阅读说明：本技术 多用途钢渣陈化处理方法 (Multipurpose steel slag ageing treatment method ) 是由 晋强 朱琳 胡荻 刘亮 于 2021-09-30 设计创作，主要内容包括：本发明涉及一种钢渣处理技术领域,是一种多用途钢渣陈化处理方法,按照下述方法进行：从钢渣上方通入蒸汽进行陈化处理,再进行喷水,最后向钢渣堆通入CO-(2)气体进行碳化,经过至少三周的陈化后得到。本发明在高温潮湿的环境可对钢渣陈化起到促进作用,通过预埋通气管通入的CO-(2)气体在水分形成致密封闭层内能够长时间留存,提高钢渣的碳化效果,进一步提高钢渣陈化效率,降低游离氧化钙、浸水膨胀率、蒸汽粉化率,分粒径钢渣砂陈化,提升了钢渣陈化的效率,提升自然陈化堆存料场的周转率,提升了钢渣砂在混凝土及砂浆领域应用的安全性。(The invention relates to the technical field of steel slag treatment, in particular to a multipurpose steel slag aging treatment method, which is carried out according to the following steps: introducing steam from the upper part of the steel slag for aging treatment, spraying water, and finally introducing CO into the steel slag pile 2 Carbonizing the gas, and aging for at least three weeks. The invention can promote the aging of the steel slag in a high-temperature and humid environment, and CO is introduced through the pre-buried vent pipe 2 The gas can be retained for a long time in a compact closed layer formed by water, the carbonization effect of the steel slag is improved, the aging efficiency of the steel slag is further improved, free calcium oxide, the water immersion expansion rate and the steam pulverization rate are reduced, the steel slag sand with different particle sizes is aged, the aging efficiency of the steel slag is improved, the turnover rate of a naturally aged stockyard is improved, and the application safety of the steel slag sand in the fields of concrete and mortar is improved.)

1. A multipurpose steel slag aging treatment method is characterized by comprising the following steps:

the first step is as follows: conveying the steel slag which is subjected to the iron removal process and the hot disintegration treatment and has the particle size of less than or equal to 10mm to a stacking bin, and flatly paving the steel slag in the stacking bin;

the second step is that: carrying out steam aging treatment from the upper part of the steel slag;

the third step: uniformly spraying water on the steel slag from the top, wherein each spraying time is 10 minutes, each time interval is 12 hours, and the spraying times are more than 1 time;

the fourth step: uniformly pre-burying vent pipes in the steel slag pile, wherein the vent pipes are vertically positioned in the steel slag pile, and introducing CO into the vent pipes₂Carbonizing by introducing gas for 10-20 min each time at intervals of 60-72 hr, and introducing gas for 2 times10 min to 20 min, each time with 168 hr interval, 2 times of aeration and then cut off, and CO is introduced₂The gas concentration is 20% +/-3%, and the gas flow rate is 0.5 m/s;

the fifth step: and repeating the steps, paving steel slag layer by layer, and aging the carbonized last layer of steel slag for at least three weeks to obtain aged steel slag.

2. The multipurpose steel slag aging method according to claim 1, wherein in the first step, the steel slag is conveyed by a conveyor belt and steam is introduced under the conveyor belt.

3. The multipurpose aging method for steel slag as claimed in claim 2, wherein the first stage of the steel slag is conveyed by a conveyor belt while CO is introduced thereinto₂A gas.

4. The multipurpose steel slag aging method according to claim 1, wherein in the first step, a feeding port of natural sand or tuff is arranged in front of the feeding port of steel slag, so that the steel slag and the natural sand or tuff are premixed by a conveyor belt, the particle size of the natural sand is less than 4.75mm, and the water content is more than 10%.

5. The multipurpose aging method for steel slag as claimed in claim 2, wherein in the third step, natural sand is laid on the sprayed steel slag through a conveyor belt, and then spraying is performed again from above.

6. The multipurpose steel slag aging method as claimed in claim 1, wherein in the first step, the steel slag after iron removal and hot braising is premixed with water and then transported by a conveyor belt, and the water temperature is 0 ℃ to 4 ℃.

7. The multipurpose steel slag aging method according to claim 2 or 6, wherein in the third step, the steel slag having a particle size of 1mm or less is laid on the steel slag of the second step to a thickness of more than 20 mm.

8. The multipurpose steel slag aging method according to claim 1, 2 or 3, wherein in the third step, a water permeable felt is spread on the surface of the steel slag before spraying.

9. The multipurpose steel slag aging method according to claim 1 or 2, wherein in the first step, the steel slag subjected to the iron removal process and the hot-pressing process is divided into three ranges of particle sizes of 4.75mm to 2.36mm, 2.36mm to 1.18mm and 1.18mm or less, and then subjected to the subsequent aging treatment.

Technical Field

The invention relates to the technical field of steel slag treatment, in particular to a multipurpose steel slag aging treatment method.

