CN112642580B - A disposal method for cascade utilization of steel slag - Google Patents

Abstract

The application relates to the technical field of steel slag utilization, in particular to a disposal method for gradient utilization of steel slag, which solves the problems that in the prior art, the steel slag is treated by hot disintegrating, cooling and decomposing, then waste steel and magnetic separation powder with larger grain size are selected, a steel slag treatment system has low metal recovery rate, unsatisfactory crushing effect, higher energy consumption and short service life of wear-resistant devices, and more and less grinding can not be realized, and iron fine particles, iron fine powder, tailings, tail mud and other products are obtained by treating the steel slag through technologies such as crushing, magnetic separation, screening, wet grinding and the like, and the iron fine particles and the iron fine powder can be directly taken out. The secondary crushing process is designed to fully crush the steel slag, reduce the average grain diameter of the steel slag, reduce the loss of wear-resistant devices of the ball mill, fully realize more crushing and less grinding, and reduce the energy consumption; the magnetic separation processes are matched with each other for multiple times, so that the recovery rate of metal resources is improved, and the problems of low grinding efficiency and high cost of the existing steel slag are solved.

Description

A disposal method for cascade utilization of steel slag

Technical field

The present invention relates to the technical field of steel slag utilization, and in particular to a disposal method for step utilization of steel slag.

Background technique

Steel slag is composed of various oxides formed by the oxidation of silicon, manganese, phosphorus, sulfur and other impurities in pig iron during the smelting process and salts reacting with solvents. Steel slag contains a variety of useful components: metallic iron 2% to 8%, calcium oxide 40% to 60%, magnesium oxide 3% to 10%, manganese oxide 1% to 8%, so it can be used as steel metallurgical raw materials.

Patent CN 110586297A discloses a steel slag treatment method and a steel slag treatment production line. The steel slag is secondary crushed using a jaw crusher and a vertical crusher to effectively separate large-grained iron particles or iron blocks, and a double-layer screening machine is used for crushing. Screen and separate the mixture of ash slag and iron particles with a particle size of ≤5mm and >1mm in the steel slag, reduce the load of the magnetic drum iron separator, effectively improve the magnetic separation efficiency of the magnetic drum iron separator, thereby effectively improving the iron particles, iron The recovery rate of metal substances such as blocks.

Patent CN 109092844A discloses a multi-stage steel slag treatment method, including the crushing, screening and magnetic separation of steel slag circulation, and finally obtains tailings with TFe>60% iron powder and MFe<1%. Tailings powder can be used as a substitute for sand and gravel aggregate as roadbed cushion, water stabilizing layer, etc., as a raw material for commercial concrete and mortar; or as an auxiliary material to make pellets, or as a mixture of scrap steel briquettes. The metal recovery rate is more than 99%, truly achieving zero emissions.

Patent CN 111036370A discloses a production method of multi-specification steel slag aggregate. The raw steel slag is recycled through a steel slag aggregate space screening and crushing system to simultaneously obtain multi-specification steel slag aggregate; the steel slag aggregate space screening and crushing The system at least includes a device cover, crushing equipment and a screening device. The steel slag aggregate space screening and crushing system in this application uses a reasonable arrangement to reduce the area occupied by the production line and at the same time reduce production dust during the production process. It is a Environmentally friendly, safe and efficient and intensive production model.

Similar to the above patents, the domestic treatment of steel slag usually involves heating, cooling, and decomposing to select scrap steel with larger particle sizes and magnetic separation powder. Due to technical bottlenecks, the steel slag treatment system has low metal recovery rates and unsatisfactory crushing effects. Problems such as high consumption and short life of wear-resistant components cannot achieve "more crushing and less wear".

Therefore, we propose a disposal method of steel slag cascade utilization to solve the above problems.

Contents of the invention

The purpose of the present invention is to propose a disposal method for step utilization of steel slag in order to solve the shortcomings existing in the prior art.

