JPS5911544B2 - Cement and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to the construction and building materials industry and
Regarding this cement industry.

More specifically, it relates to cement and its manufacturing method.

Known cements include cements containing alit, berit, and cerit [N.M. Putt (Yu, M.,
Butt) and Kay Kay Chimasiev (V,V,
Timashev) co-author, ``Portland Cement Clinker''
r) J, Moscow, Strozhizdat Publishing House (5tr
oj 1zdat PublishingHouse
), 1967].

These cements are widely used industrially,
It has the disadvantage of low activity during the initial curing stage.

A known method for producing the above-mentioned cement is a method in which a raw material mixture consisting of a calcareous component and an acidic component is pulverized and the resulting cement clinker is pulverized (see the above-mentioned literature).

In this method, various additives such as masonry wax are introduced into the clinker during the grinding process.

This conventional method of producing the above-mentioned cement has the disadvantage of high firing temperatures.

That is, the cement clinker produced by this method has a low pulverization ability, and therefore a large amount of power is consumed during its pulverization.

Known cements also include cements containing 5 to 60% by weight of calcium chloroaluminate and more than 5% by weight of allite, berite and cerite, as well as anhydrite and silicofluoride as additives (French). (See Patent No. 2,121,100)
There is also.

Calcium chloroaluminate present in cement increases the activity of the cement during the early stages of hardening.

However, the production of this cement is inseparable from the need to add anhydrite kola and silicofluoride as additives to increase the setting time.

This is because cement that does not contain the above additives has an extremely short setting time, which limits its uses.

Furthermore, the addition of the above-mentioned slowing additives reduces the activity of the cement within a controlled period of time.

Known processes for the production of cements of this type containing allite, berite and celite as well as calcium chloroaluminate include starting from a raw material mixture of calcareous, siliceous or aluminous components, ferrous components and calcium chloride to 1300% There is a method in which cement clinker is smoldered at a temperature in the range of 1400 DEG C. and then the resulting cement clinker is pulverized.

During the grinding process, various additives such as sulfates, nitrates and chlorides of alkali metals or alkaline earth metals, respectively, can be introduced into the clinker (see the above-mentioned document and British Patent Application No. 1,386,790). Please refer to the specification).

The above-mentioned conventional methods of producing the above-mentioned cements suffer from the disadvantages that chlorosilicate minerals (highly basic calcium chlorosilicate and calcium chloroorthosilicate) are difficult to obtain in the clinker, and high clinker-forming process temperatures that require high fuel consumption rates ( 1300~1400°C
) is disadvantageous in that it is used.

Furthermore, the clinker produced by the above-mentioned method has the disadvantage of insufficient crushing ability, and therefore requires a large amount of power consumption when crushing the clinker.

It is an object of the present invention to provide a cement composition which is characterized by a controlled setting time and which does not require the addition of slow-slow additives. It's about providing things.

Another object of the present invention is to provide a cement which has high hydration activity and sufficient mechanical strength during the initial setting period and which ensures considerable strength in the cement article throughout the controlled setting period. be.

Still another object of the present invention is to provide a method for producing cement having the above-mentioned characteristics, in which the temperature of the clinker forming step can be lowered to reduce the specific consumption rate of fuel, and the crushing efficiency of the cement clinker can be reduced. The goal is to provide a way to increase your

In the present invention, in order to achieve the above and other objectives, highly basic calcium chlorosilicate, calcium chloroalmoferrite and calcium orthosilicate are further added to the cement consisting of alit, berit and calcium chloroaluminate. composition(
weight%) from 1 to
50 Veritz 1-45 Calcium chloroaluminate 30-1 High basic calcium chlorosilicate 75-5 Calcium chloroorthosilicate 55-5 Calcium chloroalumoferite 2-22.

Here, calcium chloroaluminate is a compound belonging to a group represented by C1, A7CaX2, and the chlorine-containing structure is 11Ca0, 7A1203, CAC.
It is 12.

Highly basic calcium chlorosilicate is a highly basic, chlorine-containing calcyano silicate, Ca22S16
It has the chemical formula A12036C12.

Calcium chloroorthosilicate is a chlorine-containing calcium silicate, 2Ca2Si04・CaCl
It has a chemical formula of 2.

