JP6554910B2 - Cement clinker manufacturing apparatus, cement manufacturing apparatus, cement clinker manufacturing equipment method, and cement manufacturing method - Google Patents

Description

  The present invention relates to a cement clinker (hereinafter sometimes abbreviated as clinker) manufacturing apparatus, a cement manufacturing apparatus, a clinker manufacturing method, and a cement manufacturing method.

The clinker is usually manufactured by heating the raw material to about 1450 ° C. using a combustion gas such as pulverized coal having a maximum temperature of 2000 ° C. or higher. Therefore, even if waste is used as a raw fuel, organic matter is decomposed to the level of CO ₂ and H ₂ O that do not leave the properties of the original molecule, and most of the inorganic matter is taken into the clinker and is almost harmless. It becomes a state. For this reason, in recent years, a large amount of waste has been used as a raw material for cement.

  Since the exhaust gas of the kiln is usually at a high temperature of 900 ° C. or higher, the heat recovery is performed by connecting a suspension preheater (hereinafter sometimes abbreviated as SP). Since the SP exhaust gas is still at a high temperature of about 300 to 400 ° C., the amount of heat is used for drying raw materials, power generation boilers, and the like. Thereafter, the exhaust gas is collected and discharged to the atmosphere.

  The gas flow from the kiln inlet to the SP outlet is generally in a countercurrent relationship with the raw material flow. For this reason, the volatile element which is easy to make a volatile molecule is concentrated. Concentrated volatile elements adhere to the inside of the facility, and problems such as blockage of the device occur when the amount becomes large.

  As the use of waste increases, the amount of chlorine is particularly increasing as an element that easily forms volatile molecules. For this reason, an apparatus called a chlorine bypass that extracts volatile molecules such as chloride from the firing process has recently become widespread.

  The elements that are circulated and concentrated are unlikely to go out with the clinker in the amount that has entered the firing process. For this reason, if it does not discharge out of the system from the chlorine bypass, it will be exhausted to the atmosphere, or it will be exhausted to the clinker or the atmosphere when operation is disturbed.

  Patent Document 1 describes a method of introducing dust collected from exhaust gas into a clinker grinding system as a method of reducing volatile elements of heavy metals such as mercury discharged into the atmosphere.

  Patent Document 2 shows a method for extracting SP exhaust gas at 350 ° C. or higher and preventing mercury and the like from accumulating in a cement manufacturing facility as an improvement method of Patent Document 1, It describes that mercury etc. emitted into the atmosphere can be reduced.

JP 2002-284550 A JP 2005-097005 A

  The cement manufacturing industry is required to reduce harmful substances discharged into the environment during clinker production and cement use.

  The main object of the present invention is to provide a cement clinker manufacturing apparatus, a cement manufacturing apparatus, a cement clinker manufacturing method, and a cement manufacturing method in which harmful substances are hardly discharged into the environment.

  Most of the toxic substances are concentrated in SP exhaust gas (unless otherwise noted, exhaust gas contains significant dust). In the manufacture of clinker, harmful substances in the SP exhaust gas are moved to the dust side and collected to reduce harmful substances released to the atmosphere. However, since it is collected and reused as a raw material, many of the harmful substances consisting of circulating harmful elements and harmful organic substances are concentrated, and as a result, the amount discharged without being collected increases.

  Therefore, dust collected from the SP exhaust gas (hereinafter sometimes abbreviated as SP dust) can be extracted from the circulating process and used as it is in the finishing process. However, when using cement, harmful elements and harmful organic substances may elute and contaminate the environment.

  In particular, ground improvement using a solidified material containing cement has been increasing in recent years, and leaching after solidification has been strictly controlled during solidification of cement compared to conventional so-called concrete structures. Dust generated in cement production facilities cannot be easily added to clinker or cement.

  Also, handling dust requires appropriate equipment and labor, and gas is easier to handle if dust is not used directly in the finishing process. However, in order to collect mercury etc. from gas, since the additional collection | recovery apparatus was required, there existed a tendency for the installation to become complicated.

A cement clinker manufacturing apparatus according to the present invention includes a kiln, a suspension preheater, a connection pipe that connects the kiln and the suspension preheater, an extraction pipe that is connected to the connection pipe and extracts the kiln exhaust gas of the kiln, and an extraction pipe A cooler connected downstream, a cooling air introduction pipe connected to the cooler, a dust collector connected downstream of the cooler, and an exhaust gas of the suspension preheater connected to a pipe downstream of the suspension preheater And a cooling gas pipe for extracting gas from the cooling gas pipe and connected to supply gas to the cooler.

