JP5627840B2 - Cement composition - Google Patents

Description

  The present invention relates to a cement composition using a cement clinker manufactured using chlorine-containing waste as a raw material.

In recent years, due to a significant increase in waste containing chlorine, including municipal waste incineration ash, its disposal has become a major social problem. In other words, effective use and recycling of these wastes are being promoted in various directions, but there is no definitive method, and many of them are dumped. Has caused problems such as secondary pollution. For this reason, it is an urgent task to develop a method for reusing these wastes as resources.
In the cement industry, a cement clinker is being developed that uses a large amount of waste and by-products such as industrial waste and general waste as raw materials.

  In general, when cement clinker is fired in a kiln, the chlorine brought from the cement raw material is gradually concentrated by circulating in the kiln / preheater system to reach an equilibrium state, and the amount of chlorine carried from the cement raw material and the cement clinker It is known that the amount of chlorine taken out of the system is equal. For this reason, if the amount of chlorine brought in from the cement raw material is large, the amount of chlorine contained in the cement clinker also increases, which may adversely affect the quality of cement as a product. Further, when the amount of chlorine in the system is increased, a low melting point compound is formed, so that the preheater cyclone is blocked and the stable operation of the kiln may be impaired.

  Therefore, conventionally, kiln exhaust gas is extracted by a probe, outside air is taken into the probe and primary cooling is performed, coarse powder is separated by a cyclone, secondarily cooled by a cooler, and further dusted by a high chlorine concentration fine dust. Reduction of the amount of chlorine in the kiln / preheater system has been carried out by a chlorine bypass facility that collects the water (Patent Document 1).

  However, in order to cope with the significant increase in chlorine-containing waste in recent years, when increasing the amount of such chlorine-containing waste used as a raw material, it is necessary to increase the extraction amount of the kiln exhaust gas, resulting in heat loss. In addition to the increase in size, it is necessary to process a large amount of dust (hereinafter referred to as “chlorine bypass dust”), resulting in a problem of inefficiency.

Moreover, generally, a large amount of energy is required for firing the cement clinker. That is, the temperature required for firing the cement clinker is 1450 to 1470 ° C., and a large amount of fuel is consumed to maintain such a high temperature. Therefore, it is also required to reduce the firing temperature and reduce the amount of fuel used.
JP 11-35354 A

  Therefore, the object of the present invention can be produced without increasing the extraction amount of kiln exhaust gas even when the amount of chlorine-containing waste used as a clinker raw material is increased, and does not adversely affect the quality of cement. Another object of the present invention is to provide a cement composition that can be fired at a lower temperature than conventional and can also use chlorine bypass dust.

In view of such circumstances, the present inventors have intensively studied, and as a result, combined the cement clinker with a content of fluorine, SO ₃ and chlorine within a specific range and a chlorine-containing material to solve the above problems. The present invention has been completed by finding out what can be done.

That is, the present invention, (A) a chlorine-containing waste to a cement clinker produced as a raw material, the content of fluorine 400~2000mg / kg, SO ₃ content from 0.6 to 2.0 wt%, The present invention provides a cement composition comprising a ground product of cement clinker having a chlorine content of 50 to 250 mg / kg, (B) a chlorine-containing material, and (C) gypsum.

Since the cement composition of the present invention can increase the amount used as a raw material for industrial waste, general waste, etc., it can contribute to promotion of effective utilization of waste.
In addition, the cement clinker used in the present invention can be manufactured by firing at a lower temperature than before, so that the amount of fuel used can be reduced.

  The cement clinker used in the present invention has a fluorine content of 400 to 2000 mg / kg, preferably 450 to 1800 mg / kg, particularly preferably 500 to 1500 mg / kg. If the fluorine content is less than 400 mg / kg, it is difficult to lower the firing temperature, and when trying to increase the amount of chlorine-containing waste used as a clinker material, it is necessary to increase the amount of kiln exhaust gas extracted. And heat loss increases. On the other hand, if the fluorine content exceeds 2000 mg / kg, the quality of the cement composition may be adversely affected, such as setting delay and strength reduction.

