阅读说明：本技术 一种集成物化反应的钢渣强化处理方法 (Steel slag strengthening treatment method integrating physicochemical reaction ) 是由 陈惠坤 黄山 刘凯 赵晨昊 牛冬瑜 田耀刚 耿九光 陈星宇 郭佳乐 于 2021-06-02 设计创作，主要内容包括：本发明属于钢渣处理技术领域,公开了一种集成物化反应的钢渣强化处理方法,包括以下步骤：步骤1,对钢渣进行预处理,将预处理后的钢渣冲洗干净并自然干燥至恒重,得到初步钢渣；步骤2,对所述初步钢渣进行一次烘干,随后放置在自来水中进行激冷处理,并冲洗干净后进行二次烘干至恒重,得到最终钢渣。该方法对钢渣游离氧化钙去除率高达98％以上,对钢渣不会产生二次破坏,且处理后的钢渣的吸水率下降到1.91％以下,体积稳定性好；且可以实现对钢渣废物的循环利用,缓解了建筑废弃物对自然环境造成的压力,将其作为绿色建筑材料推广应用,经济环保。(The invention belongs to the technical field of steel slag treatment, and discloses a steel slag strengthening treatment method integrating physicochemical reaction, which comprises the following steps: step 1, pretreating steel slag, washing the pretreated steel slag clean, and naturally drying the steel slag to constant weight to obtain primary steel slag; and 2, drying the primary steel slag for the first time, then placing the steel slag in tap water for chilling treatment, washing the steel slag clean, and drying the steel slag for the second time until the weight of the steel slag is constant to obtain the final steel slag. The method has the advantages that the removal rate of free calcium oxide of the steel slag is up to more than 98 percent, secondary damage to the steel slag is avoided, the water absorption of the treated steel slag is reduced to below 1.91 percent, and the volume stability is good; and the steel slag waste can be recycled, the pressure of the construction waste on the natural environment is relieved, and the steel slag waste is popularized and applied as a green building material, is economic and environment-friendly.)

1. A steel slag strengthening treatment method integrating physical and chemical reactions is characterized by comprising the following steps:

step 1, pretreating steel slag, washing the pretreated steel slag clean, and naturally drying the steel slag to constant weight to obtain primary steel slag;

and 2, drying the primary steel slag for the first time, then placing the steel slag in tap water for chilling treatment, washing the steel slag clean, and drying the steel slag for the second time until the weight of the steel slag is constant to obtain the final steel slag.

2. The steel slag strengthening treatment method integrating the physicochemical reaction as described in claim 1, wherein in the step 1, the steel slag is obtained by artificially primarily crushing steel slag blocks to obtain steel slag small blocks; and then placing the small steel slag blocks into a jaw crusher for secondary crushing to obtain the steel slag blocks.

3. The steel slag strengthening treatment method integrating materialization reaction according to claim 1, wherein the particle size of the steel slag in step 1 is greater than 9.5 mm.

4. The method for steel slag reinforcement treatment by integration of physicochemical reactions according to claim 1, wherein in step 1, the pretreatment comprises at least one of acid treatment, mechanical treatment and thermal treatment.

5. The steel slag strengthening treatment method integrating materialization reaction according to claim 4, wherein the acid treatment is: soaking the steel slag in concentrated hydrochloric acid solution of 1-1.5 Mol/L for 0.5-1.5 days.

6. The steel slag strengthening treatment method integrating materialization reaction according to claim 4, wherein the mechanical treatment is: the steel slag is treated for 8-15 times in a 30-33 r/min abrasion machine and passes through a 9.5mm screen.

7. The steel slag strengthening treatment method integrating materialization reaction according to claim 4, wherein the heat treatment is: the steel slag is treated in an oven at 400-500 ℃ for 1.5-3.5 h.

8. The method for strengthening steel slag through the integrated materialization reaction according to claim 1, wherein in the step 2, the temperature of the primary drying is 700-800 ℃, and the time of the primary drying is 1-3 hours.

9. The method for strengthening steel slag through the integrated materialization reaction according to claim 1, wherein in the step 2, the temperature of the secondary drying is 100-110 ℃, and the time of the secondary drying is 20-28 hours.