Background

The steel slag produced in the steel production process has hydraulicity and is widely used as a road building roadbed material. The steel slag is used as the roadbed, so that the road becomes very hard, the roadbed strength is improved, grooves are effectively prevented from appearing on the roadbed, the safe and stable running of the road is realized, and the road roadbed repairing cost is greatly reduced. However, untreated steel slag generally contains more free calcium oxide. Free calcium oxide slowly undergoes hydration reaction when meeting water, and is expressed as volume expansion of the material, and if the volume expansion is too large, a series of engineering problems can be caused. Therefore, the untreated steel slag cannot be directly used in engineering. The steel slag can be used in the fields of roadbed materials, backfill and building materials after being aged.

The prior aging method and the problems are as follows: (1) naturally piling up, namely piling up the steel slag in a slag field, and gradually reacting moisture in rainwater with free calcium oxide, wherein the reaction time is extremely long, and is generally more than 1 to 2 years; (2) the aging time can be shortened by aging with warm water, but the aging cost is higher; (3) the steam aging has better effect, the reaction time is more than 2 days, but the aging cost is higher, and the method is less adopted. (4) The high-pressure steam ageing process is to age the steel slag under high-temperature high-pressure steam, and the ageing time is greatly shortened along with the rise of the temperature. Because the temperature of saturated steam is increased in the closed container, the speed of pressurized steam aging hydration reaction is increased by 24 times compared with the steam aging of an open storage yard. Warm water aging and steam aging require large-scale storage sites, and the aging cost is still high. The high-pressure steam aging effect is good, but the equipment investment is high and the operation cost is also high.

In the existing research and engineering projects, steel slag mixed sand (steel slag and natural sand or machine-made sand are mixed according to a mass ratio) is often adopted to prepare corresponding products and materials. But the actual mixing efficiency is low, the effect is poor and the mixing difficulty is high. The prior sand mixing process usually adopts dry mixing or wet mixing and other modes, and has advantages and disadvantages. When the steel slag is mixed with the natural sand, the following problems are easily caused: (1) when dry mixing is carried out, the dust is large, a dust falling facility needs to be configured, and the particle composition is not suitable for blending. The natural sand is usually washed sand, has certain water content, is easy to agglomerate with the steel slag sand after being mixed, and particularly has obvious surface layer agglomeration. (2) When wet mixing is carried out, the biggest problem lies in that the steel slag is difficult to be fished out by the bailer, the phenomenon of heavy bottom settlement of the steel slag is obvious, and the stirring force of the bailer is not enough to fish the steel slag sand out from the bottom, so that the load of the bailer is large, and the mixed sand is not uniformly mixed.

The tuff is judged to be active aggregate because of containing volcanic glass, and related data are consulted to find that the tuff is widely distributed in Xinjiang, the concrete aggregates of a plurality of engineering projects have tuff with different degrees, and particularly, the sandstone for buildings in Wuluqiqi areas is detected to have the main component of the tuff, and the content of the tuff is about 70-85 percent. And the investigation shows that the alkali content of the cement used in Xinjiang basically exceeds 0.60 percent, so that concrete engineering in Xinjiang has serious hidden trouble of alkali-aggregate reaction.

Disclosure of Invention

The invention provides a multipurpose steel slag aging treatment method, overcomes the defects of the prior art, and can effectively solve the problem of volume expansion of materials caused by water hydration and reaction of free calcium oxide in steel slag.

The technical scheme of the invention is realized by the following measures: a multipurpose steel slag aging treatment method is carried out according to the following steps:

the first step is as follows: conveying the steel slag which is subjected to the iron removal process and the hot disintegration treatment and has the particle size of less than or equal to 10mm to a stacking bin, and flatly paving the steel slag in the stacking bin;

the second step is that: carrying out steam aging treatment from the upper part of the steel slag;

the third step: uniformly spraying water on the steel slag from the top, wherein each spraying time is 10 minutes, each time interval is 12 hours, and the spraying times are more than 1 time;

the fourth step: uniformly pre-burying vent pipes in the steel slag pile, wherein the vent pipes are vertically positioned in the steel slag pile, and introducing CO into the vent pipes₂Carbonizing gas, introducing gas for 10 min-20 min each time at intervals of 60 hr-72 hr, introducing gas for 2 times, introducing gas for 10 min-20 min each time at intervals of 168 hr, introducing gas for 2 times, and introducing CO₂The gas concentration is 20%+/-3% and the gas flow rate is 0.5 m/s;

the fifth step: and repeating the steps, paving steel slag layer by layer, and aging the carbonized last layer of steel slag for at least three weeks to obtain aged steel slag.

The following is further optimization or/and improvement of the technical scheme of the invention:

in the first step, the steel slag is conveyed by a conveyor belt, and steam is introduced below the conveyor belt.

Introducing CO when the first-step steel slag is conveyed by a conveyor belt₂A gas.