  In the cement clinker manufacturing apparatus according to the present invention, the suspension preheater may have a calcining furnace, and the exhaust gas from the dust collector is preferably supplied to the kiln or calcining furnace.

  In the cement clinker manufacturing apparatus according to the present invention, the dust collected by the dust collector is preferably added to the cement clinker or the finishing process.

  The cement clinker manufacturing apparatus according to the present invention preferably further includes an apparatus for washing the dust before the dust collected by the dust collector is added to the cement clinker or the finishing process.

  The cement clinker manufacturing apparatus according to the present invention insolubilizes harmful elements into highly alkaline water before the dust collected by the dust collector is added to the cement clinker or the finishing process. It is preferable to further comprise an apparatus.

  The cement manufacturing apparatus according to the present invention includes the cement clinker manufacturing apparatus according to the present invention.

The cement manufacturing method according to the present invention includes a step of mixing the gas extracted from the exhaust gas of the kiln with the gas extracted from the exhaust gas of the suspension preheater and air, and a step of collecting dust from the mixed gas.

  The method for producing a cement clinker according to the present invention can reduce the circulation of mercury or thallium in a cement clinker production apparatus.

  The method for producing a cement according to the present invention produces cement from the cement clinker produced by the method for producing a cement clinker according to the present invention.

  The harmful elements in the present invention are cadmium, mercury, selenium, lead, arsenic, fluorine, boron, which are specified as hazardous substances according to the Ordinance for Enforcement of the Soil Contamination Countermeasures Law. It assumes chromium, thallium, phosphorus, antimony, germanium, tin, etc., which are stable and highly toxic compounds.

  Among these, cadmium, mercury, selenium, lead, fluorine, and thallium, which are concentrated in cement manufacturing facilities and require attention when handling dust, are a source of a wide variety of wastes in cement manufacturing facilities. The possibility of other elements becoming a problem remains as it is recycled as fuel.

  In addition, the harmful organic substances in the present invention are mainly assumed to be dioxins that are highly toxic even in small quantities, but since oil-contaminated soil is recycled, it is also generated somewhat during combustion during clinker production. Things like VOC can be a problem.

  According to the present invention, it is possible to prevent harmful elements from being discharged into the environment.

It is a schematic diagram of the manufacturing apparatus of the clinker and cement which concerns on 1st Embodiment. It is a schematic diagram of the manufacturing apparatus of the clinker and cement which concerns on 2nd Embodiment. It is a schematic diagram of the manufacturing apparatus of the clinker and cement which concerns on 3rd Embodiment. It is a schematic diagram of the manufacturing apparatus of the clinker and cement which concerns on 4th Embodiment.

  The clinker manufacturing apparatus according to the present invention is characterized in that a known clinker baking apparatus having a kiln and an SP includes an extraction pipe, a cooler, a dust collector, and a cooling gas pipe.

  The cooler is connected via a bleed pipe and a connection pipe connecting the kiln and SP, and the kiln exhaust gas is supplied from the connection pipe. Further, the cooler is connected to the SP gas side downstream pipe through the cooling gas pipe, and the extracted SP exhaust gas is supplied from the cooling gas pipe.

  The dust collector is arranged to collect dust from the exhaust gas of the cooler.

  In an apparatus in which the raw material and the gas exchange heat in a countercurrent, volatile molecules evaporated from the raw material in the high temperature portion may move on the gas and move to the low temperature portion, where they may condense again on the raw material side. When such a phenomenon occurs, volatile molecules repeat evaporation and condensation, and specific elements and molecules circulate and concentrate. Moreover, not only the physical phenomenon of evaporation and condensation but also the chemical phenomenon of decomposition and bonding occurs in the same way. Both are collectively referred to as volatilization and aggregation in this application.

  In the clinker manufacturing apparatus, the flow of gas from the kiln inlet to the SP outlet and the raw material are countercurrent. Therefore, chlorine and sulfur, and alkali metals typified by sodium and potassium circulate and concentrate and adhere to the inside of the apparatus, causing a blockage trouble.

  For this reason, due to quality requirements, devices called alkali bypass and chlorine bypass have been put into practical use that stably extract the circulating material out of the firing system.

