CN113185174B - Steel slag activity excitant, active steel slag powder and application thereof - Google Patents

Abstract

The invention discloses a steel slag active stimulating agent, its active steel slag powder and its application. The steel slag activity stimulating agent of the present invention comprises kaolin, diatomaceous earth, dried sludge, alkali metal carbonate, alkali metal chlorate, N-acyl peptide sodium, _FeCl and lanthanide catalyst; The metal carbonate is Na ₂ CO ₃ or K ₂ CO ₃ ; the alkali metal chlorate is KClO ₃ or NaClO ₃ ; the above components are mixed evenly and ground to 200-400m ² /kg to obtain the present invention The steel slag active stimulator. Spray the steel slag active activator into the liquid steel slag discharged from the boiler and mix it evenly, then lower the temperature, grind it, and obtain the active steel slag powder. The activator of the invention can improve the grindability of steel slag, greatly improve the activity of steel slag, realize resource utilization of sludge and reduce environmental pollution.

Description

A kind of steel slag active stimulating agent, its active steel slag powder and application

technical field

The invention relates to the field of building materials, in particular to a steel slag active activator, its active steel slag powder and its application.

Background technique

Steel slag is a solid waste produced in the steelmaking process, and its production volume reaches 8% to 15% of steel production. Especially, the production of steel slag is increasing rapidly with the continuous development of the steel industry. Therefore, the treatment and resource utilization of steel slag has been paid more and more attention. However, the actual comprehensive utilization of steel slag in my country is not optimistic, especially the utilization rate of converter steel slag is only 10% to 20%. The steel slag produced by domestic iron and steel enterprises cannot be disposed of in time, resulting in a large amount of steel slag occupying land and polluting the environment. However, steel slag is not an unusable solid waste, which contains a large amount of slag steel, calcium oxide, iron and magnesium oxide and other available components, which have potential activity. my country began to utilize steel slag as a resource since the 1980s. After exploration, it can be used as sinter raw materials, roadbed and backfill materials, and hydraulic machine raw materials. Among them, the use of steel slag to produce cement is one of the most important ways for comprehensive utilization of steel slag, because Cement consumes a lot. If it can be used in a large amount and efficiently in cement, it will greatly alleviate the environmental problems caused by steel slag. However, current research shows that steel slag has problems such as low activity and slow hydration. With the increase of the amount of steel slag in cement, the strength of cement decreases rapidly and the volume stability deteriorates, which limits the further use of steel slag. In order to further realize the large-scale application of steel slag, it is necessary to stimulate its activity to improve its existing problems.

At present, the excitation methods of steel slag activity mainly include mechanical excitation, chemical excitation and thermal excitation. Mechanical excitation is mainly through crushing, friction and other mechanical destruction methods to cause dislocation and defects in the mineral lattice of steel slag, promote the generation of free radicals or ions in steel slag particles, and enhance the surface activity of steel slag powder to achieve the purpose of surface modification. Chemical excitation mainly uses various acid-base salts and other corrosive substances to stimulate the activity of steel slag. Acid excitation is mainly to neutralize the alkalinity in the steel slag through acidic substances, and promote the balance to move to the dissolution direction of alkaline substances, and promote the formation of hydration products; alkali excitation is mainly to increase the pH, and promote the diffusion of alkaline substances into the steel slag to decompose the original overall structure , so that highly active substances enter the solution and accelerate the hydrolysis of steel slag vitreous body; the sulfate excitation is mainly to accelerate the formation rate of calcium vanadium stone, the hydration product of steel slag, and improve its hydration process. Thermal excitation is mainly to break the silicon-oxygen bond that constitutes its network structure after the steel slag is autoclaved at high temperature, and accelerate the disintegration, thereby promoting hydration.

Overall, the excitation method of steel slag can stimulate the activity of steel slag. However, due to the low activity of steel slag itself and the low content of potential active substances, the improvement of its activity after excitation is limited. Compared with the material composition of steel slag itself, it is not not fully activated. Therefore, in order to fully activate the activity of steel slag, it is necessary to increase the content of potential active substances in steel slag itself, but the existing treatment process of steel slag cannot meet this requirement. Therefore, according to the existing production and technical conditions, the present invention provides a new technical means for stimulating the activity of steel slag starting from the process flow of steel slag treatment.

Contents of the invention

In order to overcome the problems of low potential active substance content, low activity, and low utilization rate of steel slag, the object of the present invention is to provide a steel slag activity activator and its use method. The activator of the invention can effectively improve the activity of steel slag.

In order to achieve the above object, the present invention provides a steel slag active stimulator, which includes the following material components, each component is by mass parts:

The alkali metal carbonate is Na ₂ CO ₃ or K ₂ CO ₃ ;

The alkali metal chlorate is KClO ₃ or NaClO ₃ ;

The above-mentioned components are uniformly mixed and ground to 200-400 m ² /kg to obtain the steel slag activity activator of the present invention.

