CN103801426A - A dry coal preparation method - Google Patents

Abstract

The invention discloses a dry coal separation method, which adopts the steps of crushing, heating, temperature identification discharge, air separation and chain discharge, integrates the advantages of the chain discharge of an air heavy-medium coal separator and a bevel sieve plate of an air jigger in the prior art, does not use heavy media, greatly reduces the separation cost, saves water and electricity, fully utilizes the heat of dried raw coal, identifies metal impurities by a temperature sensor and discharges the metal impurities before entering the air separation, and uniformly recovers the metal impurities separated in the subsequent step by utilizing a chain plate, recovers the metal impurities with higher purity, prevents the waste of metal resources, and supplies pulse wind and continuous strong wind in regions of an air distribution plate to lock light gray matter; the gray matter can be combined with water vapor generated by heating raw coal before, so that the gray matter can be recovered conveniently.

Description

A dry coal preparation method

technical field

The invention relates to a coal preparation method, which belongs to the field of dry coal preparation.

Background technique

The existing coal separation method is wet separation. This method will not only cause pollution of residual coal slime after washing, but also consumes a lot of water and requires high investment. For example, the use of dense medium cyclone and hydraulic jig coal preparation. More than two-thirds of my country's recoverable coal reserves are located in Shaanxi, Inner Mongolia, Shanxi and other places that suffer from severe drought and water shortage. Therefore, there is an urgent need for a new type of dry separation technology and equipment. Therefore, air-dense medium coal separators have gradually appeared in the field of coal preparation in recent years, such as the dry fluidized bed coal preparation method and device developed by China Institute of Mining and Technology, see CN1005314A for details. Moreover, this type of technology is also very mature, and many Tangshan Heavy Industry companies are producing such products. However, the air-space coal preparation machine also has its defects. First of all, this type of machine has requirements for the selected raw coal. If the water content of the raw coal is too high, the air distribution plate will be directly blocked, and the drying of the coal only removes the water. A lot of heat is wasted in vain. Although water is saved, energy consumption is also very serious; secondly, this kind of equipment uses heavy medium, which is generally iron powder. It is also necessary to frequently replenish medium to the air-dense medium bed, which not only increases the cost of separation, but also may pollute the clean coal, which cannot meet the current higher and higher requirements for pure coal; third, it cannot handle the small Particles of non-ferromagnetic metal ore impurities, such as copper impurities, these metal ore particles have a small particle size, and are easily entrained by pulverized coal particles in the air bed and are selected into clean coal, that is, during dense medium separation. It is not easy to discharge completely and the stage of magnetic separation recovery medium will not be selected at all.

There is also a wind jigging dry coal separator, such as CN2889496Y, which utilizes the vibration of the sieve plate and the combined motion of ordinary wind and pulse wind to achieve the purpose of separation, and finally can separate pyrite particles, clean coal and gangue . However, this kind of coal separator only uses gravity separation to remove pyrite particles, and the precision is very low. Sometimes it needs to go through magnetic separation again (flotation can also remove iron ore particles, but as an area where dry coal preparation methods are used, water Resources are scarce, and flotation is rarely used for coal separation), which increases the cost of separation. And some pure iron such as damaged screws can not pass through the sieve plate and be discharged together with gangue, resulting in waste. The patent's research on air distribution only stays at the primary stage, and those skilled in the art cannot know how to use the air from it. "Air volume regulating valves can be installed on each branch channel to adjust the air volume of each small air chamber to reach the entire air volume. The air volume of the sorting bed is uniform, or the air volume of different parts of the sorting bed can be adjusted according to the needs, so as to achieve the ideal requirements of sorting materials.".

Contents of the invention

The purpose of the present invention is to provide a dry coal preparation method to solve the aforementioned defects of dry coal preparation in the prior art.

The present invention is realized by following method:

The dry coal preparation method adopts the steps of crushing, heating, temperature identification discharge, winnowing, and chain discharge, and divides raw coal into final clean coal, gangue, and metal impurities.

More preferably, the crushing step is that the raw coal enters the A-belt conveyor belt from the feeding chute, the A-belt conveyor belt is provided with crushing rollers, and crushing blocks are arranged on the circumference of the crushing rollers, and the crushing blocks are highly elastically connected with the main body of the crushing rollers, and the raw coal is Crushed into the specified particle size;

The heating is above the belt conveyor belt, and the crushing roller is connected with a heating structure, which is used to dry the crushed coal and remove excess water in the raw coal;

Temperature identification discharge, the discharge end of the belt conveyor belt is equipped with a temperature detection and discharge structure, which identifies and eliminates metal impurities, and the metal impurities are discharged to the metal impurities discharge port;

The air selection and chain discharge are carried out in the air selection room, which is located below the temperature detection and discharge structure. The air selection room has a ring chain structure, which is arranged in a triangle. The ring chain structure is connected to the excitation structure as a whole. Under the joint action of the plate and the exciting structure, the coal material slides down along the inclined surface composed of chain plates, the separated clean coal falls into the clean coal discharge port, and the gangue falls into the gangue discharge port. There is also a metal ring structure in the air selection room. The impurity outlet, the metal impurity outlet is located on the opposite side of the clean coal outlet, and the opened chain plate pushes the metal impurities to the metal impurity outlet;

The air distribution plate, the dust collector, the air supply fan and the air supply bus form the air circulation.

