Enriched Kaolin Research Articles

On the Possibility of Waste-Free Use of Mineral Resources of the Angrensky Brain Coal Deposit

The Angren lignite basin is a complex coal-kaolin deposit. Here, in addition to brown coal, there are large reserves of kaolin clays of two types - primary and secondary, occurring respectively in the soil and the roof of the coal strata. Secondary clays, in turn, subdivided into gray and variegated, which during overburden and mining of coal seams in the bulk go to the dump. Gray kaolins currently partially processed at the “Angren Kaolin” LLC factory in order to obtain enriched kaolin used for the production of building ceramics, etc.

The Way of Utilization of Fused Corundum Dust Waste for the High-Alumina Chamotte Production

High-alumina chamotte with an Al2O3 content of more than 62% is a desirable raw material to produce high-alumina refractories. The production of high-alumina aggregate (chamotte) is carried out in various ways, using plastic or semi-dry technology for briquetting from commercial alumina and refractory clay. When grinding fused corundum, the dust containing 93–95% Al2O3 is formed; it is currently a substandard material. It is of interest to involve this waste product in the production of high-alumina chamotte. The developed technology allows obtaining the desirable material and utilizing production waste. In this project the briquetting parameters to produce high-alumina chamotte using corundum waste and refractory enriched kaolin were determined.

The use of technogenic raw materials to produce a high-alumina chamotte

When fused corundum is crushed, a finely dispersed powder is formed with an Al2O3 content of 93–95%, in the form of substandard material. It is advantageous to utilize this powder to obtain high-alumina chamotte with Al2O3 content of more than 62%. High-alumina aggregate (chamotte) was obtained by semi-dry technology with intermediate briquette molding from a mixture of corundum dispersed powder and enriched kaolin. Based on a final Al2O3 content of 65 wt. % the batch composition of the mass to produce a high alumina aggregate (chamotte) was calculated. From a mixture of dispersed corundum powder and kaolin moistened with a 5–7% technical lignosulfonate solution with a density of 1050 kg·m−3, a briquette was formed at a specific pressing pressure of 15–20 MPa. The briquette was fired at a temperature of 1700°C. The fired briquette had a strength of 164 to 193 MPa. The water absorption of briquettes was 11–12%. The phase composition of the briquette is represented mainly by corundum and mullite. The enriched kaolin did not show sintering effect on fine corundum.

ВЛИЯНИЕ ДАВЛЕНИЯ НА СТРУКТУРУ КАОЛИНИТА В ОГНЕУПОРНЫХ ГЛИНАХ НИЖНЕ-УВЕЛЬСКОГО МЕСТОРОЖДЕНИЯ ПО ДАННЫМ ИК-СПЕКТРОСКОПИИ

Актуальность исследования обусловлена необходимостью изучения структуры каолиновых глин в связи с их широким промышленным применением. Физические и физико-химические свойства глин изменяются при различных техногенных воздействиях на них, что обусловлено преобразованием кристаллической структуры. Цель: изучение влияния давления на структуру каолинита. Объект: каолиновая глина Нижне-Увельского месторождения Челябинской области. Метод: инфракрасная спектроскопия. Инфракрасные спектры регистрировались на ИК Фурье-спектрометре в интервале 400…3800 см–1. Обработка ИК-спектров проводилась с помощью программного обеспечения Fspec. Результаты экспериментальных исследований показали, что обогащенная каолиновая глина Нижне-Увельского месторождения Челябинской области, не подверженная воздействию давлением, характеризуется частично упорядоченной (дефектной) структурой. При воздействии давлений от 10 до 650 МПа глина характеризуется частично упорядоченной структурой, при давлениях от 700 до 800 МПа – слабо и неупорядоченной структурой. Обработка каолина давлением повышает дефектность структуры на уровне пакета. Связи между Al-OH, Si-O-Al, внутренними и внутриповерхностными гидроксилами разрушаются, что приводит к вытеснению Al из октаэдрического и Si из тетраэдрического листов и формированию «дырочных» энергетических центров в кристаллической решетке каолинита. При этом влияние давления до 150 МПа на формирование дефектов в каолините выше, чем при давлениях от 150 до 800 МПа. Кроме того, при обработке каолина давлением происходит образование дефектов структуры на межпакетном уровне за счет скольжения, вращения и прокатки структурных пакетов между собой

The use of domestic raw materials for the production of chamotte glass melting pots with a capacity of 500 and 700 l

The possibility of a complete replacement of imported raw materials with domestic while maintaining the quality of large-sized ceramic pots and the optical glass obtained in them is considered. Imported raw materials (prosyanovsky kaolin and watch-yar clay) are characterized by high ductility, low sintering temperature, and low iron content. As an alternative to these materials, in this work, Latnian clay and Elena's kaolin are considered. The sintering temperature was established, which provides the necessary properties of the refractory (1350-1400 °C). The effectiveness of enrichment of Latnian clay has been shown: a decrease in the content of SiO 2 to the level of its content in the Elena's enriched kaolin, an increase in the content of Al 2 O 3 . Ill. 4. Ref. 2. Tab. 4.

