Vol 110

The growth of unit capacity and the cost of loading and transportation equipment requires a significant increase in the efficiency of their operation, the establishment of a rational level of reliability of machines of various types and in general transportation system of quarries.

In the last decade more and more widespread use at quarries find dump trucks and road trains of greater load capacity, working in conjunction with powerful excavators.

Measurement of the mass of the cargo directly in the body of a heavy-duty dump truck is carried out by the built-in weighing device by gas pressure in the cylinders of the pneumohydraulic suspension.

At operation of powerful excavator-truck complexes there is a problem of sharp increase of shock loads on dump truck structures in the process of their loading.

At present there is a tendency of application on the majority of large quarries of more and more powerful dump trucks with electromechanical transmission.

In the eastern part of Cuba, in the province of Holguin (Nicaro-Moa region) is located one of the richest iron-nickel deposits in the country, represented by laterite ores.

The AMKI unit was created in Leningrad for the construction of single-wall subway stations. The unit is a transportation and tunneling complex, in which the transportation devices are its main structural element.

At the mine "Leningradskaya" of PO "Leningradslanets" in place of discontinued cars VD-5,6 sectional trains PS-3,5, made by Druzhkovsky and Kiselevsky machine-building plants, are used.

The distribution of loads between the drives of a multi-drive belt conveyor has a significant impact on the amount of tension of the load-carrying belt, especially in the case of uneven loading of the conveyor along the length.

The efficiency of operation of conveyor transport can be significantly increased by using multi-drive belt conveyors (MDBC), which allow to use the full width of belts, use belts of reduced strength, as well as significantly reduce the cost of mining and capital works by eliminating transfer points.

Backbone belt conveyors, as well as main hoist conveyors installed in inclined shafts of mines, has, as a rule, a significant length.

Achievement of economic effect while ensuring the reliability of transportation plants without additional costs is the basis for the intensification of hydrotransport.

Processing of polymetallic ores with low content of useful minerals is associated with the need for fine grinding in the process of their enrichment.

The formation of mineral-organic deposits on the inner surface of slurry lines, valves and pumps leads to a sharp decrease in their service life, increased energy and operating costs, reduced productivity of the entire hydraulic conveying system.

A slurry pumping system is considered, in which there are several working lines consisting of pumps in series and several reserve lines, which are switched on in case of failure of the main working.

One of the most important environmental requirements, determining the attitude to tailings and tailings dumps of non-ferrous metallurgy enterprises as possible centers of environmental pollution - ensuring the necessary level of operation and condition of tailings dumps.

Peristaltic pump according to the principle of operation belongs to displacement pumps (volumetric). The main element, which ultimately determines the reliability of the pump, is the working hose, taking in the process of operation loads determined by the deformation of the walls of the hose and internal pressure.

Reliability and efficiency of hydrotransportation systems depends not only on the use of modern high-efficiency and highly reliable equipment, but also on the possibility of regulating the operation of such systems at various changes in the technological cycle of mineral processing at mining enterprises.

At operation - systems of main coal hydrotransportation systems reliability can be increased, if to simplify the structure of systems, for example, to apply such a facet composition of a hydraulic mixture, that in system the dewatering complex is not necessary.

Serpentinite rocks form a broad belt that can be traced across the northern part of Holguina Province in eastern Cuba. They occur in association with nickel-bearing laterite ores.

The only plant in Cuba that produces nickel and cobalt concentrate from laterites is the PedroSomo Alba plant. It uses hydraulic conveying to move mixtures with saturations ranging from 25-30 to 45-49% solids.

A distinctive feature of tailings from mining and metallurgical enterprises is their fine particle size. This is explained by the need to process depleted ores, which requires fine grinding for more complete extraction of useful components.

Backfill mixtures into the excavated space are usually fed by steel pipelines laid along the existing mine workings, and their routes are far from ideal in terms of the maximum required length of delivery in gravity mode.

The development of the USSR national economy sets the task of intensification of production, development of labor- and material-saving technologies and equipment. One of the ways to solve this problem is to create equipment of optimum productivity with simultaneous reduction of its specific material intensity.

One of the most important tasks of the national economic plan for the development of industry is the introduction of high-performance technology of mining and processing of minerals. An essential part of this technology is the movement of minerals in the form of bulk materials, as well as waste enrichment in ferrous and non-ferrous metallurgy.

One of the essential elements determining the reliability of hydrotransportation systems is their linear part - main pipelines. Service life of pipelines - one of the main criteria of reliability assessment - depends on the degree of hydro-abrasive wear of their walls.

In the case of seismic impact on a pipeline fixed on supports, the vibrations are composed of a transverse and a longitudinal component. A transverse wave of large amplitude can cause an emergency shutdown of a hydraulic transportation line.