CN111672582A - Steel slag activation technology - Google Patents
Steel slag activation technology Download PDFInfo
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- CN111672582A CN111672582A CN202010660551.6A CN202010660551A CN111672582A CN 111672582 A CN111672582 A CN 111672582A CN 202010660551 A CN202010660551 A CN 202010660551A CN 111672582 A CN111672582 A CN 111672582A
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- steel slag
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
- B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
- B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
- B02C17/10—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls with one or a few disintegrating members arranged in the container
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
- B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
- B02C23/00—Auxiliary methods or auxiliary devices or accessories specially adapted for crushing or disintegrating not provided for in preceding groups or not specially adapted to apparatus covered by a single preceding group
- B02C23/08—Separating or sorting of material, associated with crushing or disintegrating
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C1/00—Magnetic separation
- B03C1/02—Magnetic separation acting directly on the substance being separated
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K3/00—Materials not provided for elsewhere
- C09K3/14—Anti-slip materials; Abrasives
- C09K3/1409—Abrasive particles per se
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- Engineering & Computer Science (AREA)
- Food Science & Technology (AREA)
- Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
- Processing Of Solid Wastes (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
Abstract
The invention relates to the technical field of steel slag resource utilization, in particular to a steel slag activation technology. Firstly, pre-crushing and magnetically separating the steel slag, removing and recovering particles with higher iron content, then, primarily grinding the rest particles by using a ball mill to obtain particles with 50-60 meshes, then, adding a grinding aid and an activating agent into the ball mill to carry out fine grinding to obtain powder with the specific surface area of 510 plus materials and the weight of 530 square meters per kilogram, and finally, drying the obtained powder to obtain activated steel slag powder with the water content of less than 0.8 percent. The steel slag activation technology has the advantages that the grinding efficiency is high during powder preparation, the prepared steel slag powder has small granularity, and the activated steel slag, cement and other materials have high strength after being prepared into filling materials.
Description
Technical Field
The invention relates to the technical field of steel slag resource utilization, in particular to a steel slag activation technology.
Background
Steel slag is waste slag produced in metallurgical industry, and its production rate is 8% -15% of crude steel yield. The production amount of steel slag in China is rapidly increased along with the rapid development of the steel industry, and if the steel slag is not treated in time, a large amount of land is occupied and the environment is polluted. Meanwhile, a large number of goafs of the mining field exist in China and need to be filled so as to control the ground pressure of the mining field, limit the deformation of surrounding rocks, control the surface subsidence within an allowable range and avoid the surface subsidence and uneven subsidence from damaging farmlands or destroying buildings.
The national development plan of 'eleven five' indicates that the comprehensive utilization rate of the steel slag can reach more than 86 percent and zero emission is basically realized. Researches show that the activated steel slag is made into a gel material for filling a goaf in a mining field, and the gel material is a promising comprehensive utilization way.
The mineral composition of the steel slag is mainly tricalcium silicate, and then dicalcium silicate, RO phase, dicalcium ferrite and free calcium oxide. The activity of the steel slag is improved by levigating processing, and then cement is doped into the steel slag according to a certain proportion to be used as a cementing material, so that the cost of the filling material can be reduced. However, the steel slag has high hardness, which results in poor grindability, the center of the ground powder exists in the form of crystal or vitreous body, the amorphous layer generated on the surface of the particles is thickened at the later stage of grinding, the crushing force cannot directly act on the hard interior of the particles, and agglomeration among fine particles is caused due to continuous collision and extrusion among the particles, which makes further refinement of the particles difficult by prolonging the grinding time. Meanwhile, free calcium oxide in the steel slag can influence the stability of a system, so that the volume of the steel slag is expanded in the later stage of hydration, the strength is slowly increased, and even the strength is shrunk.
Disclosure of Invention
The invention aims to solve the technical problems and provides a steel slag activation technology aiming at the technical defects, the grinding efficiency is high during powder preparation, the particle size of the prepared steel slag powder is small, and the strength of the activated steel slag and cement and other materials prepared into filling materials is high.
