CN116673308A - Method for obtaining steel slag with different activities - Google Patents

Abstract

The application relates to the technical field of waste resource recovery, in particular to a method for obtaining steel slag with different activities, which comprises the following steps: s1, pre-drying a steel slag material; s2, separating iron-containing materials and magnetic separation residues by using a magnetic separator, crushing the iron-containing materials by using a double-roller crusher, separating out clean iron from the crushed materials by using a permanent magnet magnetic separator, returning the materials to the magnetic separator, and sequentially recycling to the end; s3, uniformly mixing the magnetic separation residues by using stirring equipment, crushing by using a high-pressure roller mill, separating out products with different particle sizes by using a multi-layer screen after crushing, and feeding the oversize materials into different bins, and returning the oversize materials to the high-pressure roller mill for circular crushing and screening. The method can screen the steel slag materials into materials with different particle sizes and activities, effectively improves the grindability of the steel slag and improves the use effect.

Description

A method of obtaining different active steel slags

technical field

The invention relates to the technical field of recycling waste resources, in particular to a method for obtaining different active steel slags.

Background technique

A large amount of liquid steel slag will be produced in the process of converter steelmaking, and the remaining 0-60mm steel slag material will be 0-60mm steel slag material after hot stuffing, screening, crushing and magnetic separation. The part under the 10mm sieve accounts for about 40%, and the moisture content is 8-12%. . During sieving, due to the influence of moisture, the sieving is not complete, and the part above the 10mm sieve enters into sintering. Due to the large amount of powder, the gas permeability is poor, and the use ratio is extremely limited; the part below the 10mm sieve enters the cement or concrete admixture, Due to the presence of certain particles, the activity and grindability are poor, which affects the use effect.

Contents of the invention

The purpose of the present invention is to provide a method for obtaining different active steel slags, which can screen the steel slag materials into materials with different particle sizes and activities, effectively improve the grindability of the steel slag, and improve the use effect.

The invention provides a method for obtaining different active steel slags, comprising the following steps:

S1, pre-drying the steel slag material;

S2. Use a magnetic separator to separate iron-containing materials and magnetic separation residues. The iron-containing materials are crushed by roller crushers. After crushing, the materials are returned to the magnetic separator after the pure iron is selected by the permanent magnetic separator, and the cycle is completed in turn. ;

S3. After the magnetic separation residue is mixed evenly by stirring equipment, it is crushed by high-pressure roller mill. After crushing, the products of different particle sizes are screened by multi-layer screens and entered into different silos, and the materials on the screen are returned to the high-pressure roller mill. Carry out circular crushing, and sieve again after crushing.

The 0-60mm steel slag material is the remaining material after screening, crushing and magnetic separation of converter steel slag. Its particle size composition is shown in Table 1, and its chemical composition is shown in Table 2:

Table 1 The particle size composition of steel slag materials, %

0～5mm 5～10mm 10～25mm 25～60mm total 28～30 12～14 26～28 30～32 100

Table 2 Chemical composition of steel slag material, %

CaO, SiO ₂ , MgO in steel slag materials exist in the form of tricalcium silicate, dicalcium silicate, calcium-magnesium olivine, calcium-magnesium rhodoxene, etc., among which the content of tricalcium silicate and dicalcium silicate determines The activity of steel slag.

Preferably, step S1 includes: drying the 0-60mm steel slag material with drying equipment to a moisture content below 5%, preferably below 3%, which is convenient for later magnetic separation, crushing and screening.

Preferably, step S2 includes: using a magnetic separator with a magnetic field strength of 2000-3000 gauss to separate the iron-containing material and the magnetic separation residue, the iron-containing material is transported to the roller crusher through the third conveyor belt for crushing, and the crushed material passes through The first conveying belt returns to the magnetic separator, and a 600-800 gauss permanent magnet magnetic separator is used above the first conveying belt to select clean iron, and the remaining materials enter the magnetic separator, and the cycle continues until the end.

It should be noted that the magnetic field strength of the magnetic separator and the permanent magnet magnetic separator in step S2 is not limited, and an appropriate magnetic field strength can be selected according to the actual situation of the steel slag material.

Preferably, the magnetic field strength of the magnetic separator is 2800 Gauss.

Preferably, the magnetic field strength of the permanent magnetic separator is 600 Gauss.

Optionally, the crushing equipment for ferrous materials can be replaced by other crushing equipment with the same capacity.

Preferably, all the magnetic separation residues formed in step S3 are mixed uniformly for use; the uniformly mixed magnetic separation residues are crushed by a high-pressure roller mill. The thickness is maintained in a relatively stable range.

