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duction. In this regard by NMMC specialists has been developed economic uranium extraction development program until 2020 year and have been implemented some measures:
- Bridging into service of the new perspective deposits;
- Modernization of the existing sulfate plant and construction of the new one;
- Construction and start-up in 2013-2016 new underground leaching deposits under North Kanimeh and Sugrali deposits;
- Reconstruction of the shop # 3 of the Hydrometal-lurgical plant # 1;
- Development of the program shall guarantee stable growth of the uranium production output at NMMC until 2020.
Yunusov Bokhodir, senior teacher
chair «Informatics, automation and managements», Tashkent chemical institute of technology, Tashkent, Uzbekistan E-mail: [email protected]
Development of Algorithm of process management of ore enrichment in fluidizated layer
Abstract: The automated installation with the device of multicell separation of loose material is developed, with algorithm of intellectual management air separation process in a fluidizated layer of the crushed particles of the different limiting sizes and offered a function chart of an automated control system by process of an air separation of loose materials in a fluidizated layer. For this purpose using Archimedes, Lyashchenko and Reynolds's criteria, algorithmization of calculation of speeds the beginning of a fluidization and an ablation ofparticles of different density and is carried out the sizes, the formalized equations allowed creation of computer model of process of an air separation of firm particles in a fluidizated layer with use of a package applied the MATLAB programs. Nomograms of change of speed of gas depending on density and the sizes of particles of separated loose material are received.
Keywords: mathematical model, air separation, beginning of speed fluidization, speed of ablation, algorithm of management, automated control system.
Application of methods of an air separation at enrichment of ores of rare and precious metals is caused by that use of traditional methods are accompanied by big power consumption and water.
Technological installation of an air separation offered by us in a fluidizated layer analyzed by use of the multistage system analysis [1].
For the bottom hierarchical level process of moving of particles is defined. For this purpose, considering the forces influencing a particle, possible movings of certain particles are defined. Thus, it is possible to find equilibrium speed of a stream, at which particles of a certain weight will be is in a scaled condition [2-5].
For particles of the identical size ablation from the device depends on weight (specific weight) of particles.
Calculations defined speed of an air stream for a conclusion of a particle of easy weight. The maximum
limit of this speed should not reach the speed deducing particles with heavy weight.
By fluidizated consideration with use of the criterion equations, is defined possibilities of creation of a fluidizated layer and questions of determination of speed of ablation of particles.
Considering disorder of the sizes of particles, defined equivalent diameter of a particle. Knowing equivalent diameter, it is possible to define speed of the beginning of a fluidizated and to pass to definition of criterion of Archimedes. Then, it is possible to define Reynolds's criterion for a fluidizated layer.
Reynolds's criterion for a particle is defined by the classical equation according to which it is possible to define speed of a fluidizated or speed of a ablation of particles.
If speed is known, it is possible to define a consumption of gas.
Thus, it is possible to define speed or a consumption of gas for providing a fluidization.
On the basis of such algorithm the computer model of process of a air separation of firm particles in a fluidi-zated layer with use of a package applied the MATLAB programs (the Fig. 1 is made.). By means of computer model speed or the consumption of gas (air) providing a fiuidizated or speed of ablation of particles is defined.
It is possible to define ablation limits, both heavy particles, and easy particles. If these diameters do not satisfy the put requirements, options change of an expense and speed of gas depending on diameter of particles then are considered. Choosing diameter of particles and its limits of change, it is possible to find the solution of separation of a loose material with various density.
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Fig. 1. Computer model for calculation of speeds of a ablation and the fluidizated beginning depending on diameter and a type of particles.
On figure 2. The dependences of speed ablation begins from diameter and a type of particles are given.
x 10"5
Diameter of particles (m) Fig. 2. Dependence of speed of ablation from diameter and a type of particles
From schedules (fig. 2) it is possible to define speed of air at which the components being in a mix, with certain sizes of particles in the device with a fluidizated layer, will be in a suspension.
The analysis of schedules shows that for the chosen test of ore, with reduction of the sizes of particles (0.001-0.020 mm), the limiting sizes of the particles, providing a good separation decreases to two, at most till three sizes of particles. With reduction of the limiting sizes of the particles, each test is necessary for passing through installation with the fluidizated layer, adjusted on these limiting sizes. In this regard, the air separation of particles with the smaller sizes will need bigger number
of devices with a fluidizated layer. At the big sizes of particles (0.060-0.080 mm), the limiting sizes of the particles, providing a good separating increase till seven and nine sizes of particles. On the other hand, at smaller diameters of particles of influence of the maintenance of an enriched material on particle density it is more than at big diameters of particles. Therefore, we recommend to carry out enrichment of a loose material in a range of the crushed particles 0.030-0.050 mm where the limiting sizes of particles providing a good separations are in limits of five and six sizes of particles. Thus, ore enrichment in this range will need four installations with a fluidizated layer.