The lanthanide catalyst is selected from any one of lanthanum nitrate and lanthanum sulfate, or a mixture of the two in any proportion.

The dried sludge is sludge powder or granules with a water content not higher than 5% obtained after the sludge is dried.

The invention provides an active steel slag powder, which is composed of the above steel slag active activator mixed with steel slag, and the steel slag is unquenched fluid steel slag discharged from a boiler; %.

The preparation method of the active steel slag powder of the present invention is as follows: spray the steel slag active activator into the liquid steel slag discharged from the boiler and mix evenly, then lower the temperature and grind to obtain the active steel slag powder.

The specific surface area of the ground active steel slag powder is 400-550m ² /kg.

The present invention also provides an application method of the active steel slag powder. The active steel slag powder is used as a cement admixture and ground together with cement clinker. The amount of the active steel slag powder is less than 30% of the total mass of cement.

The beneficial effects of the present invention are:

Putting the activator into the liquid steel slag taken out from the boiler can use the high temperature condition of the liquid steel slag to promote the rapid reaction between the activator and the steel slag, so that the activity of the steel slag is greatly improved, and the obtained active steel slag powder meets the requirements of the cement admixture. Performance requirements, realizing the large-scale, high utilization rate, and high value-added resource utilization of steel slag, avoiding waste of resources.

Among them, kaolin can realize the crystal form change under the activation condition, and at the same time improve its own activity, change the calcium-silicon ratio of steel slag, and improve the activity of steel slag. Diatomite can realize its own carbon consumption at high temperature and promote the formation of active silica. At the same time, under the synergistic reaction with Na ₂ CO ₃ or K ₂ CO ₃ , it can increase the alkalinity of the system and promote the formation of active substances. and activation of steel slag activity. The pyrolysis of sludge powder can increase the porosity of steel slag and promote carbon consumption. Under the action of sodium N-acyl peptide, it can further increase the porosity of steel slag, reduce the density of steel slag, and improve the grindability of steel slag; the sludge after pyrolysis Sludge can provide a large amount of silicon-aluminum active substances for steel slag and promote the activation of activity; the addition of sludge powder not only improves the activity and grindability of steel slag, but also realizes the resource utilization of sludge waste. The synergistic effect of KClO ₃ or FeCl ₃ and lanthanide catalysts can effectively improve the pyrolysis degree of sludge and carbonaceous consumption of diatomite, act as a catalyst activator, and promote the generation of active substances.

The synergistic effect of each component in the steel slag active activator of the present invention can make the active steel slag powder of the steel slag after adding the activator realize the following effects: 1) the activation of the activity between each component and the steel slag increases the porosity of the steel slag , improve the grindability of steel slag, and greatly increase the activity of steel slag; 2) realize the resource utilization of sludge and reduce environmental pollution.

Detailed ways

In order to better understand the present invention, the present invention will be further described below in conjunction with embodiment, but can not be interpreted as that the present invention is only applicable to following example, those skilled in the art make some non-essential changes to the present invention according to the content of above-mentioned invention And adjustments still belong to the protection scope of the present invention.

Comparative example 1

The steel slag is steel slag that has not undergone active excitation, and is ground to a particle size of 400m ² /kg.

Example 1

A steel slag active activator, the activator is composed of the following materials mixed uniformly in parts by mass: 15 parts of kaolin, 30 parts of diatomaceous earth, 10 parts of dried sludge, 15 parts of Na ₂ CO ₃ , 3 parts of KClO ₃ , 0.5 part of sodium N-acyl peptide, 1 part of FeCl ₃ , 1 part of lanthanide catalyst;

Mix the above-mentioned components evenly and grind them to obtain a steel slag active activator with a specific surface area of 200m ² /kg;

Described lanthanide catalyst is lanthanum nitrate;

The dried sludge is dried sludge particles with a water content of 5%.

Spray 8% activator into the liquid steel slag discharged from the boiler, mix evenly, then cool down and grind to obtain active steel slag powder; the specific surface area of the ground active steel slag powder is 400m ² /kg.

Example 2

A steel slag active activator, the activator is composed of the following substances mixed uniformly in parts by mass: 25 parts of kaolin, 20 parts of diatomaceous earth, 20 parts of dried sludge, 10 parts of K ₂ CO ₃ , 7 parts of NaClO ₃ , 0.1 part of sodium N-acyl peptide, 2 parts of FeCl ₃ , 0.2 part of lanthanide catalyst;

Mix all the components evenly, grind them, the specific surface area is 400m ² /kg, and obtain the steel slag active activator;

Described lanthanide catalyst is lanthanum sulfate;

The dried sludge is absolutely dry sludge particles with a moisture content of 0%.

Spray 10% activator into the liquid steel slag discharged from the boiler, mix evenly, then cool down and grind to obtain active steel slag powder; the specific surface area of the ground active steel slag powder is 440m ² /kg.

