In recent years, the state has attached great importance to energy conservation and emission reduction, and has issued a series of major policy measures. On May 23, 2007, the State Council issued a Comprehensive Work Plan for Energy Conservation and Emission Reduction, which comprehensively deployed energy conservation and emission reduction work. A new requirement was put forward: during the “Eleventh Five-Year Plan†period, the national energy conservation and emission reduction binding index is: the energy consumption per unit of GDP is reduced by about 20%, and the total discharge of major pollutants is reduced by 10%.†As a mineral processing field, the ore dressing The factory is a typical energy-intensive household, and its responsibilities are heavy, and the arduous task of tackling the hardship can be imagined. Energy saving and emission reduction is especially urgent for many concentrating plants with backward technology and outdated equipment. In general, the general problems in the concentrator are mainly reflected in the following aspects: 1 The final product has a coarse grain size (between -20-30mm), and the particle size composition is very unreasonable (the material composition less than 5mm is less than 7%). ). 2 Ball mills are small in scale and basically use a sliding bearing structure. 3 sorting equipment is inefficient, such as a single volume of flotation machine, self-suction structure and so on. 4 The beneficiation process has not kept pace with technological progress. In order to solve these problems fundamentally, we must make full use of the large number of scientific and technological innovations in the field of mineral processing (mineral processing) in recent years, and timely renovate the process and update equipment. Improve the basic support for the mine to develop sustainablely and build a resource-saving and environment-friendly enterprise. I. Energy-saving solutions in the process of mineral processing (A) metal leaching recovery This leaching and recovery metal process is divided into: in-situ leaching and crushed ore heap leaching. Large-scale application of this technology originated in the 1950s and 1960s only applies to a few of several metal ore, such as copper ore, gold and silver ore, rare earth ore and so on. Taking copper extraction from copper mines as an example, the technology has not been widely applied on a large scale due to problems such as low leaching efficiency, leaching material conditions and environmental requirements. However, since the 1980s, large-scale production began in the United States, Mexico, Chile, Canada and other countries and regions due to the birth of high-efficiency extractants (Lix984 series and Acorga series) and leaching agents. At the end of the 20th century, the use of leaching-extraction-electrowinning copper production exceeded 800,000 t/a, and its copper production accounted for about 15% of the total production. Domestically, large-scale leaching production mines have also emerged from the 1990s. This chemical beneficiation process for recovering valuable metals has significant advantages over traditional physical beneficiation processes in terms of energy consumption and production costs. According to reports, in the United States in 1992, the leaching-extraction electrowinning method produced 37 cents/lb of copper, while the traditional beneficiation smelting process cost 60 cents/lb of copper, of which the main cost savings were energy costs. The method utilizes secondary resources of tailings and waste. These effects are very obvious, such as Jiangxi Dexing, Yunnan Dongchuan, and Shandong, Xinjiang and other places, the scale is generally 100 ~ 3000t copper / a, more suitable for China's copper mines scattered, small, more points, conventional Copper minerals that are difficult to recycle by mineral processing methods. In this regard, this article does not need to be described in more detail, there have been many related reports. (2) Scale production In the scale economy of mineral production, the domestic market is far less than the developed countries in the West. The productivity of domestic mines is nearly one-twentieth of the former. However, this is related to the basic national conditions of China, and China’s super-large reserves of mines (such as Dexing) There are not many copper mines. Most mines are only suitable for medium and small-scale production, and solving labor employment is an important issue that cannot be ignored in the process of China's economic development. This article only emphasizes here: the conditional mine should still adopt the mode of scale production, which not only can reduce the production cost, but also can significantly reduce the electricity consumption, and the economic benefits are obvious. (3) Optimization of grinding process Although the old