The results of studies of vermiculite rock from the Tebinbulak deposit are given. It is established that this vermiculite rock consists of biotite mica minerals. The crystalline lattice of these minerals contains interpack water known as zeolite water, which is responsible for swelling of the rock in heating. Vermiculite rock fired at 200 -900°C is capable of absorbing water, i.e., of rehydration. This is important in using swelled vermiculite in the production of fire-retardant paints. The compositions of fire-retardant paints and the results of their testing for heat resistance according to GOST 30402 are given. It is established that all the developed mixtures impart fired-retardant properties to timber.The development of new technologies and promising materials make it necessary to expand the list of available raw materials. Among the promising products are fire-retardant paints that are used in different sectors of industry. Swelled vermiculite is widely used as a filler in fire-retardant paints. Such paints are not produced in the Republic of Uzbekistan and have to be imported from other countries. The development of a large deposit of vermiculite ore in Tebinbulak will make it possible to start the production of fire-retardant paints in Uzbekistan.The vermiculite ore from the Tebinbulak deposit belong to biotite mica. It should be noted that very few varieties of vermiculite rocks belong to biotite mica. For instance, the large Kovdor deposit in Russia mainly consists of phlogopite mica; therefore, all previous studies of vermiculite have been performed on these phlogopite rocks. The present study has been carried out on the biotite vermiculite rock in order to determine its applicability for the production of fireproof paints. Vermiculite samples taken from the Tebinbulak deposit have a dark gray color and comprise mainly biotite, hydrobiotite, and vermiculite minerals. The chemical composition of vermiculite samples is given in Table 1.The crystal-optical properties of vermiculite ore were determined using a microscope in immersion liquids for the biotite -vermiculite series (and for rehydrated vermiculite as well); the refraction index N*m and its variation under firing samples to 1000°C was estimated as well. As the degree of hydration grows, we observe a decrease in the refraction index from biotite to vermiculite (Table 2), which was earlier reported in studies performed on phlogopite -vermiculite minerals [1]. The refraction index presumably decreases due to the increasing content of water in mica, which is typical of many other minerals as well [2,3]. As the firing temperature grows, the refraction index perceptibly increases. Thus, N m in biotite slightly grows when fired to 800°C and then abruptly grows from 1.595 to 1.645 when fired to 1000°C. A possible reason for the increasing refractive index in biotite is the transition of Fe 2+ to Fe 3+ , which is corroborated by the color of biotite changing from dark gray to gray-brown, which is caused by oxide iron above 800°C [4].The refractive index N...

Studies are performed on the material composition of micaceous minerals of the vermiculite series in the Tebinbulak deposit. It is established that the micaceous materials studied consist of Mg-biotite, Mg-, Na-and Ca-hydrobiotite, and the chemical formula for the minerals is worked out. Results of the studies are of considerable practical value for developing the technology for preparing expanded vermiculite and preparing various materials based upon it.Vermiculite, formed from magnesium-iron micas, i.e. biotite and phlogopite, has practical applications. Under natural conditions vermiculitization of these micas occurs very slowly and therefore in minerals not only the final products of the process, i.e. vermiculite, are encountered, but also hydrated mica to a different degree of hydration [1].There are many deposits of vermiculite. The composition of micaceous minerals of any deposit has marked differences. Known deposits of vermiculite ore in the USA (Libby, Montana and Epury, South Carolina) whose overall reserve is estimated as 250 -500 thousand tons and the content of vermiculite in the rocks is on average 50%, for example represented mainly by weathered vermiculite and hydrophlogopite with a different degree of hydration [2,3].One of the largest deposits of vermiculite rock, located in the Republic of South Africa (Lulekon deposit), is represented by micaceous minerals of vermiculite in the form of two varieties: vermiculite of high quality of golden-brown color, and hydrobiotite a little worse in quality. A feature of this deposit is the fact that the natural value of the pH of the water suspension of micaceous minerals of vermiculite is 6.5, which provides the possibility of using them in hydroponics. Vermiculite of the deposit is exported i large amounts to Japan [4].In South West Africa in the territory of Rhodesia there is a deposit of copper-containing vermiculite. In Uganda and Sudan deposits of vermiculite in an ore-bearing zone have been discovered laid down with alkali and carbonate rocks. The ore consists of phlogopite and vermiculite, within whose crystal composition there are Ca 2+ ions, so-called calcium hydrophlogopite. In Sierra Leone in Hangha chromite deposit vermiculite is mined containing cations of chromium of different valency [5].A large deposit of vermiculite in Russia is the Kordovsk deposit in the Murmansk region represented by micaceous minerals Mg-hydrophlogopite, Mg-vermiculite, weathered vermiculite and sungulite. The Barchinsk deposit consists of Ca-hydrophlogopite and Ca-and Na-vermiculite.The technological properties of micaceous minerals of vermiculite depend on raw material chemical composition; the degree of mica hydration, i.e. the amount of water molecules within the crystal structure of the original material; the form of interlayer cations; grain a size and firing regime (maximum temperature, rate and duration of heating) [6].The aim of this work is to study the material composition of micaceous minerals of vermiculite of the Tebinbulak deposit that until recently ha...