The cement clinker of the present invention has an SO ₃ content of 0.5 to 2.5% by mass, preferably 0.6 to 2.0% by mass, particularly preferably 0.7 to 1.5% by mass. If the SO ₃ content is less than 0.5% by mass, it is difficult to lower the firing temperature, and if the amount of chlorine-containing waste used as a clinker material is to be increased, it is necessary to increase the amount of kiln exhaust gas extracted. And heat loss increases. On the other hand, if the SO ₃ content exceeds 2.5% by mass, the preheater cyclone may be clogged and the stable operation of the kiln may be impaired, and the quality of the cement composition may be adversely affected, such as a decrease in initial strength. .

  Furthermore, the cement clinker of the present invention has a chlorine content of 50 to 250 mg / kg, preferably 70 to 200 mg / kg, particularly preferably 100 to 150 mg / kg. If the chlorine content is less than 50 mg / kg, it is difficult to increase the amount of chlorine-containing waste used as a clinker material, and the firing temperature cannot be lowered. On the other hand, if the chlorine content exceeds 250 mg / kg, it is necessary to increase the extraction amount of the kiln exhaust gas, which increases heat loss.

In the present invention, the content of fluorine, SO ₃ and chlorine in the cement clinker is measured by JIS R 5202 (Portland cement chemical analysis method).

  The cement clinker of the present invention is manufactured using chlorine-containing waste as a raw material. Examples of chlorine-containing waste include various sludges (for example, sewage sludge, purified water sludge, construction sludge, iron sludge, etc.), various incineration ash (for example, coal ash, incineration fly ash, molten fly ash, etc.), sewage sludge dry powder And municipal waste incineration ash.

In addition, as raw materials other than chlorine-containing waste, for example, raw conslag, construction waste, concrete waste, boring waste, foundry sand, rock wool, waste glass, secondary blast furnace ash, shells, etc. It is also possible to use generated soil such as soil generated from the site or construction site, residual soil, and waste soil.
Furthermore, general Portland cement clinker raw materials, for example, CaO raw materials such as limestone, quicklime and slaked lime; SiO ₂ raw materials such as silica and clay; Al ₂ O ₃ raw materials such as clay; Fe ₂ O ₃ such as iron cake and iron cake Raw materials can be used.

If these raw materials are used and the fluorine and SO ₃ contents cannot be adjusted to the specified amount, fluorite, fluorine sludge, etc. can be used as the fluorine raw material, and gypsum as the SO ₃ raw material. Waste gypsum board, pet coke, waste sulfuric acid, sulfur (such as petroleum recovered sulfur) can be used.

  Specific examples of the cement clinker of the present invention include various Portland cement clinker, hydraulic modulus (HM) of 1.8 to 2.3, silicic acid rate (SM) of 1.3 to 3.0, and iron rate (IM) of 1.3 to 2.8. Examples thereof include adjusted cement clinker. In particular, from the viewpoint of promoting effective utilization of waste, ordinary Portland cement clinker and early strong Portland cement clinker are preferable.

  The cement clinker of the present invention can be produced by mixing the raw materials as described above in a composition that gives the desired cement clinker, and then firing and cooling using a rotary kiln.

The method for mixing the raw materials is not particularly limited, and can be performed using a conventional apparatus or the like.
In addition to coal, which is the main raw material, fuel alternative waste such as waste oil, waste tires, waste plastic, wood waste, solid waste fuel, and the like can be used as the fuel. Some of these fuels contain fluorine, SO ₃ and chlorine, and these fuels can be used as a fluorine source, SO ₃ source and chlorine source.
In the present invention, from the viewpoint of promoting effective use of waste, 300 to 600 kg of waste raw materials (including generated soil) such as chlorine-containing waste and fuel alternative waste are used per 1 ton of cement clinker. Is preferred.