More preferably, the air distribution plate is arranged parallel to the corresponding chain plate.

More preferably, the controller is connected with the crushing roller, the first belt conveyor, the temperature detection discharge structure, the heating structure, the air supply fan and the endless chain structure, and the controller has a man-machine interface, which can manually input the operating parameters of these structures.

More preferably, the air distribution plate is divided into two areas, the pulse wind area is near the upper part, and the continuous strong wind area is the lower part.

More preferably, when the chain plate is opened, it is 90 degrees to the endless chain, and this angle is maintained until the chain plate turns to the coal material transportation section.

The beneficial effects of the present invention are:

1) Combining the advantages of the chain discharge of the air-dense medium coal separator and the inclined sieve plate of the air jigging in the prior art, no heavy medium is used, which greatly reduces the separation cost and saves water and electricity;

2) Make full use of the heat of drying raw coal, use temperature sensors to identify metal impurities and discharge these metal impurities before entering the winnowing process, and use chain plates to uniformly recover the metal impurities that are further separated later, and recover them with higher purity Metal impurities to prevent waste of metal resources;

3) The air distribution plate supplies pulsed wind and continuous strong wind in different areas to lock the light ash; the ash can also be combined with the water vapor generated by heating the raw coal before, which facilitates the recovery of the ash.

Description of drawings

Figure 1 is a schematic diagram of the structure of a dry coal separator.

In the figure: 1. Feeding trough, 2. A belt conveyor belt, 3. Controller, 4. Metal impurity outlet, 5. Chain plate, 6. Air distribution plate, 7. Gangue outlet, 8. Clean coal outlet , 9. Sprocket, 10. Air supply bus, 11. Fan supply, 12. Dust collector, 13. Temperature detection discharge structure, 14. Heating structure, 15. Crushing roller.

Detailed ways

Do further description below in conjunction with accompanying drawing:

As shown in Figure 1, the dry type coal separator of the present invention comprises a sorting machine main body, a feeding chute 1 is arranged above the sorting machine main body, a belt conveyor belt 2 is placed under the feeding chute, and a belt conveyor belt 2 is provided with The crushing roller 15 is used to crush the raw coal into the specified particle size. The first belt conveyor belt 2 is a rubber conveyor belt covered with a metal plate, which can provide a relatively strong crushing base plane for crushing. The crushing roller is arranged on the circumference of the crushing block. , These crushing pieces are connected with the main body of the crushing roller with high elasticity, if encountering gangue blocks with excessive hardness, the crushing pieces will retract to the main body of the crushing roller, which can avoid damage to the crushing roller or shutdown of the entire sorting line. The crushing roller 15 is followed by a heating structure 14, which is used to dry the crushed coal, remove excess water in the raw coal, and prevent the over-wet coal powder from blocking the wind on the chain plate during the subsequent sorting. The hole and the heating structure itself are prior art, and will not be repeated here. The discharge end of the first belt conveyor belt 2 is provided with a temperature detection discharge structure 13, this is because the inventor found in the actual sorting operation that the temperature of metal impurities such as pyrite particles, damaged screws and copper ore particles will decrease when heated. It is higher than the coal particles, so using this characteristic, while the heating structure 14 removes the excess moisture of the raw coal, it also heats the metal impurities to a temperature sufficient to separate them from the coal area, so that the temperature detection and discharge structure 13 can pass the temperature detection. These metal impurities are identified and excluded, and most of the metal impurities have been excluded before entering the winnowing, and will not enter the subsequent sorting.

