JP5446936B2 - Cement manufacturing apparatus and cement manufacturing method - Google Patents

Description

  The present invention relates to a cement manufacturing apparatus, and in particular, in a cement manufacturing apparatus using solid waste as a part of cement raw material or fuel, metals can be efficiently recovered from the solid waste, and the apparatus is applied to the cement manufacturing apparatus. The present invention relates to a cement manufacturing apparatus capable of reducing the burden.

Conventionally, for example, Patent Document 1 discloses a cement manufacturing apparatus that has a configuration in which coarse particles (stone removal) from a vertical mill are circulated through a circulation unit and returned to the vertical mill again.
In recent years, from the viewpoint of environmental measures and the like, it has been proposed to use solid waste such as construction residual soil and sludge as a part of cement raw material and fuel.

JP-A-5-245405

  By the way, when solid waste is used as a part of cement raw material or fuel as described above, it is desirable to separate and recover metals from the solid waste. As one method for realizing this, for example, it is conceivable to dispose a metal separator on the upstream side of the vertical mill and separate and recover the metal using this device.

  However, in such a configuration, the metals that could not be recovered by the metal separators are vertical mills and downstream equipment (cyclones, mill fans, flue and electric dust collectors downstream of vertical mills in cement manufacturing equipment) In this case, the vertical mill and downstream equipment are severely worn by the movement of these metals. In particular, when the fixed waste contains a lot of moisture, the recovery efficiency of the metal separator is reduced, and thus the above problem becomes more remarkable.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to efficiently recover metals from waste in a cement manufacturing apparatus using fixed waste as a part of cement raw material or fuel. It is another object of the present invention to provide a cement manufacturing apparatus that can reduce the burden on the apparatus.

The cement manufacturing apparatus of the present invention for solving the above problems is as follows.
In cement production equipment that uses waste as part of cement raw material or fuel,
A pulverizing unit for pulverizing the waste, and a shape selecting unit for selecting the pulverized waste from suitable waste of a size suitable for cement raw material or fuel and other waste of other sizes. A vertical mill having,
A circulation unit for carrying out the separate waste from the shape selection unit and re-introducing it into the vertical mill;
A metal sorting section for sorting metals from the separate waste,
The metal sorting unit is provided in the circulation unit.

  According to the present invention, since the metal sorting section is provided in the circulation section, it is possible to efficiently recover the metals and reduce damage to the vertical mill and downstream equipment ( Details will be described later in [Description of Embodiments]. In addition, since the waste can be pulverized using the pulverizing part of the vertical mill, it is not necessary to provide a dedicated device for pulverizing the waste.

  As described above, according to the present invention, since the metal sorting section is provided in the circulation section, the metal is efficiently removed from the waste in the cement manufacturing apparatus using solid waste as a part of the cement raw material or fuel. It can be recovered and the burden on the apparatus can be reduced.

It is a figure which shows typically the structure of the cement manufacturing apparatus of one form of this invention. It is a longitudinal cross-sectional view which shows the structure of a vertical mill. It is a perspective view of a metal sorter. It is a figure which shows typically the other example of the cement manufacturing apparatus of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the cement manufacturing apparatus 1 includes a vertical mill 100 that pulverizes the supplied raw cement raw stone and the like, a supply unit 200 that supplies raw raw stone and the like to the vertical mill 100, and a vertical mill A raw material crushed by the vertical mill 100 is supplied to a kiln (not shown) of a cement baking apparatus, dust is removed from the vertical mill 100 and discharged, and the raw material pulverized by the vertical mill 100 And a circulation unit 300 that circulates coarse grains such as rough stones and returns them to the vertical mill again.

The cement manufacturing apparatus 1 uses solid waste as a cement raw material or fuel. In FIG. 1, the raw cement raw material and waste are supplied to a belt conveyor 208 (detailed below) of the supply unit 200. The state is drawn.
In the present specification, a mixture of the raw material for cement and waste is also simply referred to as “raw material or the like”. As the “cement raw material”, a cement raw material mainly composed of limestone and clays can be used. “Solid waste” means construction waste, landfill, incinerated ash, sludge, and the like.