  The firing temperature is preferably 1250 to 1400 ° C, particularly preferably 1300 to 1400 ° C. If the firing temperature is less than 1250 ° C, sufficient firing is difficult, and if it exceeds 1400 ° C, it will be difficult to set the chlorine content to 50 to 250 mg / kg, increasing the amount of waste containing chlorine. I can't. Moreover, if it exists in this range, the objective of this invention of reducing a calcination temperature can be achieved.

The firing time is preferably 30 to 120 minutes, particularly 40 to 60 minutes.
Moreover, the method in particular of cooling a cement clinker is not restrict | limited, It can carry out using a conventional apparatus etc.

  In the production of cement clinker, it is preferable to extract a part of the kiln exhaust gas by a chlorine bypass facility. By extracting part of the kiln exhaust gas, the amount of chlorine-containing waste used can be further increased. The extraction rate of the kiln exhaust gas (extraction ratio to the kiln kiln bottom exhaust gas amount) is preferably 10% or less, particularly preferably 2 to 8%. When the extraction rate of the kiln exhaust gas exceeds 10%, heat loss increases and a large amount of chlorine bypass dust is generated.

The chlorine-containing material used in the present invention preferably contains 0.5% by mass or more of chlorine. Specific chlorine-containing materials include chlorides such as calcium chloride and potassium chloride, pulverized products of fast-hardening ecocement and fast-hardening ecocement clinker specified in JIS R 5214, and water-washed products of chlorine bypass dust and chlorine bypass dust. Etc. In the present invention, from the viewpoint of promoting the effective use of waste and the strength development of the cement composition, as a chlorine-containing material, fast-cure ecocement, pulverized fast-cure ecocement clinker, chlorine bypass dust and chlorine bypass It is preferable to use a dust washing product, and it is particularly preferable to use chlorine bypass dust or chlorine bypass dust washing product.
The chlorine specific surface area of these chlorine-containing materials is preferably 2500 to 10,000 cm ² / g, more preferably 3000 to 7000 cm ² / g, from the viewpoint of fluidity and strength development of the cement composition.

Examples of the gypsum used in the present invention include dihydrate gypsum, α-type or β-type hemihydrate gypsum, anhydrous gypsum, and the like, and these can be used alone or in combination of two or more.
The brane specific surface area of gypsum is preferably 2000 to 10000 cm ² / g, and more preferably 2500 to 8000 cm ² / g, from the viewpoint of fluidity and strength development of the cement composition and cost.

The cement composition of the present invention contains the above pulverized cement clinker, a chlorine-containing material, and gypsum. The amount of chlorine-containing material added is preferably such that the amount of chlorine in the cement composition is 50 to 350 mg / kg, preferably 100 to 300 mg / kg, more preferably 200 to 250 mg / kg. If the amount of chlorine in the cement composition is less than 50 mg / kg, the initial strength development of the cement composition may be reduced. Moreover, when using the chlorine bypass dust or the washing product of chlorine bypass dust, the addition amount decreases, and it is not preferable from the viewpoint of promoting effective utilization of the chlorine bypass dust. On the other hand, when the chlorine content in the cement composition exceeds 350 mg / kg, the fluidity of the cement composition decreases. Moreover, when it uses for a reinforced concrete, the possibility that a reinforcing bar rusts will become high.
The amount of gypsum is preferably 1 to 6% by mass, more preferably 2 to 4% by mass in terms of total SO ₃ in the cement composition, from the viewpoint of fluidity and strength development of the cement composition.

The cement composition of the present invention can be produced by mixing the above materials, but the method is not particularly limited. For example, a cement clinker pulverized product, a chlorine-containing product, and gypsum may be mixed, The cement clinker and the chlorine-containing material may be mixed and then pulverized and gypsum added thereto. Further, a cement clinker, a chlorine-containing material, and gypsum may be mixed and pulverized.
When mixing pulverized cement clinker and other materials, the brane specific surface area of the pulverized cement clinker is 2500-4500 cm ² / g due to the fluidity and strength of the cement composition, and the cost. It is preferable that it is 3000 to 4200 cm ² / g. On the other hand, when the cement clinker is pulverized simultaneously with other materials, the brane specific surface area of the cement composition is preferably 2500 to 4500 cm ² / g from its fluidity and strength development, and cost, More preferably, it is 3000-4200 cm ² / g.