Technical Field

The invention relates to the technical field of steel slag treatment, in particular to a steel slag strengthening treatment method integrating physicochemical reaction.

Background

The steel slag has the advantages of good angularity, high hardness, high rigidity, excellent compression resistance, wear resistance and other physical and mechanical properties, so that the steel slag can be possibly used in asphalt mixtures. However, the steel slag is rich in free calcium oxide (f-CaO) and free magnesium oxide (f-MgO), and the water absorption expansion rate of the steel slag is high, so that when the steel slag is used in the asphalt mixture, the water absorption expansion of the steel slag can reduce the volume stability of the mixture, and the steel slag is prevented from being widely used in road construction.

The existing strengthening treatment technology for steel slag mainly focuses on two aspects, one method is a method for removing free calcium oxide of steel slag, wherein a hot splashing method, a hot stuffiness method, a roller method and the like are mainly adopted, and the method has the problems of poor economy, high energy consumption, easiness in causing secondary damage to the steel slag and the like; in addition, the method aims to improve the surface characteristics of the steel slag, and mainly adopts a chemical agent to improve the surface characteristics of the steel slag so as to improve the performance of the steel slag.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a steel slag strengthening treatment method integrating physical and chemical reactions, the method has the advantages that the removal rate of free calcium oxide of the steel slag is up to more than 98 percent, no secondary damage is caused to the steel slag, the water absorption of the treated steel slag is reduced to less than 1.91 percent, and the volume stability is good; and the steel slag waste can be recycled, the pressure of the construction waste on the natural environment is relieved, and the steel slag waste is popularized and applied as a green building material, is economic and environment-friendly.

In order to achieve the purpose, the invention is realized by adopting the following technical scheme.

A steel slag strengthening treatment method integrating physical and chemical reactions comprises the following steps:

step 1, pretreating steel slag, washing the pretreated steel slag clean, and naturally drying the steel slag to constant weight to obtain primary steel slag;

and 2, drying the primary steel slag for the first time, then placing the steel slag in tap water for chilling treatment, washing the steel slag clean, and drying the steel slag for the second time until the weight of the steel slag is constant to obtain the final steel slag.

Preferably, in the step 1, the steel slag is obtained by manually primarily crushing steel slag blocks to obtain small steel slag blocks; and then placing the small steel slag blocks into a jaw crusher for secondary crushing to obtain the steel slag blocks.

Preferably, in step 1, the particle size of the steel slag is greater than 9.5 mm.

Preferably, in step 1, the pretreatment comprises at least one of acid treatment, mechanical treatment and thermal treatment.

Further preferably, the acid treatment is: soaking the steel slag in concentrated hydrochloric acid solution of 1-1.5 Mol/L for 0.5-1.5 days.

Further preferably, the mechanical treatment is: the steel slag is treated for 8-15 times in a 30-33 r/min abrasion machine and passes through a 9.5mm screen.

Further preferably, the heat treatment is: the steel slag is treated in an oven at 400-500 ℃ for 1.5-3.5 h.

Preferably, in the step 2, the temperature of the primary drying is 700-800 ℃, and the time of the primary drying is 1-3 h.

Preferably, in the step 2, the temperature of the secondary drying is 100-110 ℃, and the time of the secondary drying is 20-28 h.

Compared with the prior art, the invention has the beneficial effects that:

1) the steel slag is pretreated to remove a part of free calcium oxide, and then deep free calcium oxide is further removed in a high-temperature environment of 700-800 ℃, so that the method can basically and completely remove the free calcium oxide of the steel slag, the removal rate of the free calcium oxide reaches more than 98 percent, the basic physical properties of the steel slag are obviously improved, the water absorption expansion rate of the steel slag is reduced, and the water absorption rate is reduced to less than 1.91 percent.

2) Compared with a hot splashing method, a hot stuffiness method, a roller method and the like, the steel slag strengthening treatment method has obvious effect of reducing the water absorption rate of the steel slag, and does not cause secondary damage to the steel slag; compared with a pure chemical treatment method, the method has good economical efficiency and is environment-friendly.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention.

