya; 1972, 239 p. (In Russ.)

4. Gasik MI, Gasik MM. Electrothermics of Silicon (physics-chemistry and technology). Dnepropetrovsk: National Metallurgical Academy of Ukraine; 2011, 487 p. (In Russ.)

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17. Hacifazlioglu H. Enrichment of silica sand ore by cy-clojet flotation cell. Separation Science and Technology. 2014;49(10):1623-1632. https://doi.org/10.1080/01496395.2014.893357

18. Tuncuk A, Akcil A. Removal of iron from quartz ore using different acids a laboratory-scale reactor study. Mineral Processing and Extractive Metallurgy Review. 2014;35(4):217-228.

https://doi.org/10.1080/08827508.2013.825614

19. Zhang Zhizhen, Li Jingsheng, Li Xiaoxia, Huang Houquan, Zhou Lifen, Xiong Tiantian. High efficiency iron removal from quartz sand using phosphoric acid. International Journal of Mineral Processing. 2012;114-117:30-34. https://doi.org/10.1016/j.minpro.2012.09.001

20. Ibrahim SS, Selim AQ, Hagrass AA. Gravity separation of silica sands for value addition. Particulate Science and Technology. 2013;31(6):590-595. https://doi.org/10.1080/02726351.2013.800930

21. Kheloufi A, Fathi M, Rahab H, Kefaifi A, Keffous A, Medjahed SA. Characterization and quartz enrichment of the Hoggar deposit intended for the electrometallurgy. Chemical Engineering Transactions. 2013;32:889-894. https://doi.org/10.3303/CET1332149

ВЕСТНИК ИРКУТСКОГО ГОСУДАРСТВЕННОГО ТЕХНИЧЕСКОГО УНИВЕРСИТЕТА 2020'24(5):1137-1149

22. Von Ketelhodt L, Bergmann C. Dual energy X-ray transmission sorting of coal. Journal of the Southern African Institute of Mining and Metallurgy. 2010;110(7):371 —378.

23. Zobnin NN, Mandryukov GV, Kuzembaeva AA. Operational aspects of silicon oxidereduction process and their

effects on the material and thermal flows balance in car-bothermic reactors. Oriental Journal of Chemistry. 2018;34(6):3079—3087. http://doi.org/10.13005/ojc/340651

Библиографический список

1. Schei A., Tuset J.Kr., Tveit Н. Production of high silicon alloys. Trondheim: Tapir, 1998. 363 p.

2. Супоненко А.Н. Новые направления применения кремния в промышленности // Цветные металлы и минералы - 2016: сб. тез. докл. VIII Междунар. конгр. (г. Красноярск, 13-16 сентября 2016 г.). Красноярск: Научно-инновационный центр, 2017. С. 130.

3. Рагулина Р.И., Емлин Б.И. Электротермия кремния и силумина. М.: Металлургия, 1972. 239 с.

4. Гасик М.И., Гасик М.М. Электротермия кремния (физикохимия и технология). Днепропетровск: Изд-во НМетАУ, 2011. 487 с.

5. Andresen B. The metallurgical silicon process revisited // Silicon for the Chemical and Solar Industry X: Proceedings of the International Conference (Alesund - Gei-ranger, 28 June - 2 July 2010). Alesund - Geiranger, 2010. P. 11-23.

6. Degel R., Frohling C., Koneke M., Hecker E., Oterdoom H., Van Niekerk A. History and new milestones in submerged arc furnace technology for ferro alloy and silicon production // Infacon XIV - The Fourteenth International Ferro-Alloys Congress (Kiev, 31 May - 4 June 2015). Kiev, 2015. Р. 7-16.

7. Nemchinova N.V., Leonova M.S., Tyutrin A.A., Bel'skii S.S. Optimizing the charge pelletizing parameters for silicon smelting based on technogenic materials // Metallurgist. 2019. Vol. 63. Issue 1-2. Р. 115-122. https://doi.org/10.1007/s11015-019-00800-3

8. Li Fei, Tangstad M., Solheim I. Quartz and carbon black pellets for silicon production // Infacon XIV: The Fourteenth International Ferroalloys Congress (Kiev, 31 May -4 June 2015). Kiev, 2015. Р. 390-401.

9. Ringdalen E. Changes in quartz during heating and the possible effects on si production // JOM. 2015. Vol. 67. No. 2. P. 484-492. https://doi.org/10.1007/s11837-014-1149-y

10. Зобнин Н.Н. Влияние термической стойкости кварца и гранулометрического состава шихтовых материалов на процесс электротермической плавки металлургического кремния // Цветные металлы и минералы - 2017: сб. докл. IX Междунар. конгресса (г. Красноярск, 11-15 сентября 2017 г.). Красноярск: ООО «Научно-инновационный центр», 2017. С. 779-786.