In the cement composition of the present invention, one or more inorganic powders selected from blast furnace slag powder, fly ash, limestone powder, silica stone powder and silica fume, 2CaO · SiO ₂ (hereinafter referred to as C ₂ S) and 2CaO ・ Al ₂ O ₃・ SiO ₂ (hereinafter referred to as C ₂ AS) is an essential component, and C ₂ AS + 4CaO ・ Al ₂ O ₃・ Fe ₂ O ₃ (hereinafter referred to as C ₄ AS) relative to 100 parts by mass of C ₂ S (Referred to as AF) 10 to 100 parts by mass and 3CaO · Al ₂ O ₃ (hereinafter referred to as C ₃ A) content of 20 parts by mass or less, a baked product pulverized product Can do.

Cement compositions containing one or more inorganic powders selected from blast furnace slag powder, fly ash, limestone powder, silica stone powder, and silica fume reduce heat of hydration, improve fluidity, and improve durability and long-term strength. The improvement etc. can be aimed at.
C ₂ S and C ₂ AS are essential components, C ₂ AS + C ₄ AF is contained in 10 to 100 parts by mass with respect to 100 parts by mass of C ₂ S, and the content of C ₃ A is 20 parts by mass or less. In the cement composition containing the pulverized product of the fired product, heat of hydration can be reduced and fluidity can be improved. Further, since the fired product is made from industrial waste or the like, promotion of effective use of waste can be promoted.

In the present invention, the Blaine specific surface area of blast furnace slag powder, fly ash, silica stone powder, limestone powder is preferably 2500 to 10,000 cm ² / g from the viewpoint of fluidity and strength development of the cement composition, in particular. from the viewpoint of strength development, more preferably 3000~10000cm ² / g, and further preferably from 4000~9000cm ² / g.
Moreover, the blending amount of the blast furnace slag powder is 80% by mass or less, particularly 75% by mass or less in the cement composition from the viewpoint of heat of hydration of the cement composition, fluidity, durability and strength development. It is preferable that the amount is as follows. The blending amount of fly ash, silica stone powder or limestone powder is 50% by mass or less, especially 40% by mass in the cement composition from the viewpoint of heat of hydration, fluidity, durability and strength development of the cement composition. It is preferable that the amount be less than or equal to%.
In this case, the amount of gypsum in the cement composition is 1 to 5% by mass, particularly 1.5 to 4% by mass, and further 1.8 to ₃ % by mass in terms of total SO ₃ . It is preferable from the viewpoints of heat of hydration, condensation, fluidity, durability and strength development.

In the present invention, the BET specific surface area of silica fume is preferably 5 to ²⁰ m ² / g from the viewpoints of availability, fluidity and strength development of the cement composition, and particularly fluidity and strength development. in terms of sex, more preferably 6~18m ² / g, and further preferably from 7~15m ² / g. Further, the amount of silica fume is 40% by mass or less, particularly 30% by mass or less, in the cement composition from the viewpoint of heat of hydration, fluidity, durability and strength development of the cement composition. An amount is preferred.
In this case, the amount of gypsum in the cement composition is 1 to 5% by mass, particularly 1.5 to 4% by mass, and further 1.8 to ₃ % by mass in terms of total SO ₃ . It is preferable from the viewpoints of heat of hydration, condensation, fluidity, durability and strength development.

The cement composition of the present invention contains C ₂ S and C ₂ AS as essential components, contains 10 to 100 parts by mass of C ₂ AS + C ₄ AF with respect to 100 parts by mass of C ₂ S, and contains C ₃ A The pulverized product of the fired product having an amount of 20 parts by mass or less can be contained.該焼Narubutsu is as an essential component a C ₂ S and C ₂ AS, with respect to C ₂ S100 parts by 10 to 100 parts by weight of C ₂ AS, those preferably contain 20 to 90 parts by weight is there. When the C ₂ AS content is less than 10 parts by mass, the fluidity of the cement composition becomes poor. Also, even if the firing temperature is raised during firing, the amount of free lime is unlikely to decrease, making firing difficult, and the possibility that C ₂ S produced is also γ-type C ₂ S without hydration activity increases. The strength development property of the cement composition may be greatly reduced. On the other hand, when the C ₂ AS content exceeds 100 parts by mass, the strength development property of the cement composition may be lowered.