  The part of the device including the extraction pipe, the cooler, and the dust collector (hereinafter sometimes abbreviated as “chlorine bypass dust collector”) of the present invention is a device generally called a chlorine bypass.

  From the analysis of dust collected by the chlorine bypass dust collector, alkali metals such as sodium, potassium, rubidium and cesium, chlorine, bromine, sulfur, selenium, cadmium and lead are stably released outside the clinker manufacturing process. I found out that it was extracted. However, it has been found that mercury and thallium vary in the concentration of chlorine bypass dust, and a certain amount is discharged to the atmosphere.

  The cause of the variation is that the elements in the new raw material are relatively difficult to volatilize until they enter the kiln and melt and form volatile molecules (the volatility of such new raw materials is called the primary volatility) On the other hand, volatile elements once volatilized are collected in the form of molecules that are likely to volatilize and are often trapped on the surface of the raw material, so most of them are volatilized by SP before entering the kiln (such as This is thought to be because the volatilization rate of the circulation is called secondary volatility) and is difficult to recover by chlorine bypass.

  In other words, when mercury or thallium is introduced as new raw fuel from incoming raw materials, some of the volatilization in the kiln is extracted into the chlorine bypass, and other than that, most of it is extracted into the chlorine bypass because of volatilization with SP. Therefore, it was speculated that it might be difficult to recover as chlorine bypass dust.

  Therefore, the inventor of the present application has a high secondary volatilization rate at SP, and the elements recovered and circulated by SP dust are SP dust collectors (hereinafter abbreviated as SP dust collectors) and SP. Because it circulates mainly between the exhaust gas, it is noticed that it is concentrated in the SP exhaust gas, and if harmful elements are recovered from the SP exhaust gas, harmful elements that have not been recovered in the chlorine bypass dust will be discharged to the atmosphere. I thought it could be reduced.

  Moreover, in this case, if a chlorine bypass that has already recovered volatile elements efficiently can be used, it can be efficiently recovered and the present invention has been achieved.

  In Table 1, as an example, the clinker, chlorine bypass dust, SP cyclone raw material collected by the uppermost and lowermost cyclones of the clinker, the raw material of the clinker, the incoming raw material, and the SP dust of the clinker production apparatus actually operated Represents the concentration of the element analyzed by XRF in%. The analysis value of XRF is an oxide conversion value that normalizes measured values of elements heavier than sodium so that the total is 100% in terms of oxides other than halogen.

  The feed material is a material that is put into the SP for the production of clinker, and almost all of the SP dust is recovered and added to the newly prepared and ground material.

Chlorine, selenium, cadmium and lead have the highest concentration of chlorine bypass dust. It is presumed that these elements are concentrated in a circulation that volatilizes in the kiln and aggregates in the SP. Therefore, these elements can be recovered in chlorine bypass dust by extracting the kiln exhaust gas from the connection portion through the extraction pipe.

  In contrast, mercury and thallium have the highest SP dust concentration. It is presumed that these elements are mainly condensed by being volatilized by SP, aggregated and collected in SP dust, recovered in the feed material, and sent back to SP. The That is, elements such as mercury and thallium that have a high secondary volatility in SP and are difficult to recover only by chlorine bypass have a high concentration in the SP exhaust gas that is a circulation path.

  Therefore, in the present invention, SP exhaust gas is used for the whole or a part of the cooling gas for the chlorine bypass. Therefore, harmful elements that have a high secondary volatility at SP and are difficult to extract with the conventional chlorine bypass, It can be recovered from the SP exhaust gas to a chlorine bypass cooler and recovered as chlorine bypass dust.

  At this time, it is preferable that the SP exhaust gas is cooled, and heat radiation from the pipe can be expected. Therefore, the cooling gas pipe may be somewhat longer, and it is possible to extract air immediately after leaving the uppermost cyclone of the SP. is there.

  In addition, since the SP exhaust gas contains a considerable amount of dust, molecules with a high secondary volatilization rate are often contained in dust fines due to their agglomeration mechanism and physical adsorption, so they are coarse using a dust collector such as a cyclone. It is preferable to put an apparatus excluding dust in the middle of the cooling gas pipe so that the amount of chlorine bypass dust does not increase, since this contributes to cooling of the extracted SP exhaust gas.