  As shown in FIG. 2, the vertical mill 100 includes a cylindrical main body 141, and a crushing unit 120 for crushing raw raw stone or the like is provided therein. A raw material supply path 122 extending in the vertical direction is provided on a side surface of the main body 141, and raw raw material or the like is supplied into the main body 141 through the raw material supply path 122.

  The crushing unit 120 is located at the bottom of the main body 141, and includes a crushing table 121B that rotates around the vertical axis using the electric motor 127 as a driving source, and a plurality of crushing rollers 121A that roll on the upper surface. The raw raw material or the like supplied into the main body 141 is supplied onto the crushing table 121B and is crushed by the crushing roller 121A while rotating on the crushing table 121B.

  A gas inlet 124 is provided on the bottom side surface of the main body 141, and a high-temperature gas (for example, 300 ° C.) is introduced into the main body 141 from the gas inlet 124. The introduced gas becomes an ascending gas flow 129 in the main body 141, and the ascending gas flow 129 causes fine powder such as crushed raw stones to fly upward (details will be described later). The fine powder is discharged together with the gas from the discharge port 125 at the top of the main body 141.

  An opening 126 for stone removal is provided around the crushing table 121B. Roughly large coarse particles or lumps that cannot get on the rising gas 129 (including unground metal) fall from the periphery of the pulverizing table 121B to the opening 126. Coarse grains (also called waste stone or separate waste) that have dropped into the opening 126 are conveyed to the outside by a belt conveyor. The crushing table 121B functions as a shape selection unit in combination with the action of the rising gas flow 129.

  A classifier 123, which is another shape selection unit, is provided in the upper part of the main body 141. The classifier 123 classifies the fine powder carried by the rising gas flow 129.

Refer to FIG. 1 again. The supply unit 200 receives a raw cement raw material and waste and conveys the raw material belt conveyor 208, a magnetic separator 203 disposed in the middle of the belt conveyor 208, and a raw material disposed on the terminal end side of the belt conveyor 208. A tank 202 and a raw material belt feeder 207 that conveys raw raw stones and the like from the raw material tank 202 to the vertical mill 100 are provided.
Thus, when the magnetic separator 203 is provided in the supply part 200, before supplying to the raw material tank 202, an iron piece etc. are preferable from the point which can be removed.

  The circulation unit 300 includes a stone removal belt conveyor 305 that conveys the stone discharged from the vertical mill 100 in a substantially horizontal direction, and a stone removal bucket elevator 306 that conveys the stone discharged by the belt conveyor 305 upward. have.

  A metal sorting device 350 that sorts metals (iron pieces, non-ferrous metal, etc.) from the transported waste stone is provided on the upper portion of the stone removal bucket elevator 306. Details of the sorting device 350 will be described later with reference to FIG.

  The transport unit 400 includes a cyclone 409 that sends fine powder discharged from the discharge port 125 (see FIG. 2) of the vertical mill 100 to a kiln (not shown) of a cement manufacturing apparatus, and an exhaust fan 410 through which gas from the cyclone 409 passes. And an electric dust collector 411 that removes foreign matters in the gas, and a chimney 412 that discharges the gas from the dust collector 411 to the atmosphere.

Next, the metal sorting apparatus 350 will be described with reference to FIG.
A commercially available metal sorter 350 can be used (for example, “Multi Sorter F600” manufactured by Earth Technica Co., Ltd.). Two hoppers 364 and 365 provided near the end of the belt conveyor 354 are provided. The side closer to the belt conveyor 354 is a first hopper 365 and the side far from the belt conveyor 354 is a second hopper 365. The sorting device 350 further includes a magnetic field sensor 353 disposed in the belt conveyor 354. In addition, air nozzles 356 arranged in the lateral direction are provided between the end portion of the belt conveyor 354 and the first hopper 364.

  The sorting device 350 configured as described above operates the air nozzle 356 at a predetermined timing when the metal in the stone is detected by the magnetic field sensor 353, so that the metal is removed from the second hopper 365 by wind pressure. Blow away. On the other hand, a lump other than metals falls into the first hopper 364. Thereby, metals can be separated from the waste stone.

