Steel slag treatment process and equipment

Abstract

The invention discloses a steel slag treatment process and equipment, and relates to the technical field of steel slag treatment.The steel slag treatment equipment comprises a separation pipe arranged at an outlet of a cyclone dust collector, a pressurizing part is arranged between the separation pipe and the outlet of the cyclone dust collector, and the separation pipe is provided with a spherical dust removal net and a metal elastic piece; and after the dust removal net is blocked, the air pressure in the separation pipe is increased, so that dust on the dust removal net is shaken off by the metal elastic piece and the reverse bend, and a dust collection cavity is formed in the air inlet side, located on the dust removal net, of the separation pipe. Steel and iron materials in the steel slag are effectively separated from aggregate, the steel and iron materials are subsequently used for concrete or cement aggregate, waste utilization is effectively carried out, a dust removal net of the secondary dust remover can change the state of a metal elastic piece according to the change of air pressure, and therefore the dust removal net is adjusted, dust blocked on the dust removal net is cleaned away, and long-term use is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of steel slag treatment, and specifically to a steel slag treatment process and equipment. Background Art

[0002] As waste generated during steel production, steel slag still contains a certain amount of iron and steel. Moreover, other components such as calcium silicate formed by the oxidation of metal elements can be used as cement, concrete, or subgrade materials for waste utilization.

[0003] During the treatment of steel slag, a large amount of dust (extremely fine particles) is generated during the treatment of the above-mentioned aggregates that can be used as cement, concrete, or subgrade materials. When these dusts are only treated by a cyclone dust collector, it is difficult to screen out the fine particles, and only preliminary dust removal can be achieved. Therefore, secondary dust removal, such as electrostatic dust removal or bag dust removal, is usually set after cyclone dust removal. The dust removal rates of both are relatively high. However, electrostatic dust removal equipment is large and costly, and is sensitive to the dust specific resistance and requires pretreatment (such as ammonia spraying for conditioning). For bag dust removal, the filter bags are easily corroded by humidity and acid-base gases (corrosion-resistant materials need to be selected). On the other hand, incomplete dust cleaning may lead to "bag sticking", increasing the pressure drop and relatively high cost. Therefore, we propose a steel slag treatment process and equipment. Summary of the Invention

[0004] The purpose of the present invention is to provide a steel slag treatment process and equipment to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A steel slag treatment process and equipment, including the following steps:

[0006] Step 1: Raw material crushing. The steel slag enters the pair-roller machine from the raw material bin for crushing to make the raw material into granular form.

[0007] Step 2: Screening. The particles crushed in Step 1 enter the screening drum. The screening drum has a double-layer screening structure and screens the crushed particles into three parts, namely particles with a diameter of more than 4.5 mm, particles with a diameter of more than 1.0 mm and less than 4.5 mm, and particles with a diameter of less than 1.0 mm.

[0008] Step 3: Magnetic separation of particles with a diameter of more than 4.5 mm. The iron and steel after magnetic separation enter the iron material bin, and the non-iron and steel particles form semi-finished aggregates or enter the raw material bin to circulate and form smaller particles.

[0009] Step 4: Sand making, which is a parallel step to Step 3. The particles with a diameter of more than 1.0 mm and less than 4.5 mm after screening in Step 2 enter the sand making machine for sand making, and after sand making, they enter the next step, while the particles with a diameter of less than 1.0 mm directly enter the next step.

[0010] Step Five: Powder Separation. The dust in the particles after sand making is discharged by wind force. The dust enters the cyclone dust collector, while the remaining aggregate particles are subjected to secondary magnetic separation. The steel after secondary magnetic separation enters the batching bin, and the non-steel particles enter the special fine aggregate bin for storage as concrete or cement additives.

[0011] Step Six: Secondary Dust Removal. The inlet of the secondary dust collector is docked with the outlet of the cyclone dust collector. The dust enters the secondary dust collector to separate the air flow and the dust. The dust enters the dust bin for storage as raw materials for commercial concrete.

[0012] Preferably, a steel slag treatment device includes a separation pipe provided at the outlet of the cyclone dust collector. There is a pressurizing part between the separation pipe and the outlet of the cyclone dust collector. The pressurizing part cuts off and pressurizes the air flow at the outlet of the cyclone dust collector and transports it into the separation pipe. Inside the separation pipe, a dust removal net with a spherical surface and a metal elastic sheet are arranged in sequence along the air flow direction. The dust removal net and the metal elastic sheet are in contact, and the circumferential side walls of both are fixed to the inner wall of the separation pipe. When the air flow passes through the dust removal net, the dust is intercepted. After the dust removal net is blocked, the air pressure in the separation pipe increases, causing the metal elastic sheet to bend reversely and shake off the dust on the dust removal net. A dust collection chamber is provided on the air inlet side of the separation pipe where the dust removal net is located, and a one-way valve that only allows air to pass out is arranged at the outlet end of the separation pipe.