In the first step, the natural sand or tuff feed opening is arranged in front of the steel slag feed opening, so that the steel slag and the natural sand or tuff are premixed by a conveyor belt, the particle size of the natural sand is less than 4.75mm, and the water content is more than 10%.

And in the third step, natural sand is paved on the sprayed steel slag upper layer through a conveyor belt, and then spraying is carried out again from the upper part.

In the first step, the steel slag after iron removal and hot braising is premixed with water and then conveyed by a conveyor belt, and the water temperature is 0-4 ℃.

In the third step, the steel slag with the grain diameter of less than 1mm is paved on the steel slag in the second step, and the paving thickness is more than 20 mm.

In the third step, a layer of permeable felt cloth is paved on the surface of the steel slag before spraying.

In the first step, the steel slag subjected to the iron removal process and the hot disintegration treatment is divided into three particle size ranges of 4.75mm to 2.36mm, 2.36mm to 1.18mm and less than 1.18mm, and the subsequent aging treatment is respectively carried out.

The invention can promote the aging of the steel slag in a high-temperature and humid environment, and CO is introduced through the pre-buried vent pipe₂The gas can be retained for a long time in the compact closed layer formed by the water, the carbonization effect of the steel slag is improved, the aging efficiency of the steel slag is further improved, and the free calcium oxide, the water immersion expansion rate and the steam pulverization rate are reduced.

Drawings

FIG. 1 is a graph showing the change rate of volume with aging time of the test pieces in example 15.

FIG. 2 is a graph showing the change rate of volume with aging time after mixing the steel slag with full particle size in example 17 with concrete.

FIG. 3 is a graph showing the change rate of volume with aging time after mixing the steel slag with different particle size ranges of example 17 with concrete.

Detailed Description

The present invention is not limited by the following examples, and specific embodiments may be determined according to the technical solutions and practical situations of the present invention.

The invention is further described with reference to the following examples and figures:

example 1: the multipurpose steel slag aging treatment method is carried out according to the following method:

the first step is as follows: conveying the steel slag which is subjected to the iron removal process and the hot disintegration treatment and has the particle size of less than or equal to 10mm to a stacking bin, and flatly paving the steel slag in the stacking bin;

the second step is that: carrying out steam aging treatment from the upper part of the steel slag;

the third step: uniformly spraying water on the steel slag from the top, wherein each spraying time is 10 minutes, each time interval is 12 hours, and the spraying times are more than 1 time;

the fourth step: uniformly pre-burying vent pipes in the steel slag pile, wherein the vent pipes are vertically positioned in the steel slag pile, and introducing CO into the vent pipes₂Carbonizing gas, introducing gas for 10 min-20 min each time at intervals of 60 hr-72 hr, introducing gas for 2 times, introducing gas for 10 min-20 min each time at intervals of 168 hr, introducing gas for 2 times, and introducing CO₂The gas concentration is 20% +/-3%, and the gas flow rate is 0.5 m/s;

the fifth step: and repeating the steps, paving steel slag layer by layer, and aging the carbonized last layer of steel slag for at least three weeks to obtain aged steel slag.

The thermal-braising steel slag is a process for automatically disintegrating and powdering liquid steel slag under high-temperature, high-humidity and high-pressure environment, so that the steel slag is granulated, which is a common way for treating the steel slag at present.

The following is further optimization or/and improvement of the technical scheme of the invention:

example 2: as an optimization of the above embodiment, in the first step, the steel slag is conveyed by a conveyor belt, and steam is introduced below the conveyor belt.

Example 3: as optimization of the above embodiment, the first step steel slag is introduced with CO while being conveyed by the conveyor belt₂A gas.

Example 4: as the optimization of the above embodiment, in the first step, the feeding port of the natural sand or tuff is arranged in front of the steel slag feeding port, so that the steel slag and the natural sand or tuff are premixed by a conveyor belt, the particle size of the natural sand is less than 4.75mm, and the water content is more than 10%.

Example 5: as the optimization of the above embodiment, in the third step, natural sand is laid on the sprayed steel slag through a conveyor belt, and then spraying is performed again from above.

Example 6: as the optimization of the embodiment, in the first step, the steel slag after iron removal and hot braising is premixed with water and then conveyed by a conveyor belt, and the water temperature is 0-4 ℃.

Example 7: as the optimization of the above embodiment, in the third step, the steel slag with the grain size of less than 1mm is paved on the steel slag in the second step, and the paving thickness is more than 20 mm.

When the method is used for aging steel slag, in case of three seasons of spring, summer and autumn, in order to avoid too fast water vapor evaporation in dry areas, steel slag with the particle size of less than 1mm is used for forming a sealing layer, and a water permeable felt cloth is laid on the upper side of the steel slag with the particle size of less than 1mm, however, in case of winter, areas with lower temperature are easy to freeze after being sprayed, the water permeable felt cloth is not needed to be used for moisture preservation, and the water permeable felt cloth is not easy to be taken down after being frozen, so that the water permeable felt cloth is not arranged in case of aging in winter in example 7.

