Ore preparation including ore transportation, crushing and grinding from the stope to the ore-dressing plant. The energy consumed by the ore preparation workshop accounts for a large proportion of the total energy consumption of the ore dressing plant. In order to reduce energy consumption and make full use of natural resources, the following three measures are used in ore preparation:
First, promote the preparation of circulating water ore
At present, about 70% of the ore in Russia is mined by the open mining method. Many open pit mining has reached a great depth. For example, the mining depth of the Kachary Kalsk mining company has reached 700-720m. If you use a dump truck to transport ore, it will increase transportation costs. In recent years, Russia's ferrous metals mining promotion recirculating ore preparation process, namely in open pit with a crusher for crushing ore, and then use the trunk conveyors and high-angle belt conveyor will transport the ore to the concentrator. Compared with dump truck transportation, the cost of ore preparation is reduced several times after the circulating water ore preparation process, and the dust of the concentrator is greatly reduced. At present, the amount of ore used in the circulating water ore preparation process in Russia and the CIS countries accounts for 10% of the total ore.
Second, strengthen the crushing process
The new crusher is used to reduce the final crushed product particle size by 37% to 70% and crushed to less than 13mm. Russian-made crusher (ΚΜД-3000-T2-Д fine crusher and ΚΜД-2200-T5-Д fine crusher) open crushed ore size 85mm, product size 14~16mm, processing capacity 200~400t /h, these crushers are suitable for the transformation of old ore dressing plants. The inertia cone crusher made in Russia can reduce the particle size of the crushed product to 3 to 6 mm. For example, the ΚΜД-2200 inertia cone crusher has a feed size of 120 mm, a discharge size of 6 mm, and a throughput of 250 m 3 /h (Fig. 1).
Figure 1 Schematic diagram of the inertia cone crusher
1. Old frame; 2. Spring; 3. Fixed cone; 4. Eccentric block; 5. Moving cone; 6. Hollow shaft
Third, in the treatment of viscous ore crushing, the promotion of semi- autogenous grinding machines, especially for some large new concentrators, will not only improve the production capacity of the concentrator, but also reduce electricity consumption. The most famous in the CIS countries is the Lavoisk (ÐавонйÑк) concentrator, which uses a semi-autogenous mill made in the country. The semi-self-grinding scheme has been used in large-scale concentrators built in the CIS. Such as Russia's Udokan (Удокон) copper concentrator, New Norilsk copper and nickel concentrator (ÐоваÑ-ноилъÑк), Kazakhstan's Bosgurisk ( The concentrator and the ÐлмалыÑк concentrator in Uzbekistan, but all imported semi-autogenous mills (Fig. 2 and Fig. 3).
Figure 2 Self-grinding machine for the application of the company 金еóедиÑк
Figure 3 The largest MMC 90×30 type grinding machine in the ÐавоийÑк mining and metallurgy company
(its production capacity is 300t / h)
In the concentrator, about 70% of the energy is consumed in ore crushing and grinding operations. According to the type of ore, the energy consumption of grinding is 20~60kW·h/t. And in many cases, increasing the fineness of the grinding does not increase the dissociation of the mineral, but rather increases the amount of fine ore (-10 μm). Grinding energy analysis shows that 35% to 40% of energy consumption is in the dissociation of the continuum, and 30% to 35% of the energy consumption is in the formation of -40μm. In order to reduce the energy consumption in the treatment of fine-grained ore and to ensure the dissociation of mineral monomers in the case of ore-free grinding, selective disintegration should be used instead of the conventional non-selective routine consisting of jaw crushers and ball mills . Grinding method.
The conventional grinding technology of ore is inconsistent with the principle of selective separation of minerals. A crusher capable of selectively separating minerals has a pulverization method using an energy of a compressed air medium, an explosion pulverization electric pulse (plasma) pulverization method, and the like.
The new vibratory grinding equipment developed by the Mihanopur Mineral Processing Research Institute of Russia is characterized by high dissociation selectivity of the mineral phase. In this type of crusher, the inertial centrifugal force enhances the crushing action, and the material to be crushed in the layer undergoes strong vibration as a result, so that the ore particles are disintegrated along the interface thereof. ВЩД type inertial vibration crusher capable of crushing large pieces of material, can replace medium and fine crushing, and sometimes can replace the first section of grinding КИД type inertial cone crusher, crushing fibrous material I-I cylindrical inertia The crusher and the ВИМ inertia vibratory roller mill for superfine grinding are among the types of grinding equipment.