  In the clinker manufacturing apparatus according to the present invention, the exhaust gas from the chlorine bypass dust collector contains harmful substances that have not aggregated into the chlorine bypass dust, so the exhaust gas from the chlorine bypass dust collector is installed in the kiln or SP. It is preferable to be supplied to a calcining furnace.

  In the clinker manufacturing apparatus according to the present invention, the chlorine bypass dust may be added to the clinker or the finishing process. In this case, it is preferable to further include a water washing device before adding the chlorine bypass dust to the clinker or the finishing process. Furthermore, insolubilization treatment can be added.

By washing with water, components unfavorable in terms of cement quality contained in the chlorine bypass dust can be removed. In addition, most harmful elements such as selenium, cadmium, mercury, thallium, lead, etc. make sulfur and sulfides that seem to be contained in trace amounts of CaS _x (calcium polysulfide) and are almost soluble in highly alkaline water. Disappear. Furthermore, since accompanying CaO becomes CaOH ₂ and solidifies, many harmful substances are contained in the solidified body. Further, when the chlorine bypass dust is solidified, if an insolubilizing treatment such as addition of chelate or cement is performed, the same effect as insolubilization by cement solidification can be obtained. Even if the dust treated in this way is added to the clinker or the finishing process, the dissolution to the environment when adding water to solidify the cement can be extremely reduced.

  The cement manufacturing apparatus according to the present invention includes the clinker manufacturing apparatus according to the present invention. Therefore, it is possible to effectively reduce harmful substances discharged into the environment from the cement manufacturing apparatus according to the present invention, and to effectively discharge harmful substances discharged into the environment when using the cement manufactured with the cement manufacturing apparatus according to the present invention. Can be suppressed.

  In the clinker manufacturing method according to the present invention, the extracted SP exhaust gas is mixed with the extracted kiln exhaust gas, and dust is collected from the mixed gas. In this process, mercury and thallium, which were difficult to extract with the conventional chlorine bypass, are also collected as chlorine bypass dust, and the circulation in the clinker manufacturing process is reduced.

  The kiln exhaust gas contains mainly volatile elements that are volatilized in the kiln and agglomerated and circulated in the SP. The amount of the volatile elements is large and discharged outside the firing system using a conventional chlorine bypass. SP exhaust gas contains many elements with high secondary volatility in SP, which are difficult to remove by chlorine bypass and are circulated by being volatilized mainly by SP, trapped in SP dust and supplied to SP again. It is. Therefore, if the present invention is used, SP exhaust gas is also supplied to the chlorine bypass, whereby elements having a high secondary volatilization rate at SP, particularly mercury and thallium, can be recovered as chlorine bypass dust.

  Therefore, the amount of circulation in the clinker manufacturing process is reduced and the amount discharged to the atmosphere is also reduced.

  The exhaust gas of SP or the gas in which the exhaust gas of kiln and the exhaust gas of SP are mixed is preferably cooled in order to agglomerate volatile harmful elements.

  The chlorine bypass dust collector is preferably operated at a temperature lower than the exhaust gas temperature of SP for the purpose of aggregating volatile components in the SP exhaust gas. Also, a physical adsorbent that is harmless to cement such as zeolite can be added before the chlorine bypass dust collector for the purpose of agglomeration. It is also possible to intentionally raise the temperature of the chlorine bypass dust collector and collect mercury and thallium at the outlet. In that case, it is possible to lower the gas temperature or use a physical adsorbent such as activated carbon.

  In the cement manufacturing method according to the present invention, cement is manufactured from the clinker manufactured by the clinker manufacturing method according to the present invention. Therefore, according to the cement manufacturing method according to the present invention, it is possible to reduce harmful substances discharged into the environment from a cement manufacturing apparatus and effectively suppress harmful substances discharged into the environment when using cement. Can do.

  Below, the example of the preferable form which implemented this invention is demonstrated. The following embodiment is an exemplification, and is not limited to the following embodiment.

  In the drawings, the same portions are referred to by the same reference numerals, and can be replaced with other devices having similar functions. Further, the block in the figure is a functional illustration of the apparatus, and is not related to specific actual dimensions or structure.

(First embodiment)
FIG. 1 is a schematic view of a clinker and cement manufacturing apparatus according to the first embodiment. In FIG. 1 and FIGS. 2 to 4 to be described later, the solid line indicates the flow of the solid such as the raw material and the accompanying liquid and gas, and the broken line indicates the flow of the gas and the accompanying dust.