Example 8: as the optimization of the above embodiment, in the third step, a layer of permeable felt cloth is spread on the surface of the steel slag before spraying.

Example 9: in the first step, the steel slag subjected to the iron removal process and the hot disintegration treatment is divided into three particle size ranges of 4.75mm to 2.36mm, 2.36mm to 1.18mm and less than 1.18mm, and then the subsequent aging treatment is respectively carried out.

Example 10: the multipurpose steel slag aging treatment method is carried out according to the following method:

the method comprises the following steps that firstly, hot stuffy steel slag after hot stuffy treatment in a steel plant is subjected to iron removal process, the steel slag with the screened particle size of 1 mm-10 mm is placed into a special closed conveying device, the closed conveying device is composed of a conveying belt and a heat preservation device, in the closed conveying device, waste heat steam generated by the hot stuffy steel slag is conveyed to the bottom of the steel slag through the conveying belt with holes through a steam pipe with holes, the steam aging and heating effects are achieved, the steel slag needing aging treatment is conveyed into a stockpiling bin by the device, and the steel slag in the bin is flatly paved;

secondly, arranging a heat-insulating cover with a downward opening above the stockpiling bin, wherein an opening is formed in the middle of the heat-insulating cover, and introducing steam from the opening to carry out steam aging treatment on the steel slag in the first step for 2 hours;

and thirdly, paving a layer of permeable felt cloth (geotextile, permeable cloth, cotton felt and other permeable materials) on the surface. Then uniformly spraying water from the upper part of the steel slag for 10 minutes/12 hours, wherein the spraying interval is 1 m/1 m (or the spraying interval is flexibly set according to the size of the spraying, and all areas are uniformly sprayed);

fourthly, uniformly pre-burying vent pipes in the steel slag pile, wherein the vent pipes are vertically positioned in the steel slag pile and are filled with CO₂The gas is introduced at a frequency of 10 min/72 h, after 2 times of aeration, 10 min/168 h is changed, after 2 times of aeration, CO is introduced₂The gas concentration is 20 +/-3%, and the gas flow rate is 0.5 m/s;

fifthly, as the steel slag is piled up layer by layer from the bottom layer, the steel slag can be used for the roadbed and the backfill material by ensuring that the aging time of the uppermost layer of the steel slag reaches 3 weeks, but the aging time of the steel slag aged under the condition is further prolonged when the steel slag is used for steel slag slurry and steel slag concrete, and the aging time of the uppermost layer of the steel slag reaches more than 3 months.

The steel slag obtained in example 10 was subjected to reference standard: the steel slag application technical requirements GB/T32546, the steel slag stability detection method GB 24175, the steel slag for common ready-mixed mortar YB 4201 and the steel slag for engineering backfilling YB/T801 are detected according to the method in the standards, the detection data are shown in Table 1, and as can be seen from Table 1, the steel slag is in the eight steel plant compartments of Wulu wood Qicity, XinjiangWhen aged for more than one year under external natural conditions, the multiple stations show free calcium oxide between 1.5% and 1.9%, and have the following effects: (1) the method has low requirement on the steel slag storage yard, reduces the construction cost and has better steel slag aging effect; (2) waste heat steam generated by hot smoldering steel slag is used as a steam source, so that the aging of the steel slag can be obviously promoted, and the aging cost is increased less; (3) the steel slag is in a high-temperature and humid environment in the whole process from the closed conveying device to the stacking process, and the environment can effectively promote the aging efficiency of the steel slag; (4) CO introduced by pre-buried vent pipe₂The gas can be retained for a long time in the compact closed layer formed by the moisture, so that the carbonization effect of the steel slag is improved, and the aging efficiency of the steel slag is promoted from another angle.

Example 11: the multipurpose steel slag aging treatment method is carried out according to the following method:

the hot stuffy steel slag after the hot stuffy treatment in a steel plant is treated by an iron removal process, the steel slag with the screened particle size of 1mm to 10mm is placed into a special closed conveying device, the closed conveying device consists of a conveying belt and a heat preservation device, in the closed conveying device, waste heat steam generated by the hot stuffy steel slag is conveyed to the bottom of the steel slag through the conveying belt with holes through a steam pipe with holes, the steam aging and heating effects are achieved, the steel slag needing aging treatment is conveyed into a stockpiling bin by the device, and the steel slag in the bin is tiled;

secondly, arranging a heat-insulating cover with a downward opening above the stockpiling bin, wherein an opening is formed in the middle of the heat-insulating cover, and introducing steam from the opening to carry out steam aging treatment on the steel slag in the first step for 2 hours;

thirdly, paving the steel slag with the grain size of less than 1mm on the steel slag with the grain size of more than 1mm in the second step by adopting a closed conveying device, wherein the paving thickness is more than 20 mm;