traditional techniques of some old mines also emphasize the "small grinding and grinding", the effect is not satisfactory. The final crushing size of the general crushing ore is -30~-15mm. In recent years, due to the continuous advancement of mineral processing technology , “multi-breaking and less grinding†can be achieved better. After the transformation of the Dahongshan Mine in Yunnan, the particle size of the crushed product decreased from -15mm to -10mm. Similarly, the mill treatment increased from 7500t/d to 10000t/d, an increase of about 33%. Cheng Chao iron ore crushed mineral grain size decreased from -15mm -8mm, mill equipment without increasing the main concentrator processing capacity increased from 2 million t / a to 3,000,000 t / a. Energy saving effects (lower steel consumption and lower energy consumption) are significant. In order to increase the efficiency of the ball mill, the Shizishan Copper Mine improved the processing capacity of the ball mill by 7% after using the micro-stage grinding technology, and the power consumption decreased, and achieved good economic benefits. Bauxite grinding process in the presence of significant selective grinding behavior, A1 2 O 3 concentrate in the coarse fraction, while the fine fraction enriched in SiO 2. After the grinding aid is added to the grinding process, the process can be strengthened. Compared with the ungrinded abrasive, the product yield of A/S greater than 9 can be further increased by 9%, and the recovery of Al 2 O 3 is increased by 10 %the above. These technical measures to optimize the main energy-consuming processes have produced significant effects in terms of energy conservation and consumption reduction in the concentrator. (4) Conveyor material transportation Here we only make some analysis of the material handling in the production process of the traditional concentrator. We know that the material handling of the concentrator includes: raw ore transportation, in-plant transportation, and tailings transportation. Some old mines, especially those that have been put into operation in the 1980s, are concentrated in the whole mining area. The mining stope, the concentrating plant and the tailings pond are close to each other, and the material transportation scheme is better. Moreover, at the time of slurry material transportation, transportation The pump has been controlled by electrical frequency conversion. In the entire material handling of the concentrator, the design is more reasonable. However, after many years of continuous production, many tail mines have reached the service life. They need to be sited separately or re-arranged according to the current environmental assessment standards. This requires designers to fully compare the optimization and comparison between environment and energy consumption. Second, energy saving programs in mineral processing equipment (1) crushing equipment After entering the 1990s, the technology of crushing equipment has made rapid progress. Among them, the medium and fine crushing equipment, which is the key to energy saving, is the most important. This paper mainly describes the cone crusher suitable for mass production. At present, cone crushers commonly used at home and abroad include PY, PYY, Simmons, mesto HP, MP, GP series cone crushers, SANDVIK H, S series crushers, H8800 and so on. These cone crushers basically have the following four common features: 1. High-energy design, which achieves high productivity by greatly increasing the transmission power, and indirectly realizes the miniaturization of the equipment. 2. Change the type of crushing cavity to achieve the crushing of the mineral material layer. 3. Apply advanced hydraulic system for easy operation and adjustment. 4, computer automatic control, to achieve a good man-machine interface. For example, HP series cone crusher adopts slow cone, high swing frequency, large eccentricity, peripheral multi-cylinder hydraulic compression and spherical bearing support structure to facilitate mining and improve processing capacity, and can also produce ideal ground material. It is precisely because of the excellent performance of these devices that the final crushing size of the crushed ore is greatly reduced. In the product, the composition of -l0mm accounts for 80%. It has created very good conditions for energy saving in the concentrator. (2) Grinding and grading equipment 1. Large-scale ball mill Large equipment is one of the ways to save energy and reduce consumption. The comparison between the φ6.5m × 9.65m ball mill and the small-size ball mill of Nawei Sydvarangers iron ore dressing shows that the electricity consumption per unit is 22.7%, the consumption of single-product steel is 14% lower, and the consumption of liner is 33%. The φ6 produced by Australian ANI Group The .706m×13.106m ball mill is currently the world's largest ball mill with an installed power of lOMW. The largest ball mill currently used in China is the φ5.49m×8.83m ball mill (power 4500k) imported from the United States and the φ5.49m×8.53m ball mill from the United States Fuller Company. 