Furthermore, calcium chloroalmoferrite has the formula CA-F
(CaX2) (wherein C=CaO, A--n A1203, F=Fe203, X=C4F, n-
1 to 0) of the alumoferrite composition.

The cement of the present invention has the following properties.

Setting time (minutes) Starting point of setting 7-95 Ending point of setting 14-260 Temperature of specimen (4 x 4 x 16 cfrL) consisting of 1 part by weight of cement, 3 parts by weight of silica sand and 0.5 part by weight of water, 20 ± 2°C Compressive strength of underwater materials up to 28 days (
kg f/crit) Material age 1 day 15
~212 Material age 3 days 47-275 Material age 7 days 140-386 Material age 28 days 390-610 Specific power consumption when crushing the cement clinker of the present invention to a residual rate of 12% on a sieve with a pore diameter of 80 mcm is 11 to 15 kW/l, and the residual rate on the same sieve is 4.
Specific power consumption when pulverizing to 5 is 37-41kW
・Hour/l.

No corrosion is observed in the steel reinforcement in concrete specimens made from the cement of the present invention.

The method for manufacturing the cement of the present invention is as follows.

That is, calcareous component, siliceous component, alumina component,
Ferrous components and calcium chloride are mixed to form a raw material mixture, and then this raw material mixture is heated at 1000 to 1400°C.
The clinker is then cooled and crushed.

In the method of the present invention, especially at this time,
The calcination was carried out in two stages, a first stage at a temperature within the range of 1000 to 1200°C, and a second stage at a temperature within the range of 1200 to 1400°C. The composition of the raw material mixture is weight%: Calcareous component (CaO conversion) 43.4 to 60.4 Siliceous component (S 102 conversion) 12.5 to 23.3 Aluminous component (A1203 conversion) 2゛2 ~18°5 Iron component (Fe203 conversion) 1°1~6°6 Calcium chloride 1□.

~29.4 (CaC12 conversion) shall be.

As calcareous component, for example limestone can be used.

As siliceous components, silica sand and diatomaceous earth can be used.

As the alumina component, commercially available alumina and china clay can be used.

Various clay minerals such as loess loam can be used as the siliceous and aluminous components.

As ferrous components, hematite, pyrite cinder and commercially available iron oxides may be used.

It is preferable that the raw material mixture composition further contains sodium chloride and/or potassium chloride in an amount of 5 to 60% by weight based on the amount of calcium chloride used, in addition to calcium chloride.

The above sodium chloride and/or potassium chloride is
It contributes to strengthening the clinker formation process and also improves the ability to crush the clinker.

Furthermore, when using the alkali metal chlorides mentioned above, the use of alkali-containing dust recycling materials is possible.

This widens the range of starting materials with respect to chloride-containing components, in particular making industrial waste available.

To produce verit clinker, the second stage of calcination is carried out at a temperature in the range of 1200-1250 °C, and to produce arit clinker, the same stage is carried out at 125 °C.
In each case, it may be recommended to carry out the process at a temperature within the range of 0 to 1400°C.

If the above conditions are followed, i.e. if the smoldering step is carried out in two stages, the most power consuming part of the clinker forming step can be carried out at a lower temperature, i.e. at a temperature of the order of 1000-1200°C.

The cement of the present invention contains allite, verite, calcium chloroaluminate, highly basic calcium chlorosilicate, calcium chloroorthosilicate and calcium chloroalmoferrite in the above proportions, and the maximum amount of calcium aluminate in the cement. 6
It is possible to reduce the content from 0% by weight to 40% by weight.

This cement does not require any additives to control setting time.

Cement having the composition of the present invention has a longer setting period (ie, from a few minutes to 4-6 hours) than conventional cements, and a wider range of initial setting rates than conventional cements.

The cement of the present invention with an increased content of highly basic calcium chlorosilicate or calcium chloroaluminate has high water utilization activity, especially in the early stage of hardening.

Cement with an increased content of verite and calcium orthochlorosilicate (dicalcium silicate) is characterized by an increased final density and mechanical strength of the articles produced therefrom.

Owing to the properties of the cement of the invention discussed above and the possibility of varying its mineral composition within a wide range as mentioned above, the cement can be widely used for various purposes.