Example 1

A steel slag strengthening treatment method integrating physical and chemical reactions comprises the following steps:

step 1, pretreating steel slag, washing the pretreated steel slag clean, and naturally drying the steel slag to constant weight to obtain primary steel slag; wherein, the steel slag is obtained by manually primarily crushing steel slag blocks; and then placing the small steel slag blocks into a jaw crusher for secondary crushing to obtain the steel slag brick.

The pretreatment adopts an acid treatment mode, and specifically comprises the following steps: the steel slag is soaked in 1.2Mol/L concentrated hydrochloric acid solution for 1d, and then is washed by tap water and dried to constant weight. The acid treatment is a neutralization reaction between main components such as CaO and MgO in the steel slag and a hydrochloric acid solution, and can dissolve and remove the CaO and MgO in the steel slag.

And 2, drying the primary steel slag in an oven at 750 ℃ for 2h for the first time, then placing the primary steel slag in tap water for chilling treatment, washing the primary steel slag clean, and then placing the primary steel slag in an oven at 110 ℃ for secondary drying for 24h to constant weight to obtain the final steel slag.

The steel slag asphalt mixture prepared by the steel slag obtained by the method comprises the following steps: mixing 5kg steel slag (containing 3-10mm coarse steel slag and 0-3mm fine steel slag) with 1kg asphalt, 4.1kg stone (containing 10-15mm limestone, 10-13mm limestone and 5-10mm limestone) and 0.9kg mineral powder to obtain the steel slag asphalt mixture. Wherein, the asphalt adopts straight-run 70# asphalt for road; the aggregate composition of the steel slag asphalt mixture is limestone with the particle size of 10-15 mm: 10-13mm limestone: 5-10mm limestone: 3-10mm coarse steel slag: 0-3mm fine steel slag: 12 parts of mineral powder: 7: 22: 20: 30: 9.

example 2

A steel slag strengthening treatment method integrating physical and chemical reactions comprises the following steps:

step 1, pretreating steel slag, washing the pretreated steel slag clean, and naturally drying the steel slag to constant weight to obtain primary steel slag; wherein, the steel slag is obtained by manually primarily crushing steel slag blocks; and then placing the small steel slag blocks into a jaw crusher for secondary crushing to obtain the steel slag brick.

The pretreatment adopts a mechanical treatment mode, and specifically comprises the following steps: the steel slag is processed 10 times in a 33r/min los Angeles abrasion machine, and is sieved by a 9.5mm sieve, and coarse steel slag is remained. The mechanical treatment method is that the steel slag particle shape can be improved by mutual impact and grinding between the steel slag and the los Angeles wearing machine or the steel slag, thereby achieving the purpose of strengthening the surface of the steel slag.

And 2, drying the primary steel slag in an oven at 750 ℃ for 2h for the first time, then placing the primary steel slag in tap water for chilling treatment, washing the primary steel slag clean, and then placing the primary steel slag in an oven at 110 ℃ for secondary drying for 24h to constant weight to obtain the final steel slag.

The steel slag asphalt mixture prepared by the steel slag obtained by the method comprises the following steps: mixing 5kg steel slag (containing 3-10mm coarse steel slag and 0-3mm fine steel slag) with 1kg asphalt, 4.1kg stone (containing 10-15mm limestone, 10-13mm limestone and 5-10mm limestone) and 0.9kg mineral powder to obtain the steel slag asphalt mixture. Wherein, the asphalt adopts straight-run 70# asphalt for road; the aggregate composition of the steel slag asphalt mixture is limestone with the particle size of 10-15 mm: 10-13mm limestone: 5-10mm limestone: 3-10mm coarse steel slag: 0-3mm fine steel slag: 12 parts of mineral powder: 7: 22: 20: 30: 9.

example 3

A steel slag strengthening treatment method integrating physical and chemical reactions comprises the following steps:

step 1, pretreating steel slag, washing the pretreated steel slag clean, and naturally drying the steel slag to constant weight to obtain primary steel slag; wherein, the steel slag is obtained by manually primarily crushing steel slag blocks; and then placing the small steel slag blocks into a jaw crusher for secondary crushing and screening to obtain the steel slag block.

The pretreatment adopts a heat treatment mode, and specifically comprises the following steps: the steel slag is processed in a baking oven at 450 ℃ for 2 hours, and after the steel slag is heated, free calcium oxide in the steel slag is removed.