According to the technical scheme adopted by the invention, the steel slag activation technology comprises the following steps:
A. pre-crushing the steel slag to obtain particles with the particle size diameter of 6-8 mm, carrying out magnetic separation on the obtained particles, removing and recycling the particles with higher iron content, and leaving the rest particles for the next step;
B. activating the particles obtained in the step A:
(1) primary grinding: b, adding the particles obtained in the step A into a ball mill for ball milling, and stopping ball milling when the average particle size of the particles is 50-60 meshes;
(2) fine grinding: continuously adding a grinding aid and an activating agent into the ball mill in the step (1) for ball milling to obtain powder with the specific surface area of 510-530 square meters per kilogram;
the grinding aid is quartz particles, and the particle size composition of the grinding aid is as follows: 12-15% of 100-sand-type 120-mesh particles, 35-37% of 150-sand-type 180-mesh particles, 32-34% of 200-sand-type 220-mesh particles and 16-18% of 250-sand-type 300-mesh particles;
the activating agent comprises the following raw materials in parts by weight: 12-15 parts of urea, 5-7 parts of polyetheramine, 3-7 parts of cane sugar, 21-26 parts of ammonium sulfate, 1-3 parts of sodium metaphosphate, 5-8 parts of sodium carbonate, 5-9 parts of calcium chloride, 18-25 parts of aluminum sulfate and 52-61 parts of water;
C. and D, drying the powder obtained in the step B to obtain activated steel slag powder with the water content of less than 0.8%.
Preferably, the activating agent comprises the following raw materials in parts by weight: 13-14 parts of urea, 5-7 parts of polyetheramine, 5-6 parts of cane sugar, 22-25 parts of ammonium sulfate, 2-3 parts of sodium metaphosphate, 5-7 parts of sodium carbonate, 6-8 parts of calcium chloride, 20-23 parts of aluminum sulfate and 53-58 parts of water.
Preferably, the activating agent comprises the following raw materials in parts by weight: 13 parts of urea, 6 parts of polyetheramine, 5 parts of cane sugar, 23 parts of ammonium sulfate, 2 parts of sodium metaphosphate, 6 parts of sodium carbonate, 7 parts of calcium chloride, 21 parts of aluminum sulfate and 56 parts of water.
Preferably, the addition amount of the grinding aid is 0.3-0.7% of the weight of the steel slag obtained in the step A.
Preferably, the addition amount of the activating agent is 1-3% of the weight of the steel slag obtained in the step A.
Compared with the prior art, the invention has the following advantages: quartz particles are added in the ball milling process as grinding aids, so that the fine steel slag particles can be further crushed, the prepared powder has smaller particle size and higher activity, and the grinding efficiency is higher; the urea and the polyetheramine can reduce the tendency of secondary coalescence of ultrafine particles formed in the ball milling process, and the sucrose and the calcium chloride can improve the flowability of powder and improve the milling efficiency; under the existence of water and the action of ball milling, the sodium carbonate, the ammonium sulfate, the sodium carbonate and the aluminum sulfate can convert part of free calcium oxide into calcium sulfate or calcium carbonate, so that the stability of the filling material is improved.
Detailed Description
The present invention will be further described with reference to specific examples, but the present invention is not limited to the following examples.
Example 1
A steel slag activation technology comprises the following steps:
A. pre-crushing the steel slag to obtain particles with the particle size diameter of 6-8 mm, carrying out magnetic separation on the obtained particles, removing and recycling the particles with higher iron content, and leaving the rest particles for the next step;
B. activating the particles obtained in the step A:
(1) primary grinding: b, adding the particles obtained in the step A into a ball mill for ball milling, and stopping ball milling when the average particle size of the particles is 50-60 meshes;
(2) fine grinding: continuously adding a grinding aid and an activating agent into the ball mill for ball milling to obtain powder with the specific surface area of 510-530 square meters per kilogram;
the grinding aid is quartz particles, and the particle size composition of the grinding aid is as follows: 12-15% of 100-sand-type 120-mesh particles, 35-37% of 150-sand-type 180-mesh particles, 32-34% of 200-sand-type 220-mesh particles and 16-18% of 250-sand-type 300-mesh particles; and the addition amount of the grinding aid is 0.6 percent of the weight of the steel slag obtained in the step A.