After being sorted by the temperature detection discharge structure 13, the coal material enters the winnowing room. The winnowing room has an annular chain structure, and the ring chain structure is connected with the excitation structure as a whole. The annular chain structure is supported by three internal sprockets 9, forming a A triangular structure, with a plurality of chain plates 5 installed on the ring chain structure, one end of the chain plates 5 is pivotally connected to the ring chain structure, when the chain plates 5 are located on the side where the coal material falls, the chain plates 5 form a plane for coal material transportation, The chain plate 5 is located under the endless chain structure or on the side of the running track of the discharged metal impurities, and the chain plate 5 rotates and is in an open state. Preferably, when the chain plate 5 is opened, it is 90 degrees to the endless chain. There are a plurality of air holes on the chain plate 5, and the wind blown by the air distribution plate 6 can act on the coal material flow through the air holes. The air distribution plate is preferably arranged parallel to the corresponding connecting plate. The wind force of the air distribution board 6 and the exciting structure act together on the coal material flow. The air distribution board 6 is divided into two areas, and the pulse wind area is near the upper part. The pulse wind separates the coal particles and gangue particles in this area. On top of gangue grains. When the coal material flows through the lower area of the air distribution plate 6, the strong wind blown by the air distribution plate will separate the coal particles from the gangue, and the clean coal will fall into the clean coal discharge port 8, and the gangue will fall into the gangue discharge port 7. The pulsed wind throws the gray matter into the air, and the gray matter turns back after encountering a strong wind such as a continuous wind, and is locked in a certain area, and then captured by the dust collector 12 . In this way, the possibility of preventing ash from being discharged by mistake from the clean coal discharge port 8 and the gangue discharge port 7 is realized. In addition, the coal material is inclined downward on the ring chain structure, and under the action of wind, the pressure between it and the chain plate 5 decreases, so the friction force also decreases, and the coal material flow moves along the surface of the ring chain under the component force of gravity Speed up, which not only speeds up the sorting but also reduces the output of the transport power of the ring chain structure. Persons skilled in the art can select the angle of the inclined winnowing surface, and the angle should not be too large, otherwise the coal material flow cannot be controlled.

In the air separation stage, the pyrite particles that have not been discharged in the temperature impurity removal stage fall to the bottom of the wind separation chamber through the air holes on the chain plate, and are pushed to the metal impurity outlet 4 by the chain plate below the ring chain structure. If the metal impurities discharged in the temperature impurity removal stage are blocked by the opened chain plate 5 when they fall to the metal impurity outlet 4, they will slide to the bottom of the winnowing chamber and be pushed to the metal impurity outlet 4 as well. In this way, metal impurities are separated from the coal stream with higher purity, which is convenient for subsequent recovery.

The air distribution plate 6, the dust collector 12, the air supply fan 11 and the air supply bus 10 form an air circulation, and the water vapor generated by the heating structure 14 heating the coal is introduced into the air circulation, and combined with the ash matter, it is beneficial for the ash to flow in the dust remover 12. settlement.

The controller 3 is connected with the crushing roller 15, the first belt conveyor belt 2, the temperature detection, the discharge structure 13, the heating structure 14, the fan 11 and the endless chain structure. The controller 3 has a man-machine interface, and the operating parameters of these structures can be input manually. So that the whole sorting process is stable.

Although the disclosed dry coal preparation method has been specifically described with reference to the embodiments, the embodiments described above are illustrative rather than restrictive, and all changes and modifications are made without departing from the scope of the present invention. Within the protection scope of the present invention.

Claims (6)

1. A dry coal preparation method, which adopts the steps of crushing, heating, temperature identification discharge, winnowing, and chain discharge to divide raw coal into final clean coal, gangue, and metal impurities. 2. The method according to claim 1, characterized in that: the crushing is that the raw coal enters the first belt conveyor belt from the feeding chute, the first belt conveyor belt is provided with crushing rollers, and broken pieces are arranged on the circumference of the crushing rollers, and the broken pieces Connected with the main body of the crushing roller with high elasticity, the raw coal is crushed into the specified particle size; The heating is above the belt conveyor belt, and the crushing roller is connected with a heating structure, which is used to dry the crushed coal and remove excess water in the raw coal; Temperature identification discharge, the discharge end of the belt conveyor belt is equipped with a temperature detection discharge structure, which identifies and eliminates metal impurities, and the metal impurities are discharged to the metal impurities discharge port; The air selection and chain discharge are carried out in the air selection room, which is located below the temperature detection and discharge structure. The air selection room has a ring chain structure. The ring chain structure is arranged in a triangle. The ring chain structure is connected to the excitation structure as a whole. Under the joint action of the excitation structure, the coal material slides down along the inclined surface composed of chain plates, the separated clean coal falls into the clean coal discharge port, and the gangue falls into the gangue discharge port. There are also metal impurities in the lower part of the ring chain structure in the air selection room. Outlet, the metal impurity outlet is located on the opposite side of the clean coal outlet, and the opened chain plate pushes the metal impurities to the metal impurity outlet; The air distribution plate, the dust collector, the fan and the gas supply bus form an air circulation, and the ash is combined with the water vapor generated by heating the raw coal before, which facilitates the recovery of the ash. 3. The method according to claim 1 or 2, characterized in that: the air distribution plate is arranged parallel to the corresponding chain plate. 4. The method according to any one of claims 1-3, characterized in that: the controller is connected with the crushing roller, the first belt conveyor belt, the temperature detection discharge structure, the heating structure, the supply fan and the endless chain structure, and the controller has a man-machine The operating parameters of these structures can be input manually through the interface. 5. The method according to any one of claims 1-4, characterized in that: the air distribution plate is divided into two areas, the upper part is the pulse wind area, and the lower part is the continuous strong wind area. 6. The method according to any one of claims 1-5, characterized in that: when the chain plate is opened, it is 90 degrees to the endless chain, and this angle is maintained until the chain plate turns to the coal material transportation section.