The fired product has a C ₃ A content of 20 parts by mass or less, preferably 10 parts by mass or less, with respect to 100 parts by mass of C ₂ S. When the content of C ₃ A exceeds 20 parts by mass, the heat of hydration of the cement composition increases and the fluidity also deteriorates.

Further, the fired product has a P ₂ O ₅ content of 0.2 to 8.0 mass% (more preferably 0.5 to 6.0 mass%) and an alkali (Na ₂ O + K ₂ O) of 0.4 to 4.0 mass% (more preferably 0.5 to 6.0 mass%). (3.5% by mass) is preferable. When P ₂ O ₅ or an alkali is contained in the above range, C ₂ S is activated, so that the strength development of the cement composition is improved even when there is no calcium aluminate such as C ₃ A. And the less calcium aluminate, the better the fluidity of the cement composition and the lower the heat of hydration.
The amount of free lime in the fired product is preferably 1.5% by mass or less, particularly 1.0% by mass or less, from the heat of hydration, fluidity, strength development, etc. of the cement composition.

The fired product can be produced by firing one or more materials selected from industrial waste, general waste, and construction generated soil. Industrial waste includes, for example, coal ash; raw sludge, sewage sludge, purified water sludge, construction sludge, iron sludge, red mud, and other sludge; boring waste, various incineration ash, foundry sand, rock wool, waste glass, blast furnace Secondary ash, construction waste, concrete waste, and the like; examples of general waste include sewage sludge dry powder, municipal waste incineration ash, and shells. Examples of construction generated soil include soil and residual soil generated from construction sites and construction sites, and waste soil.
Also, general Portland cement clinker raw materials, for example, CaO raw materials such as limestone, quicklime and slaked lime, SiO ₂ raw materials such as silica and clay, Al ₂ O ₃ raw materials such as clay, Fe ₂ O ₃ such as iron cake and iron cake Raw materials can also be used.

Depending on the raw material composition of the fired product, in particular, when one or more selected from the industrial waste, general waste and construction generated soil (hereinafter referred to as waste raw material) is used as the raw material, C ₄ AF is In the present invention, a part of C ₂ AS of the fired product, preferably 70% by mass or less of the mass of C ₂ AS may be substituted with C ₄ AF in the present invention. If C ₄ AF is substituted beyond this range, the temperature range for firing becomes narrow, and manufacturing control becomes difficult.

Mineral composition of the burned material may be determined CaO use in the raw material, from the content of _{SiO 2, Al 2 O 3,} Fe 2 O 3 ( wt%), the following equation.
C ₄ AF = 3.04 × Fe ₂ O ₃
C ₃ A = 1.61 × CaO−3.00 × SiO ₂ −2.26 × Fe ₂ O ₃
C ₂ AS = -1.63 x CaO + 3.04 x SiO ₂ + 2.69 x Al ₂ O ₃ + 0.57 x Fe ₂ O ₃
C ₂ S = 1.02 × CaO + 0.95 × SiO ₂ −1.69 × Al ₂ O ₃ −0.36 × Fe ₂ O ₃

The firing temperature of the fired product is preferably from 1000 to 1350 ° C., particularly from 1200 to 1330 ° C., because the molten phase in the firing step is in good condition.
The apparatus to be used is not specifically limited, For example, a rotary kiln etc. can be used. Moreover, when baking with a rotary kiln, a fuel alternative waste, for example, waste oil, a waste tire, a waste plastic, etc. can be used.
By such firing, C ₂ AS is generated, and a fired product having the above composition can be obtained.