  As shown in FIG. 1, the waste stone dropped on the first hopper 364 is sent again to the raw material tank 202 and re-entered into the vertical mill 100, while the metals blown off on the second hopper 365 are recovered. It is collected in the container 318.

Operation | movement of the cement manufacturing apparatus 1 of this embodiment comprised as mentioned above is demonstrated below.
First, the raw raw cement material and solid waste are supplied to the belt conveyor 208 of the supply unit 200. The raw material or the like is conveyed into the raw material tank 202 by the belt conveyor 208. While being conveyed by the belt conveyor 208, the magnetic separator 203 sorts and removes iron pieces and the like mixed in the raw raw stone.

  Next, raw raw stones and the like from the raw material tank 202 are conveyed to the vertical mill 100 by the belt feeder 207. The conveyed raw stone or the like is supplied to the raw material supply path 122 of the vertical mill 100 and is sent into the main body 141 through the raw material supply path 122 (specifically, through the triple damper 128 and the like).

  As shown in FIG. 2, the raw raw material sent into the main body 141 falls on the crushing table 121B and is finely crushed by the crushing roller 121A.

During the operation of the pulverization table 121B and the pulverization roller 121A, hot air having a kiln exhaust gas temperature of 300 ° C. is introduced from the gas introduction port 124, and the hot air is sent upward as a rising gas flow 129 from the periphery of the pulverization table 121B. . By this ascending gas flow 129, fine powders (applicable waste) such as crushed raw stones are carried upward, classified by the classifier 123, and riding on the ascending gas flow 129 and discharged from the pulverized product outlet 125 to the outside. Is done.
Since the metals classified by the classifier 123 and discharged to the outside do not have any quality problems as cement products, they are sent to the cement kiln in the next process as described below.

  The fine powder discharged from the outlet 125 is then collected by a cyclone 409 and sent to the cement kiln as shown in FIG. The gas from which most of the fine powder has been separated by the cyclone 409 passes through the exhaust fan 410 and is almost completely removed by the electric dust collector 411 and discharged from the chimney 412 to the atmosphere. The dust collected by the electric dust collector 411 is conveyed to a cement kiln and fired to become a cement clinker (cement intermediate product).

  Returning to the description of the vertical mill 101 again (see FIG. 2), most of the relatively large coarse grains (separate waste) containing unpulverized metals that could not get on the rising gas flow 129 are used for waste stones. It falls from the opening 126.

  The fallen stones are transported by the stone belt conveyor 305 as shown in FIG. The waste stones transported by the conveyor 305 are then transported upward by the waste stone bucket elevator 306 and sent to the metal sorting device 350.

In the metal sorter 350 (see FIG. 3), first, the waste stone from the elevator 306 is received by the belt conveyor 354, and the belt conveyor 354 conveys the waste stone toward the hoppers 364 and 365.
The metal that has been detected by the magnetic field sensor 353 and formed into a lump is blown off by the injection of the air nozzle 356 and jumps into the second hopper 365. Powders and lumps other than metals fall into the first hopper 364 from the end of the belt conveyor.

  The metals that have entered the second hopper 365 are collected in a metals collection container 318 as shown in FIG. On the other hand, the waste stone that has entered the first hopper 364 is again put into the raw material tank 202 and pulverized again in the vertical mill 100. Of the crushed waste stone, fine powder is discharged outside the main body 141 on the rising gas flow 129 as described above. On the other hand, the coarse particles are sent again to the circulation unit 300 and are again sorted by the metal sorter 350.

(1) A cement manufacturing apparatus 1 according to an embodiment of the present invention includes:
In the cement manufacturing apparatus 1 using waste as a cement raw material or fuel,
A pulverizing unit 120 for pulverizing the waste, and a shape selecting unit (121B) for selecting the pulverized waste from a compatible waste having a size suitable for a cement raw material or fuel and another waste having a size other than that. And a vertical mill 100 having
A circulation unit 300 for carrying out the separate waste from the shape selection unit (121B) and re-introducing it into the vertical mill 100;
A metal sorting unit 350 for sorting metals from the separate waste,
The metal sorting unit 350 is provided in the circulation unit 300.