It should be noted that, in step S3, the number of screen layers and the selection of the apertures of each layer of screens can be appropriately adjusted according to actual needs, for example: the number of layers of the screen can be two to ten layers; the aperture of the screen can be 5mm and Any aperture below 5mm, such as: 0.1mm, 0.2mm, 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm or even other apertures.

Preferably, the number of sieves in step S3 is four layers, and products of four particle sizes are screened out respectively.

Preferably, the apertures of the four layers of screens in step S3 are 0.5mm, 1mm, 2mm, and 3mm respectively, and the products of four particle sizes of 0-0.5mm, 0.5-1mm, 1-2mm, and 2-3mm are screened out respectively and Coarse grade on 3mm sieve.

Preferably, the products of the four particle sizes enter into the four finished product bins respectively, and the coarse-grained grades on the 3mm sieve enter into the standby bin.

It should be noted that the number of finished product bins is not limited, and can be adjusted adaptively according to the number of screen layers. For example, if the number of screen layers is five, the number of finished product bins is five; the number of screen layers is Ten floors, the number of finished product silos is ten, and so on, no more examples here.

Preferably, the four finished product silos include: 0-0.5mm silos, 0.5-1mm silos, 1-2mm silos and 2-3mm silos; In the silo, the products with particle size of 0.5~1mm enter the silo of 0.5~1mm, the products with particle size of 1~2mm enter the silo of 1~2mm, and the products of particle size of 2~3mm enter the silo of 2~3mm.

Preferably, the activity of the same particle size of the previous batches is slightly different, but the difference is not large. In order to avoid the influence caused by the difference, it can be considered that the materials of the same particle size of the previous batches are properly mixed.

Preferably, the coarse-grained grade on the 3mm sieve in the spare silo is returned to the silo of the high-pressure roller mill through the second conveying belt and the elevator, and is crushed again by the high-pressure roller mill. Grain-sized products enter different silos and circulate to the end in turn.

Beneficial effect:

In the technical solution of the present invention, after the iron-containing materials in the steel slag materials are selected, the remaining materials are crushed to screen out materials of different particle sizes. Among the materials of different particle sizes, the content of tricalcium silicate and dicalcium silicate It is different, so materials with different particle sizes have different activities, which effectively improves the grindability of steel slag and improves the use effect.

Description of drawings

In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the specific implementation or description of the prior art. Obviously, the accompanying drawings in the following description The drawings show some implementations of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

Fig. 1 is a process flow chart of the method for obtaining different active steel slags according to the present invention.

Detailed ways

It should be pointed out that the following detailed description is exemplary and intended to provide further explanation to the present application. Unless defined otherwise, 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 application belongs.

It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form also includes the plural form, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this description, it indicates that there are Features, steps, operations, devices, components and/or combinations thereof.

The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in Figure 1, the present embodiment provides a method for obtaining different active steel slags, comprising the following steps:

(1) The particle size distribution of 0-60mm steel slag material is shown in Table 3, and the physical and chemical indicators are shown in Table 4:

Table 3 The particle size composition of steel slag materials, %

0～5mm 5～10mm 10～25mm 25～60mm total 28.64 12.79 27.19 31.38 100.00

Table 4 Chemical composition of steel slag material, %

(2) After the material is baked by drying equipment, the moisture content is 2.81%.

(3) A magnetic separator with a magnetic field strength of 2800 Gauss is used to separate the iron-containing material and the magnetic separation residue.

(4) Iron-containing materials are crushed by roller crushers, and the crushed materials are returned to the 2800 Gauss magnetic separator through the conveyor belt to complete subsequent separation.

(5) After the rollers are broken, return to the top of the belt of the magnetic separator to select clean iron by a permanent magnetic separator whose magnetic field strength is 600 gauss.

(6) After the iron-containing materials magnetically separated by the 2800 Gauss magnetic separator are crushed by the rollers, the permanent magnetic separator is used to select the net iron, and the remaining materials enter the 2800 Gauss magnetic separator, and the cycle continues until the end.

(7) The magnetic separation residues formed in the early stage and the magnetic separation residues formed after being crushed by the rollers in the later stage will inevitably have differences in composition. Mixing equipment can be used to mix the magnetic separation residues in the early and late stages evenly.

(8) The uniformly mixed magnetic separation residue is crushed by a high-pressure roller mill. In order to ensure the stability of the crushing process, the feeding speed can be controlled by belt feeding, so that the material accumulation height of the high-pressure roller mill can be maintained at relatively stable range.