  The cement manufacturing equipment includes a raw material process (equipment) 1, a firing process (equipment) 2, and a finishing process (equipment) 3.

  In the raw material process 1, the raw material which sprinkled SP21 contained in SP exhaust gas G1 is collect | recovered to the raw material which mix | blended and grind | pulverized the new raw material, and the input raw material M1 is made. Since the SP exhaust gas G1 has a considerable amount of heat, it is used for drying new raw materials.

  In the firing step 2, the feed material M1 is charged into the SP 21 to perform heat exchange, enters the kiln 23 through the connection pipe 22, and is fired in the kiln 23 to produce the clinker M2.

  Today, it is common to increase the production amount by providing a calcining furnace at the gas side inlet of SP21 and using NSP (New Suspension Preheater) for supplying fuel. In the present invention, since there is no essential difference between SP and NSP, they are collectively expressed as SP.

  Although not shown in the drawing, the clinker M2 that has exited the kiln 23 needs to be rapidly cooled for quality, and is cooled by a heat exchanger called a clinker cooler. For this cooling, a gas mainly composed of air is used and used for combustion of fuel in the kiln 21. In the case of NSP, it is also used for burning fuel in a calciner. The kiln exhaust gas G2 of the kiln 23 passes through the connecting pipe 22 and is used for heating the feed raw material M1 in SP21 together with the combustion gas of the calciner.

  In the finishing step 3, plaster or the like is added to the clinker M2 and pulverized to produce a cement M3.

  The present embodiment is directed to a general clinker and cement manufacturing apparatus having such SP23.

In recent years, it has become common to recycle a wide variety of waste as raw fuel for cement production, and the amount of chlorine in particular has increased. Chlorine produces relatively stable molecules with many metals and high saturated vapor pressure, so the kiln produces KCl, NaCl, and CaCl ₂ , increasing the circulating material.

  For this reason, the amount of deposits in the apparatus increases, resulting in increased clogging trouble, and due to quality requirements, a chlorine bypass for extracting circulating substances such as chlorides from the firing process has become widespread.

  The manufacturing apparatus according to this embodiment includes such a chlorine bypass 4.

  In the chlorine bypass 4, the chlorine bypass bleed gas G3 obtained by extracting a part of the kiln exhaust gas G2 is processed. The extraction is performed by connecting the extraction pipe 41 to the connection pipe 22 and extracting the air, and often 0.3 to 30% of the kiln exhaust gas G2 is extracted. This ratio is called the bleed rate.

  The extraction rate can be 0 to 100% depending on the purpose. If you want to stabilize the operation by reducing the circulation of chloride, less than 1% is usually enough, the raw fuel contains a lot of chlorine, and the quality of cement M3 If you want to remove it, extract 3% or more and reduce the chlorine in the clinker M2.

  The chlorine bypass bleed gas G3 is sent to the cooler 42 and is cooled by mixing the cooling air. As for cooling air, ambient air is usually used, but other gases can be mixed and used if cooling is possible.

  Since the kiln exhaust gas G2 contains a large amount of components that aggregate and cause clogging, the kiln exhaust gas G2 is prevented from contacting the wall surface of the apparatus until the volatile substances are aggregated. The cooling gas is flowed so as to protect the inner wall surface of the apparatus until the volatile component is solidified, so that the volatile component does not adhere to the inner wall surface.

In actual operation, the volatile molecules of the chlorine bypass bleed gas G3 are mainly KCl and SO _{2, and} they are affected by the lowering of the melting point due to eutectic, the heat of aggregation when the gas is liquefied, and the heat of reaction during desulfurization. The solidification temperature seems to be about 600 ° C. Therefore, it is preferable to operate so as not to contact the inner wall surface until the maximum temperature of the chlorine bypass bleed gas G3 becomes 600 ° C. or lower. At this time, the chlorine bypass bleed gas G3 is not so mixed with the cooling gas, and has a non-uniform temperature distribution in which the center of the tube is hot and the surroundings are cold. When a gas having such a temperature distribution was completely mixed at a central portion of 600 ° C., the result of simulation or the like was 300 to 400 ° C.

  The chlorine bypass bleed gas G3 cooled by the cooler 42 is sent to the chlorine bypass dust collector 43, and the chlorine bypass dust M4 is recovered. If cooling is performed only by the cooler 42 to the heat resistant temperature of the chlorine bypass dust collector 43, the efficiency is usually poor. Therefore, the exhaust gas of the cooler 42 is sufficiently cooled by blowing in another heat exchanger (not shown) or air for natural cooling or cooling by piping, and is supplied to the chlorine bypass dust collector 43.