  According to the cement manufacturing apparatus 1, since the metal sorting device 350 is provided in the circulation unit 300, metals in the waste can be recovered well while the waste circulates in the circulation unit 300. . That is, if the metal sorting unit is not provided in the circulation unit 300, the sorting cannot be performed again once the magnetic separator 203 (see FIG. 1) has left the metals due to erroneous sorting. However, according to this apparatus, even if the magnetic separator 203 cannot sufficiently recover the metals, the metal sorting unit 350 in the circulation unit 300 can perform another sorting. Therefore, the metals contained in the metals discharged to the equipment (cyclone 409, exhaust fan 410, electric dust collector 411, etc.) provided downstream of the vertical mill are greatly reduced, and the vertical mill 100 and vertical mill are reduced. Damage to equipment provided downstream can be reduced.

  In particular, when using waste containing non-ferrous metal such as construction residual soil and landfill, non-ferrous metal cannot be recovered by the magnetic separator 203 alone, and the non-ferrous metal may circulate in the circulation unit 300. On the other hand, in this application, since the nonferrous metal can be sorted by the metal sorting unit 350 provided in the circulation unit 300, a more remarkable effect can be obtained.

  Further, since the solid waste can be pulverized by using the vertical mill 100 that is generally provided in the cement manufacturing apparatus, it is not necessary to separately provide a dedicated pulverizing apparatus for pulverizing the waste. In other words, a dedicated process for pretreating the waste is not necessary. In particular, the pulverization by the vertical mill 100 has an advantage that the waste can be pulverized at a stretch.

A large amount of raw cement raw material with respect to waste contains a lot of moisture, and iron pieces are agglomerated and buried in the raw raw material. Therefore, the magnetic separator 203 alone cannot sufficiently remove it. However, in this apparatus, the feed is dried and crushed in the vertical mill, and the metal is separated and recovered in the subsequent circulation section 300, so that the efficiency is greatly improved.
Moreover, about the waste stone, the vertical mill 100 has removed the fine powder from the cement raw material and the waste, and the metal ratio with respect to the raw material is increased. Therefore, it is easy to separate and remove the nonmagnetic metal and the magnetic metal from the waste mixed with the cement raw material.
Furthermore, regarding the stones discharged from the vertical mill 100, the particle size of the stones is composed of only those having a large particle size and dried, and entrainment of the raw material powder is reduced. Metals can be separated and removed with high accuracy.
In addition, according to the configuration in which the metal sorting device 350 is installed in the circulation section 300, the metals are separated and recovered from the dry waste, etc., so the metal sorting device has a relatively small processing capacity. Mu
The internal wear of the vertical mill that grinds the cement raw material and each downstream device can be separated and removed from the bulk metal, so the wear of the device is the same as when no waste is blended. It doesn't matter.
According to this embodiment, a single pulverizer can separate and remove magnetic metal such as iron pieces and nonmagnetic metal such as nonferrous metal from solid waste in the cement raw material with high accuracy. Such processing by a single-stage crusher can simplify the process.

(2) The circulation unit 300
A discharge path (305) for carrying out another waste from the lower part of the vertical mill 100;
A supply path (306) for supplying the separate waste to a vertical upper side of the vertical mill 100, connected to the discharge path (305), and a metal sorter is provided in the supply path (306). Yes.

According to such a configuration, the following advantages can be obtained.
That is, the vertical mill 100 is often provided on the ground because of its heavy weight. Therefore, a discharge path for carrying out large-diameter waste (separate waste) that does not get on the airflow is often provided close to the ground, and there is no room in the vicinity of the discharge path in terms of layout.
On the other hand, when the raw material or the like is fed into the vertical mill 100, the material to be crushed is input from the upper side of the vertical mill 100 due to the property of crushing on the table. Due to such a structure, when another waste is thrown in again, another waste is thrown from the vertical upper side of the vertical mill 100, and the supply path (306) for supplying the separate waste is provided by the vertical mill. It will be provided vertically above. That is, the supply path (306) is not close to the ground, and there are fewer restrictions on the layout than the discharge path (305). According to the configuration in which the metal sorting unit (350) is provided in the supply path (306), the metal sorting unit can be easily installed without any special layout.