fourthly, after the vent pipes are pre-buried, a layer of permeable felt cloth (geotextile, permeable cloth, cotton felt and other permeable materials) can be paved on the surface of the material pile. Uniformly spraying water from the upper part of the steel slag for 10 minutes/12 hours, wherein the spraying interval is 1 m/1 m (or the spraying interval is flexibly set according to the spraying size and all areas are uniformly sprayed), when more water is sprayed, the water flows out of the steel slag pile and contains alkali, and the water is introduced into an alkali liquor collecting pool to be repeatedly used for spraying operation;

fifthly, implanting pre-buried vent pipes (with the spacing of 1.5 meters to 1.5 meters) into the steel slag yard, and introducing CO₂Gas was applied at a frequency of 10 minutes/72 hours, followed by 2 passes of aeration, followed by 10 minutes/168 hours, and then cut off after 2 passes of aeration. Introducing CO₂The gas concentration is 20 +/-3%, and the gas flow rate is 0.5 m/s;

and sixthly, because the steel slag is accumulated upwards from the bottom layer by layer, the steel slag can be used for the roadbed and the backfill material by ensuring that the aging time of the uppermost layer of the steel slag reaches 3 weeks, but the aging time of the steel slag aged under the condition is further prolonged when the steel slag is used for steel slag slurry and steel slag concrete, and the aging time of the uppermost layer of the steel slag reaches more than 3 months.

The steel slag obtained in example 11 was subjected to the following reference standard: according to the method in the above standard, the detection data are shown in table 2, and as can be seen from table 2, when the steel slag is aged for more than one year under the outdoor natural condition of eight steel plants in Wulu wood city, Xinjiang, a plurality of measuring points show that the free calcium oxide is between 1.4% and 1.8%, and the steel slag has the following effects: (1) the method has low requirement on the steel slag storage yard, greatly reduces the construction cost and has better steel slag aging effect; (2) waste heat steam generated by hot smoldering steel slag is used as a steam source, so that the aging of the steel slag can be obviously promoted, and the aging cost is increased less; (3) the steel slag is in a high-temperature and humid environment in the whole process from the closed conveying device to the stacking process, and the aging efficiency of the steel slag can be effectively improved in the environment; (4) the compact sealing layer formed by the steel slag with the particle size of less than 1mm can greatly reduce the water evaporation of the steel slag in dry areas such as Xinjiang and the like, improve the water content of the steel slag and ensure that the steel slag with large particle size forms saturated sand which is full of water. The aging of the large-particle-size steel slag is promoted rapidly; (5) CO introduced by pre-buried vent pipe₂The gas can be retained for a long time in the water-forming compact closed layer, and the carbonization effect of the steel slag is improved, thereby promoting from another waySteel slag aging efficiency; (6) the water content and the alkali content in the alkali liquor collecting tank are high, and the alkali liquor collecting tank can be used for spraying water to further promote steel slag with the particle size of less than 1mm to form a compact closed layer, so that the aging efficiency of the steel slag under the high-water condition is improved.

Example 12: the multipurpose steel slag aging treatment method is carried out according to the following method:

firstly, the hot stuffy steel slag after the hot stuffy treatment in a steel plant is treated by an iron removal process, screened steel slag with the particle size of 1mm to 10mm is premixed with outdoor snow water or low-temperature water (0 to 4 ℃) and then placed into a conveying device, the steel slag needing aging treatment is conveyed to a stockpiling bin by the conveying device, and at the moment, steam is not introduced, and the steel slag is tiled;

secondly, arranging a heat-insulating cover with a downward opening above the stockpiling bin, wherein an opening is formed in the middle of the heat-insulating cover, and introducing steam from the opening to carry out steam aging treatment on the steel slag in the first step for 2 hours;

thirdly, paving the steel slag with the particle size of less than 1mm on the steel slag with the particle size of more than 1mm in the second step through a conveying device, wherein the paving thickness is more than 20 mm;

fourthly, spraying water for 10 minutes at one time, wherein the spraying interval is 1 m/1 m (or the spraying is flexibly set according to the size of the spraying, and all areas are uniformly sprayed);

the fifth step: vertically implanting pre-buried vent pipes (with the spacing of 1.5 m to 1.5 m) into a steel slag yard, and vertically implanting waste heat steam and CO₂Introducing gas at 20 min/60 hr, introducing gas 2 times, changing to 20 min/168 hr, stopping introducing CO 2 times₂The gas concentration is 20 +/-3%, and the gas flow rate is 0.5 m/s;

and sixthly, the aging effect of the steel slag treated at low temperature is better than that of the steel slag treated at summer, the aging time of the last layer is 3 weeks, the aging time of the steel slag is further prolonged when the steel slag is used for steel slag slurry and steel slag concrete, and the aging time of the steel slag laid at the uppermost surface of the material pile for the last time is required to be more than 3 months.

