With the increasing demand for coal in the market, the selection of reliable coal preparation technology and equipment in coal mine production is related to the efficiency of coal preparation. Under the influence of this situation, as an important equipment for thermal coal separation, the rational use of jigs has brought an important role in guaranteeing the smooth completion of the coal preparation operation plan. Cost of production. With the acceleration of the development of modern coal mines, it is necessary to strengthen the research on jigging coal preparation technology and equipment, reduce equipment energy consumption, maintain good economy and energy saving and environmental protection in the use of coal preparation technology, and comprehensively improve the overall production of coal mining enterprises in my country efficiency.
Among the existing coal preparation processes in my country, jigging coal preparation is one of the most widely used coal preparation processes. It has many advantages in the process of coal preparation, such as mature technology, strong negative, and high separation quality. , the technology is relatively simple, and the cost of process control is low. With the continuous progress of the economy and society, coal preparation methods are also facing new challenges. How to carry out a new understanding and repositioning of jigging coal preparation has become a key issue for the coal industry.
1. Overview of jigging coal preparation technology
Jig coal preparation has a history of more than 100 years and is a mature coal preparation method. Jig coal preparation is a coal preparation process carried out according to the difference in particle density in a vertically pulsating medium. The medium for jigging coal preparation is water or air, and some suspensions are also used. The jigging process has the advantages of simple process flow, large production capacity, convenient maintenance and management, and low production cost. Suitable for handling very and easy selectable and medium selectable coals. The upper limit of separation can reach 50-100mm, and the lower limit of separation is 0.3-0.5mm, which can be selected by classification or not. The separation efficiency of jigging coal preparation method is greatly affected by the properties of materials. Under the condition of poor selectivity, the sorting efficiency will drop significantly. The jig machine is equivalent to the heavy medium separation, but when low ash clean coal is required, if the separation density is lower than 1.4g/cm3, it may be difficult to operate the jig machine due to the difficulty in selectivity, and normal operation cannot be guaranteed. Sorting effect. In recent years, with the research and application of new technologies, jigging coal preparation equipment has also made great progress, mainly in the structure of the jigging machine is more scientific and reasonable, the level of automation is becoming more and more perfect, and the separation effect is further improved. Today's jigging machine has developed from mechanization in the past to automation and intelligence, which better meets the process requirements, and the quantity and efficiency of jigging coal preparation are closer to the theoretical value. Our country has done a lot of work on the automatic control of the jig machine, and achieved many results. Currently commonly used jigs are LTX, LTG, X and SKT. LTX type and LTG type are early design models, both adopt the discharge mechanism composed of overflow weir, straight gate, discharge wheel and guard plate. Because the discharge wheel is too close to the discharge port, the material on the discharge wheel is easily affected by the pulsating water flow and flows out by itself, so it is difficult to control the discharge volume. In addition, it is easy for the discharge wheel to be stuck by bulk materials when it is placed in the discharge channel. Therefore, this structure has not been able to achieve a good application effect. The main contradictions of jigging coal preparation are: density stratification and looseness, the loose form of overall support and numerical control air valve, high acceleration and looseness, wide grade and non-graded washing.
2. Application of jigging coal preparation technology
The application of jigging coal preparation technology mainly depends on the jig machine. Therefore, the application of jigging coal preparation technology and the development and application of jigging machine, the Baum jig machine appeared earlier in our country, this kind of machine It was more popular in the 1960s, and many coal preparation plants would use this kind of jig for coal preparation. However, after entering the new century, the rapid economic development has made the jigging coal preparation technology encounter more severe challenges. In this century, jig coal preparation has the following applications:
2.1 Application of moving screen jig
During the development of jigging coal preparation technology, most of the jiggers used by people are designated sieve jiggers. In fact, the jig can be divided into two types: the fixed sieve jig and the dynamic sieve jigger. The dynamic sieve jigger is an ancient coal preparation method, but it has gradually been fixed because it is mainly used in lump coal. Replaced by sieve jigging technology. In recent years, with the gradual development of coal enterprises, people have higher and higher requirements for coal quality, and almost all kinds of coal need to be processed. Under this social demand, the dynamic screen jigging method has returned to coal preparation In the ranks of advanced technologies, and certain technological changes have taken place under the new situation, the effective combination with modern technology has endowed the dynamic screen jig coal preparation technology with new connotations.
Based on the experience of using the TD series hydraulic dynamic screen jig in the past few years, my country has developed a new mechanical drive method. Compared with the traditional hydraulic drive coal preparation technology, the structure of this method is relatively simple. The reliability of the machine is also gradually increasing, and in the process of maintenance, it brings certain convenience to the maintenance work, which is why it is welcomed by the industry.
At present, the new power quick return mechanism dynamic screen jig proposed by Tangshan Coal Research Institute in my country has good quick return characteristics, and the processing time during work is basically kept within the range of 80t/h~120t/h, which can be used for the selected It provides a reliable guarantee for the completion of the coal operation plan on schedule. The dynamic screen jig using this new Dongliu quick-return mechanism has good environmental applicability, good separation effect and stable operation status due to its quick-return speed ratio of about 1.8, which fully meets the requirements of actual operations. program specific requirements.
