CN1124723A

CN1124723A - Process for producing ultra-quick cement from calcium-aluminium sulfate

Info

Publication number: CN1124723A
Application number: CN 95104019
Authority: CN
Inventors: 具龙善; 全宗协
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-04-19
Filing date: 1995-04-19
Publication date: 1996-06-19
Anticipated expiration: 2015-04-19
Also published as: CN1047372C

Abstract

The method for producing ultra-quick-hardening cement includes such steps as mixing ordinary clinker or cement (30-70%) with pulverized cube spar (5-25%) and calcium aluminium sulfate obtained by high-temp. burning (25-40%), addition of fluidizing agent, pulverization and mixing. Obtained cement features ultra-quick-hardening, high-strength and slight expansion.

Description

Method for producing ultra-fast cement by using calcium-aluminium sulfate

The present invention relates to cement producing process, and is especially the process of producing super fast cement with calcium aluminum sulfate.

The conventional ultra-rapid cement product mainly comprises calcium-fluorine-aluminum salt (11 CaO.7 Al)₂O₃·CaF₂) The manufacturing method comprises: adding 10-20% of dihydrate gypsum into the calcium-fluorine-aluminum salt clinker to obtain the calcium-fluorine-aluminum salt clinker. (ordinary cement clinker is not used). Such as: the ultra-speed hard calcium fluoride aluminium salt cement takes calcium fluoride aluminium sulfate as a main material, and does not use cheap ordinary cement clinker.

For another example: the quick hardening sulphoaluminate cement is C₄A₃90 percent of S and 10 percent of dihydrate gypsum, and low-cost common cement clinker is not used.

The invention aims to: the method for producing the ultra-fast hard cement by using the calcium-aluminum sulfate by using the ordinary cement clinker or the ordinary cement as the main material is provided, and the product with low price and remarkable economic benefit is provided.

The purpose of the invention is realized as follows: a method for manufacturing overspeed hard cement by using calcium-aluminum sulfate, which is basically composed of ordinary cement clinker or ordinary cement, anhydrous gypsum and calcium-aluminum sulfate, and is characterized in that: the super-speed hard cement is produced by mixing crushed anhydrous gypsum, high-temperature calcined calcium-aluminium sulfate clinker and proper amount of high fluidizing agent in common cement clinker or common cement, and through crushing and mixing, wherein the content of common cement clinker or common cement is 30-70%, the content of calcium-aluminium sulfate clinker is 25-45%, the content of anhydrous gypsum is 5-25%, and the content of high fluidizing agent is proper amount.

The invention is further illustrated by the following examples and figures thereof:

FIG. 1: is a process flow chart of the invention.

FIG. 2: the XRD (X-ray reverse image) of the cement paste 3 days later in the invention was used.

FIG. 3: the water and heat versus water and time diagram of the present invention.

The specific manufacturing method and the working principle of the invention are as follows:

the method for producing the overspeed hard cement by using the calcium-aluminum sulfate clinker and the product are characterized in that:

the calcium aluminium sulphate properties utilize the concept.

Calcium aluminium sulfate 4CaO 3Al₂O₃·SO₃(abbreviation C)₄A₃S) is CaO-Al₂O₃The property of the steel material changes with the change of chemical composition components, namely, the more CaO components, the larger the expansibility; al (Al)₂O₃The more the component, the harder the composition; SO (SO)₃The more the composition, the more the strength. See CaO-Al₂O₃-SO₃The relationship between the chemical composition and the performance of the system is shown in a graph.

The three components form an equilateral triangle relationship, wherein the large triangle represents large quantity, the small triangle represents small quantity, and the arrow represents the trend of performance change.

The water content and structure of the conventional calcium-aluminum sulfate is ettringite (3 CaO. Al)₂O₃·3CaSO₄·32H₂O) is a constituent mineral which has been unusable because the formation process is rapid hardening-high strength development-expansion failure process. However, in order to produce ultra-rapid hardening cement, it is necessary to induce the cement strength from (A) to (B), and the changes of the solid line (A) and the broken line (B) in the table, the formation process of ettringite and the performance thereof are shown.