2. Automatic control of grinding classification process Through automatic control, the quality of powder materials and the stability of powder quality are improved. This is also the main aspect of the gap between China's powder products and foreign products. Through the automation of the grinding and grading process, the Lingchang Mining Company's concentrating plant has improved the grinding treatment capacity by about 10%, and the annual iron powder of more than 67.5% of the product is about 300,000 tons, which improves the economic benefits of the enterprise and improves the efficiency. Utilization efficiency of mineral resources. 3, the application of high frequency fine screen High-frequency fine screening is a high-efficiency fine-grain screening equipment with high processing capacity, high screening efficiency and significant economic benefits. In China, an iron ore mine adopts a 2SG48 high-frequency fine screen in the process of technical transformation, replacing the cyclone and nylon fine screen in the original two-stage grinding process, which can remove one of the two-stage grinding mills. station. After the process transformation, the screening efficiency is greatly improved, and the production capacity of the new-200 mesh of the second-stage mill is increased from the original 1.1t/(h·m 3 ) to the current 1. 6t/(h·m 3 ). Its grinding energy saving and consumption reduction is very large. 4, the application of column mill Since the column mill is, the thickness of the layer between the roller and the liner can be flexibly fluctuated according to the size of the material particles, and there is no contact therebetween, thereby effectively avoiding the energy consumption caused by the impact of the roller and the liner. The ultra-fine crushing process is used to transfer a part of the grinding work of the ball mill to the column mill. When the grinding size is -25mm, the product size can reach -3mm, the system energy consumption can be reduced by more than 30%, and the final grinding can save 30%. 50%. The energy saving and consumption reduction is also quite obvious. 5, the application of the stirring mill After the 1990s, high-strength ultra-fine agitating ball mills (peeling machines) have been widely used. The equipment has the advantages of high stirring speed, high ultra-fine grinding efficiency, large production capacity, continuous production, etc. It is a new type of high-efficiency ultra-fine grinding equipment with broad development prospects. The representative of the agitating mill is Attritor, JM-1000 type, SJ-90 type and the like. This is a very important energy-saving design principle, so that most of the energy consumed is used to directly agitate the medium to achieve the grinding effect, instead of consuming energy to rotate or vibrate the huge heavy grinding cylinder. The results of the University of Utah study show that under the same feed particle size, the vibration mill, ball mill and agitator mill have an average particle size of 6 mm, 4.9 mm and 2.lmm at 100 kWh/t. 6, the application of high pressure roller mill At present, Hamburg and Krupp have sold more than 50 high-pressure roller mills for more than a dozen cement plants and concentrators in the US, Canada and Germany. The specifications of the high-pressure roller mill have reached φ2.8m, the feed size is 250mm, the drive power is 1400kW, and the processing capacity can reach 250-400t/h. The advantages of high-pressure roller mill are: reducing energy consumption by 20% to 30%, increasing processing capacity by 30% to 40%, saving steel consumption by 90%, simplifying process flow, saving investment by 25% to 30%, and reducing operation and maintenance costs. The ore is highly adaptable and can handle 15% ore of ore. Therefore, it is a new type of equipment that is energy efficient. High-pressure roller mill is an effective measure to further reduce the particle size of human grinding. The Los Angeles Colorado Iron Mine in Chile installed the 1700/1800 high-pressure roller mill from Humboldt, Germany. The results show that the average grain size of the roller press is -2.5mm. The grain size accounts for 80%. The roller press can replace the two-stage crushing. If the roller press is not used, the third stage (with a short-head cone crusher) should be installed when the processing capacity is 120t and the crushing size is -6.5mm. The fourth stage is broken (using a Cyradisk cone crusher). The energy saving effect can be imagined. 