[0013] Preferably, a Venturi tube is provided on the air inlet side of the separation pipe where the dust removal net is located.

[0014] Preferably, the metal elastic sheet and the dust removal net are spherical surfaces protruding towards the air inlet side.

[0015] Preferably, the metal elastic sheet and the dust removal net are spherical surfaces protruding towards the air outlet side, and the circumferential side wall of the metal elastic sheet is arranged in a limited sliding manner with the separation pipe, and a baffle in contact with the middle position of the metal elastic sheet is arranged inside the separation pipe.

[0016] Preferably, the metal elastic sheet is a hollow frame elastic sheet.

[0017] Preferably, multiple groups of separation pipes can be provided for alternate air supply.

[0018] Preferably, the initial state of the dust prevention net is a plane and it adheres to one side of the metal elastic sheet.

[0019] Preferably, the dust collection chamber is a tubular cavity with a wide mouth facing the inside of the separation pipe and the other end extending downward.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] Through processes such as crushing, screening, sand making, and magnetic separation of steel slag waste, the present invention effectively separates the steel materials and aggregates in the steel slag, and the aggregates are screened into corresponding diameter sizes, so as to be used as concrete or cement aggregates in the follow-up, effectively achieving waste utilization.

[0022] In the present invention, a secondary dust collector is arranged behind the cyclone dust collector. The dust removal net of the secondary dust collector can change the state of the metal elastic sheet according to the change of air pressure, so as to adjust the dust removal net and clean the blocked dust on it, which is convenient for long-term use;

[0023] Due to the setting mode of the spherical surface of the dust removal net in the present invention, when the state changes due to air pressure after being blocked, the gap on the surface in the thickness direction of the dust prevention net can be adjusted, so that the pores on the blocked side are enlarged, which is more conducive to the falling of dust and improves the efficiency of continuous use. Brief Description of the Drawings

[0024] Figure 1 It is a schematic process flow diagram of the present invention;

[0025] Figure 2 It is a schematic structural diagram between the separation pipe and the cyclone dust collector;

[0026] Figure 3 It is a half-sectional structural diagram of the separation pipe;

[0027] Figure 4 It is a half-sectional structural diagram of the dust removal net and the metal elastic sheet;

[0028] Figure 5

[0029] Figure 6

[0030] Figure 7

[0031] Figure 8

[0032] Figure 9

[0033] It is a schematic diagram of three states of the dust removal net.

[0033] In the figure: 1 - separation pipe; 2 - pressurizing part; 3 - dust removal net; 4 - metal elastic sheet; 5 - dust collection chamber; 6 - Venturi tube; 7 - baffle; 101 - outer cylinder; 102 - air inlet; 103 - conical cylinder; 104 - ash discharge port; 105 - inner cylinder. Detailed Embodiments

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] Please refer to Figures 1-4 , the present invention provides a technical solution: a steel slag treatment process, including the following steps:

[0036] Step 1, raw material crushing. The steel slag is conveyed from the raw material bin by an inclined belt into a pair-roll crusher, and the pair-roll crusher crushes the massive steel slag entering it to make the raw material into granular form.

[0037] Step 2, screening. The particles crushed in Step 1 enter a screening drum. The screening drum has a double-layer screening structure, that is, it has two screen structures with different screening mesh numbers, and the crushed particles are screened into three parts, namely particles with a diameter of more than 4.5 mm, particles with a diameter of more than 1.0 mm and less than 4.5 mm, and particles with a diameter of less than 1.0 mm.

[0038] Step 3, for a part of the screened particles with a diameter exceeding 4.5 mm, this part is conveyed by a magnetic belt to separate the steel materials and non-steel materials therein, and the steel materials are recycled into the iron bin.

[0039] For non-steel materials with a diameter exceeding 4.5 mm, they can be directly sent to another warehouse for sale as raw materials, or the materials of this part can be recycled back to the raw material bin, and Steps 1 and 2 above are repeated to further crush the particles into smaller particles.

[0040] Step 4, sand making. Step 4 is synchronized with Step 3 to process the other two parts of the particles screened in Step 2. For particles with a diameter less than 1.0 mm, since their diameter already meets the usage requirements, they can be directly conveyed to a powder separator by a conveyor belt or a hoist.

[0041] For particles with a diameter of more than 1.0 mm and less than 4.5 mm, they are sent into a sand making machine, and under the action of a high-speed rotating rotor or hammer head, they are accelerated and projected, collide and rub with the surrounding impact plates, liners or other materials, and finally are broken into sand grains, that is, the target particle diameter (diameter less than 1.0 mm). After crushing, they converge with the particles with a diameter less than 1.0 mm after screening and are conveyed to a powder separator by a conveyor belt or a hoist.

[0042] Step 5: Powder Separation. The dust in the particles after sand making is discharged by wind force. The dust enters the cyclone dust collector, while the remaining aggregate particles are subjected to secondary magnetic separation. The steel after secondary magnetic separation enters the batching bin, and the non-steel particles enter the special fine aggregate bin for storage as concrete or cement additives.