In order to achieve the above objects, the present invention adopts the following technical solutions:

The invention proposes a disposal method for step utilization of steel slag, which includes the following steps:

S1 pre-crushing: Use the jaw crusher to pre-crushed the steel slag to a particle size of 0 to 40 mm, and then crush the pre-crushed steel slag for a second time to a particle size of 0 to 5 mm;

S2 magnetic separation: Screen the secondary crushed steel slag again. The steel slag with a particle size less than 5mm is sent to the strong magnetic machine equipment, and the iron fine particles with Mfe>60% are selected and stacked on the ground. The steel slag with a particle size greater than 5mm is returned to the raw material warehouse to continue. Perform secondary crushing to form a closed loop;

S3 wet grinding: After the magnetic separation, the remaining steel slag is added to the water in the clear pool, mixed and evenly transported to the wet ball mill, and the parameters of the ball mill are adjusted so that the discharged particle size meets ≤1mm;

S4 wet magnetic separation: The ball mill discharge is transported to the permanent magnet drum magnetic separator for wet magnetic separation to select the refined iron slurry. After dehydration by the dehydration device, the refined iron powder product is obtained. The residue is also precipitated and filtered to obtain the final product. slag;

S5 sedimentation filter press: The residual slurry after magnetic separation is screened to obtain tailings slurry and ore liquid under the screen. The tailings slurry is transported to the sedimentation tank for precipitation and filtered to obtain tailings;

S6 cake making: The ore liquid and tailings under the screen are drained from the filter press to the sedimentation tank. The tailings slurry undergoes sedimentation, filtered water and filtered tailings mud. The filtered water is collected into the clean water tank through sedimentation. The precipitated mud The slurry pump is used to input the sludge into the filter press to form a mud cake that is stored on the floor.

Preferably, in the S2, the iron fine particles with Mfe>60% are selected to be 5mm or less, and Mfe is metallic iron.

Preferably, in S1, the secondary crushing crusher is a vertical crusher, the frequency is 25HZ, and the processing capacity is 5t/h.

Preferably, in S2, the strong magnetic machine equipment is a magnetic drum iron separator, and the magnetic field intensity is 6000-8000GS.

Preferably, in S6, the upper clear water in the sedimentation tank can be used for wet ball milling to achieve water resource recycling.

Preferably, it also includes S11: Add potassium sodium tartrate to the steel slag after secondary crushing, and continue to stir and mix it. The stirring time is 5 to 10 minutes.

Preferably, the mass ratio of the steel slag to potassium sodium tartrate is 100: (0.01～0.03).

Preferably, the particle size of the obtained fine iron particles is 0-5 mm, the particle size of the fine iron powder is 0-1 mm, and the particle size of the tailings is 0-1 mm.

Preferably, the particle size of the obtained fine iron particles is 3 mm, the particle size of the fine iron powder is 0.5 mm, and the particle size of the tailings is 0.5 mm.

Compared with the prior art, the beneficial effects of the present invention are:

1. The present invention pretreats the steel slag through two crushing processes, controls the particle size of the steel slag entering the wet ball mill tank to be within the range of 0 to 5 mm, reduces the steel slag grinding test piece in the ball mill, protects the wear-resistant components of the ball mill, and increases the use Long service life, achieving "more crushing and less grinding" and reducing energy consumption.

2. The waste slag after magnetic separation in the present invention is evenly mixed with water and then transported to a wet ball mill. The wet ball mill can effectively select steel slag with an iron content of less than 40%. At the same time, the wet ball mill can avoid the reduction in the size of the steel slag. Dust pollution, effectively ensuring the cleanness and safety of the production environment.

3. The tailings slurry of the present invention undergoes sedimentation, filtered water and filtered water obtained from the filtered tail mud and flows into the clear water tank through sedimentation. It can be used for wet ball milling to form a second closed loop, realize the recycling of water resources, and avoid sewage discharge.

4. The present invention rationally arranges each process device to process steel slag to obtain refined iron granules, refined iron powder, tailings and tailing sludge. The refined iron granules and refined iron powder can be directly exported to the steel plant and returned to the furnace for remelting to achieve economic value. The tailings slag Hewei mud can be used as a building material in the construction field, greatly reducing project construction costs.

In summary, the present invention crushes steel slag twice, reduces the particle size of steel slag, effectively reduces the equipment pressure of the ball mill, protects wear-resistant components, increases service life, fully embodies "more crushing and less grinding", and effectively reduces the energy consumption of the production system. At the same time, the use of wet ball mill can avoid dust pollution caused by the reduction of steel slag size, and effectively ensure the cleanness and safety of the production environment. The processed products obtained through screening include refined iron granules, refined iron powder, tailings and tailing mud, refined iron granules and refined iron powder. It can be directly exported and remelted. The tailings and tailing mud can be used as building materials in the construction field, which can effectively reduce project construction costs and achieve green environmental protection.