  In the present embodiment, a cooling gas pipe 5 for using the SP exhaust gas G1 is installed as the whole or a part of the cooling air.

  Although FIG. 1 depicts the cooling gas pipe 5 connected directly to the cooler 42, it is not limited to this figure. The cooling gas pipe 5 may be connected so as to supply the SP exhaust gas G1 to the cooler 42. For example, an inlet of a fan for blowing cooling air, a pipe for blowing cooling air into the cooler 42, or a bleed pipe 41 can be connected.

  The total amount of circulating material contained in the SP exhaust gas G1 is not reduced unless dust is removed from the exhaust gas. Therefore, the cooling gas pipe 5 may be connected so that the SP exhaust gas G1 can be extracted with dust before the raw material is mixed with the SP exhaust gas G1 and removed by an individual apparatus in the raw material process. If the temperature of the extracted SP exhaust gas G1 is higher than the temperature of the chlorine bypass exhaust G4, the chlorine bypass dust collector 43 can efficiently recover the circulating material.

The dust in the SP exhaust gas G1 extracted by the cooling gas pipe 5 may be contained because volatile molecules are physically adsorbed. However, since coarse and heavy dust has few pores and has a small specific surface area, physical adsorption cannot be expected so much. Therefore, if the amount of chlorine bypass dust G4 increases excessively, it is preferably removed. The dust in the SP exhaust gas G1 is mainly fine and light dust that could not be collected by the SP cyclone, but there are also coarse and heavy dust due to re-scattering. A settling chamber or the like can be used. Of course, for the purpose of cooling, the SP exhaust gas G1 extracted by the cooling gas pipe 5 is preferably cooled.

(Second Embodiment)
FIG. 2 is a schematic view of a clinker and cement manufacturing apparatus according to the second embodiment.

  2 differs from FIG. 1 in that the chlorine bypass exhaust G4 is connected to the gas entering the kiln 23 and the gas entering the calciner. In FIG. 2, the chlorine bypass is connected to two places of the calciner, but the chlorine bypass may be connected to only one place of the calciner.

The gas entering the kiln 23 is an O ₂ source gas for kiln fuel combustion that enters the kiln from a cooler (not shown) or enters from the main burner of the kiln. The gas entering the calcination furnace is an O ₂ source gas for burning the calcination furnace fuel that enters the calcination furnace from a cooler (not shown) or enters from the burner of the calcination furnace. When returning the chlorine bypass exhaust G4 to the cooler, it is preferable to return the chlorine bypass exhaust G4 so that heat exchange is performed.

  The chlorine bypass dust collector 43 that processes the high-temperature gas that recovers the chlorine bypass dust G4 is often operated at a high temperature that the dust collector can withstand in order to reduce the equipment cost. In the case of a bag filter, the upper limit of the use temperature is about 200 ° C. because of the heat resistance of the filter, and in the case of EP or ceramic filter, the upper limit of the use temperature is about 350 ° C. because of the heat resistance of the casing or fan. Of course, higher temperature operation is possible if the device is designed to withstand high temperatures.

  Due to the high temperature, harmful elemental molecules are not sufficiently adsorbed by the chlorine bypass dust G4 and easily escape to the chlorine bypass exhaust G4. Therefore, the chlorine bypass exhaust G4 is not discharged into the atmosphere as it is, but is returned to the clinker production apparatus again, thereby reducing harmful elements discharged into the atmosphere.

(Third embodiment)
FIG. 3 is a schematic view of a clinker and cement manufacturing apparatus according to a third embodiment.

  3 differs from FIG. 1 in that the chlorine bypass dust M4 is connected to the clinker M2 and the finishing process 3. In FIG. 2, the chlorine bypass is connected to two places of the calciner, but the chlorine bypass may be connected to only one place of the calciner.

  Chlorine bypass dust M4 can be added to the clinker as it is in a small amount. At that time, if a small amount of water is added, the chlorine bypass dust M4 adheres to the clinker M2, and when the powder and lump are separated (called seguri, often occurs when handling the clinker), the dust is directed toward the powder. This is preferable because the risk of concentration variations occurring due to a large amount of decrease decreases.

