JP3285523B2 - Manufacturing method of cement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an amine-based organic substance,
The present invention relates to a novel method for producing cement using sludge containing odorous compounds such as fatty acid-based organic substances and sulfide-based substances as a part of raw materials. Specifically, there is provided a method for producing a cement capable of producing cement with a stable quality without separately requiring a deodorizing facility for the odorous compound and without adversely affecting the production of cement by using the sludge. To provide.

[0002]

2. Description of the Related Art The treatment of sludge containing odorous compounds such as sewage sludge, industrial wastewater sludge, and activated sludge has become a serious problem due to restrictions on disposal sites due to the odor.

On the other hand, in recent years, attempts have been made to use industrial waste such as plastic waste materials as a part of fuel in a cement plant, and utilization of the above-mentioned sludge in a cement plant is being studied.

However, when the above-mentioned sludge is directly introduced into a high-temperature combustion area such as a calciner or a kiln (firing furnace) for treatment in a cement production process, the odorous compound is decomposed and disappears due to the high temperature during combustion. However, in this case, since many sludges contain a large amount of water, there has been a problem that heat is consumed by evaporation of the water of the sludge, resulting in a loss of combustion energy. Also, when a large amount of sludge is introduced,
Fluctuations in the water content cause a sudden change in the calcination temperature of the cement raw material or the calcination temperature of the cement.

[0005] Therefore, it is conceivable that the sludge is previously dried in a dryer and then charged into the calcining furnace or the combustion furnace.

However, in order to avoid deterioration of the working environment due to odorous compounds generated in the dryer and generation of offensive odor, etc., the exhaust gas of such a dryer is treated by a deodorizing facility such as an activated carbon adsorption tower, and specified by law. It must be discharged at a concentration lower than the specified standard, and there is a concern that the equipment may be increased and the operation may be complicated.

[0007]

Therefore, according to the present invention, when sludge containing an odorous compound is treated in the cement production process, a separate deodorizing facility for the odorous compound contained in the sludge is not required. A method for producing a cement capable of producing a cement with stable quality by preventing the deterioration of the working environment and offensive odor pollution due to the addition of the sludge into a calciner and a kiln. The purpose is to provide.

[0008]

Means for Solving the Problems The present inventors have intensively studied to solve the above problems. As a result, the sludge, calcium, sodium, by contacting the cement raw material powder powder containing an alkali component such as potassium,
It has been found that even when the sludge contains a large amount of odorous compounds, the odorous compounds can be effectively deodorized.

As a result of further studies based on the above findings, the sludge is brought into contact with a cement material mainly composed of limestone in the cement production process, thereby eliminating the need for a separate means for removing odorous compounds. that it is possible to process in the cement manufacturing process, further, as such contact points, such as drying and / or milling process of cement material, raw material powder powder in the contact area is much contact frequently step the is valid and desirable
Out we have seen, and have completed the present invention.

That is, the present invention mainly comprises a sludge containing an odorous compound , limestone, a clay raw material, a siliceous raw material, and an acid.
Inui and cement raw materials blended with iron raw materials of cement raw materials
After contacted by way of the燥step and / or grinding process, a method for producing cement and supplying the baked formation step, as a preferred embodiment, the sludge is supplied to as dry Engineering cement material drying with the cement raw materials Te
The present invention also provides a method for producing cement which is further pulverized and then supplied to a firing step.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, as a cement raw material, a known raw material mainly composed of limestone is used without any particular limitation. If Shimese cement raw specifically, limestone as the main, this clay material, silica containing material, because it uses oxidation Cheorwon charge distribution <br/> combined and there. In the case of Portland cement, a composition generally comprising 50 to 90% by weight of limestone, 10 to 40% by weight of clayey raw material, 5 to 20% by weight of siliceous raw material, and 2 to 8% by weight of iron oxide raw material.

Of the cement raw materials, limestone as a main raw material varies depending on the place of production, storage conditions, and the like.
It contains about 10% by weight of water and has an average particle size of about 10 to 40 mm in many cases. In the present invention,
Limestones of known properties as described above can all be used.

In the present invention, the sludge used contains an inorganic substance which can be a raw material in the production of cement or an organic substance which can be a fuel and contains a large amount of odorous compounds. For example, sludge such as sewage sludge, factory wastewater sludge, and activated sludge is typical.

Most of the above-mentioned sludge generally contains 20 to 99.9% by weight of water, and all of them can be used. In the present invention, in particular, from the viewpoint of deodorizing effect,
Those having a water content of 50 to 99.9% by weight are preferably used.

The odorous compounds contained in the sludge vary depending on the type of the sludge, but generally include amine organic substances, fatty acid organic substances, sulfide substances and the like.

An important requirement in the present invention is that the sludge is brought into contact with a cement raw material as a pretreatment for supplying the sludge to the firing step. Means for Solving the Problems In the method for producing cement using sludge, the present inventors can efficiently and efficiently remove odors without separately deodorizing equipment for odorous compounds contained in the sludge, and use the sludge. As a method capable of producing cement with stable quality without adverse effect on the production of cement due to this, by bringing the cement raw material and sludge into contact with each other, deodorization of odorous compounds contained therein is performed extremely effectively. I found something.