And 2, drying the primary steel slag in an oven at 750 ℃ for 2h for the first time, then placing the primary steel slag in tap water for chilling treatment, washing the primary steel slag clean, and then placing the primary steel slag in an oven at 110 ℃ for secondary drying for 24h to constant weight to obtain the final steel slag.

The steel slag asphalt mixture prepared by the steel slag obtained by the method comprises the following steps: mixing 5kg steel slag (containing 3-10mm coarse steel slag and 0-3mm fine steel slag) with 1kg asphalt, 4.1kg stone (containing 10-15mm limestone, 10-13mm limestone and 5-10mm limestone) and 0.9kg mineral powder to obtain the steel slag asphalt mixture. Wherein, the asphalt adopts straight-run 70# asphalt for road; the aggregate composition of the steel slag asphalt mixture is limestone with the particle size of 10-15 mm: 10-13mm limestone: 5-10mm limestone: 3-10mm coarse steel slag: 0-3mm fine steel slag: 12 parts of mineral powder: 7: 22: 20: 30: 9.

example 4

A steel slag strengthening treatment method integrating physical and chemical reactions comprises the following steps:

step 1, pretreating steel slag, washing the pretreated steel slag clean, and naturally drying the steel slag to constant weight to obtain primary steel slag; wherein, the steel slag is obtained by manually primarily crushing steel slag blocks; and then placing the small steel slag blocks into a jaw crusher for secondary crushing to obtain the steel slag brick.

The pretreatment adopts an acid treatment mode, and specifically comprises the following steps: the steel slag is soaked in 1.5Mol/L concentrated hydrochloric acid solution for 0.5d, and then is washed by tap water and dried to constant weight.

And 2, drying the primary steel slag in an oven at 780 ℃ for 1.8h for the first time, then placing the primary steel slag in tap water for chilling treatment, washing the primary steel slag clean, and then placing the primary steel slag in an oven at 100 ℃ for secondary drying for 28h to constant weight to obtain the final steel slag.

Example 5

A steel slag strengthening treatment method integrating physical and chemical reactions comprises the following steps:

step 1, pretreating steel slag, washing the pretreated steel slag clean, and naturally drying the steel slag to constant weight to obtain primary steel slag; wherein, the steel slag is obtained by manually primarily crushing steel slag blocks; and then placing the small steel slag blocks into a jaw crusher for secondary crushing to obtain the steel slag brick.

The pretreatment adopts a mechanical treatment mode, and specifically comprises the following steps: the steel slag is processed for 12 times in a 30r/min los Angeles abrasion machine, and is sieved by a 9.5mm sieve, and coarse steel slag is remained.

And 2, drying the primary steel slag in an oven at 800 ℃ for 1h for the first time, then placing the primary steel slag in tap water for chilling treatment, washing the primary steel slag clean, and then placing the primary steel slag in an oven at 105 ℃ for secondary drying for 24h to constant weight to obtain the final steel slag.

Test of

Referring to a test method in steel slag treatment technical specification, the influence of the technical scheme of the invention on the steel slag performance is detected, the basic performance before and after the steel slag treatment is contrastively analyzed, and the research indexes of the physical performance of the steel slag are shown in Table 1.

TABLE 1 index of physical Properties of the Steel slags

As can be seen from Table 1, the steel slag obtained in examples 1 to 3 has a slightly decreased apparent density, a sharply decreased water absorption rate within the acceptable range of the specification requirements, and no great change in other physical and mechanical parameters, which indicates that the steel slag strengthening treatment method of the present invention only changes the water absorption capacity of the steel slag and does not affect the material properties of the steel slag.

Test 2

The steel slag asphalt mixtures obtained in examples 1 to 3 were tested for high-temperature performance, low-temperature performance and water stability, respectively, and the results are shown in tables 2 to 5. The method comprises the following steps of referring to the technical specification of highway asphalt pavement construction (JTG F40-2004), testing final deformation by adopting an asphalt mixture rutting test, testing dynamic stability by adopting the asphalt mixture rutting test, testing maximum bending strain by adopting an asphalt mixture low-temperature bending test, testing bending tensile strength by adopting the asphalt mixture low-temperature bending test, and testing bending stiffness modulus by adopting the asphalt mixture low-temperature bending test; performing a freeze-thaw anti-splitting experiment at a loading rate of 50mm/min according to a specification T0716 to obtain the maximum load and residual strength ratio of the experiment; the stability and residual stability were tested using a water immersion marshall experiment.