  Note that addition to the clinker is also possible in the finishing step 3, and in the case of powder, if it is performed before the separator at the finishing mill outlet, it is effective because it does not interfere with the pulverization and generates less dust.

(Fourth embodiment)
FIG. 4 is a schematic view of a clinker and cement manufacturing apparatus according to a fourth embodiment.

  FIG. 4 is different from FIG. 3 in that the water-washing device 6 is inserted before the chlorine bypass dust M4 is connected to the clinker M2 and the finishing process 3. In FIG. 2, the chlorine bypass is connected to two places of the calciner, but the chlorine bypass may be connected to only one place of the calciner.

  If the chlorine bypass dust M4 contains many harmful components such as chlorides in terms of cement quality, it is preferable to remove them. At that time, most of the chloride is easily dissolved in water and harmless, so it can be removed by washing with water. Further, it is also preferable because it also becomes an insolubilization treatment in which elution of harmful elements is suppressed during washing, and harmful substances discharged from the cement to the environment can be reduced.

  Moreover, it replaces with the water washing apparatus 6, or in addition to the water washing apparatus 6, an insolubilization processing apparatus which adds and solidifies cement and a chelate can be arrange | positioned.

  According to the present invention, by using chlorine bypass during the production of clinker and cement, not only volatile harmful elements having a high secondary volatility in SP, but also harmful substances, particularly circulating harmful substances, are extracted, The amount discharged into the atmosphere can be reduced.

  In addition, elements that are recovered from SP dust into chlorine bypass dust can be recovered not only as components that are undesirable for cement products, such as chlorine, potassium, and sodium, but also as useful materials by changing the method of processing chlorine bypass dust. Is also possible.

M1 feed material M2 clinker (cement clinker)
M3 Cement M4 Chlorine bypass dust G1 SP exhaust gas G2 Kiln exhaust gas G3 Chlorine bypass extraction G4 Chlorine bypass exhaust 1 Raw material process 2 Firing process 21 SP (suspension preheater)
22 Connection piping 23 Kiln 3 Finishing process 4 Chlorine bypass 41 Extraction pipe 42 Cooler 43 Chlorine bypass dust collector 5 Gas piping for cooling 6 Water washing device or insolubilization processing device

Claims (11)

Kiln and
Suspension preheater,
A connection pipe connecting the kiln and the suspension preheater;
An extraction pipe connected to the connection pipe for extracting the kiln exhaust gas of the kiln;
A cooler connected downstream of the extraction pipe;
Piping for introducing cooling air connected to the cooler;
A dust collector connected downstream of the cooler;
A cooling gas pipe connected to a pipe downstream of the suspension preheater and extracting the exhaust gas of the suspension preheater;
And a cement clinker manufacturing apparatus connected to supply gas from the cooling gas pipe to the cooler. The manufacturing apparatus of the cement clinker of Claim 1 provided with the apparatus which removes coarse powder in the middle of the said gas piping for cooling. The manufacturing apparatus of the cement clinker of Claim 1 or 2 with which the waste gas from the said dust collector is supplied to the said kiln or the said suspension preheater. The manufacturing apparatus of the cement clinker as described in any one of Claims 1-3 with which the dust collected with the said dust collector is added to a cement clinker or a finishing process. The manufacturing apparatus of the cement clinker of Claim 4 further equipped with the apparatus which rinses the said dust before the dust collected with the said dust collector is added to a cement clinker or the said finishing process. 6. The apparatus according to claim 4 or 5 , further comprising a device for insolubilizing the harmful element into highly alkaline water before the dust collected by the dust collector is added to the cement clinker or the finishing process. An apparatus for producing a cement clinker as described in 1. The cement manufacturing apparatus provided with the cement clinker manufacturing apparatus as described in any one of Claims 1-6 . Mixing the gas extracted from the exhaust gas of the kiln with the gas extracted from the exhaust gas of the suspension preheater, and air ;
Collecting dust from the mixed gas;
A method for producing a cement clinker. 9. The method of producing a cement clinker according to claim 8, wherein the exhaust gas of the suspension preheater is mixed with a gas extracted from the exhaust gas of the kiln after coarse powder separation. 9. The method for producing a cement clinker according to claim 8 , wherein circulation of mercury or thallium in the cement clinker production apparatus is reduced. The manufacturing method of the cement which manufactures a cement from the cement clinker manufactured by the manufacturing method of the cement clinker as described in any one of Claims 8-10 .