Description of the drawings

Figure 1 is a flow chart of a steel slag step utilization disposal method proposed by the present invention.

Detailed ways

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In the event of conflict, the definitions in this specification shall prevail. "When mass, concentration, temperature, time, or other value or parameter is expressed in terms of a range, a preferred range, or a range defined by a series of upper preferred values and lower preferred values, this shall be understood to specifically disclose that any upper range or preferred range is defined by All ranges formed by any pairing of a value with any lower range limit or preferred value, regardless of whether the range is separately disclosed. For example, a range of 1-50 should be understood to include a range selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or any number, or subdivision of 50 ranges, and all decimal values between the above integers, for example, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, and 1.9. Regarding subranges, consider specifically those extending from any endpoint within the range "Nested subranges." For example, a nested subrange of the exemplary range 1-50 may include 1-10, 1-20, 1-30, and 1-40 in one direction, or 50 in the other direction -40, 50-30, 50-20 and 50-10.”

The present invention will be further explained below with reference to specific examples. In the following examples, various processes and methods not described in detail are conventional methods well known in the art. The materials, reagents, devices, instruments, equipment, etc. used in the following examples can all be obtained from commercial sources unless otherwise specified.

Embodiment 1

The invention proposes a disposal method for step utilization of steel slag, which includes the following steps:

S1 pre-crushing: Use the jaw crusher to pre-crushes the steel slag to a particle size of 5mm, and then crush the pre-crushed steel slag for a second time to a particle size of 1mm;

S11: Add potassium sodium tartrate to the secondary crushed steel slag, continue to stir and mix it, the stirring time is 5 minutes, the mass ratio of steel slag to potassium sodium tartrate is 100:0.01;

S2 magnetic separation: Screen the secondary crushed steel slag again. The steel slag with a particle size less than 5mm is sent to the strong magnetic machine equipment, and the iron fine particles with Mfe>60% are selected and stacked on the ground. The steel slag with a particle size greater than 5mm is returned to the raw material warehouse to continue. Perform secondary crushing to form a closed loop;

S3 wet grinding: After the magnetic separation, the remaining steel slag is added to the water in the clear pool, mixed and evenly transported to the wet ball mill, and the parameters of the ball mill are adjusted so that the discharged particle size meets ≤1mm;

S4 wet magnetic separation: The ball mill discharge is transported to the permanent magnet drum magnetic separator for wet magnetic separation to select the refined iron slurry. After dehydration by the dehydration device, the refined iron powder product is obtained. The residue is also precipitated and filtered to obtain the final product. slag;

S5 sedimentation filter press: The residual slurry after magnetic separation is screened to obtain tailings slurry and ore liquid under the screen. The tailings slurry is transported to the sedimentation tank for precipitation and filtered to obtain tailings;

S6 cake making: The ore liquid and tailings under the screen are drained from the filter press to the sedimentation tank. The tailings slurry undergoes sedimentation, filtered water and filtered tailings mud. The filtered water is collected into the clean water tank through sedimentation. The precipitated mud The slurry pump is used to input the sludge into the filter press to form a mud cake that is stored on the floor.

Among them, in S2, the iron fine particles with Mfe>60% are selected to be less than 5mm, and Mfe is metallic iron. In S1, the secondary crushing crusher is a vertical crusher, the frequency is 25HZ, and the processing capacity is 5t/h. , In S2, the strong magnetic machine equipment is a magnetic drum iron separator with a magnetic field strength of 6000GS. In S6, the upper clear water in the sedimentation tank can be used for wet ball milling to achieve water resource recycling.

In addition, the particle diameter of the obtained refined iron particles was 1 mm, the particle diameter of the refined iron powder was 0.2 mm, and the particle diameter of the tailings was 0.2 mm.

