On the separation of kaolin from Tugan sands
Abstract Generated abstract
This paper examines the extraction of kaolin clay from the kaolinized sands of the Tugan deposit, with attention to how particle-size separation affects the quality and potential industrial use of the recovered clay. The authors analyze grain-size distribution, chemical composition, refractoriness, and mineralogical characteristics of clay fractions finer than 5, 10, 20, and 50 microns. The study finds that the finest material has a kaolin composition, while fractions finer than 10 microns and 20 microns meet requirements for different classes of refractory chamotte products. Material separated at a 50 micron limit is unsuitable for chamotte refractories but may be used in sanitary and construction faience ceramics.
Full Text
ON THE EXTRACTION OF KAOLIN FROM TUGAN SANDS
P. G. Usov, N. F. Voronova
(Presented by the scientific seminar of the Department of Silicate Technology)
The sands of the productive bed of the Tugan deposit contain about 20% clay of kaolin composition. The extraction of clay from the sands is of great practical value for the metallurgical and ceramic industries of Western Siberia and for the paper-and-pulp mill newly being built in the city of Asino. The grain-size structure of the kaolinized sands of the productive bed has the following characteristics (Table 1).
Table 1
| Fraction content in %, with grain size in mm | Fraction content in %, with grain size in mm | Fraction content in %, with grain size in mm | Fraction content in %, with grain size in mm | Fraction content in %, with grain size in mm | Fraction content in %, with grain size in mm | Fraction content in %, with grain size in mm | Fraction content in %, with grain size in mm |
|---|---|---|---|---|---|---|---|
| 1.0–0.5 | 0.5–0.25 | 0.25–0.05 | 0.05–0.01 | 0.01–0.005 | 0.005–0.001 | Less than 0.001 | Sum 0.005 |
| None | 1.65 | 73.65 | 6.20 | 2.30 | 5.00 | 11.20 | 16.20 |
The sandy part of the rock is composed of fine-grained fractions with a highly concentrated grain-size structure. The intermediate size groups, with grain size 0.05–0.005 mm, located between the main fractions of sand and clay, are represented in small quantities. Establishing the limiting particle-size boundaries in extracting clay material from sands is of practical interest. Determining the influence of the indicated fractions of dust-like sand on the quality of the extracted clay constitutes the subject of the present work. The composition of the clayey substance—the fraction finer than five microns, whose extraction from sands under industrial conditions presents considerable difficulties—was investigated. The combined compositions of fractions finer than 10 and 20 microns—accessible for extraction under industrial conditions—were studied. Also studied were the compositions of clayey material with a limiting grain size of 50 microns, which are obtained directly when sands are treated in hydrocyclones. The chemical composition of the clayey substance—the fractions finer than 5 microns extracted from the sands—is given in Table 2.
The molecular ratio of SiO₂ to Al₂O₃ in the clayey substance is 2.14. This corresponds to kaolin. The kaolin composition of the product
is also established by mineralogical studies, the results of which are presented as graphs in Figs. 1, 2, and 3. [1, 2].
Table 2
| LOI | SiO₂ | TiO₂ | Al₂O₃ | Fe₂O₃ | CaO | MgO | Total |
|---|---|---|---|---|---|---|---|
| 13,86 | 45,78 | 1,14 | 36,92 | 1,44 | 0,57 | 0,31 | 100,0 |
When fractions finer than 10 microns are separated, the clay product has a refractoriness of 1730° and higher. It is suitable for the manufacture of chamotte refractory products of class “A”.
At a limiting grain size of 20 microns, the separated clay material meets the technical requirements for raw material for refractory chamotte brick of class “B,” used in the lining of air heaters and in the lining of steel-teeming ladles (GOST 5341-58) [3]. Fractions with a limiting particle size of 50 microns are not suitable for the production of chamotte refractory products. They can be fully used for the production of sanitary-construction faience products.
Fig. 1. Weight loss
Table 3
Chemical compositions of clay material with different limiting particle sizes of separation
| Fractions finer than | LOI | SiO₂ | TiO₂ | Al₂O₃ | Fe₂O₃ | CaO | MgO | Total |
|---|---|---|---|---|---|---|---|---|
| 10 microns | 12,0 | 51,47 | 0,75 | 33,35 | 1,13 | 0,57 | 0,54 | 99,81 |
| 20 —″— | 10,26 | 57,96 | 1,01 | 28,50 | 1,03 | 0,61 | 0,71 | 100,0 |
| 50 —″— | 8,57 | 64,50 | 1,00 | 23,59 | 0,67 | 0,70 | 0,67 | 100,0 |
Table 4
Chemical composition of the clay material in the calcined state
| Fractions finer than | SiO₂ | Al₂O₃ | TiO₂ | Fe₂O₃ | CaO | MgO | Total |
|---|---|---|---|---|---|---|---|
| 5 microns | 53,00 | 42,00 | 1,31 | 1,67 | 0,66 | 0,36 | 100,0 |
| 10 —″— | 59,80 | 37,00 | 0,81 | 1,29 | 0,51 | 0,59 | 100,0 |
| 20 —″— | 65,40 | 31,10 | 1,00 | 1,22 | 0,53 | 0,75 | 100,0 |
| 50 —″— | 71,65 | 25,70 | 1,02 | 0,74 | 0,71 | 0,68 | 100,0 |
Fig. 2. DTA curve
Fig. 3. X-ray diffraction pattern. 1 — Yeleninsky kaolin; 2 — Tugan kaolin
Conclusions
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For the refractory industry, the clay substance from the Tugan kaolinized sands must be separated with a limiting particle size of no more than 20 microns.
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For the ceramic industry—all fractions finer than 50 microns.
Literature
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P. G. Usov, N. S. Dubovskaya, A. V. Petrov. Local Nonmetallic Raw Materials for the Metallurgical, Silicate, and Construction Industries of Western Siberia. Tomsk University Press, 1964.
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P. G. Usov, N. F. Voronova. Local Nonmetallic Raw Materials for the Metallurgical, Glass, and Ceramic Industries. Tomsk University Press, 1963.
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Industrial Requirements for the Quality of Mineral Raw Materials. Handbook for Geologists. Issue 54. Clays and Kaolins, 1962.