In the invention, high-content high-temperature sintered calcium-aluminum sulfate clinker (C) is adopted₄A₃S: 55%) above, 1250 ℃ -1400 ℃ and the like as main materials, and the fields of super-rapid hardness, high-strength expression, non-expansion self-stress maintenance and the like are developed by matching common cement clinker or common cement with anhydrous gypsum.

The specific method comprises the following steps:

1. pure 4CaO 3Al in calcium aluminium sulphate clinker used in ultra-fast cement manufacture₂O₃·SO₃Is more than 55 percent, which is obtained by the following formula:

C₄A₃S(％)＝1.995Al₂O₃＋1.63Fe₂O₃

the cement made from the ultra-rapid hard cement of the invention contains pure 4CaO 3Al₂O₃SO₃The required content is 10% -30%.

2. Using raw materials and mixing ratio

Using materials	Quality specification of material	Mixing ratio
Using materials	Quality specification of material	Mixing ratio	1, ordinary cement clinker	One kind of common cement clinker	30-70％
2, calcium aluminium sulphate clinker	1) Lime saturation ratio (cm): the content of the active carbon is more than 0.8, 2) anhydrous sulfuric acid/alumina ratio (a/S): 2.5-5.0 3) Free lime (%): 4.0% or less 4)C₄A₃S (%): over 55 percent	25-45％	1, ordinary cement clinker	One kind of common cement clinker	30-70％
2, calcium aluminium sulphate clinker		25-45％	3, Anhydrous gypsum	CaSO₄Percent: over 70 percent	5-25
4, high fluidizing agent	High fluidity agents for cement (naphthalene sulfate series, melamine sulfate series, lignin sulfate series)	Appropriate amount of	3, Anhydrous gypsum	CaSO₄Percent: over 70 percent	5-25

Note: Cm-CaO-O.7 (Fe)₂O₃＋TiO₂＋SO₃)/1.87SiO₂＋0.55Al₂O₃

A/S＝Al₂O₃SO₃

C₄A₃S＝1.995Al₂O₃＋1.63Fe₂O₃

3, manufacturing equipment and manufacturing process: referring to FIG. 1, a process flow diagram of the present invention is shown.

(in the manufacturing process of the first correct adjustment of material mixing ratio, also can be mixed and then crushed) the invention of the embodiment as follows: the materials used in the invention are ordinary cement clinker, calcium-aluminum sulfate clinker and anhydrous gypsum,

the chemical components are as follows: table 1: using the chemical composition of the material

Using materials	SiO₂	Al₂O₃	Fe₂O₃	TiO₂	CaO	HgO	SO₃	Ig-Loss	Free Cao	Total up to
Using materials	SiO₂	Al₂O₃	Fe₂O₃	TiO₂	CaO	HgO	SO₃	Ig-Loss	Free Cao	Total up to	1. Ordinary cement clinker	22.18	5.46	3.50	64.89	2.72	0.28	0.67	0.70	99.75
2. Calcium aluminium sulphate clinker	11.18	30.76	2.38	1.8	43.21	2.00	8.31	tr	0.65	99.64	1. Ordinary cement clinker	22.18	5.46	3.50	64.89	2.72	0.28	0.67	0.70	99.75
2. Calcium aluminium sulphate clinker	11.18	30.76	2.38	1.8	43.21	2.00	8.31	tr	0.65	99.64	3. Anhydrous gypsum	0.68	0.10	0.08	40.62	tr	0.56	2.85		98.89

Note: igloss-amount of chemical component lost

Free-Free calcium oxide, tr-trace, generally means less than 0.01,

the materials are crushed into the specific surface area of 4,800 +/-50 cmz/g in a ball mill crusher, and the specific surface area is compounded into the ultra-rapid hard cement sample according to the following table 2, wherein the compounding ratio is 22 percent of the content of C4A3S in the ultra-rapid hard cement (sample 1); 21% (sample 2); 20% (sample 3).

The purpose of adding the high fluidizing agent is to improve the fluidity of cement. In this respect, the high fluidizing agent having a good water reducing and dispersing effect is used in Lignin sulfonate (Lignin sulfonate), naphthalene sulfate (naphthalene sulfonate) or Melamine sulfonate (Melamine sulfonate), and naphthalene sulfate is used in the present invention.