The activating agent comprises the following raw materials in parts by weight: 12 parts of urea, 7 parts of polyetheramine, 3 parts of cane sugar, 21 parts of ammonium sulfate, 3 parts of sodium metaphosphate, 5 parts of sodium carbonate, 7 parts of calcium chloride, 25 parts of aluminum sulfate and 61 parts of water; the addition amount of the activating agent is 1.5 percent of the weight of the steel slag obtained in the step A.
C. And D, drying the powder obtained in the step B to obtain activated steel slag powder with the water content of less than 0.8%.
Example 2
A steel slag activation technology comprises the following steps:
A. pre-crushing the steel slag to obtain particles with the particle size diameter of 6-8 mm, carrying out magnetic separation on the obtained particles, removing and recycling the particles with higher iron content, and leaving the rest particles for the next step;
B. activating the particles obtained in the step A:
(1) primary grinding: b, adding the particles obtained in the step A into a ball mill for ball milling, and stopping ball milling when the average particle size of the particles is 50-60 meshes;
(2) fine grinding: continuously adding a grinding aid and an activating agent into the ball mill for ball milling to obtain powder with the specific surface area of 510-530 square meters per kilogram;
the grinding aid is quartz particles, and the particle size composition of the grinding aid is as follows: 12-15% of 100-sand-type 120-mesh particles, 35-37% of 150-sand-type 180-mesh particles, 32-34% of 200-sand-type 220-mesh particles and 16-18% of 250-sand-type 300-mesh particles; and the addition amount of the grinding aid is 0.6 percent of the weight of the steel slag obtained in the step A.
The activating agent comprises the following raw materials in parts by weight: 13 parts of urea, 6 parts of polyetheramine, 5 parts of cane sugar, 23 parts of ammonium sulfate, 2 parts of sodium metaphosphate, 6 parts of sodium carbonate, 7 parts of calcium chloride, 21 parts of aluminum sulfate and 56 parts of water; the addition amount of the activating agent is 1.5 percent of the weight of the steel slag obtained in the step A.
C. And D, drying the powder obtained in the step B to obtain activated steel slag powder with the water content of less than 0.8%.
Example 3
A steel slag activation technology comprises the following steps:
A. pre-crushing the steel slag to obtain particles with the particle size diameter of 6-8 mm, carrying out magnetic separation on the obtained particles, removing and recycling the particles with higher iron content, and leaving the rest particles for the next step;
B. activating the particles obtained in the step A:
(1) primary grinding: b, adding the particles obtained in the step A into a ball mill for ball milling, and stopping ball milling when the average particle size of the particles is 50-60 meshes;
(2) fine grinding: continuously adding a grinding aid and an activating agent into the ball mill for ball milling to obtain powder with the specific surface area of 510-530 square meters per kilogram;
the grinding aid is quartz particles, and the particle size composition of the grinding aid is as follows: 12-15% of 100-sand-type 120-mesh particles, 35-37% of 150-sand-type 180-mesh particles, 32-34% of 200-sand-type 220-mesh particles and 16-18% of 250-sand-type 300-mesh particles; and the addition amount of the grinding aid is 0.6 percent of the weight of the steel slag obtained in the step A.
The activating agent comprises the following raw materials in parts by weight: 15 parts of urea, 5 parts of polyetheramine, 7 parts of cane sugar, 26 parts of ammonium sulfate, 1 part of sodium metaphosphate, 8 parts of sodium carbonate, 9 parts of calcium chloride, 18 parts of aluminum sulfate and 52 parts of water; the addition amount of the activating agent is 1.5 percent of the weight of the steel slag obtained in the step A.