Combined with the various needs of the coal preparation operation plan, gradually expanding the practical application range of the large-scale dynamic screen jig will help to improve the separation efficiency in the coal preparation process, increase the sales volume of different coal qualities, and meet the actual needs of users to the greatest extent. need. Under the action of a reliable moving screen jig, it is possible to carry out targeted operations on high-sulfur coals with a particle size of less than 300mm and greater than 50mm, and select coals that meet actual needs. Through the rational use of large-scale dynamic screen jigs, the ash content of the final clean coal can be kept at 3.2%, and the actual separation efficiency can reach 95.3%, which basically meets the actual requirements of coal preparation. Therefore, the actual application scope of large-scale dynamic screen jig should be expanded in the implementation of coal preparation operation plan in the future.
In addition, the development and popularization of the moving screen jig machine is a major achievement of coal preparation technology in my country in recent years. The moving screen jig has many advantages: first, its structure is relatively compact, and its process is relatively simple compared with the previous technology; second, it consumes less water, which saves a large part of the investment cost for the enterprise. The moving sieve jig is mainly used in the process of pre-discharging gangue and the washing process of thermal coal, and is used in alpine regions and water-deficient regions because of its low water consumption.
2.2 Application of fixed screen jig
While competing with other coal preparation technologies, the jigging machine is also gradually improving its own shortcomings. In the new era, various research institutions are actively researching and summarizing the experience of using the jigging machine, and devoting themselves to the development The diversified jigging machines required by social development and market demand have the advantages of high efficiency and automation. In the development of jigging machines in recent years, SKT series and X series are widely used, among which SKT intelligent jigging Machine-screened coal technology has occupied a considerable share in the market.
SKT jig has many advantages: first, for the under-screen air chamber, it mainly adopts the U-shape oscillation mode, which keeps the pulsation of the bed stable; second, for the air valve, its The sliding type numerical control air valve is adopted, which not only saves labor when opening, but also produces less noise, and is very reliable in the application process; thirdly, it adopts computer numerical control device, which is easy to operate. It is very convenient, and can be observed intuitively, and the amount of maintenance in the later stage is small; fourth, advanced technology is adopted in the automatic discharge system, so that the discharge amount can be continuously and stably; fifth, the design of the discharge wheel is relatively In the past, it was more scientific and reasonable. It was placed at the lower part of the body, which not only effectively reduced the length of the wheel, but also prevented the phenomenon of jamming; sixth, the body adopted a combined assembly structure, which provided certain convenience for installation and disassembly. . In recent years, new jig products have adopted multi-chamber shared CNC cone air valve technology. This technology has greatly reduced energy consumption, reduced equipment maintenance, and improved Sorting efficiency and unit processing capacity have increased by nearly 20% compared with previous jig machines.
In the process of continuous improvement, the SKT jig has developed better and better, among which the SKTZD-14 jig has realized automatic control, and its control includes the following aspects: First, the parameter control system, mainly Refers to the parameter control of wind, water, discharge, etc.; second, automatic start-stop control of related equipment; third, automatic optimization control of processing capacity; fourth, automatic perception control, mainly for the perception of incoming coal quality The change.
3. Future process development of jigging coal preparation technology
Under the background of the new century, my country's coal preparation plants are developing rapidly, but there is a certain imbalance in the development process, that is, emphasizing the washing of coking coal and ignoring the washing of steam coal. The Chinese government has also given a certain amount of attention to this situation, promulgated relevant policies to actively promote the industrialization of clean coal technology, and increased efforts to develop technologies such as coal washing and coal blending. Clean coal technology is a relatively complex and huge project, based on the washing and processing of coal. Due to its low price and simple process, steam coal has become the preferred coal preparation technology that people pay attention to, and its development space is very broad. In the new century, jigging coal preparation technology should follow the following development process:
(1) When washing raw coal, if the ash content of the raw coal is not high and there are many lump coals, the moving screen jig can be used simply for washing, which can not only reduce investment and processing costs, but also ensure that the factory economic benefits. On this basis, it is necessary to keep up with the pace of the times, see market demand clearly, actively organize relevant personnel to conduct in-depth exploration of dynamic screen jigging coal preparation technology, and develop coal preparation technology that is more suitable for the development of the times and market demand, so as to promote my country's economic development.
(2) When coal preparation is carried out on raw coal, if the quality of the raw coal is relatively low, but the quality of coal preparation is high, the joint operation of moving sieve jigging coal preparation and fixed sieve jigging coal preparation can be adopted. The joint use of these two methods can effectively improve the efficiency of coal preparation operations, and at the same time enable the two methods to play their respective advantages and bring more economic benefits to the factory.
(3) Facing the current situation of jigging coal preparation technology, relevant personnel must continue to study the theory of jigging separation process in depth, build a mathematical model of its separation, and develop an adaptive control system for jigging in combination with related theories of automatic control , in order to realize the intelligent control of jigging coal preparation. The realization of this method requires a lot of practical experience and a lot of science and technology as a basis. Therefore, it is necessary to strengthen the training of relevant personnel, gradually improve their own capabilities, and lay a human foundation for the development of jigging coal preparation technology.
In short, my country has gradually moved towards the forefront of world development in terms of jig machine technology, but in the actual development process, there are still certain problems in my country's equipment manufacturing level, detection methods, and intelligent control. In response to the above problems, coal preparation plants should actively improve while ensuring the normal development of jigging coal preparation technology, and reposition jigging technology in combination with actual development to pave the way for my country's economic development.