Embodiment 2

The invention proposes a disposal method for step utilization of steel slag, which includes the following steps:

S1 pre-crushing: Use the jaw crusher to pre-crushed the steel slag to a particle size of 10mm, and then crush the pre-crushed steel slag for a second time to a particle size of 3mm;

S11: Add potassium sodium tartrate to the secondary crushed steel slag, continue to stir and mix it, the stirring time is 7 minutes, the mass ratio of steel slag to potassium sodium tartrate is 100:0.02;

S2 magnetic separation: Screen the secondary crushed steel slag again. The steel slag with a particle size less than 5mm is sent to the strong magnetic machine equipment, and the iron fine particles with Mfe>60% are selected and stacked on the ground. The steel slag with a particle size greater than 5mm is returned to the raw material warehouse to continue. Perform secondary crushing to form a closed loop;

S3 wet grinding: After the magnetic separation, the remaining steel slag is added to the water in the clear pool, mixed and evenly transported to the wet ball mill, and the parameters of the ball mill are adjusted so that the discharged particle size meets ≤1mm;

S4 wet magnetic separation: The ball mill discharge is transported to the permanent magnet drum magnetic separator for wet magnetic separation to select the refined iron slurry. After dehydration by the dehydration device, the refined iron powder product is obtained. The residue is also precipitated and filtered to obtain the final product. slag;

S5 sedimentation filter press: The residual slurry after magnetic separation is screened to obtain tailings slurry and ore liquid under the screen. The tailings slurry is transported to the sedimentation tank for precipitation and filtered to obtain tailings;

S6 cake making: The ore liquid and tailings under the screen are drained from the filter press to the sedimentation tank. The tailings slurry undergoes sedimentation, filtered water and filtered tailings mud. The filtered water is collected into the clean water tank through sedimentation. The precipitated mud The slurry pump is used to input the sludge into the filter press to form a mud cake that is stored on the floor.

Among them, in S2, the iron fine particles with Mfe>60% are selected to be less than 5mm, and Mfe is metallic iron. In S1, the secondary crushing crusher is a vertical crusher, the frequency is 25HZ, and the processing capacity is 5t/h. , In S2, the strong magnetic machine equipment is a magnetic drum iron separator with a magnetic field strength of 6500GS. In S6, the upper clear water in the sedimentation tank can be used for wet ball milling to achieve water resource recycling.

In addition, the particle diameter of the obtained refined iron particles was 3 mm, the particle diameter of the refined iron powder was 0.4 mm, and the particle diameter of the tailings was 0.4 mm.

Embodiment 3

The invention proposes a disposal method for step utilization of steel slag, which includes the following steps:

S1 pre-crushing: Use the jaw crusher to pre-crushes the steel slag to a particle size of 30mm, and then crush the pre-crushed steel slag for a second time to a particle size of 4mm;

S11: Add potassium sodium tartrate to the secondary crushed steel slag, continue to stir and mix it, the stirring time is 9 minutes, the mass ratio of steel slag to potassium sodium tartrate is 100:0.02;

S2 magnetic separation: Screen the secondary crushed steel slag again. The steel slag with a particle size less than 5mm is sent to the strong magnetic machine equipment, and the iron fine particles with Mfe>60% are selected and stacked on the ground. The steel slag with a particle size greater than 5mm is returned to the raw material warehouse to continue. Perform secondary crushing to form a closed loop;

S3 wet grinding: After the magnetic separation, the remaining steel slag is added to the water in the clear pool, mixed and evenly transported to the wet ball mill, and the parameters of the ball mill are adjusted so that the discharged particle size meets ≤1mm;

S4 wet magnetic separation: The ball mill discharge is transported to the permanent magnet drum magnetic separator for wet magnetic separation to select the refined iron slurry. After dehydration by the dehydration device, the refined iron powder product is obtained. The residue is also precipitated and filtered to obtain the final product. slag;

S5 sedimentation filter press: The residual slurry after magnetic separation is screened to obtain tailings slurry and ore liquid under the screen. The tailings slurry is transported to the sedimentation tank for precipitation and filtered to obtain tailings;

S6 cake making: The ore liquid and tailings under the screen are drained from the filter press to the sedimentation tank. The tailings slurry undergoes sedimentation, filtered water and filtered tailings mud. The filtered water is collected into the clean water tank through sedimentation. The precipitated mud The slurry pump is used to input the sludge into the filter press to form a mud cake that is stored on the floor.

Among them, in S2, the iron fine particles with Mfe>60% are selected to be less than 5mm, and Mfe is metallic iron. In S1, the secondary crushing crusher is a vertical crusher, the frequency is 25HZ, and the processing capacity is 5t/h. , In S2, the strong magnetic machine equipment is a magnetic drum iron separator with a magnetic field strength of 7000GS. In S6, the upper clear water in the sedimentation tank can be used for wet ball milling to achieve water resource recycling.