Enriched primary kaolins of Uzbekistan as a raw material for chamotte lightweight refractories

The results of studies of the phase formation process of enriched primary kaolins of the Angren and Samarkand fields during firing in the range of 1250‒1400 oC are presented. It is shown that the stability of the phase composition, the optimal ratio of the crystalline phases, shrinkage and water absorption indices allow us to consider the enriched kaolin of the Samarkand field as a promising material for making chamotte lightweight refractories. Ill. 3. Ref. 11. Tab. 3.

Technology of manufacture of high-alumina refractories based on Shurtan Gas-Chemical complexs used sorbent and enriched kaolin

Technology of manufacture of high-alumina refractories based on Shurtan Gas-Chemical complexs used sorbent and enriched kaolin

Cagulation structure of cement slurry whith a variety of clay component

We have shown the particularities of the coagulation structure formation in water dispersed systems such as the cement slurries based on chalkstone with the usage of clay components with different chemical and mineralogical compositions and dispersion abilities. There is the comparison of the properties of the polymineral clay used for production of Portland cements against different types of the kaolin clay used for making of white cements. It has been noticed that varying types of the clay component in raw stuff mixtures used for making of Portland cement clinker with prescribed properties (such as saturation factor, modules, and phase composition) would constitute an important factor influencing the coagulation structure formation and the clinker properties in the cases of wet and combined methods of production. When the said methods are applied in the white cement technology, the use of enriched kaolin as the clay component would facilitate increasing both the whiteness of the final product and the stability of the slurries.

On the kinetics of pozzolanic reaction in metakaolin–lime–water system

The kinetics of pozzolanic reaction metakaolin–lime is studied in the present work. Metakaolin is prepared by calcination of enriched kaolin (deposit “Senovo”, Bulgaria) at temperature of 830 ± 10 °C in a labscale muffle oven. The reaction is performed in intensively stirred water suspension at different temperatures in the range 20–100 °C. The kinetics is analyzed by comparing the experimental data with theoretical curves, derived according to appropriate kinetic and diffusion models taking into account the grain size distribution of metakaolin. The macroscopic mechanism and activation energy of the reaction are determined. It is found, that the activation energy decreases gradually from 71 to 45 kJ/mol[Ca(OH)2] with the increase of the reaction degree from 0.2 up to 0.6, respectively, which is a characteristic for transition regime reactions.

On the kinetics of pozzolanic reaction in the system kaolin–lime–water

The kinetics of the pozzolanic reaction of enriched kaolin from the “Senovo” deposit (Bulgaria) with lime is the object of this article. The kaolin contains kaolinite as a major clay mineral as well as admixtures of quartz and illite. The experimental data of pozzolanic activity at temperatures of 100 and 23 °C are obtained for different reaction times. The reaction degrees of kaolinite and lime at 100 °C are determined from the pozzolanic activity data using a powder X-ray diffraction analysis. The kinetic analysis is performed by joint presentation of theoretical and experimental data in dimensionless coordinates having in mind the influence of particle size distribution on the reaction rate. It is found by the kinetic analysis that the rate of entire reaction is limited by the rate of chemical reaction on the reaction surface up to degree of reaction near to 0.4. The rate of penetration of the chemical reaction into the kaolinite particles for this area—from the beginning to degree of reaction 0.4, is determined to be equal to 2.10−11 m/s.

Refractories made of kaolins from the Poletayevskiy deposit

Refractory parts made of enriched kaolin with the addition of Baskul' clay correspond to class B (i.e., ladle brick as specified by the GOST 5341-58 standard, and stopper pipes and siphon brick by the GOST 4978-49 standard).

Ladle brick and stopper pipes made of enriched Kyshtym kaolin

We have demonstrated the possibility of manufacturing high-grade refractories for steel-casting from enriched kaolin from the Kyshtym deposit.

Means of using new techniques for producing enriched kaolin

Means of using new techniques for producing enriched kaolin