The steel slag obtained in example 12 was subjected to the following reference standard: steel slag application technical requirement GB/T32546, steel slag stability detection method GB 24175 and steel slag for ordinary ready-mixed mortar YB 4201 and "steel slag for engineering backfill" YB/T801, the detection is performed according to the method in the above standard, the detection data is shown in Table 3, and as can be seen from Table 3, when the steel slag is aged for more than one year under the natural condition outside the eight steel mill compartment of Wulu wood city, Xinjiang, a plurality of measuring points show that the free calcium oxide is between 1.5% and 1.9%, and the following effects are achieved: (1) by utilizing the climatic characteristics of cold and severe cold regions such as Xinjiang and the like, on one hand, the naturally formed low-temperature snow water is utilized, on the other hand, the high-temperature steam is used, and the natural freeze-thaw cycle of the steel slag is formed by utilizing the natural conditions, so that a better aging effect is formed on large steel slag particles; (2) the spray formed water freezes under the weather effect to enable the spray formed water to act together with a compact closed layer formed by the steel slag, the sealing effect is improved, and therefore the closed space and high-concentration CO are efficiently utilized₂The aging efficiency of the steel slag is improved in a gas environment.

Example 13: the multipurpose steel slag aging treatment method is carried out according to the following method: firstly, carrying out iron removal process treatment on hot stuffy slag after hot stuffy treatment in a steel plant, placing the steel slag with the particle size of less than or equal to 4.75mm after screening into a special closed conveying device, wherein the closed conveying device consists of a conveying belt and a heat preservation device, conveying waste heat steam generated by the hot stuffy slag into the bottom of the steel slag through a steam pipe with holes in the closed conveying device through the conveying belt with holes to play a role in steam aging and heating, conveying the steel slag needing aging treatment into a stockpiling bin by the device, and flatly paving the steel slag in the bin;

secondly, arranging a heat-insulating cover with a downward opening above the stockpiling bin, wherein an opening is formed in the middle of the heat-insulating cover, and introducing steam from the opening to carry out steam aging treatment on the steel slag in the first step for 2 hours;

thirdly, spraying water for 10 minutes, wherein the spraying interval is 1 meter by 1 meter (or the spraying interval is flexibly set according to the size of the spraying, and all areas are uniformly sprayed);

fourthly, conveying natural sand with the particle size of less than or equal to 4.75mm through a conveyor belt, paving the natural sand on the upper layer of the steel slag, and spraying water for 10 minutes at the spraying interval of 1 m/1 m (or flexibly setting according to the size of the spraying and uniformly spraying all areas);

fifthly, pre-burying vent pipes (intervals)1.5 m by 1.5 m) is vertically implanted into a steel slag yard and is filled with CO₂Gas, frequency 10 minutes/72 hours, 2 times aeration; then 10 minutes/168 hours, after 2 aeration cuts off, CO is introduced₂The gas concentration is 20 +/-3%, and the gas flow rate is 0.5 m/s;

and sixthly, because the steel slag is accumulated upwards from the bottom layer by layer, the steel slag can be used for the roadbed and the backfill material by ensuring that the aging time of the uppermost layer of the steel slag reaches 3 weeks, but the aging time of the steel slag aged under the condition is further prolonged when the steel slag is used for steel slag slurry and steel slag concrete, and the aging time of the uppermost layer of the steel slag reaches more than 3 months.

The steel slag obtained in example 13 was subjected to reference standard: in the methods of the above standards, the detection parameters are shown in tables 4 to 7, the detection results are shown in table 8, and it can be seen from table 8 that when the steel slag is aged for more than one year under the natural conditions outside the eight steel plant compartments of Wulu wood, Xinjiang city, a plurality of measurement points show that the free calcium oxide is between 1.5% and 1.9%, and the steel slag has the following effects: (1) by adopting the mixing scheme, on one hand, the aim of premixing is achieved, on the other hand, the steel slag aging efficiency is further improved through premixing, the steam pulverization rate and the water immersion expansion rate are reduced, the method changes the steel slag mixing mode, reduces the mixing flow, improves the mixing efficiency, reduces the mixing links, effectively controls the investment of mixing fields and equipment, reduces the mixing cost, and improves the market competitiveness of the steel slag mixed sand; (2) the natural sand is laid in layers, so that on one hand, the mixing proportion can be preset according to market needs, on the other hand, the aging efficiency of the steel slag is improved by laying in layers, and meanwhile, the grading curve of the steel slag mixed sand is optimized, and the fineness of the steel slag mixed sand is reduced; (3) the whole process from the closed conveying device to the stockpiling is carried out at high temperature, humidity and high concentration CO₂Under the gas environment, the environment can effectively promote the aging efficiency of the steel slag; (4) CO introduced by pre-buried vent pipe₂Gas, and the wet steel slag and the natural sand surface are subjected to carbonization reaction, and then the gas is extractedThe carbonization effect of the steel slag is high, thereby promoting the aging efficiency of the steel slag.