Table 2: mixing proportion of ultra-fast cement

Sample NO	Mix proportion (increment%)
	Mix proportion (increment%)				Ordinary cement clinker	Calcium aluminium sulphate clinker	Anhydrous gypsum	High fluidizing agent
	1	50	34	16	Ordinary cement clinker	Calcium aluminium sulphate clinker	Anhydrous gypsum	High fluidizing agent	1 (extra)

2	50	32	18	1 (extra)
2	50	32	18	1 (extra)	3	50	30	20	1 (extra)

The physical properties of the ultra-rapid cement according to the mix ratio of Table 2 are shown in Table 3 below:

table 3: physical properties of ultra-rapid cement

Sample NO	Specific surface area cm²/g	Coagulation time		Compressive strength (kg/cm)²)
		Coagulation time		Compressive strength (kg/cm)²)				Initial knot	Terminating	3 hours	6 hours	One day	3 days
		1	4,830	0：25	0：35	125	152	Initial knot	Terminating	3 hours	6 hours	One day	3 days	189	203
2	4,830	1	4,830	0：25	0：35	125	152	0：35	0：50	220	258	297	305	189	203
2	4,830	3	4,830	0：40	0：55	218	254	0：35	0：50	220	258	297	305	300	308

The water content and structure of the ultra-rapid cement of the invention composed of calcium aluminate, ordinary cement clinker and anhydrite is ettringite (3 CaO. Al)₂O₃·3CaSO₄·32H₂O) production, and the overspeed hardness was found by correlating the production rate of ettringite (ettringite), and the cause of the overspeed hardness was CaO-Ae₂O₃-SO₃The water content and the reaction formula of the three components are as follows: (1) (2)(1)＋(2)

FIG. 2 is an XRD (X-ray reverse image) of a cement slurry 3 days after the ultra-rapid hardening cement

Shown in the figure: h represents: c₄AH₁₃

O represents: c₄A₃S

Represents: s_aSO₄

The water and heat of the overspeed hard cement are higher than those of common cement, and the water and heat of the overspeed hard cement are good materials for construction in winter. FIG. 3 is a water and heat comparison of ultrarapid cement and portland cement (one type of ordinary cement).

FIG. 3 Water and Heat of the ultra-rapid cement.

Shown in the figure: the X-axis is water and time (minutes), the Y-axis is water and heat,

the solid line represents ultra-rapid cement and the dotted line represents portland cement.

The above tests illustrate that: the invention relates to ultra-fast hard cement (4 Cao.3Al)₂O₂O₃.SO₃) Has the advantages that: has the characteristics of high strength, good construction effect in winter, sulfuric acid resistance (sea sand can be used by seawater), high fluidity, corrosion resistance and the like,

therefore, the product has better practicability and economy, and is a product with low price, excellent quality, use and construction performance. Meanwhile, a new field of super-rapid hardness-high strength performance-unexpanded self-stress maintenance and the like is developed for a manufacturing method of the super-rapid hard cement.

Claims

1. A method for preparing overspeed hard cement by using calcium-aluminium sulfate, which is basically composed of ordinary cement clinker or ordinary cement, anhydrous gypsum and calcium-aluminium sulfate, and is characterized in that: the super-speed hard cement is produced by mixing crushed anhydrous gypsum and high-temperature sintered calcium-aluminium sulfate clinker with proper amount of high fluidizing agent, crushing and mixing,

wherein the clinker of the common cement or the common cement is 30 to 70 percent, the clinker of calcium aluminum sulfate is 25 to 45 percent, the anhydrous gypsum is 5 to 25 percent, and the proper amount of the high fluidizing agent.

2. The method for producing ultra-rapid cement according to claim 1, wherein: the quality specification of the calcium-aluminum sulfate clinker is as follows: 4CaO 3AL₂O₃·SO₃The content of the lime is more than 55 percent, the ratio CM of the rest lime is more than 0.8, and the ratio A/S of anhydrous sulfuric acid and alumina is 2.5-5.0; the content of free lime is below 4.0%.

3. The method of claim 1, wherein the method comprises the steps of: the high-temperature sintered calcium-aluminum sulfate clinker is sintered at 1250-1400 ℃.

4. The method of claim 1, wherein the method comprises: as the high-fluidity agent, naphthalene sulfate, melamine sulfate and lignosulfonate may be used.