That is, the present inventors confirmed the deodorization of the odorous compound by the above-mentioned characteristic means of the present invention using the experimental equipment shown in FIG. The experiments performed are as follows. That is, N ₂ gas 3 mixed with ₂ % by volume of O ₂ to which hydrogen sulfide 1 and methyl mercaptan 2 at a certain concentration are added is further added with N.
₂ gas ratio of 5 volume% of H ₂ O vapor 5 humid gas added was adjusted. The gas was passed through the sedimentary layer 6 of the cement raw material powder heated to 105 ° C. in the annular furnace 4 for 10 seconds, and the change in the concentration of these odorous compounds was detected by the detector tube 7 for hydrogen sulfide and the detector tube 8 for methyl mercaptan. confirmed. As a result, as shown in Table 1, it was confirmed that the concentrations of hydrogen sulfide and methyl mercaptan were reduced to levels below the detection limit of the detector tube. Similar results were obtained with other odorous compounds usually contained in sludge, confirming the effectiveness of the present invention.

[0018]

[Table 1]

[0019] The deodorizing effect is presumed to odorous compounds in the sludge are deodorized is more oxidized or chemically adsorbed to the cement raw material. Further, the adsorbed odorous compound is presumed to be thermally decomposed in the calcination step and the calcination step.

In this case, the contact between the sludge and the cement raw material is preferably performed in the presence of oxygen, particularly preferably in the presence of 1% by volume or more of oxygen. In addition, it has been confirmed that the presence of water contained in the sludge or cement raw material is also effective in oxidizing or adsorbing the odorous compound. In particular, the contact in an atmosphere having a water content of 4% by volume or more is effective.

[0021] Such contact is achieved by the step of calcining the cement raw material,
Be carried out in the drying step and / or grinding process of cement raw material up to the firing step, the sludge contacted cement material surface and efficiently, and preferred to be able to carry out drying at the same time. Further, the atmosphere in the drying step and / or the pulverizing step is also advantageous in that the oxygen concentration and the humidity at the time of the contact can be satisfied, and is a preferable contact portion in the present invention.

In the drying step, it is preferable to use the exhaust gas of the kiln as a drying gas in order to effectively use the exhaust gas. Of course, it is also possible to provide a separate heating device to heat the air and supply it as a drying gas.
As the drying device, one having a known structure is used without any particular limitation. For example, a rotary drier, a fluidized bed drier and the like can be mentioned. Among them, in a mode in which the sludge is supplied to the drying device in the drying step to treat the sludge, a type in which the cement raw material flows is preferable in order to sufficiently contact with the cement raw material.

The above-mentioned pulverizing step is a step carried out to enhance the reaction efficiency in firing the cement raw material in the kiln. In the pulverizing step, the cement raw material is
Blaine specific surface area 1500~4500cm ² / g, and preferably, ground to 2000~4000cm ² / g. The pulverizing apparatus used in the pulverizing step is not particularly limited as long as the pulverizing apparatus has a known structure. The method of the following method is preferably used. For example, a pulverizing device such as a ball mill and a roller mill is preferably used.

The drying step and the pulverizing step include drying and
It is also possible to perform drying and pulverization at the same time as the pulverization step. In this case, the sludge is supplied to the drying / pulverization step.

In the present invention, the sludge from which the odorous compound has been removed by contact with the cement raw material as described above is supplied to the cement firing step together with the cement raw material. Such a firing step generally comprises a calciner and a kiln. Known structures and operating conditions for the calciner and kiln are not particularly limited.

In the cement firing step, the cement raw material is
If necessary, it is put into a kiln via a calciner and fired. At this point, the sludge has been dried and increasing the rate of supply to the calciner or kiln has little effect on the operating conditions of the kiln.

The organic matter contained in the sludge acts as a part of the fuel in the calciner or kiln, and the inorganic matter is contained in the cement as a part of its composition.

In the present invention, the cement clinker obtained from the firing step is pulverized to an appropriate particle size to obtain a product.

[0029]

According to the present invention, when sludge containing an odorous compound is used in the cement production process, the odorous odorous compound contained in the sludge can be removed by a simple operation without providing a deodorizing facility. Substances can be excluded.

Further, since the process of the present invention is Oite performed as grinding <br/> Engineering cement material, the fluctuation of the quality of waste and products of energy by placing the juicy sludge to a high temperature combustion region The sludge can be eliminated, and the utilization rate of the sludge can be improved.

[0031]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Example 1 A cement production method using sewage sludge was carried out as follows in accordance with the cement production process shown in FIG.

The sludge was supplied to the raw material drying step (5% by weight vs. clinker) from the sludge addition route 52 from the sewage sludge storage tank 14 and brought into contact with the cement raw material.