C. And D, drying the powder obtained in the step B to obtain activated steel slag powder with the water content of less than 0.8%.
Comparative examples
The same steel slag raw material is used for refining treatment, and the refining treatment method comprises the following steps:
A. pre-crushing the steel slag to obtain particles with the particle size diameter of 6-8 mm, carrying out magnetic separation on the obtained particles, removing and recycling the particles with higher iron content, and leaving the rest particles for the next step;
B. and D, performing ball milling on the particles obtained in the step A to obtain powder with fine particle size, wherein the specific surface area of the powder is 400-500 square meters per kilogram under the condition of long-time ball milling.
As no grinding aid is added in the comparative example, the grinding and crushing efficiency is lower when the particles are smaller in the ball milling process, so that the ball milling is required for more than 13 hours when the powder reaches the specific surface area of 400-530 square meters per kilogram, the specific surface area of the powder is hardly reached to 510-530 square meters per kilogram, and the specific surface area of the powder in examples 1-3 reaches 510-530 square meters per kilogram and only needs 7-8 hours.
33 parts of the steel slag powder obtained in examples 1-3 and comparative example and 67 parts of PO42.5R cement are respectively mixed, then 900 parts of standard sand are added and uniformly mixed to prepare a filling material, then 400 parts of water are added into the obtained filling material, the mixture is uniformly stirred by a cement mortar stirrer and then poured into a 70.7cm triple test mold, then the test mold is placed into a curing box with the temperature of 20 ℃ and the humidity of more than 90 percent for curing for 48 hours, then the mold is removed to obtain a sample, and then the sample is cured in the curing box under the same conditions. The compressive strength of the resulting samples is shown in the following table:
as can be seen from the table, the fillers of examples 1 to 3 have a significantly improved compression strength over the comparative examples in 3 days, 7 days and 28 days, and particularly, the compression strength over 3 days is more than twice that of the comparative examples. The steel slag powder prepared by the steel slag activation technology has large specific surface area and good activation effect, so that the hydration speed is high, and the early compressive strength of a sample is greatly improved.
Claims (5)
1. A steel slag activation technology is characterized by comprising the following steps:
A. pre-crushing the steel slag to obtain particles with the particle size diameter of 6-8 mm, carrying out magnetic separation on the obtained particles, and removing and recycling the particles with higher iron content;
B. activating the particles obtained in the step A:
(1) primary grinding: b, adding the particles obtained in the step A into a ball mill for ball milling, and stopping ball milling when the average particle size of the particles is 50-60 meshes;
(2) fine grinding: continuously adding a grinding aid and an activating agent into the ball mill in the step (1) for ball milling to obtain powder with the specific surface area of 510-530 square meters per kilogram;
the grinding aid is quartz particles, and the particle size composition of the grinding aid is as follows: 12-15% of 100-sand-type 120-mesh particles, 35-37% of 150-sand-type 180-mesh particles, 32-34% of 200-sand-type 220-mesh particles and 16-18% of 250-sand-type 300-mesh particles;
the activating agent comprises the following raw materials in parts by weight: 12-15 parts of urea, 5-7 parts of polyetheramine, 3-7 parts of cane sugar, 21-26 parts of ammonium sulfate, 1-3 parts of sodium metaphosphate, 5-8 parts of sodium carbonate, 5-9 parts of calcium chloride, 18-25 parts of aluminum sulfate and 52-61 parts of water;
C. and D, drying the powder obtained in the step B to obtain activated steel slag powder with the water content of less than 0.8%.
2. The steel slag activation technology according to claim 1, characterized in that: the activating agent comprises the following raw materials in parts by weight: 13-14 parts of urea, 5-7 parts of polyetheramine, 5-6 parts of cane sugar, 22-25 parts of ammonium sulfate, 2-3 parts of sodium metaphosphate, 5-7 parts of sodium carbonate, 6-8 parts of calcium chloride, 20-23 parts of aluminum sulfate and 53-58 parts of water.