TABLE 2 high-temperature Performance index of steel slag asphalt mixture

As can be seen from Table 2, the final deformation of the steel slag asphalt mixtures obtained in examples 1 to 3 is not very different, the final deformation of the untreated steel slag asphalt mixtures is the largest, and the final deformation of the steel slag asphalt mixtures obtained after the steel slag strengthening treatment of the invention is reduced to some extent, but still larger than that of the stone asphalt mixtures.

The dynamic stability values are compared, the dynamic stability of the steel slag asphalt mixture obtained in the embodiment 1-3 is far higher than that of the stone asphalt mixture, and the dynamic stability value of the steel slag asphalt mixture is improved after the steel slag is reinforced by the steel slag reinforcing treatment; therefore, through treatment, the high-temperature stability of the treated steel slag asphalt mixture is improved to a certain extent compared with that of the untreated steel slag asphalt mixture, the high-temperature stability is increased by more than about 12 percent, and the anti-rutting performance of the treated steel slag asphalt mixture is better; and the dynamic stability value of the asphalt is far higher than that of stone asphalt and is about 2.2 times of that of the stone asphalt.

TABLE 3 Low-temperature Performance index of steel slag asphalt mixture

It can be intuitively found from table 3 that the maximum bending strain of the five mixtures is basically the same and tends to be about 2100 μm, which also meets the requirement that the failure of the asphalt mixture in the asphalt mixture low-temperature bending test in the technical Specification for road asphalt pavement construction (JTG F40-2004) should be no less than 2000 μm. The bending tensile strength and the bending stiffness modulus of the processed steel slag asphalt mixture are greatly improved compared with the untreated steel slag asphalt mixture by the processing process, and the tensile strength and the bending stiffness modulus are increased by more than 5 percent on a same scale. The steel slag after being treated can be used for the asphalt mixture to effectively improve the low-temperature crack resistance of the mixture. Meanwhile, the mode of acid treatment and high-temperature heat treatment is optimal.

TABLE 4 Water stability index of steel slag asphalt mixture (freezing and thawing cleavage resistance experiment)

As can be seen from Table 4, the residual strength ratios in the freeze-thaw splitting test of the ordinary asphalt mixture, the untreated steel slag asphalt mixture, and the treated steel slag asphalt mixtures obtained in examples 1 to 3 gradually increased. The residual strength ratio of the steel slag asphalt mixture obtained in the examples 1 to 3 is larger than that of the ordinary asphalt mixture, which shows that the water damage resistance of the steel slag asphalt mixture after treatment is stronger than that of the ordinary asphalt mixture.

Examples 1-3 the residual strength ratio of the freeze-thaw cleavage test of the treated steel slag asphalt mixture was greater than the residual strength ratio of the untreated steel slag asphalt mixture, indicating that the treated steel slag asphalt mixture had a greater resistance to water damage than the untreated steel slag asphalt mixture, further indicating that the treatment method used in this study had a significant treatment effect and improved the durability of the asphalt mixture.

TABLE 5 Water stability index of slag asphalt mixture (Water immersion Marshall experiment)

In tables 4 and 5, the control group was not soaked in water.

As can be seen from Table 5, the residual stability of the processed steel slag-asphalt mixture obtained in examples 1-3 was 94.1% or more, which is far higher than 80% required by the technical Specification for road asphalt pavement construction (JTG F40-2004). The residual stability of the treated steel slag asphalt mixture obtained in examples 1-3 was greater than that of the untreated steel slag asphalt mixture, and the residual stability of the untreated steel slag asphalt mixture was greater than that of a common asphalt mixture, which indicates that the treatment method used in this study has an obvious reinforcing effect on steel slag and improves the water stability of the asphalt mixture.

Although the present invention has been described in detail in this specification with reference to specific embodiments and illustrative embodiments, it will be apparent to those skilled in the art that modifications and improvements can be made thereto based on the present invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.