The pulverized product of the fired product preferably has a Blaine specific surface area of 2500 to 5000 cm ² / g from the viewpoints of heat of hydration, fluidity, strength development and the like of the cement composition. The pulverization method is not particularly limited, and for example, it can be pulverized by a usual method using a ball mill or the like.
The blended amount of the pulverized product of the fired product is 50% by mass or less, particularly 40% by mass or less, in the cement composition from the viewpoint of heat of hydration, fluidity, durability and strength development of the cement composition. It is preferable that the amount is as follows.
The amount of gypsum in the cement composition containing the pulverized product of the fired product is 1 to 5% by mass, particularly 1.5 to 4% by mass, and more preferably 1.8 to ₃ % by mass in terms of total SO ₃ . The cement composition is preferable from the viewpoint of heat of hydration, setting, fluidity, durability and strength development.

The method for producing a cement composition containing an inorganic powder such as blast furnace slag powder or a pulverized product of fired product is not particularly limited. The mixture may be mixed with a material and gypsum, or an inorganic powder such as a cement clinker, a chlorine-containing material, gypsum, and a blast furnace slag powder or a fired product may be simultaneously pulverized.
In addition, the cement composition containing inorganic powder such as blast furnace slag powder or pulverized product of the fired product has a specific surface area of 2500-4500 cm ² / g to reduce bleeding of mortar and concrete, fluidity, strength It is preferable from the viewpoint of expression.

  EXAMPLES Next, although an Example is given and this invention is further demonstrated, this invention is not limited by these Examples.

Example 1
(1) Production of cement clinker:
Using the raw materials having the composition shown in Table 1, ordinary Portland cement clinker having the mineral composition, fluorine, SO ₃ and chlorine contents shown in Table 2 was produced.
Baking was performed using a rotary kiln, and wood chips and waste plastic were used as part of the fuel. Moreover, it carried out, extracting some kiln exhaust gas with a chlorine bypass facility. The extraction rate of the kiln exhaust gas is 4%. Table 2 also shows the firing temperature and the amount of waste used per ton of clinker.
The No. 4 cement clinker corresponds to the current ordinary Portland cement clinker.

(2) Cement clinker grinding:
The cement clinker obtained above was pulverized to prepare a pulverized product having a brain specific surface area of 3300 ± 50 cm ² / g.

(3) Materials other than cement clinker:
The following materials were used.
Chlorine-containing material A: Calcium chloride (reagent grade 1, chlorine content 64% by mass, Blaine specific surface area 400000 cm ² / g)
-Chlorine-containing material B: Chlorine bypass dust (chlorine content 20% by mass, Blaine specific surface area 2500cm ² / g)
Gypsum: dihydrate gypsum with a brain specific surface area of 4000 cm ² / g.
Limestone powder: Limestone powder having a Blaine specific surface area of 4000 cm ² / g.
・ Fine aggregate: Standard sand of JIS R 5201 (Cement physical test method).
Water reducing agent: polycarboxylic acid-based high performance AE water reducing agent (trade name: SP8N).

(5) Production of cement composition:
Each cement clinker pulverized product and each of the above materials were mixed in the formulation shown in Table 3 to produce a cement composition.

About the obtained cement composition, setting, mortar flow, and mortar compressive strength were measured. The results are shown in Table 4.
(Measuring method)
(1) Condensation:
In accordance with JIS R 5201, the standard soft water amount and the start / end were measured.
(2) Mortar flow:
Measured according to JIS R 5201.
(3) Mortar compressive strength:
The mortar compressive strength after 3, 7 and 28 days was measured according to JIS R 5201.

From Table 2, the cement clinker used in the present invention can be manufactured without increasing the extraction amount of kiln exhaust gas even when the amount of chlorine-containing waste used as a raw material is increased, and can be fired at a lower temperature than before. I understand.
Table 4 also shows that the cement composition of the present invention has good quality and can effectively use chlorine bypass dust.