Metal sorting department
A belt conveyor 354 for conveying the separate waste;
A first receiving portion 364 provided at the end of the belt conveyor;
A second receiving portion 365 provided at a position farther from the end portion than the first receiving portion;
Detection means 353 for detecting metals in the separate waste to be conveyed;
Transfer means (356) for transferring the metals to the second receiving part by operating based on the detection result of the detection means 353;
It is characterized by having.
Even with such a configuration, the effects of the present invention can be obtained in the same manner as described above.

(3) A method for producing a cement according to one aspect of the present invention includes:
In a cement manufacturing method using waste as a cement raw material or fuel,
A grinding step for processing a part of the waste into a size suitable for the cement raw material or fuel;
A shape sorting step of sorting waste that has passed through the pulverization step into compatible waste of a size suitable for the cement raw material or fuel, and another waste of a size other than that,
A circulation step of carrying out the separate waste from the shape selection unit and re-introducing it into the pulverization step;
A metal sorting process for sorting metals from the separate waste,
The metal sorting step is performed in the circulation step.

  The present invention is not limited to the form shown in FIG. 1, and various modifications can be made. For example, as shown in FIG. 4, the structure which abbreviate | omitted the magnetic separator 203 in the middle of the raw material belt conveyor 208 may be sufficient. Such a configuration can be effectively applied when there are relatively few iron pieces in the waste. Even in such a cement manufacturing apparatus, since the metal sorter 350 is provided in the circulation part 300, the same effect as that of the above embodiment can be obtained. However, according to the configuration in which the magnetic separator 203 is provided as shown in FIG. 1, the iron pieces can be removed at two places, so that the removal can be performed with very high accuracy.

  Further, the metal sorting device provided in the circulation section is not particularly limited as long as it can recover the metal from the waste stone, and other than the method of blowing the metal by the wind pressure as shown in FIG. It may be.

DESCRIPTION OF SYMBOLS 1 Cement manufacturing apparatus 100 Vertical mill 120 Grinding part 121A Grinding roller 121B Grinding table 122 Raw material supply path 126 Opening part 129 Ascending gas flow 141 Main body part 200 Feeding part 202 Raw material tank 203 Magnetic separator 208 Belt conveyor 300 Circulation part 305 Excavation belt Conveyor 306 Waste stone bucket elevator 350 Metal sorter 354 Belt conveyor 356 Air nozzle 364 First hopper 365 Second hopper 400 Discharge unit 409 Cyclone 410 Exhaust fan 411 Electric dust collector 412 Chimney

Claims (3)

In cement production equipment that uses waste as part of cement raw material or fuel,
A pulverizing unit for pulverizing the waste, and a shape selecting unit for selecting the pulverized waste from suitable waste of a size suitable for cement raw material or fuel and other waste of other sizes. A vertical mill having,
A circulation unit for carrying out the separate waste from the shape selection unit and re-introducing it into the vertical mill;
A metal sorting section for sorting massive metals from the separate waste,
The cement manufacturing apparatus, wherein the metal sorting section is provided in the circulation section. In the cement manufacturing apparatus according to claim 1,
The circulation part is
A discharge path for carrying out the separate waste from the lower part of the vertical mill;
A supply path that is connected to the discharge path and supplies the separate waste to a vertical upper side of the vertical mill,
The cement manufacturing apparatus, wherein the metal sorter is provided in the supply path. In a cement manufacturing method using waste as part of cement raw material or fuel,
A grinding step for processing a part of the waste into a size suitable for the cement raw material or fuel;
A shape sorting step of sorting waste that has passed through the pulverization step into compatible waste of a size suitable for the cement raw material or fuel, and another waste of a size other than that,
A circulation step of carrying out the separate waste from the shape selection step and re-introducing it into the crushing step;
A metal sorting step of sorting massive metals from the separate waste,
The cement manufacturing method, wherein the metal sorting step is performed in the circulation step.

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