In addition, the particle diameter of the obtained refined iron particles was 4 mm, the particle diameter of the refined iron powder was 0.8 mm, and the particle diameter of the tailings was 0.8 mm.

Embodiment 4

The invention proposes a disposal method for step utilization of steel slag, which includes the following steps:

S1 pre-crushing: Use the jaw crusher to pre-crushed steel slag to a particle size of 40mm, and then crush the pre-crushed steel slag for a second time to a particle size of 5mm;

S11: Add potassium sodium tartrate to the secondary crushed steel slag, continue to stir and mix it, the stirring time is 10 minutes, the mass ratio of steel slag to potassium sodium tartrate is 100:0.03;

S2 magnetic separation: Screen the secondary crushed steel slag again. The steel slag with a particle size less than 5mm is sent to the strong magnetic machine equipment, and the iron fine particles with Mfe>60% are selected and stacked on the ground. The steel slag with a particle size greater than 5mm is returned to the raw material warehouse to continue. Perform secondary crushing to form a closed loop;

S3 wet grinding: After the magnetic separation, the remaining steel slag is added to the water in the clear pool, mixed and evenly transported to the wet ball mill, and the parameters of the ball mill are adjusted so that the discharged particle size meets ≤1mm;

S4 wet magnetic separation: The ball mill discharge is transported to the permanent magnet drum magnetic separator for wet magnetic separation to select the refined iron slurry. After dehydration by the dehydration device, the refined iron powder product is obtained. The residue is also precipitated and filtered to obtain the final product. slag;

S5 sedimentation filter press: The residual slurry after magnetic separation is screened to obtain tailings slurry and ore liquid under the screen. The tailings slurry is transported to the sedimentation tank for precipitation and filtered to obtain tailings;

S6 cake making: The ore liquid and tailings under the screen are drained from the filter press to the sedimentation tank. The tailings slurry undergoes sedimentation, filtered water and filtered tailings mud. The filtered water is collected into the clean water tank through sedimentation. The precipitated mud The slurry pump is used to input the sludge into the filter press to form a mud cake that is stored on the floor.

Among them, in S2, the iron fine particles with Mfe>60% are selected to be less than 5mm, and Mfe is metallic iron. In S1, the secondary crushing crusher is a vertical crusher, the frequency is 25HZ, and the processing capacity is 5t/h. , In S2, the strong magnetic machine equipment is a magnetic drum iron separator with a magnetic field strength of 8000GS. In S6, the upper clear water in the sedimentation tank can be used for wet ball milling to achieve water resource recycling.

In addition, the particle diameter of the obtained refined iron particles was 5 mm, the particle diameter of the refined iron powder was 1 mm, and the particle diameter of the tailings was 1 mm.

Comparative Example 1

A steel slag disposal method includes the following steps:

S1 pre-crushing: Use the jaw crusher to pre-crushed steel slag to a particle size of 40mm, and then crush the pre-crushed steel slag for a second time to a particle size of 5mm;

S2 magnetic separation: Screen the secondary crushed steel slag again. The steel slag with a particle size less than 5mm is sent to the strong magnetic machine equipment, and the iron fine particles with Mfe>60% are selected and stacked on the ground. The steel slag with a particle size greater than 5mm is returned to the raw material warehouse to continue. Perform secondary crushing to form a closed loop;

S3 wet grinding: After the magnetic separation, the remaining steel slag is added to the water in the clear pool, mixed and evenly transported to the wet ball mill, and the parameters of the ball mill are adjusted so that the discharged particle size meets ≤1mm;

S4 wet magnetic separation: The ball mill discharge is transported to the permanent magnet drum magnetic separator for wet magnetic separation to select the refined iron slurry. After dehydration by the dehydration device, the refined iron powder product is obtained. The residue is also precipitated and filtered to obtain the final product. slag;

S5 sedimentation filter press: The residual slurry after magnetic separation is screened to obtain tailings slurry and ore liquid under the screen. The tailings slurry is transported to the sedimentation tank for precipitation and filtered to obtain tailings;

S6 cake making: The ore liquid and tailings under the screen are drained from the filter press to the sedimentation tank. The tailings slurry undergoes sedimentation, filtered water and filtered tailings mud. The filtered water is collected into the clean water tank through sedimentation. The precipitated mud The slurry pump is used to input the sludge into the filter press to form a mud cake that is stored on the floor.