The cement of the invention can be used in the production of prefabricated reinforced concrete structures, the construction of large monolithic concrete structures and other areas of construction work.

Therefore, the cement of the present invention exhibits special effects in the construction of hydropower utilization facilities.

That is because this cement ensures a high degree of homogeneity (integrity) of the concrete mass, its excellent mechanical durability, waterproofness and environmental resistance.

Cement with increased calcium alumoferrite content is
Can be used for special purposes as high iron content cement.

The method of the invention makes it possible to use lower clinker formation process temperatures in the manufacture of cement.

This lower temperature is about 1000-1200℃, and at this temperature, the fuel consumption rate is reduced by 5-10% compared to the conventional method in which the raw material mixture is baked at a temperature in the range of 1300-1400℃. do.

Furthermore, the clinker produced according to the method of the invention has a high grinding capacity (1.4 to 1.8 times that of conventional products), which substantially reduces the power consumption for grinding.

The cement manufacturing method of the present invention is technically simple and can be carried out as follows.

The starting materials, i.e. calcareous components, siliceous components, ferrous components and chlorides such as Ca C12, are subjected to fractional milling or mixed milling (in the case of fractional milling of the mixture, it is necessary to subsequently homogenize the mixture). ).

Grinding can be carried out both in the presence of water (wet grinding) and in the absence of water (wet grinding).
This can also be done by dry grinding.

In wet grinding, 25 to 3
Add water at a rate of 5% by weight.

When wet grinding the starting material, calcium chloride is
It can be used both as a dry product and as an aqueous solution at the required concentration.

After dry grinding, the resulting raw compound is granulated,
It can be formed into granules with a particle size of 5 to 20 mm.

By putting the thus prepared raw material mixture into a furnace and smoking the mixture at a temperature within the range of 1000 to 1200 DEG C., cement clinker can be reliably obtained from the above raw material mixture.

During a short final stage of smoking in the same furnace or in a special heating device, the clinker is heated to 1200-1400°.
Process at a temperature within the range of C.

The time for this additional treatment is 5 to 40 minutes.

This operation results in a decrease in the content of chlorosilicate components (overbased calcium chlorosilicate and calcium chloroorthosilicate) and an increase in the content of allites and verites.

At this time, at a temperature of about 1200 to 1250°C, the clinker is rich in verite, and at a temperature of about 1250 to 1400°C, it is rich in alit.

By varying the operating parameters of the clinker smoldering process, it is possible to produce cement of a given mineralogical composition and to obtain a product with the desired properties.

In order to explain the present invention more specifically, Examples are given below.

In each example, a 4X4X1 compound of 1 part by weight cement, 3 parts by weight silica sand and 0.5 part by weight water was used.
Cement activity is represented by the ultimate compressive strength measured for 6 cfrL specimens up to 28 days in water at a temperature of 20±2°C.

Material A measured by the above method? iB: The curing speed is determined from the change in mechanical strength on days 3, 7, and 28.

Setting times are measured on cement pastes of standard thickness using a Vicat needle apparatus.

The grinding ability of cement clinker is measured by the power consumption required to grind it to a predetermined fineness.

Corrosion of steel reinforcement in concrete using the cement of the present invention is determined by the weight loss of the reinforcement bars after the specimen is stored in air with 100% relative humidity at a temperature of 20°C. The determination was made using a quantitative method.

Example 1 A raw material mixture having the following composition is prepared.

The above ingredients are mixed and subjected to dry grinding.

The pulverized product has a residual rate on a sieve with a pore diameter of mcm of 12% or less.

The raw material mixture thus prepared is granulated to a particle size of 10 to 15.
Make granules of mm.

The granular raw material mixture is placed in a furnace where the temperature is 1100.
Smoking is performed at ℃ to complete the clinker formation process.

In the final stage of smoking, the temperature is raised to 1250°C.

The smoked clinker is cooled in air and pulverized in a ball mill so that the residual rate on a sieve with a pore size of 80 mcm is 12% or less.

The pressure power consumption required to crush this cement clinker to a residual rate of 12% on a sieve with a pore diameter of 80 mcm is 12
．． 5kW・hr/l, and up to the same residual rate of 4.5%, 3
It is 8kW/hour/l.