Example 3

A steel slag active activator, the activator is composed of the following substances mixed uniformly in parts by mass: 20 parts of kaolin, 25 parts of diatomaceous earth, 15 parts of dried sludge, 12 parts of Na ₂ CO ₃ , 5 parts of KClO ₃ , 0.3 parts of sodium N-acyl peptides, 1.5 parts of FeCl ₃ , 0.6 parts of lanthanide catalysts;

Mix all the components evenly, grind them, the specific surface area is 325m ² /kg, and obtain the steel slag active activator;

The lanthanide catalyst is that the mass ratio of lanthanum nitrate to lanthanum sulfate is 1:1;

The dried sludge is dried sludge powder with a water content of 0.4%.

Spray 12% activator into the liquid steel slag discharged from the boiler, mix evenly, then cool down and grind to obtain active steel slag powder; the specific surface area of the ground active steel slag powder is 550m ² /kg.

Example 4

A steel slag active activator, the activator is composed of the following materials uniformly mixed in parts by mass: 25 parts of kaolin, 25 parts of diatomaceous earth, 15 parts of dried sludge, 15 parts of K ₂ CO ₃ , 4 parts of KClO ₃ , 0.3 parts of sodium N-acyl peptides, 1.5 parts of FeCl ₃ , 0.5 parts of lanthanide catalysts;

Mix all the components evenly, grind them, the specific surface area is 368m ² /kg, and obtain the steel slag active activator;

The lanthanide catalyst is that the mass ratio of lanthanum nitrate to lanthanum sulfate is 1:2;

The sludge powder is dried sludge powder with a water content of 2.3%.

Spray 10% activator into the liquid steel slag discharged from the boiler, mix evenly, then cool down and grind to obtain active steel slag powder; the specific surface area of the ground active steel slag powder is 487m ² /kg.

Performance Testing

The activity of steel slag in each embodiment and comparative example compares the activity of steel slag by the method of cement mortar 28d compressive strength ratio test in GB/T12957-2005, and the mixing amount of active steel slag powder is by the regulation of standard GB/T12957-2005, The active steel slag powder and dihydrate gypsum are mixed evenly at a mass ratio of 90:10, and the total mixing amount is 30% of the cement mass.

The experiment uses Shanshui 42.5 ordinary Portland cement, place of origin: Shandong Cement Factory. Its chemical composition is shown in Table 1.

Table 1 P.O42.5 main chemical composition of cement /%

composition SiO₂ Al₂O₃ Fe₂O₃ Ca0 MgO Na₂O K₂O SO₃ W% 20.87 6.7 3.86 58.32 4.23 0.07 0.61 2.42

According to the relevant regulations of GB/T12957-2005, the 28d compressive strength and PAI value of each group of samples are tested as shown in Table 2:

Table 2 different examples of steel slag activity PAI value

It can be seen from Table 2 that compared with Comparative Example 1, the strength of cement mortar mixed with activated steel slag powder has been greatly improved. It can also be seen from the PAI value that the activity of steel slag has been greatly improved. It shows that the activator can effectively improve the activity of steel slag.

Claims (4)

1. An active steel slag powder comprising a steel slag active activator is characterized in that the steel slag active activator is mixed with steel slag, and the steel slag is unquenched fluid steel slag discharged from a boiler; the steel slag active activator accounts for the steel slag total amount The mass ratio is 8%~12%; The steel slag active stimulator is composed of the following substances, each component is by mass parts: Kaolin 15~25 parts, 20~30 parts of diatomaceous earth, Dry sludge 10~20 parts, Alkali metal carbonate 10~15 parts, 3~7 parts of alkali metal chlorate, Sodium N-acyl peptide 0.1~0.5 parts, FeCl ₃ 1~2 parts, Lanthanide catalyst 0.2~1 part; The alkali metal carbonate is Na ₂ CO ₃ or K ₂ CO ₃ ; The alkali metal chlorate is KClO ₃ or NaClO ₃ ; Mix the above-mentioned components evenly, and grind them to 200-400m ² /kg to obtain the steel slag activity activator; The dried sludge is sludge powder or granules with a water content not higher than 5% obtained after the sludge is dried. 2. a kind of active steel slag powder that comprises steel slag active stimulator according to claim 1, is characterized in that, described lanthanide catalyst is selected from any one or two kinds of arbitrary ratio mixings in lanthanum nitrate, lanthanum sulfate. 3. the preparation method of a kind of active steel slag powder that comprises steel slag active activator as claimed in claim 1, is characterized in that, comprises: in the liquid steel slag that boiler is discharged, spray into steel slag active activator and mix, then cooling treatment, Grinding to obtain active steel slag powder; The specific surface area of the ground active steel slag powder is 400-550m ² /kg. 4. the application method of a kind of active steel slag powder that comprises steel slag active activator as claimed in claim 1, is characterized in that, described active steel slag powder uses as cement admixture, grinds together with cement clinker during use, and described The amount of active steel slag powder is less than 30% of the total mass of cement.