Among them, in S2, the iron fine particles with Mfe>60% are selected to be less than 5mm, and Mfe is metallic iron. In S1, the secondary crushing crusher is a vertical crusher, the frequency is 25HZ, and the processing capacity is 5t/h. , In S2, the strong magnetic machine equipment is a magnetic drum iron separator with a magnetic field strength of 8000GS. In S6, the upper clear water in the sedimentation tank can be used for wet ball milling to achieve water resource recycling.

In addition, the particle diameter of the obtained refined iron particles was 5 mm, the particle diameter of the refined iron powder was 1 mm, and the particle diameter of the tailings was 1 mm.

Comparative Example 2

A steel slag disposal method includes the following steps:

S1 pre-crushing: Use the jaw crusher to pre-crushed steel slag to a particle size of 40mm, and then crush the pre-crushed steel slag for a second time to a particle size of 5mm;

S11: Add potassium sodium tartrate to the secondary crushed steel slag, continue to stir and mix it, the stirring time is 10 minutes, the mass ratio of steel slag to potassium sodium tartrate is 100:0.03;

S2 magnetic separation: Screen the secondary crushed steel slag again. Steel slag with a particle size less than 5mm is sent to the strong magnetic machine equipment, and the iron fine particles with Mfe>60% are selected and stacked on the ground;

S3 wet grinding: After the magnetic separation, the remaining steel slag is added to the water in the clear pool, mixed and evenly transported to the wet ball mill, and the parameters of the ball mill are adjusted so that the discharged particle size meets ≤1mm;

S4 wet magnetic separation: The ball mill discharge is transported to the permanent magnet drum magnetic separator for wet magnetic separation to select the refined iron slurry. After dehydration by the dehydration device, the refined iron powder product is obtained. The residue is also precipitated and filtered to obtain the final product. slag;

S5 sedimentation filter press: The residual slurry after magnetic separation is screened to obtain tailings slurry and ore liquid under the screen. The tailings slurry is transported to the sedimentation tank for precipitation and filtered to obtain tailings;

S6 cake making: The ore liquid and tailings under the screen are drained from the filter press to the sedimentation tank. The tailings slurry undergoes sedimentation, filtered water and filtered tailings mud. The filtered water is collected into the clean water tank through sedimentation. The precipitated mud The slurry pump is used to input the sludge into the filter press to form a mud cake that is stored on the ground.

Among them, in S2, the iron fine particles with Mfe>60% are selected to be less than 5mm, and Mfe is metallic iron. In S1, the secondary crushing crusher is a vertical crusher, the frequency is 25HZ, and the processing capacity is 5t/h. , In S2, the strong magnetic machine equipment is a magnetic drum iron separator with a magnetic field strength of 8000GS. In S6, the upper clear water in the sedimentation tank can be used for wet ball milling to achieve water resource recycling.

In addition, the particle diameter of the obtained refined iron particles was 5 mm, the particle diameter of the refined iron powder was 1 mm, and the particle diameter of the tailings was 1 mm.

Comparative Example 3

A steel slag disposal method includes the following steps:

S1 pre-crushing: Use the jaw crusher to pre-crushed steel slag to a particle size of 40mm, and then crush the pre-crushed steel slag for a second time to a particle size of 5mm;

S11: Add potassium sodium tartrate to the secondary crushed steel slag, continue to stir and mix it, the stirring time is 10 minutes, the mass ratio of steel slag to potassium sodium tartrate is 100:0.03;

S2 magnetic separation: Screen the secondary crushed steel slag again. The steel slag with a particle size less than 5mm is sent to the strong magnetic machine equipment, and the iron fine particles with Mfe>60% are selected and stacked on the ground. The steel slag with a particle size greater than 5mm is returned to the raw material warehouse to continue. Perform secondary crushing to form a closed loop;

S3 wet grinding: Add water to the remaining steel slag in the magnetic separation, mix it evenly, and transport it to the wet ball mill. Adjust the parameters of the ball mill so that the discharged particle size meets ≤1mm;

S4 wet magnetic separation: The ball mill discharge is transported to the permanent magnet drum magnetic separator for wet magnetic separation to select the refined iron slurry. After dehydration by the dehydration device, the refined iron powder product is obtained. The residue is also precipitated and filtered to obtain the final product. slag;

S5 sedimentation filter press: The residual slurry after magnetic separation is screened to obtain tailings slurry and ore liquid under the screen. The tailings slurry is transported to the sedimentation tank for precipitation and filtered to obtain tailings;

S6 cake making: The ore liquid and tailings under the screen are drained from the filter press to the sedimentation tank, and the precipitated mud is fed into the filter press using a slurry pump to form mud cakes and stored on the ground.