The product cement has the following composition (% by weight):

stomach.

Example 2 A raw material mixture having the following composition is prepared.

Weight part Weight% Limestone (CaO conversion) 34 43.4 Loess loam (Si02 conversion) 14 17°9 (A
1203 conversion) 5.76 7.4 (F
(e203 conversion) 1.45 1.9 Commercially available calcium chloride.

3. 9.4 (calculated as Ca C12) 78.21 100.0 The pulverization of these components, the granulation of the raw material mixture, the cooling and pulverization of the cement clinker are carried out according to the method described in Example 1 above.

■The first stage of baking is carried out at a temperature within the range of 1050 to 1100°C, and the second stage is carried out at a temperature of 1200°C for 40 minutes.
There are two stages in total, and the clinker forming process is completed.

The obtained cement has the following composition (% by weight):

Allit 1 Beritz
1 Calcium chloroaluminate 11 Calcium chloroalumoferite 2 Highly basic calcium chlorosilicate
75 Calcium chloroorthosilicate 10 The specific power consumption required to crush this cement clinker to a residual rate of 12% on a sieve with a pore size of 80 mcm is 11.
8kW・hr/l, and up to the same residual rate of 4.5%, it is 37
．． It is 2kW/hour/l.

The product cement has the following properties:

Setting time (minutes) Starting time 35, Ending point 54 Ultimate compressive strength (yuf/crIL) Material age 1 day 212 Material age 3 days 275 Material age 7 days 386 Material/+28 days 610 In the concrete specimen manufactured from this cement So,
No corrosion is observed on the steel reinforcement.

Example 3 A raw material mixture having the following composition is prepared.

Weight part Weight% Limestone (CaO equivalent) 35.4 46.6
Diatomite (SIO2 conversion) 9.5 12°5 China clay (A1203 conversion) 14°0 18°5 Hematite (F e 20 a conversion) 5.0 6.6 Commercially available calcium chloride □2 15.8 (Ca C
12 equivalent) 75.9 100.0 The pulverization of these components, the granulation of the raw material mixture, and the pulverization of the cement clinker are carried out according to the method described in Example 1 above.

(1) The first stage of firing is carried out at a temperature of 1000°C to complete the clinker forming process, and (2) the final stage of firing is carried out at a temperature of 1200°C for 20 minutes.

The specific power consumption required to crush this cement clinker to a residual rate of 12% on a sieve with a pore diameter of 80 mcm is 14
．． 7kW・hr/l, and up to the same residual rate of 4.5%, it is 3.
It is 9.5kW・hour/l.

This cement has the following mineralogical composition (% by weight):

Allit 2 Beritz
2 Calcium chloroaluminate 30 Calcium chloroalmoferite 22 Highly basic calcium chlorosilicate 28 Calcium chloroorthosilicate
The cement in No. 1 has the following properties.

Setting time (minutes) Starting point 7 Ending point 14 Ultimate compressive strength (kg f /crr*) Material age 1 day
162 Material 7+3 days 184 Material age 7 days 225 Material/+28 days 424 No corrosion was observed in the steel reinforcement in the concrete specimens manufactured from the above cement.

Example 4 A raw material mixture having the following composition is prepared.

Weight part Weight% Limestone (CaO conversion) 44 60.4 Silica sand (SiO2 conversion) 17 23.3 Commercially available alumina (A1203 conversion) 1.62.2 Iron oxide
2.24 3.1 Commercially available calcium chloride, □1. .

(Calculated as CaC12) 72.84 100.0 The above-mentioned pulverization of the components, granulation of the raw material mixture and pulverization of the cement clinker are carried out according to the method described in Example 1 above.

Sintering is performed at a temperature of 1200°C to complete the clinker forming process.

■In the final stage of grilling, the temperature is raised to 1400°C and the material is smoked at the same temperature for 5 minutes.

The specific power consumption required to crush this cement clinker to a residual rate of 12% on a sieve with a pore diameter of 80 mcm is 15
．． 6 kW/hr/l, and up to the same residual rate of 4.5%, it is 4.
It is 1.2kW・hour/l.