Fig. 3. A function chart of an automated control system for process of an air separating of loose materials in a fluidizated layer
Computer models air separation particles in a fluidizated layer, both for a periodic mode, and for a continuous operating mode of the device are formalized. The design procedure of air separation of particles in a continuous operating mode of the device is developed.
On the basis of the carried-out analysis and calculation installation with the device multicell separation of a loose material is developed. This device has the extended case of corridor type which on length is divided into the squares, each square has separate air intakes with the set expense and each square has a partition for maintenance of a fluidizated layer.
The offered technological scheme of preliminary enrichment with use of installation of separation is provided in a fluidizated layer on rice 3. For separation in a fluidizated layer ore is crushed previously by means of a grid-iron roar, a rotor inertial crusher, an loading elevator, an inertial roar, a crusher of the combined shock action and a centrifugal mill of counter blow. The crushed ore moves in system 1, established consistently, for separation on the sizes of particles on sets 50, 44, 39, 34 and 30 microns. The exit with everyone sieves goes to separate bunkers 2-6 and gravel pumps 7-11, moves in the loading bunker 13 of installation of a multistage air separation in a fluidizated layer 12. Installation works as follows:
From one of capacities 2-6 through a feeder the 14th material arrives in the first section of a air separator where under the influence of the air submitted from under grids 15, the boiling layer and easy components is formed are carried away by air in a cyclone 20, and the ore rest, because of a fluidizated to pass through a partition 18 to the following step of a separation.
Air moves in separate sections of a separator. In process of transition of ore to the following step, ore is more and more released from easy components. From the last step the rest of ore arrives in the collection of heavy components 19 and from there the enriched ore is loaded into containers.
Considering higher to carry out the provided recommendations enrichment of a loose material in a range of the crushed particles 0.030-0.050 mm, from nomograms, the limiting sizes of particles providing a good separation (0.030-0.034, 0.035-0.039, 0.040-0.044 and 0.045-0.050 mm) were defined. Exits from each of these sieve go to separate capacities 2-6. The crushed ore of the next sizes gathering in various capacities is exposed to process of an air separation: A) particles in the size less than 30 microns (capacity 2); B) particles in the size of
30-34 microns (capacity 3); C) particles in the size of 35-39 microns (capacity 4); D) particles in the size of 40-44 microns (capacity 5); F) particles in the size of 45-50 microns (capacity 6). It is necessary to provide a process continuity for what gravel pumps different fractions move serially in the loading bunker and from there in the first section of an air separation. In process of a dumping of a loose material in the bunker, there is a switching on other bunker and each time a consumption of air submitted to a air separation changes depending on the sizes of particles.
We offered the automation scheme in which switching for new speeds (expenses) of air depending on the sizes of particles is carried out by an automated control system (fig. 3) for what algorithms of management of giving in the loading bunker ofparticles ofthe different sizes (fig. 4) are developed.
Algorithm of management of air separation process in a fluidizated layer is as follows:
In this system there are bunkers for five fractions of a loose material, each of which are supplied with primary converters of level with analog that target signal. Usually, capacities are filled not evenly. At separation of the crushed ore with the help sieve some capacities are filled quicker, and some slowly. For management of such processes use adaptive control systems. Process an air separation begins supply of the crushed ore with the bunker in which level of a loose material has the maximum value. Signals from primary converters continuously appears in the controller. After a dumping of this bunker, the controller carries out shutdown of its capacity pump, comparison of levels in all other capacities further is carried out, the capacity pump turns on where level has the maximum value and a loose material from this capacity moves in the loading bunker. The controller switches the consumption of air corresponding to the new size of particles.
Each time when level of a loose material reaches the bottom level, is disconnected the bunker pump from which the loose material is selected and the bunker pump starts to work where level has the maximum value and a consumption of air is switched according to the limiting sizes of particles in this bunker.
In case in any bunker level reaches maximum-permissible maximum value, the bunker pump with which is disconnected the loose material is selected and the bunker pump starts to work where level reached extremely maximum value and a consumption of an air is switched according to the limiting sizes of particles in this bunker.
Fig. 4. Algorithm of management of an automated control system for an air separation process in a fluidizated layer
References:
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2. Yusupbekov N. R., Nurmukhamedov H. S., Zokirov S. G. Main processes and devices of chemical technology -Tashkent, Teacher, 2003. - 557 B.
3. Formalization of mathematical model of process of air separation of loose materials/D. T. Karabaev, B. I., Yu-nusov, A. A., Artikov./Sixth, World Conference on Intelligent Systems for Industrial Automation. - Tashkent, Uzbekistan November 25-27, 2010.
4. Pneumoseparation process computer modeling of the crushed ore in a fluidizated layer/B. I. Yunusov., D. T. Karabaev A. A. Artikov./Seven, World Conference on Intelligent Systems for Industrial Automation. - Tashkent, Uzbekistan November 25-27, 2012.
5. Determination of speeds of fluidizated separation of loose materials./Yunusov B. I., Karabayev D. T., Ar-tikov A. A./TamrTy Chemical technology. Control and Management. 2/2011.