Among them, in S2, the iron fine particles with Mfe>60% are selected to be less than 5mm, and Mfe is metallic iron. In S1, the secondary crushing crusher is a vertical crusher, the frequency is 25HZ, and the processing capacity is 5t/h. , In S2, the strong magnetic machine equipment is a magnetic drum iron separator, and the magnetic field strength is 8000GS.

In addition, the particle diameter of the obtained refined iron particles was 5 mm, the particle diameter of the refined iron powder was 1 mm, and the particle diameter of the tailings was 1 mm.

Comparative Example 4

A steel slag disposal method includes the following steps:

S1 pre-crushing: Use the jaw crusher to pre-crushed steel slag to a particle size of 40mm, and then crush the pre-crushed steel slag for a second time to a particle size of 5mm;

S2 magnetic separation: Screen the secondary crushed steel slag again. Steel slag with a particle size less than 5mm is sent to the strong magnetic machine equipment, and the iron fine particles with Mfe>60% are selected and stacked on the ground;

S3 wet grinding: Add water to the remaining steel slag in the magnetic separation, mix it evenly, and transport it to the wet ball mill. Adjust the parameters of the ball mill so that the discharged particle size meets ≤1mm;

S4 wet magnetic separation: The ball mill discharge is transported to the permanent magnet drum magnetic separator for wet magnetic separation to select the refined iron slurry. After dehydration by the dehydration device, the refined iron powder product is obtained. The residue is also precipitated and filtered to obtain the final product. slag;

S5 sedimentation filter press: The residual slurry after magnetic separation is screened to obtain tailings slurry and ore liquid under the screen. The tailings slurry is transported to the sedimentation tank for precipitation and filtered to obtain tailings;

S6 cake making: The ore liquid and tailings under the screen are drained from the filter press to the sedimentation tank, and the precipitated mud is fed into the filter press using a slurry pump to form mud cakes and stored on the ground.

Among them, in S2, the iron fine particles with Mfe>60% are selected to be less than 5mm, and Mfe is metallic iron. In S1, the secondary crushing crusher is a vertical crusher, the frequency is 25HZ, and the processing capacity is 5t/h. , In S2, the strong magnetic machine equipment is a magnetic drum iron separator, and the magnetic field strength is 8000GS.

In addition, the particle diameter of the obtained refined iron particles was 5 mm, the particle diameter of the refined iron powder was 1 mm, and the particle diameter of the tailings was 1 mm.

The results of the steel slag treated in the above-mentioned Examples 1 to 4 and Comparative Examples 1 to 4 were tested. Among them, the equipment life span includes long (more than 10 years), long (7 to 10 years), medium (3 to 7 years). years), short (less than 3 years), the results are as follows in Table 1:

Table 1

According to the above Table 1, it can be clearly obtained that in Examples 1 to 4, the steel slag is pretreated through two crushing processes to control the particle size of the steel slag entering the wet ball mill tank, so that the equipment life is long, and due to the The second closed loop clean water tank can effectively reduce water consumption, realize recycling of water resources, and avoid sewage discharge;

In Example 4 and Comparative Example 1 where other conditions are the same, since S11 potassium sodium tartrate pretreatment was not performed in Comparative Example 1, the percentage of water consumption increased, and the service life of the equipment also decreased due to the increase in operating frequency. At the same time, the The recovery rate of steel slag after treatment is reduced;

In Example 4 and Comparative Example 2, Comparative Example 2 did not return the steel slag to the raw material bin for secondary crushing to form a closed loop, resulting in a reduction in the service life of the equipment and a reduction in the recovery rate of the steel slag;

In Example 4 and Comparative Example 3, Comparative Example 3 did not use a clean water tank for closed circulation of water, which resulted in a significant increase in the water consumption ratio for processing steel slag, and also partially affected the recovery rate of steel slag;

In Example 4 and Comparative Example 4, in Comparative Example 4, the potassium sodium tartrate pretreatment of S11 was not performed, the steel slag was not returned to the raw material bin for secondary crushing to form a closed loop, and a clean water tank was not used for closed circulation of water, resulting in The percentage of water consumption increases, and the service life of the equipment is also reduced due to the increase in working frequency. At the same time, the recovery rate of steel slag is reduced, the overall processing efficiency is poor, the service life of the equipment is low, and the water consumption is high.