11. Nemchinova N.V., Mineev G.G., Tyutrin A.A., Ya-kovleva A.A. Utilization of dust from silicon production // Steel in Translation. 2017. Vol. 47. Issue 12. Р. 763-767. https://doi.org/10.3103/S0967091217120087

12. Сафонов А.А., Маусымбаева А.Д., Портнов В.С., Парафилов В.И., Коробко С.В. Анализ возможного использования углей месторождения Шубарколь при выплавке технического кремния // Уголь. 2019. № 2. С. 68-72.

http://doi.org/10.18796/0041-5790-2019-2-68-72

13. Nemchinova N.V., Tyutrin A.A., Zelinskaya E.V. Acidic-ultrasonic refining of silicon by carbothermic technology // Metallurgist. 2015. Vol. 59. No. 3. P. 258-263. https://doi.org/10.1007/s11015-015-0094-5

14. Manel BF, Gallala W, Saadi A. Quartz sand beneficia-tion using magnetic and electrostatic separation to glass industries // Journal of New Technology and Materials. 2016. Vol. 6. No. 1. P. 60-72. https://doi.org/10.12816/0043925

15. Bouabdallah S., Bounouala M., Chaib A.S. Removal of iron from sandstone by magnetic separation and leaching: case of El-Aouana deposit (Algeria) // Mining Science. 2015. Vol. 22. 33-44. https://doi.org/10.5277/msc152203

16. Deniz A.F., Abakay T.H., Bozkurt V. Removal of Impurities from tailing (quartz) obtained from bitlis kyanite ore by flotation method // International Journal of Applied Science and Technology. 2011. Vol. 1. No. 1. 74-81.

17. Hacifazlioglu H. Enrichment of silica sand ore by cy-clojet flotation cell // Separation Science and Technology. 2014. Vol. 49. Issue 10. P. 1623-1632. https://doi.org/10.1080/01496395.2014.893357

18. Tuncuk A., Akcil A. Removal of iron from quartz ore using different acids a laboratory-scale reactor study // Mineral Processing and Extractive Metallurgy Review. 2014. Vol. 35. Issue 4. P. 217-228. https://doi.org/10.1080/08827508.2013.825614

19. Zhang Zhizhen, Li Jingsheng, Li Xiaoxia, Huang Houquan, Zhou Lifen, Xiong Tiantian. High efficiency iron removal from quartz sand using phosphoric acid // International Journal of Mineral Processing. 2012. Vol. 114-117. P. 30-34. https://doi.org/10.1016/j.minpro.2012.09.001

20. Ibrahim S.S., Selim A.Q., Hagrass A.A. Gravity separation of silica sands for value addition // Particulate Science and Technology. 2013. Vol. 31. Issue 6. P. 590-595. https://doi.org/10.1080/02726351.2013.800930

21. Kheloufi A., Fathi M., Rahab H., Kefaifi A., Keffous A., Medjahed S.A. Characterization and quartz enrichment of the Hoggar deposit intended for the electrometallurgy // Chemical Engineering Transactions. 2013. Vol. 32. P. 889-894. https://doi.org/10.3303/CET1332149

22. Von Ketelhodt L., Bergmann C. Dual energy X-ray transmission sorting of coal // Journal of the Southern African Institute of Mining and Metallurgy. 2010. Vol. 110. No. 7. P. 371-378.

23. Zobnin N.N., Mandryukov G.V., Kuzembaeva A.A. Operational aspects of silicon oxidereduction process and their effects on the material and thermal flows balance in carbothermic reactors // Oriental Journal of Chemistry. 2018. Vol. 34. No. 6. P. 3079-3087. http://doi.org/10.13005/ojc/340651

ВЕСТНИК ИРКУТСКОГО ГОСУДАРСТВЕННОГО ТЕХНИЧЕСКОГО УНИВЕРСИТЕТА 2020;24(5):1137-1149

Authorship criteria

Zobnin N.N., Korobko S.V., Vetkovsky D.L., Moiseev A.A., Aganin A.O., Nurumgaliev A.Kh., Pikalova I.A. declare equal participation in obtaining and formalization of scientific results and bear equal responsibility for plagiarism.

Conflict of interests

The authors declare that there is no conflict of interests regarding the publication of this article.

The final manuscript has been read and approved by all the authors.

