The underground mining of the ore deposits by means of the intensive methods of the traditional technologies is characterized by the loss of the reserves, which are off-balance for the technologies applied. The experience, which was accumulated by the state-of-the-art enterprises before the economic reforms and the crisis indicates, that it is possible to decrease the loss of metals. This can be assumed by means of involving the off-balance reserves into the production process with the metal lixiviation during closed work. The purpose of the present-day research is the substantiation of the technical possibility and economic reasonability of the lixiviation of metals from the off-balance reserves and poorly balance ores. The correct estimation of the perspectives of those combined technology is still one of the purposes. It is a matter of fact that combining traditional technologies of the underground mining with new ones concerned with the creation of the effective lixiviation of metals from ores can be carried out with the two-stage processing. It happens when the excavation of some amount of the balance reserves creates the compensational space for crushing off-balance reserves. Involving off-balance ores into the production process solves a set of the mining production problems. For example, the fullness of mineral resources usage, the strengthening of the resource base, the reduction of load of the environment and the security of works. The involvement of the off-balance reserves into the development in the course of the revaluation of the resources and in the technological facilities of the development in the context of the growth of the scale of production reduces the production price to the competitive level. The field of application of these results is in the mining enterprises which extract solid metal-containing ores by means of the underground mining. These ores are mostly of the nonferrous, rare and precious metals, which are easily opened by chemical reagents. Combining the technologies of the development for the arrangement of conditions for the lixiviation of metals from the off-balance ores considerably increases the mineral resources of the mining enterprises. It is also a reserve for the survival of the mining enterprises under the conditions of the continuing crisis. Conversion in the lixiviation technology is especially topical for the old mines of the Urals, which have a great reserve of the off-grade raw material.Keywords: deposit; metals; off-balance reserves; lixiviation; underground mining. Подземная разработка рудных месторождений интенсивными методами тради-ционных технологий характеризуется потерями в недрах запасов, забалансовых для применяемых технологий. Опыт передовых предприятий, накопленный до реформирования экономики и разразившегося кризиса, свидетельствует о том, что снижение уровня потерь металлов возможно при вовлечении в производство забалансовых запасов технологиями с выщелачиванием металлов в подземных условиях. Целью исследований последних лет является обоснование техн...

An analysis is made of the performance of pneumatic screw pumps at the Bereznikovsky Soda Plant in order be able to transport light soda along a prescribed route and make use of a new nozzle section to make the pumps' operation more reliable. Specific recommendations are made to increase the throughput and reliability of pneumatic screw pumps. The expediency of replacing long lines of screw pumps by chamber pumps is also discussed.Keywords: pneumatic screw pump (PSP), productivity, light soda, transport pipe, compressed air, nozzles, modernization.Continuous pneumatic screw pumps (PSPs) are designed to transport dust-sized or fine-grained materials along a conduit by means of compressed air. Pneumatic rotary pumps are used as feeders in the pneumatic conveyors employed by cement plants for the in-factory transport of cement. They serve the same function in plants that make ferroconcrete products and in factories that make products used in home construction. PSPs are also commonly used at plants in the chemical, metallurgical, glass, and cellulose-paper sectors, among other industries. There, they are employed in pneumatic conveyors that transport calcined soda, sodium sulfate, alumina, potassium chloride, phosphates, ash, coal dust, ores in powder form, fertilizers, and many other materials. The PSPs currently being built in Russia can convey materials over a distance of 230 -430 m, including 30 m vertically [1 -3].At present, Russian industry makes four main types of PSPs. They range in capacity from 10 to 100 tons/h. The design of these pumps was initially the same as the design of the pumps made by the "Fuller" company in the U. S. The design of the main working elements of the Russian pumps was later modernized so as to significantly improve the pumps' service characteristics, durability, and reliability.When operated under normal conditions and given the proper maintenance, pneumatic screw pumps perform reliably over many years. On the average, PSPs last more than 10 yrs. Among the parts of PSPs that wears most rapidly is the fast-moving pumping screw. The length of the period of continuous operation of the screw is within the range 50 -1000 h, depending on the type of electrodes used. The bronze sleeve and the disk of the check valve undergo considerably less wear. The gland packings in the latest designs of the seal of the screw's shaft average 300 -350 h of continuous use. To optimize the service life of the parts that wear quickly, it is necessary to regularly check the condition of the corresponding components.The wear of the screw is determined by periodically measuring the gap between it and the sleeve. When the size of this gap reaches 5 mm, the screw should be replaced and the worn screw reconditioned by hard-facing its turns with VSN-b electrodes. Electrodes of the T-590 or T-620 type can be used if VSN-b electrodes are not available, but such a substitution will result in a nearly twofold reduction in the remaining life of the screw. The hard-facing operation should be performed by a qualified we...

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The article describes a steeply inclined pneumatic conveyor that transports alumina dust from electrostatic precipitators to the receiving chamber of a rotary kiln in the calcination shop at OAO "BAZ-SUAL". The dust travels through the conveyor in a cascade motion. New equipment is proposed for the continuous transport of bulk materials and relations are presented for determining the technical parameters of the conveyor.

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