Although vibration crushing and grinding have a good theoretical basis, there are still many problems that need to be solved for scientists in this respect. The first and foremost is the problem of wear and prevention of damage to the equipment itself. The application of vibratory grinding equipment in the industry is largely determined by the solution of this problem. In addition, reducing energy consumption is a common and urgent problem to be solved by all grinding methods.
The physical basis of selective grinding is that mineral fracture does not occur randomly in the direction of pressure, but rather along the boundary between the useful mineral and the gangue mineral. The Mihanopur Mineral Processing Research Institute of Russia has developed a power self-grinding machine, an inertial cone crusher and an ultra-fine airflow mill to achieve this grinding process. Some non-mechanical grinding methods belong to this column, which can form small cracks in the ore under the electrochemical treatment of the slurry, or create a breakdown channel under the action of accelerated electron energy and high-power electromagnetic pulse to ensure that the mineral phase breaks along its boundary. .
Comprehensive Development Research Institute of Mineral Resources of the Russian Academy of Sciences in the 1980s developed electrochemical process pulp grinding process of new technology, in Dzhezkazgan copper-zinc ore (ДжезказкганÑк) and Mikhaylovsk mining company (МихайловÑк) magnetic iron ore beneficiation, the cathodic polarization treatment and the pulp was added to the cathode during grinding ball consumption can be reduced by 25% to 30%. The factory has produced electrochemical treatment equipment for industrial water. This technology saves 5.10 5 tons of metal per year after being promoted by Russian mining companies.
The Siberian Branch of the Russian Academy of Sciences and the Institute of Mineral Resources Development of the Russian Academy of Sciences have obtained significant results in irradiating ore with accelerated electron energy of 0.4-0.7 Mrad before grinding. Russia produces mass-produced electron accelerators of the ЛД and ÐЛВ models, which continuously illuminate the ore on the belt conveyor with a neutron beam. Since the dielectric package is fast, only a few tenths of a second, the energy consumption of the electron beam to irradiate the ore is not large, but the processing capacity of the operation is limited, usually only equivalent to the capacity of the transporter. The application of electron beams in grinding operations can effectively affect the process performance of iron-bearing quartzite , polymetallic ore and gold ore. Electron beam irradiation can increase the processing capacity of these ore mills by 20% to 80%, while also improving the beneficiation index. The calculations show that after the application of the new process by the six mining companies in the Kursk magnetic anomaly zone, the annual energy savings is 800 MkW·h.
The Institute of Radio Technology and Electronics of the Russian Academy of Sciences and the Institute of Mineral Resources Development of the Russian Academy of Sciences have proposed the use of high-energy electromagnetic pulses to act on mineral raw materials and beneficiation products to selectively grind mineral components. The energy of high-energy short pulses is much higher than the energy of the material in the electrostatic field. When using this high-energy short-wave pulse to process refractory gold ore, the dissociation of minerals is better than the existing grinding equipment with mechanical and physical fracture characteristics. many. The exploratory experiment on the refractory gold ore by the Institute of Mineral Resources Development of the Russian Academy of Sciences, the Institute of Radio Technology and Electronics of the Russian Academy of Sciences and the Central Institute of Nonferrous Metals and Metal Mines has proved that the ore is acted upon by high-energy electromagnetic pulses. The power consumption of crushing mill is reduced by 2/3 to 4/5, and the dissociation degree of mineral monomers is improved. Therefore, the recovery rate of gold and silver in the noble liquid is increased by 25% to 30%, and the concentrate can obtain a high process index without roasting and high-pressure oxidation treatment, and the recovery rate of gold reaches 90%.
In order to commemorate the academician of Prakish, Russia held a symposium on “Meticistic changes in the mineral process properties through mineral physicochemical interactions in useful mineral dressings†in September 2003. 93 papers were read out. The essay is divided into four parts: the physical role in the mineral ore dressing process (high-energy electromagnetic pulse, electric pulse and electrochemical action); the application of physicochemical action to strengthen the useful mineral beneficiation process; the application of purposeful action to strengthen the ore dressing process of different ores; Purpose The process mineralogy in the process of useful components.
The gold-bearing sulfide ore is treated with a 2.45 Henry Hertz ultra-high frequency field, followed by grinding and cyanidation. The test results show that the total energy consumption of grinding is 2kw·h/t, which is 20%-30% lower than that of untreated, reducing the wear of the mill and increasing the dissociation of useful minerals by 2 times. The possibility of using high-frequency electromagnetic field energy to improve the grinding effect of gold-bearing sulfide ore is confirmed.Pedal With Toe Clips,Resin Bike Pedals,Flat Pedals Mountain Bike,Mountain Bike Pedals
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