Example 14: the multipurpose steel slag aging treatment method is carried out according to the following method:

the first step is that the steel slag after being processed by the iron removal process in the hot disintegrating steel slag of the iron and steel plant is premixed with natural sand through a conveyor belt, and a natural sand feed opening is arranged in front of a steel slag feed opening, conveyed to a storage bin and then tiled.

Secondly, arranging a heat-insulating cover with a downward opening above the stockpiling bin, wherein an opening is formed in the middle of the heat-insulating cover, and introducing steam from the opening to carry out steam aging treatment on the steel slag in the first step for 2 hours;

thirdly, spraying water for 10 minutes, wherein the spraying interval is 1 meter by 1 meter (or the spraying interval is flexibly set according to the size of the spraying, and all areas are uniformly sprayed);

fourthly, implanting pre-buried vent pipes (with the spacing of 1.5 meters to 1.5 meters) into the steel slag mixed sand storage yard, and introducing CO₂Gas, frequency 10 minutes/72 hours, 2 times aeration; then 10 minutes/168 hours, after 2 aeration cuts off, CO is introduced₂The gas concentration is 20 +/-3%, and the gas flow rate is 0.5 m/s;

fifthly, as the steel slag is piled up layer by layer from the bottom layer, the steel slag can be used for the roadbed and the backfill material by ensuring that the aging time of the uppermost layer of the steel slag reaches 3 weeks, but the aging time of the steel slag aged under the condition is further prolonged when the steel slag is used for steel slag slurry and steel slag concrete, and the aging time of the uppermost layer of the steel slag reaches more than 3 months.

The steel slag obtained in example 14 was subjected to the following reference standard: according to the method in the above standard, the detection is carried out according to the methods in the 'steel slag application technical requirement' GB/T32546 'GB 24175' steel slag for ordinary ready-mixed mortar 'YB 4201' and 'steel slag for engineering backfill' YB/T801. the detection parameters are shown in tables 9 to 10, the detection results are shown in table 11, and as can be seen from table 11, when the steel slag is aged for more than one year under the natural condition outside the eight steel plant compartments in Wulu wood City, Xinjiang, a plurality of measuring points show that the free calcium oxide is between 1.5% and 1.9%, and the following effects are achieved: on the basis of embodiment 12, the premixing effect is more outstanding, and the premixing uniformity is greatly improved, has avoided the local caking phenomenon that probably appears in the slag mixing process, has improved the degree of consistency to can be from the customization slag sand (slag mass ratio customization, the slag sand that mixes of different fineness satisfies multiple demands in market), this premixing mode has reduced the cost that slag sand mixes in advance by a wide margin, has further promoted the market competitiveness of slag sand.

Example 15: the multipurpose steel slag aging treatment method, referring to example 14, replaces natural sand with tuff. The steel slag obtained in example 15 was subjected to the following reference standard: in the 'test method standard of ordinary concrete long-term performance and durability' GB/T5008 'alkali-aggregate test (concrete prism test method)', the expansion rates of test pieces before and after treatment of steel slag mixed sand are respectively subjected to activity detection, the stability of tuff (the active ingredient is mainly microcrystalline quartz) fine aggregate and steel slag (before and after aging) in Wuluqiqi area is detected, the inactive coarse aggregate is granite, and the inactive fine aggregate is standard sand. After the concrete test piece is manufactured, the reference length and the lengths of 1w (week, the same below), 2w, 4w, 8w, 13w, 18w, 26w, 39w and 52w of age of the concrete test piece are measured respectively, the free expansion rate of the concrete test piece in different ages is calculated, the specific test scheme is shown in table 12, table 13 and attached drawing 1, the specification of the standard GB/T5008 of the test method for the long-term performance and the durability of common concrete is provided, and if the expansion rate of 52w of the concrete test piece is less than 0.04%, the aggregate is judged to be non-reactive aggregate. If the expansion rate of the concrete sample 52w is not less than 0.04%, the aggregate is judged to be a reactive aggregate having a potentially harmful reaction, and as can be seen from table 12, table 13 and fig. 1, the concrete samples all exhibit volume expansion with the age. The expansion rate of tuff 52w reaches 0.129%, the expansion rate of 52w before the treatment of the steel slag mixed sand reaches 0.049%, the expansion rate of 52w after the treatment of the steel slag mixed sand reaches 0.028%, and the expansion rate of 52w (50%) of tuff reaches 0.066%. The results show that: after the steel slag mixed sand is treated, the adverse effect of the steel slag can be eliminated, and the adverse effect of tuff can also be eliminated.

Example 16: the multipurpose steel slag aging treatment method refers to the embodiment10, introducing CO while introducing steam under the first-step conveyor belt₂A gas.