Example 2
(1) Production of cement clinker:
Using the raw materials having the composition shown in Table 1, ordinary Portland cement clinker having the mineral composition, fluorine, SO ₃ and chlorine contents shown in Table 5 was produced.
Baking was performed using a rotary kiln, and wood chips and waste plastic were used as part of the fuel. Moreover, it carried out, extracting some kiln exhaust gas with a chlorine bypass facility. The extraction rate of the kiln exhaust gas is 4%. Table 5 also shows the firing temperature and the amount of waste used per ton of clinker.

(2) Production of Portland cement:
100 parts by mass of the cement clinker (No. 7) obtained above was mixed with 2.1 parts by mass of dihydric gypsum (Brain specific surface area 4000 cm ² / g) in terms of SO ₃ , and the Brain specific surface area 3230 cm ² / g using a batch-type ball mill. Portland cement was manufactured by simultaneous pulverization.

(3) Production of fired product:
Using calcined limestone, sewage sludge, and coal ash with the chemical composition shown in Table 6 as a raw material, a calcined product (free lime) of 32 parts by mass of C ₂ AS, 15 parts by mass of C ₄ AF, and 15 parts by mass of C ₃ A0 with respect to 100 parts by mass of C ₂ S Amount 0.1% by weight). Firing was performed at 1350 ° C. using a rotary kiln. The total amount of sewage sludge and coal ash (total amount of waste, etc.) used to produce 1 ton of calcined product was 528 kg / ton.
The fired product was pulverized to prepare a pulverized product having a Blaine specific surface area of 3250 cm ² / g.

(4) Materials other than the above:
The following materials were used.
-Chlorine-containing material: Chlorine bypass dust (chlorine content 20% by mass, Blaine specific surface area 2500cm ² / g)
Gypsum: dihydrate gypsum with a brain specific surface area of 4000 cm ² / g.
Inorganic powder A: Limestone powder having a Blaine specific surface area of 4000 cm ² / g.
・ Inorganic powder B: Blast furnace slag powder with Blaine specific surface area of 4500cm ² / g ・ Fine aggregate: Standard sand of “JIS R 5201 (Cement physical test method)” ・ Water reducing agent: Polycarboxylic acid-based high-performance AE water reducing agent ( Product name "SP8N")

(5) Formulation of cement composition:
Portland cement and each of the above materials were mixed in the composition shown in Table 7 to produce a cement composition.

(6) Evaluation About the obtained cement composition, the heat of hydration, the mortar flow, and the mortar compressive strength were measured. The results are shown in Table 8.
(1) Heat of hydration:
Measured according to “JIS R 5203”.
(2) Mortar flow:
A mortar in which W / C = 0.35, S / C = 2, and 0.65% by mass of a water reducing agent mixed with a cement composition is kneaded for 5 minutes is specified in “JIS R 5201-1997”. Using a flow cone, according to “JIS R 5201”, the mortar flow immediately after production and after 30 minutes was measured.
(3) Mortar compressive strength:
The mortar compressive strength after 3 days, 7 days and 28 days was measured according to “JIS R 5201”.

  From Table 8, it can be seen that the cement composition containing the blast furnace slag powder and the pulverized product of the fired product defined in the present application has a low heat of hydration and good fluidity and strength development.

Claims (3)

(A) a chlorine-containing waste to a cement clinker produced as a raw material, the content of fluorine 400~2000mg / kg, SO ₃ content of 0.6 to 2.0 wt%, the content of chlorine 50 A cement composition comprising: a ground product of cement clinker that is ˜250 mg / kg, (B) a chlorine-containing material, and (C) gypsum.   The cement composition according to claim 1, comprising (D) one or more inorganic powders selected from blast furnace slag powder, fly ash, limestone powder, silica stone powder and silica fume. (E) 2CaO · SiO ₂ and 2CaO · Al ₂ O ₃ · SiO ₂ are essential components, and 2CaO · Al ₂ O ₃ · SiO ₂ + 4CaO · Al ₂ O ₃ · Fe with respect to 100 parts by mass of 2CaO · SiO ₂ The cement composition according to claim 1 or 2, further comprising 10 to 100 parts by mass of ₂ O ₃ and a pulverized product of a fired product having a content of 3CaO · Al ₂ O ₃ of 20 parts by mass or less.