The Composition and Crushing Principle of Jaw Crushers

Jaw crusher mainly consists of frame, supporting device, the working mechanism (fixed jaw plate and moving jaw plate), drive mechanism (eccentric connecting rod, thrust plate, flywheel and eccentric shaft), safety device and adjusting device of ore discharging port (wedge adjustment device, gasket adjustment device). The working parts of jaw crushers are two jaw plates. The first one is the fixed jaw plate (fixed jaw), vertically (or the upper end slightly camber) fixed in front of body wall, and the other mobile jaw plate(moving jaw) is located tilt and connected with fixed jaw to form the next upper big and lower small crushing chamber (working chamber). The mobile jaw plate moves towards the fixed jaw plate to do periodic reciprocating motion, sometimes separately and sometimes closely. During the Separation, the material going into the crushing chamber and the finished product is discharged from the lower port; when they are closed, the material is squeezed between the two jaw plates and broken by bending and splitting.
Breaking is a basic procedure during the preparation of raw materials and processing work, and its purpose is to control the particle size of the raw material to achieve the requirements of blast furnace smelting. Jaw crushers and cone crushers all can be used to break hard and medium hard ore and stones. And the structure of cone crusher mainly consists of frame, horizontal axis, moving cone, balance wheel, eccentric sleeve, the upper breaking wall (fixed cone), the lower crushing wall (dynamic cone), fluid couplings, lubrication system, hydraulic system and control system.
Jaw crushers have a variety of structural forms, but their working principle is the same, namely, by the periodical cyclical movement of the movable jaw to break materials. During the process of mobile jaw waving to the fixed swing plate, materials located between the two jaw plates would be crushed, split and bent.

Vibrating Feeder is a Necessary Device in Sand Producing Line

The feeding machine produces centrifugal force depending on the rotation of the eccentric block in the vibrating device to make the sieve and vibrating device move in circle or nearly circle. Materials are continuously thrown on the surface of the sieve together with the sieve box, and are transferred into the receiving port continuously and evenly.
Electromagnetic vibrating feeders are widely used in automatic production, such as machinery, electronic product, food and pharmacy manufacturing. As electromagnetic vibratory feeder’s structure, orienting mechanism and driving system are determined and affected by the diverse materials’ characters, shapes, and surface features and feeding demands, The matching of multi-performance and multi-factors is still a big headache. Therefore, further study and experimentation the kinematics and dynamics of electromagnetic vibratory feed are necessary for design. Researches of the kinematics and dynamics of electromagnetic vibratory feed system by theoretical and experimental approaches for the vibrating chassis and materiel orienting are described. Analyzed the working principle of electromagnetic vibratory feeding system and established the mathematic models of kinematics and dynamics of electromagnetic vibratory fluted feeding system, the critical conditions of the sliding and tossing are given, and the relationship between natural frequency and vibratory frequency is given in the amplitude-frequency curves as well.
The ore feeding machine is used to distribute bulk and granular materials to receiving equipment evenly, timely, and continuously from the storage bin and other storage devices. In the sand producing line, the ore feeder is used to feed the crusher continuously and evenly, and to coarsely separate materials just like the valve of adjusting the current volume, which is the necessary equipment in automated flowing line. The mineral feeding machine is widely used in metallurgy, coal mine, ore beneficiation, construction, chemical industry and materials grinding industry. Factors should be considered when we choose a vibrating feeder include the feeding amount, adjusting range, feeding accuracy, the characteristics of materials, installing way, outer size, safety and reliability, environmental protection and self-weight.