7, ball mill structural transformation Due to the improvement of bearing materials and manufacturing technology, the use of rolling bearing structures in small and medium-sized ball mills has become a reality. The characteristics of this transformation technology are: (1) Replace the sliding bearing with a dedicated rolling bearing, and replace the bearing housing at the same time, retaining the original ball mill foundation. (2) Adopt a one-way flow soft seal. (3) The outer joint member of the ball mill is not changed. (4) Increase the bearing temperature control device. After adopting this technology, not only the maintenance workload is greatly reduced, but also the energy saving effect is also obvious. According to the application situation of many concentrators, the electricity saving is about 7%. (3) Sorting equipment Sorting equipment in energy concentrator, although far larger than the comminution equipment, but still can not be ignored at the time of design choice, as the size of flotation devices, the outer pneumatic structure; high field strength permanent magnetic separator; high weight Selection of equipment, etc., are the design of choice. In comparison, the energy-saving effect is considerable. Since the sorting equipment is highly targeted, it is not convenient to describe it one by one. Third, the practice of energy saving renovation of the ore dressing plant A mining company's concentrating plant's capacity expansion optimization project in Hubei Province, through a series of transformations such as crushing, grinding and floating. The total investment is nearly 30 million yuan. The technical transformation was carried out in the following four aspects: 1. Replace the original old-fashioned hydraulic cone crusher with Mesto's HP and GP series cone crushers. 2. Replace the original JJF-4 flotation machine with KYF-8 flotation machine; 3. Renovate the main bearing of 2736 ball mill, adopting rolling bearing structure; 4. The slurry conveying pump adopts electrical frequency conversion control. After the project is implemented, the production capacity of the concentrator will be increased from the original 3000t (ore) / d to 4000t (ore) / d. The most outstanding performance is that the electricity consumption per ton of raw ore is reduced from the original 31.17kWh/t to 23.77kWh/t. At the same time, due to the advanced technology and equipment, the recovery rate of ore is increased by about 2%. According to this calculation, the energy saved by the mining company's concentrator will be: Tons of raw ore directly converted into electricity consumption decreased standard coal: 1.32 million t* (31.17-23.77) Kwh/t=976.8 million kWh/a The equivalent standard coal is 9.668 million kWh*4.04t/10,000 kWh=3946.27t (coal)/a Increase mine copper discount into standard coal: 132*31.17/132*0.64%*77%=6325kWh/t mine copper 132*0.64*(79%-77%)*6325=106.89 million Kwh/a 106.89 million kWh/a*4.04t/10,000 kWh=431.83t (coal)/a Total savings in electricity consumption converted into standard coal: 3946. 27t+431.83t=4378.1t coal/a Fourth, the conclusion Mine production enterprises are a special industry. On the one hand, they directly have a significant impact on the local natural ecological environment. On the other hand, they consume a lot of electric energy in the process of utilizing mineral resources. It belongs to the main target of “energy saving and emission reduction†in this country. This is a spur and an opportunity. A number of mine concentrators have successfully completed the technical transformation of the concentrator with the good opportunity of the continuous increase in the price of mineral products in recent years, and achieved remarkable results. However, there are still a few concentrators still using the backward processes and equipment that should be eliminated. In this regard, the relevant departments may refer to the mandatory elimination policies of other industrial sectors to fundamentally change the high energy consumption problem. Several institutional reforms in the mining industry in the past few years have activated the mining economy, but they have also weakened the industry's binding mechanism. What kind of mechanism is adopted to strengthen the technological progress of the industry, and coordinate and guide enterprises to go out of the internal energy-saving and emission reduction mode based on their own “single-play†style. Taking the road of multi-enterprise and inter-regional circular economy is conducive to a wide range of areas and greatly improving the effectiveness of energy conservation and emission reduction. It will be an issue that the relevant state departments should pay attention to in the future. Belt Tensioner Pulley,Stamping Belt Pulley,Rivet Tensioner Pulley,Bearing Pulley Taizhou Chenhui Machinery Manufacturing Co., Ltd , https://www.chenhuipulley.com
Design of energy-saving renovation plan for mineral processing plant