The steel slag obtained in example 16 was subjected to the following standard: in the methods of the above standards, the test data are shown in table 14 and table 14 shows that the method can promote CO to be detected by the methods of the above standards, namely, the technical requirements for steel slag application GB/T32546, the method for detecting steel slag stability GB 24175, the steel slag for ordinary ready-mixed mortar YB 4201 and the steel slag for engineering backfill YB/T801₂The reaction speed of gas and water on the surface of the steel slag improves the precipitation of soluble calcium ions. High temperature steam induced reaction rate of free calcium oxide and free magnesium oxide, CO₂The gas promotes the precipitation of calcium and magnesium ions in the solution, and promotes the degree of reaction of free calcium oxide and free magnesium oxide with water. Thus macroscopically appearing as a rapid elimination of free calcium oxide.

Example 17: the multipurpose steel slag aging treatment method is carried out according to the following method:

the first step, the hot disintegrating steel slag after the hot disintegrating treatment in the steel plant is treated by an iron removing process and is divided into three particle size grades: the device comprises a closed conveying device, a storage bin and a storage bin, wherein the closed conveying device is composed of a conveying belt and a heat preservation device, waste heat steam generated by hot stuffy steel slag is conveyed to the bottom of the steel slag through a steam pipe with holes in the closed conveying device to play a role in steam aging and heating, the steel slag needing aging treatment is conveyed into the storage bin by the device, and the steel slag in the storage bin is flatly paved;

secondly, arranging a heat-insulating cover with a downward opening above the stockpiling bin, wherein an opening is formed in the middle of the heat-insulating cover, and introducing steam from the opening to carry out steam aging treatment on the steel slag in the first step for 2 hours;

and thirdly, spraying water for 10 minutes at one time, wherein the spraying interval is 1m by 1m (or the spraying interval is flexibly set according to the spraying size, and all areas are uniformly sprayed).

Fourthly, uniformly pre-burying vent pipes in the steel slag pile, wherein the vent pipes are vertically positioned in the steel slag pile and use the waste heat steam and CO₂The gas is introduced at a frequency of 20 minutes/60 hours, and after 2 times of gas introduction, the gas flow is changed to 20 minutes/168 hoursAt time, it was cut off after 2 ventilations. Introducing CO₂The gas concentration is 20 +/-3%, and the gas flow rate is 0.5 m/s;

fifthly, because the steel slag is piled up layer by layer from the bottom layer upwards, the aging time of the steel slag on the uppermost layer is ensured to reach 3 weeks, and the steel slag with the thickness of less than 1.18mm can be used for plastering mortar and mixed with other natural sand; 1.18 to 2.36mm of steel slag can be used for masonry mortar and mixed with other natural sand for use after being aged for 1 month; the steel slag with the thickness of 2.36-4.75 mm can be mixed with other natural sand for use after being aged for 3 months, and the steel slag can be used for preparing masonry mortar, backfilling and the like.

The steel slag obtained in example 17 was subjected to reference standard: the steel slag application technical requirements GB/T32546, the steel slag stability detection method GB 24175, the steel slag for ordinary premixed mortar YB 4201 and the steel slag for engineering backfill YB/T801 are detected by referring to the methods in the standards, (1) the full-grain-size aged steel grit processed by the method of the embodiment 16 is mixed with cement, water, natural stone and natural sand, specific concrete proportioning parameters are shown in a table 15, the steel slag mixing amount represents the percentage of the content of the mixed steel slag relative to the content of the natural sand when the steel slag is not initially added, and the change rate of the volume of the concrete of the full-grain-size proportioning steel slag is shown in a table 2; (2) in order to further refine and analyze the concrete characteristics and forms of the influence of the steel slag on the concrete, the steel slag is divided into 6 types according to the particle size, as shown in table 16, the steel slag with different particle sizes is mixed with the concrete, wherein the content of the steel slag accounts for 50% of the content of the natural sand when the steel slag is not added at first, the water-cement ratio is 0.42, the sand rate is 40% (the sum of the mass of the natural sand and the steel slag accounts for the sum of the mass of the natural sand, the steel slag and the natural stone), the LJZ is a reference mixture ratio, the steel slag is not added, the mixture ratio is shown in table 17, the influence of the steel slag with different particle sizes on the volume and the surface appearance of the concrete in the 156w age period is analyzed, and the influence result of the steel slag with different particle sizes on the volume of the concrete is shown in fig. 3; the comparative analysis of fig. 2 and 3 shows that the full-grain steel slag can cause the volume expansion of the concrete, and the single-grain steel slag can cause the volume contraction of the concrete. According to the characteristics, the steel slag is classified, screened and utilized in a classified manner, so that the steel slag can be utilized to the maximum extent, the comprehensive aging time is reduced, the application modes and the aging time of the steel slag in different fields are determined, the turnover rate of a natural aging stockyard is greatly improved, and the application safety of the steel slag in the fields of concrete and mortar is improved.

The above technical features constitute the best embodiment of the present invention, which has strong adaptability and best implementation effect, and unnecessary technical features can be increased or decreased according to actual needs to meet the requirements of different situations.