3. The steel slag activation technology according to claim 1, characterized in that: the activating agent comprises the following raw materials in parts by weight: 13 parts of urea, 6 parts of polyetheramine, 5 parts of cane sugar, 23 parts of ammonium sulfate, 2 parts of sodium metaphosphate, 6 parts of sodium carbonate, 7 parts of calcium chloride, 21 parts of aluminum sulfate and 56 parts of water.
4. The steel slag activation technology according to claim 1, characterized in that: and the addition amount of the grinding aid is 0.3-0.7% of the weight of the steel slag obtained in the step A.
5. The steel slag activation technology according to claim 1, characterized in that: the addition amount of the activating agent is 1-3% of the weight of the steel slag obtained in the step A.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010660551.6A CN111672582A (en) | 2020-07-10 | 2020-07-10 | Steel slag activation technology |
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| CN202010660551.6A CN111672582A (en) | 2020-07-10 | 2020-07-10 | Steel slag activation technology |
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1374150A (en) * | 2002-01-28 | 2002-10-16 | 赵庆杰 | Magnetic and gravitational separation and comprehensive utilization of vonsenite |
| CN1451624A (en) * | 2002-04-19 | 2003-10-29 | 尹小林 | Industrial waste residue activating grinding aid |
| CN101062845A (en) * | 2007-04-30 | 2007-10-31 | 上海国冶工程技术有限公司 | Industrial residue activating grinding aid |
| CN102351460A (en) * | 2011-07-19 | 2012-02-15 | 孙贤文 | Steel slag grinding aid and preparation method thereof |
| CN102732652A (en) * | 2011-04-13 | 2012-10-17 | 许兴康 | Superfine grinding method for steel slag slurry |
| JP2012197204A (en) * | 2011-03-22 | 2012-10-18 | Taiheiyo Cement Corp | Method of manufacturing cement |
| CN103819104A (en) * | 2014-01-10 | 2014-05-28 | 中建材（合肥）粉体科技装备有限公司 | Slag and steel slag grinding-assisted activating agent |
| CN108424012A (en) * | 2018-04-13 | 2018-08-21 | 沈阳建筑大学 | A kind of liquid grinding aid improving steel slag grinding efficiency |
-
2020
- 2020-07-10 CN CN202010660551.6A patent/CN111672582A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1374150A (en) * | 2002-01-28 | 2002-10-16 | 赵庆杰 | Magnetic and gravitational separation and comprehensive utilization of vonsenite |
| CN1451624A (en) * | 2002-04-19 | 2003-10-29 | 尹小林 | Industrial waste residue activating grinding aid |
| CN101062845A (en) * | 2007-04-30 | 2007-10-31 | 上海国冶工程技术有限公司 | Industrial residue activating grinding aid |
| JP2012197204A (en) * | 2011-03-22 | 2012-10-18 | Taiheiyo Cement Corp | Method of manufacturing cement |
| CN102732652A (en) * | 2011-04-13 | 2012-10-17 | 许兴康 | Superfine grinding method for steel slag slurry |
| CN102351460A (en) * | 2011-07-19 | 2012-02-15 | 孙贤文 | Steel slag grinding aid and preparation method thereof |
| CN103819104A (en) * | 2014-01-10 | 2014-05-28 | 中建材（合肥）粉体科技装备有限公司 | Slag and steel slag grinding-assisted activating agent |
| CN108424012A (en) * | 2018-04-13 | 2018-08-21 | 沈阳建筑大学 | A kind of liquid grinding aid improving steel slag grinding efficiency |
Non-Patent Citations (2)
| Title |
|---|
| 孙传尧主编: "《选矿工程师手册 第1册 上 选矿通论》", 31 March 2015 * |
| 梁文杰等: "《石油化学（第二版）》", 28 February 2009 * |
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