In summary, the present invention crushes the steel slag twice in advance, controls the particle size of the steel slag within the range of 0 to 5 mm, and wet-mills the steel slag with unqualified iron content in the magnetic separation process to improve the metal recovery efficiency and arranges two crushings at the same time. The process reduces the particle size of the steel slag entering the ball mill, reduces the loss of grinding equipment, and reduces energy consumption. Through each process, the steel slag is processed to produce 0-5mm fine iron particles, 0-1mm tailings, fine iron powder and tailings. Mud, refined iron granules and refined iron powder can be directly exported. The tailings can be used as admixtures to replace part of the sand and gravel fine aggregate. The tailings mud contains active substances such as calcium oxide with a high content, and can be used as cementitious materials to replace part of the cement. and other materials, greatly reducing the construction cost of concrete projects.

The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can, within the technical scope disclosed in the present invention, use the technical solutions of the present invention and its Equivalent substitutions or changes of the inventive concept shall be included in the protection scope of the present invention.

Claims (6)

1. A disposal method for cascade utilization of steel slag, which is characterized in that it includes the following steps: S1 pre-crushing: Use the jaw crusher to pre-crushed the steel slag to a particle size of 0 to 40 mm, and then crush the pre-crushed steel slag for a second time to a particle size of 0 to 5 mm; S11: Add potassium sodium tartrate to the secondary crushed steel slag, continue to stir and mix it, the stirring time is 5 to 10 minutes, the mass ratio of the steel slag to potassium sodium tartrate is 100: (0.01 to 0.03); S2 Magnetic Separation: Screen the secondary crushed steel slag again. Steel slag with a particle size less than 5mm is sent to the strong magnetic machine equipment, and the iron fine particles with Mfe>60% are selected and stacked on the ground. Steel slag with a particle size greater than 5mm is returned to the raw material warehouse to continue. Perform secondary crushing to form a closed loop; S3 wet grinding: After the magnetic separation, the remaining steel slag is added to the water in the clear pool, mixed and evenly transported to the wet ball mill, and the parameters of the ball mill are adjusted so that the discharged particle size meets ≤1mm; S4 wet magnetic separation: The ball mill discharge is transported to the permanent magnet drum magnetic separator for wet magnetic separation to select the refined iron slurry. After dehydration by the dehydration device, the refined iron powder product is obtained. The residue is also precipitated and filtered to obtain the final product. slag; S5 sedimentation filter press: The residual slurry after magnetic separation is screened to obtain tailings slurry and ore liquid under the screen. The tailings slurry is transported to the sedimentation tank for precipitation and filtered to obtain tailings; S6 cake making: The ore liquid and tailings under the screen are drained from the filter press to the sedimentation tank. The tailings slurry undergoes sedimentation, filtered water and filtered tailings mud. The filtered water is collected into the clean water tank through sedimentation. The precipitated mud The slurry pump is used to feed the filter press to form mud cakes that are stored on the ground; The particle size of the obtained fine iron particles is 0 to 5 mm, the particle size of the fine iron powder is 0 to 1 mm, and the particle size of the tailings is 0 to 1 mm. 2. A disposal method for step utilization of steel slag according to claim 1, characterized in that, in the S2, iron fine particles with Mfe>60% are selected to be 5 mm or less, and Mfe is metallic iron. 3. A disposal method for step utilization of steel slag according to claim 1, characterized in that in S1, the secondary crushing crusher is a vertical crusher, the frequency is 25HZ, and the processing capacity is 5t/h. 4. A disposal method for step utilization of steel slag according to claim 1, characterized in that, in said S2, the strong magnetic machine equipment is a magnetic drum iron separator, and the magnetic field intensity is 6000-8000GS. 5. A disposal method for cascade utilization of steel slag according to claim 1, characterized in that, in S6, the upper layer of clear water in the sedimentation tank can be used for wet ball milling to realize recycling of water resources. 6. A disposal method for step utilization of steel slag according to claim 1, characterized in that the particle diameter of the obtained fine iron particles is 3 mm, the particle diameter of the fine iron powder is 0.5 mm, and the tail The particle size of the slag is 0.5mm.