That is, in FIG. 2, the cement raw material mainly composed of limestone is quantitatively introduced into the dryer 11 from the raw material storage 40 by the cement raw material line 25. On the other hand, sludge is withdrawn from the sewage sludge storage tank 14 at a constant rate, similarly supplied to the dryer 11 through the sludge addition route 52, and dried while contacting with the cement raw material.
The raw material enters the raw material pulverizer 21, and the cement raw material is pulverized and comes into contact with sludge at the same time. The combustion exhaust gas 26 (20
(0 to 400 ° C.) is led to the raw material dryer 11 through a calciner. At this time, the oxygen concentration in the dryer was 1.5% by weight, and the water concentration was 8% by volume (all show average values). This exhaust gas is adjusted to about 100 ° C,
The dust passed through the dust collector 12 and was discharged from the flue 13 to the atmosphere .

Without contacting the sludge with the cement raw material,
Table 2 shows the concentration of the theoretical odorous compound (the amount brought in) of the exhaust gas and the concentration of the actually measured odorous compound measured by gas chromatography after flue gas sampling , assuming that the odorous compound was supplied to the production process. Hydrogen sulfide, methyl mercaptan,
Trimethylamine and normal valeric acid). According to this, the concentration of the odorous compound in the exhaust gas 26 was reduced to a level below the detection limit of the detector, and the deodorizing action of the cement raw material was confirmed.

[0036]

[Table 2]

Comparative Example 1 In comparison with Example 1 described above, for comparison, the sludge is directly supplied from the sewage sludge storage tank 14 of FIG. Experiments were also conducted for the embodiment of treating with (weight% vs. clinker).

Table 3 shows the fluctuations in the components of the clinker 60 which were burned out and the unit fuel consumption when the stable operation was performed for one month in each of the embodiment 1 and the comparative example 1. As a result, compared to Comparative Example 1, in Example 1, the components of the clinker were stable, and the firing energy was further reduced,
Example 1 was found to be a stable and low-loss sludge treatment method.

[0039]

[Table 3]

Example 2 In contrast to the production method of Example 1, the sludge is supplied to the raw material pulverizing step from the sludge addition route 53 from the storage tank 14 for sewage sludge (5% by weight to clinker) to obtain a cement raw material. The mode of contact was implemented.

That is, in FIG. 2, a cement raw material 25 mainly composed of limestone is supplied to the raw material pulverizer 21 in a fixed amount and pulverized to form a cement raw material powder. Since heat was generated by the pulverization, water was supplied inside to control the temperature. Sewage sludge stored in the tank 14 was supplied to the raw material pulverizer through the sludge addition route 53 at a constant rate. In this case, the oxygen concentration in the pulverizing device was 20% by volume, and the water content was 5% by volume (in each case, an average value is shown).

Further, the swept air 20 of the raw material crusher is used.
Was released to the atmosphere through the bag filter 22.

Table 3 shows the concentration of the theoretical odorous compound in the exhaust gas and the concentration of the actually measured odorous compound measured by gas sampling at the bag filter outlet 22 assuming that there is no deodorizing action in the raw material pulverizing step. (Hydrogen sulfide, methyl mercaptan, trimethylamine and normal valeric acid). According to this, the concentration of the odorous compound decreased to a level below the detection limit of the detector, and the deodorizing action of the cement raw material was confirmed.

[0044]

[Table 4]

The pulverized material of the cement and sludge taken out of the pulverizer was supplied to a cement kiln via a suspension preheater to obtain a cement clinker.

The cement clinker was pulverized to a Blaine specific surface area of 3200 cm ² / g to obtain a cement. The resulting cement was measured for the development of mortar compressive strength. As a result, the cement exhibited excellent properties of a 28-day strength of 61 N / mm ² , and was of the same quality as the cement without the addition of sludge.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an apparatus used to confirm the effects of the present invention.

FIG. 2 is a schematic diagram showing an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Hydrogen sulfide cylinder 2 Methyl mercaptan standard gas 3 O2 ₂ % by volume mixed N ₂ cylinder 4 Annular furnace 5 Steam 6 Cement raw material powder layer 7 Hydrogen sulfide detector tube 8 Methyl mercaptan detector tube 9 Flow meter 11 Raw material dryer 12 Electricity Dust collector 13 Flue 14 Tank for storing sewage sludge 20 Raw material crusher Swept Air 21 Raw material crusher 22 Bag filter 25 Cement raw material supply line 26 Kiln combustion exhaust gas 30 Firing process 40 Raw material storage 51 Sewage sludge addition route (calcination furnace supply Route) 52 Sewage sludge addition route (raw material dryer supply route) 53 Sewage sludge addition route (raw material pulverizer supply route) 60 Clinker

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Claims (2)

(57) [Claims] 1. Drying of cement raw material by mixing sludge containing odorous compound and cement raw material (excluding carbon-containing coal ash) mainly composed of limestone and containing clay raw material, siliceous raw material and iron oxide raw material A method for producing cement, comprising contacting via a step and / or a crushing step and then supplying the resulting mixture to a firing step. 2. The contact between sludge containing an odorous compound and a cement raw material ( excluding carbon-containing coal ash) mainly composed of limestone and containing a clay raw material, a siliceous raw material and an iron oxide raw material is excluded by 1% by volume. The method for producing a cement according to claim 1, wherein the method is performed in the presence of the above oxygen.