(9) After crushing, four-layer screens are used for screening. The apertures of the screens are 0.5mm, 1mm, 2mm, and 3mm, respectively, and four types of 0-0.5mm, 0.5-1mm, 1-2mm, and 2-3mm are screened out. Product and coarse fraction on 3mm sieve. Products with different particle sizes enter different finished product bins, and the coarser particles on the 3mm sieve enter the spare silo.

(10) The upper part of the screen is returned to the high-pressure roller mill silo through the belt and the elevator, and the material in the high-pressure roller mill silo is maintained in a relatively stable range by controlling the feeding speed from the spare silo to the belt. Until the crushing and sieving is completed.

(11) the steel slag powder material sampling detection chemical composition of different particle size, the result is as shown in table 5:

Table 5 Chemical composition of steel slag material, %

It can be seen from Table 5 that the material activity of the steel slag with different particle sizes obtained by this method is different, and the material activity of the steel slag with a particle size of 2-3mm is the highest up to 91.21%.

In this embodiment, after the iron-containing materials in the steel slag materials are selected, the remaining materials are crushed to screen out materials with different particle sizes. Among the materials with different particle sizes, the contents of tricalcium silicate and dicalcium silicate are different. , so that materials with different particle sizes have different activities, which effectively improves the grindability of steel slag and improves the use effect.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.

Claims (10)

1. A method for obtaining steel slag with different activities, which is characterized by comprising the following steps:

s1, pre-drying a steel slag material;

s2, separating iron-containing materials and magnetic separation residues by using a magnetic separator, crushing the iron-containing materials by using a double-roller crusher, separating out clean iron from the crushed materials by using a permanent magnet magnetic separator, returning the materials to the magnetic separator, and sequentially recycling to the end;

s3, uniformly mixing the magnetic separation residues by using stirring equipment, crushing by using a high-pressure roller mill, separating out products with different particle sizes by using a multi-layer screen after crushing, and feeding the oversize materials into different bins, and returning the oversize materials to the high-pressure roller mill for circular crushing and screening.

2. The method for obtaining steel slag with different activities according to claim 1, wherein step S1 comprises: and drying the steel slag material with the thickness of 0-60 mm by adopting drying equipment until the moisture content is below 5%.

3. The method for obtaining steel slag with different activities according to claim 1, wherein step S2 comprises: and separating out iron-containing materials and magnetic separation residues by adopting a magnetic separator with the magnetic field strength of 2000-3000 gauss, conveying the iron-containing materials to a roller crusher for crushing by a third conveying belt, returning the crushed materials to the magnetic separator by a first conveying belt, separating out clean iron by adopting a permanent magnet separator with the magnetic field strength of 600-800 gauss above the first conveying belt, and sequentially recycling the residual materials to the magnetic separator.

4. A method for obtaining steel slag with different activities according to claim 3 wherein the magnetic field strength of the magnetic separator is 2800 gauss.

5. The method for obtaining steel slag with different activities according to claim 3, wherein the magnetic field strength of the permanent magnet separator is 600 gauss.

6. The method for obtaining steel slag with different activities according to claim 1, wherein the number of screens in the step S3 is four, and products of four grades are respectively screened out.

7. The method for obtaining steel slag with different activities according to claim 6, wherein the pore diameters of the four layers of screens in the step S3 are respectively 0.5mm, 1mm, 2mm and 3mm, and products with four particle sizes of 0-0.5 mm, 0.5-1 mm, 1-2 mm and 2-3 mm and coarse particle sizes on the 3mm screen are respectively sieved.

8. The method for obtaining steel slag with different activities according to claim 7, wherein the products with four grades are respectively fed into four finished product bins, and coarse grades on a 3mm sieve are fed into a standby bin.

9. The method for obtaining steel slag with different activities according to claim 8, wherein the four finished product bins comprise: 0-0.5 mm bin, 0.5-1 mm bin, 1-2 mm bin and 2-3 mm bin; the product with the grain size of 0-0.5 mm enters a 0-0.5 mm feed bin, the product with the grain size of 0.5-1 mm enters a 0.5-1 mm feed bin, the product with the grain size of 1-2 mm enters a 1-2 mm feed bin, and the product with the grain size of 2-3 mm enters a 2-3 mm feed bin.

10. The method for obtaining the steel slag with different activities according to claim 8, wherein coarse grain grades on a 3mm sieve in the standby bin are returned to the bin of the high-pressure roller mill through the second conveying belt and the lifting machine, the high-pressure roller mill is used for crushing again, products with different grain grades are separated out by adopting a multi-layer sieve after crushing and enter different bins, and the products are sequentially circulated to the end.