The obtained cement has the following composition (% by weight):

Arrit 50 Beritz
34 Calcium chloroaluminate 1 Calcium chloroalumoferite 5 Highly basic calcium chlorosilicate 5 Calcium chloroorthosilicate
The cement of the 5 products has the following characteristics.

Setting time (minutes) Starting point 95 Ending point 260 Ultimate compressive strength (kl/ff1) Age 1 day 12 Age 3 days 26 Age 7 days 264 Age 428 days 574 Steel in concrete specimen using the above cement No corrosion was observed on the reinforcement material.

Example 5 A raw material mixture having the following composition is prepared.

Weight part Weight% Limestone (CaO equivalent) 39.7 56.8
Loess loam (S i02 conversion) 15°30 21.9 (A 12
03 conversion) 6.13 8.8 (Fe2
0.03 conversion) 0.80 1.1 Commercially available calcium chloride 8. .

1□, 4 (Ca C12 equivalent) 69.93 100.0 The above-mentioned pulverization of the components, granulation of the raw material mixture and pulverization of the cement clinker are carried out according to the method described in Example 1 above.

(2) Calcining is carried out at a temperature of 1150°C to complete the clinker formation process.

In the final stage of smoking, the temperature is raised to 1250°C.

The obtained cement has the following composition (% by weight):

'Alit 10 Beritz 45 Calcium chloroaluminate 13-Calcium chloroalumoferrite 2 Highly basic calcium chlorosilicate 20 Calcium chloroorthosilicate 10 Specific power consumption required to crush this cement clinker to a residual rate of 12% on a sieve with a pore size of 80 mcm The amount is 13.9kW·hr/l, and at the same residual rate up to 4.5%, it is 38.9kW·hr/l.

The product cement has the following properties:

Setting time (minutes) Starting point 49 Ending point 140 Ultimate compressive strength (kgf/d) Age 1 day 22 Age 3 days 30 Age 7 days 140 Age 28 days 390 No corrosion is observed on the steel reinforcement.

Claims (1)

[Scope of Claims] 1 Consisting of Arihet, Berit, calcium chloroaluminate, highly basic calcium chlorosilicate, calcium chloroorthosilicate and calcium chloroalmoferrite, and having the following composition (wt%) Arihet 1 to 50 Berit 1 -45 Calcium chloroaluminate 30-1 High basic calcium chlorosilicate 75-5 Calcium chloroorthosilicate 55-5 Calcium chloroalmoferite 2-22 Cement. 2 Consists of Arihet, Berit, calcium chloroaluminate, highly basic calcium chlorosilicate, calcium chloroorthosilicate, and calcium chloroalumoferrite, and has the following composition (wt%) Arihet 1-50 Berit 1-45 Calcium chloroaluminate High basic calcium chlorosilicate 75-5 Calcium chloroorthosilicate 55-5 Calcium chloroalmoferrite 2-22 In the method for producing cement, a calcareous component, a siliceous component, an alumina component, a ferrous component and calcium chloride are mixed. Calcareous component (CaO equivalent) 43
．． 4-60.4 Siliceous component (SiO□ conversion) 12
．． 5~23.37/L': f-@component
. , 2~□8.5 (A1203 conversion) Iron component (Fe203) 1.1~6.6 salty/L"7'7A
□ 1. . ~29.4 (calculated as Ca C12), and the first step is to carry out the obtained raw material mixture at a temperature within the range of 1000 to 1200°C, and
The above-mentioned production method is characterized in that the clinker obtained is subjected to a two-stage firing process, which comprises a second stage carried out at a temperature within the range of 100 to 100%, and the resulting clinker is cooled and then pulverized. 3. The raw material mixture further contains an alkali metal chloride selected from the group consisting of sodium chloride, potassium chloride, and a mixture of these two in an amount of 5 to 60% by weight based on the calcium chloride used. The manufacturing method described in Section 2. Claim 2, wherein the second stage of the 42-stage roasting is carried out at a temperature within the range of 1200 to 1250°C.
Manufacturing method described in Section. Claim 2, wherein the second stage of the 52-stage roasting is carried out at a temperature within the range of 1250 to 1400°C.
Manufacturing method described in Section.