INFORMATION ABOUT THE AUTHORS

Nikolay N. Zobnin,

Cand. Sci. (Eng.),

Associate Professor of the Department of Metallurgy

and Materials Science,

Karaganda State Industrial University,

30 Respubliki Ave., Temirtau 101400, Kazakhstan;

Production Engineer,

Tau-Ken Temir LLP,

accounting quarter 018, bldg 133, Oktyabrsky district, Karaganda 100018, Kazakhstan; !"■■■".! e-mail: zobninnn@mail.ru

Sergey V. Korobko,

Master of Engineering Sciences, Deputy Director General for Production, Tau-Ken Temir LLP,

accounting quarter 018, bldg 133, Oktyabrsky district, Karaganda 100018, Kazakhstan; e-mail: s.korobko@tks-temir.kz

Dmitry L. Vetkovsky,

Master of Engineering Sciences,

Lecturer of the Department of Metallurgy

and Materials Science,

Karaganda State Industrial University,

30 Respubliki Ave., Temirtau 101400, Kazakhstan;

e-mail: dimon55597@mail.ru

Andrey A. Moiseev,

Master of Engineering Sciences,

Lecturer of the Department of Metallurgy

and Materials Science,

Karaganda State Industrial University,

30 Respubliki Ave., Temirtau 101400, Kazakhstan;

e-mail: ravl_kz@mail.ru

Aleksandr O. Aganin,

Master of Engineering Sciences,

Lecturer of the Department of Metallurgy

and Materials Science,

Karaganda State Industrial University,

30 Respubliki Ave., Temirtau 101400, Kazakhstan;

e-mail: aganin95@mail.ru

Критерии авторства

Зобнин Н.Н., Коробко С.В., Ветковский Д.Л., Моисеев А.А., Аганин А.О., Нурумгалиев А.Х., Пикалова И.А. заявляют о равном участии в получении и оформлении научных результатов и в равной мере несут ответственность за плагиат.

Конфликт интересов

Авторы заявляют об отсутствии конфликта интересов.

Все авторы прочитали и одобрили окончательный вариант рукописи.

СВЕДЕНИЯ ОБ АВТОРАХ

Зобнин Николай Николаевич,

кандидат технических наук,

доцент кафедры металлургии и материаловедения,

Карагандинский индустриальный университет,

101400, г. Темиртау, пр. Республики, 30, Казахстан;

инженер производственно-технической службы,

ТОО «Tau-Ken Temir»,

100018, г. Караганда, Октябрьский район,

018-й учетный квартал, корп. 133, Казахстан;

!"■■■".! e-mail: zobninnn@mail.ru

Коробко Сергей Владимирович,

магистр технических наук,

заместитель генерального директора по производству,

ТОО «Tau-Ken Temir»

100018, г. Караганда, Октябрьский район,

018-й учетный квартал, корп. 133, Казахстан;

e-mail: s.korobko@tks-temir.kz

Ветковский Дмитрий Леонидович,

магистр технических наук, преподаватель кафедры металлургии и материаловедения,

Карагандинский индустриальный университет, 101400, г. Темиртау, пр. Республики, 30, Казахстан; e-mail: dimon55597@mail.ru

Моисеев Андрей Андреевич,

магистр технических наук, преподаватель кафедры металлургии и материаловедения,

Карагандинский индустриальный университет, 101400, г. Темиртау, пр. Республики, 30, Казахстан; e-mail: ravl_kz@mail.ru

Аганин Александр Олегович,

магистр технических наук, преподаватель кафедры металлургии и материаловедения,

Карагандинский индустриальный университет, 101400, г. Темиртау, пр. Республики, 30, Казахстан; e-mail: aganin95@mail.ru

ВЕСТНИК ИРКУТСКОГО ГОСУДАРСТВЕННОГО ТЕХНИЧЕСКОГО УНИВЕРСИТЕТА 2020'24(5):1137-1149

Asylbek Kh. Nurumgaliev,

Dr. Sci. (Eng.), Professor,

Professor of the Department of Metallurgy

and Materials Science,

Karaganda State Industrial University,

30 Respubliki Ave., Temirtau 101400, Kazakhstan;

e-mail: as_nurum@mail.ru

Irina A. Pikalova,

Master of Metallurgy,

Senior Lecturer at the Department of Metallurgy and Materials Science, Karaganda State Industrial University, 30 Respubliki Ave., Temirtau 101400, Kazakhstan; e-mail: irina.p77.77@mail.ru

Нурумгалиев Асылбек Хабадашевич,

доктор технических наук, профессор, профессор кафедры металлургии и материаловедения,

Карагандинский индустриальный университет, 101400, г. Темиртау, пр. Республики, 30, Казахстан; e-mail: as_nurum@mail.ru

Пикалова Ирина Анатольевна,

магистр металлургии,

старший преподаватель кафедры металлургии и материаловедения,

Карагандинский индустриальный университет, 101400, г. Темиртау, пр. Республики, 30, Казахстан; e-mail: irina.p77.77@mail.ru

ВЕСТНИК ИРКУТСКОГО ГОСУДАРСТВЕННОГО ТЕХНИЧЕСКОГО УНИВЕРСИТЕТА 2020;24(5):1137-1149