The Preheating Process of Rotary Kiln during Ore Beneficiation

Preheater uses the waste heat of rotary kiln and calciner to heat the raw material in the aim of preheating the raw material and decomposing part of carbonate. The main forms of preheaters are cyclone, shaft, and cyclone-shaft compound preheater. The preheater mainly consists of the cyclone (cylinder, cone, inner cylinder, volute, back mixing cone drop Board), links duct, the discharge pipe and flap valve, sprinkle bins, material clearing holes and temperature and press testing devices.
Rotary kiln, suitable for the process of various industrial materials sintering, roasting, volatilization, calcining, isolation for its strong ability to provide good mixing and effectively heat transferring, has been widely used in metallurgical, concrete, usalite and chemical industrial process. However, rotary kiln still has some difficult control problems, such as complex mechanism process, high frequency changed production condition, multi-variable, strong coupled, strong nonlinearity, large lag, non-determinism, thus conversional control strategy cannot reach automatic control. Most of rotary kilns are still under manual control with human operators. As a result, the operator’s workload is high and the product quality is hard to be kept consistent. Furthermore, the kiln running rate and yield remains low and energy consumption remains high. Therefore, it is significant to research automatic control and optimization technology of the rotary kiln sintering process to improve product quality and save energy. The cement rotary kiln sintering process is a typical distributed parameter system. The gas temperature distribution and solid temperature distribution correlate each other along rotary kiln aix, which are restricted by the adjusted control variable in different time scale and the process disturbance.
The materials are fed from the feeding port, spreading and hanging in the air immediately. Heat transference between gas and solid happens immediately in a high speed. 80% heat happens in the connecting pipe, and only less than 20% happens in the cyclone cylinder. Most parts of the preheater is made by metal, and some parts may be made by heat-resistant steel according to the requirements, and the heat-resistant steel can work under 1000~1100 Celsius degree. Besides, the design of refractory break is much novel with good seal, which can make sure the materials can reach their required temperature in the preheater. During the whole process of preheating, materials move from top to bottom, and the hot air moves from the bottom to top. Full heat transference happens between materials and the hot air, and part of the waste gas will be discharged from the air outlet of cyclone through discharging pipe.

Defects of Current China Cone Crushers and Their Future

Cone crusher is the main crushing equipment of rock materials, and it is widely used in metallurgy and mining industries. However, the domestic rock cone crusher hasn’t developed too much since the successful imitation in twentieth century. The technique is staying in the first and second generation level of foreign countries. Besides, the domestic cone crushers are too conservative, heavy with low efficiency, high energy consumption and low crushing quality. Therefore, hard working should be done to improve the performance of China cone crusher.
Encircling in order to improve working performance of the cone crusher, and based on research basic results of Evertsson who is a scholar of Chalmers University of Technology, the research was expanded from various eyes of crusher working mechanism and working performance, and several researchs were finished, including crushing mechanism, crusher capacity model, chamber design model, crushing product grain size distribution model and multi-objective optimization model and so on. The paper mainly included these research contents as follows: The significance of chamber optimization design and improvement working performance of cone crushers was discussed after analyzing home and overseas situations of study on cone crusher. Kinetic characteristic of spreading and granular materials in crushing chamber was deeper studied and three different forms of particles flowing state, that is sliding, free-falling, sliding and free-falling state of coexistence were discussed in this paper. Moving track model of spreading and granular materials in crushing chamber was built up by analyzing the effect of moving state to working performance of cone crusher.
The calculation model of crushing product size distribution of rock based on the overall balance model was built up after analyzing the effect of chamber to product size distribution of rock. A new formula calculating production capacity Q was put forward after taking into account fully the effect of volume filling rate at level section to production capacity. For researching and developing of high-performance laminated cone crusher, multi-objective optimization model about production capacity, crushing product size distribution and chamber based on researches of working mechanism and working performance was built up.
In order to further improve the working principles and performance of cone crusher, according to its shortcomings, more research aims, methods and content should be done. The result of the researches can be used to research and develop automated, highly efficient, energy-saving and environmental friendly modern cone crushers.

The Steps of the Transformation of Flotation Machines

Comparing between the BF flotation machine and the traditional flotation machine, the difference is mainly in the structure of the impellers. The former is in closed structure and the latter is in semi-open structure. The reason why the efficiency of the semi-open type is low is the problem of radial returning flow and axial slipping flow. The BF flotation machine overcomes the problem of radial returning flow and axial slipping flow, which make the impellers get a much larger absorbing strength with a low rotary speed. The energy consumption is reduced and within the flotation cell, double circular, large absorbing amount, and low energy consumption are suitable for the course flotation, so the BF flotation separator is widely used.
The flotation machines’ transformation is divided into 4 steps. The first step is transforming the third flotation system’s flotation machines which locates in the south part of separation workshop, After getting satisfied technology index, we start the second step which is using the BF-1 flotation from the third flotation system replace the JJF flotation machines of the forth flotation system. The third step is transforming the second flotation system’s flotation machines which locate in the north part of separation workshop. The forth step is using the BF-1 flotation from the second flotation system replace the JJF flotation machines of the first flotation system. After adopting BF-T flotation machines, the separating equipments run stably, the high of pulp is easily adjusted, and the index of flotation is proved.
Currently, our domestic flotation machine can basically meet the different requirements of ore selective factories. According to the type of ore, it can deal with non-ferrous metals, precious metals, ferrous metals and non-metallic. As for the size of the ore selective factory, it can be used by factories whose daily processing ability is under ten tons. In terms of granularity, it can separate normal sized ore as well as course ore. Flotation machines can be used in course separation, sweeping separation, fine separation and milling cycle.

Ways to Maintain and Repair the Lower Bearing Grader of Classifiers

The specification of classifier.html">screw classifier is decided according to its size, which is convenient and rapid, but the defect is short service life, which is normally nine to fifteen months. Users could depend on the processing capacity and broken degree of main bearing of the classifier to decide the repairing methods or replace completely.
There are generally two structural forms in the lower bearing grader of classifiers: the first is the rolling bearing and the second is rubber bearing supports. The main cause of damage of rolling bearings is the leak of seal which leads to the damage of rolling bearing, and the main reason for sealing leaks are that the packing wear loose and high-pressure grease isn’t maintained timely. Replace the rolling bearings, and pack the oil asbestos repeatedly to compress it tightly. Fully fill the bearing internal cavity with grease lubrication, and add lubricating grease frequently into the bearing to maintain the outer pressure to avoid pulp invasive, which needs a higher sense of responsibility of the operation and maintenance workers. Normally, the lower supporting base can be used up to a year, but because of the quality of installation and replacement, or the untimely lubrication, its service life could be reduced to less than one month sometimes. Therefore, many users have improved the seal of the base, and they replace the oil asbestos with V-shaped ring of rubber or polyurethane material successfully, so the multilayer stack together instead of seals asbestos packing. Because rubber and polyurethane have good flexibility and abrasion resistance, the sealing performance compared to asbestos packing is significantly improved, and the service life of the rolling bearing is also longer.
In the preparation of the raw material, due to the negative pressure generated by the high speed rotation of the wind wheel and the negative pressure generated by the outlet connected to the rear fan, hot air from the hot air inlet is introduced, and continuously fed by the wind wheel radially. The broken materials form much even materials curtain after the sinking process in the wind separating area, and then they contact with hot wind fully and have heat transfer to be dried. Wet air is discharged from wind port. After wind sub-constituency materials in contact with the hot air in the suspended state, the efficiency of the classifier is higher, and the drying effect is remarkable.

The Research and Development of Intelligent Automated Rotary Kiln

Large-scaled rotary kilns are widely used in metallurgy, ore beneficiation, cement production line and environmental protection. It is hard to achieve the automated control and optimized control of rotary kiln because of their multi-factors, close coupling, non-linear and serious interference of key parameters. It is much meaningful for the improvement of the quality of clinkers and the using rate of rotary equipment, and the reduction of energy consumption to research the intelligent optimized controlling technology and intelligent optimized controlling platform.
The intelligent optimal control software platform of rotary kiln is a kind of application software to control and monitor rotary automation. The technology of foreign control system software is non-transparent. Although their control on basal loop is stable, intelligent control is rarely mentioned. Because of the development of domestic software platform starts later than abroad, their structure of the platform isn’t strong enough and reuse rate of code isn’t high enough. Therefore, the research on intelligent optimal control software platform with modular structure and the function of developing intelligent optimal control strategies is necessary. The detailed works have been summarized as follows: 1. The whole structure and function of the platform are designed. The structure of the platform is established and combined with modules organically. We organize the structure of intelligent optimal control software platform with more clarity and reusability.2. The platform is divided into four modules: plot module for human machine interaction of rotary kiln, database module for the management of control volume and detection volume, communicate module for data transmission with lower computer, strategy module for development of intelligent optimal control. In order to achieve ease of use and scalability, powerful base classes are designed and implemented by the object-oriented language.3. To the strategy module, a method is proposed based on the design of flow chart, generating script dynamically, explaining and implementing by compiler of the system. This method can reduce the volume of developers programming, so they can focus on the development of intelligent control algorithm.
The active lime is the basic raw material for steel and ore industry. it can shorten the calcining time, improve purity and recycling rate of liquid steel, reduce the consumption of quartz and fluorite and improve the service life of kiln bucket, besides, it can also be used in the process of steel perfection. The rotary kiln, as one of the major calcining equipments, is widely used in our country, and it has wide materials shape, size adaptability and good inner mixture.