[0043] The powder separation includes two small steps. First, the dust (i.e., dust or powder with extremely fine particle diameter) in the particles after sand making is blown into the cyclone dust collector by a wind mechanism through a powder separator. The dust separates from the air flow in the cyclone dust collector, and then the dust-free air flow is discharged to achieve the environmental protection purpose.

[0044] Another step is the remaining aggregate particles blown out by the wind mechanism after the powder separator. They are subjected to secondary magnetic separation to select the extremely small amount of steel materials contained in the non-steel material particles after primary magnetic separation, effectively purify the steel materials in the steel slag, and improve the effective utilization rate of the materials.

[0045] Step 6: Secondary Dust Removal. The inlet of the secondary dust collector is docked with the outlet of the cyclone dust collector. The dust enters the secondary dust collector to separate the air flow and the dust. The dust enters the dust bin for storage as raw materials for commercial concrete.

[0046] Through the settings of two magnetic separations and powder separation, the steel and non-steel materials can be effectively separated, and the non-steel materials are sorted out with specific diameters, and then used as raw materials for different materials.

[0047] Refer to Figure 2 、 Figure 3 and Figure 4 A steel slag treatment device includes a separation pipe 1 provided at the outlet of the cyclone dust collector. The cyclone dust collector mainly includes an outer cylinder 101. The top of the outer cylinder 101 is provided with an air inlet 102, and the bottom of the outer cylinder 101 is provided with a conical cylinder 103. The lower end of the conical cylinder 103 is a dust discharge port 104. The inner part of the outer cylinder 101 is provided with a coaxial inner cylinder 105. The top of the inner cylinder 105 is an air outlet, and the air outlet is docked with one end of the separation pipe 1 for discharge.

[0048] The separation pipe 1 is sequentially provided with a pressurizing part 2, a dust removal net 3 and a metal elastic sheet 4 along the air flow direction. The pressurizing part 2 cuts off the air flow discharged from the inner cylinder 105, conveys a single fixed amount into the separation pipe 1, and pressurizes the air flow in the separation pipe 1 after cutting off. After pressurization, it is discharged after dust removal by the dust removal net 3. The dust removal net 3 is a dust removal aggregate, which can be simply understood as a filter element. The dust removal net 3 intercepts the dust in the air flow, and the dust-free air flow is discharged. One side of the dust removal net 3 close to the outlet end of the separation pipe 1 is attached to the metal elastic sheet 4. The metal elastic sheet 4 is spherical, and the dust removal net 3 adheres to the shape of the metal elastic sheet 4. A one-way valve is provided at the outlet position of the separation pipe 1 to only discharge the air flow.

[0049] After the air flow is pressurized, it will quickly discharge from the dust removal net 3. After long-term use, the dust removal net 3 will be blocked by accumulated dust. After the blockage, the subsequent air flow in the separation tube 1 will be pressurized to a higher pressure state, reaching the critical state of deformation of the metal elastic sheet 4, causing the metal elastic sheet 4 to change from protruding towards one end of the separation tube 1 to protruding in the reverse direction, that is, towards the other end. During the deformation process, different from the continuous deformation and compression of a spring, when the metal elastic sheet 4 bends in the reverse direction, there will be a state of quickly popping out. This state causes the blocked dust on the dust removal net 3 to be bounced off, thus achieving the purpose of automatic cleaning. Since the metal elastic sheet 4 needs to deform back and forth, metal materials with excellent elastic modulus and fatigue life, such as phosphor bronze (C5191), beryllium copper (C17200), stainless steel (SUS301 / SUS304), etc., are used;

[0050] See Figure 3 and Figure 7 , the pressurizing part 2 changes the states of the dust removal net 3 and the metal elastic sheet 4 by pressurizing the air flow. The pressurizing part 2 can adopt various methods, such as Figure 3 the piston structure shown. Through the intermittent air intake interruption of the piston structure, and the moving and pushing compression of the piston is greater than the air flow outflow speed at the dust removal net 3 to generate pressure. Only one group of pistons is shown in the figure, and it can also be set as multiple groups in alternation. The outlet ends of multiple separation tubes 1 then converge the air flow. Or as Figure 7 shown, through the rotation of several telescopic plates around an axis, a spiral shrinking fitting surface is set at the outer end of the telescopic plate. As it rotates, the volume between adjacent two telescopic plates decreases to pressurize. The separation tube 1 is then docked to the cavity between two adjacent telescopic plates after pressurization. The outlet of the corresponding inner cylinder 105 has at least one spaced position corresponding to the separation tube 1, so that the two will not be directly connected due to the space between the telescopic plates. As the telescopic plate rotates (rotates in the shrinking direction), the air flow is pressurized, and the air pressure decreases instantly when it is connected to the separation tube 1. As it continues to advance, the air flow is pressurized again, thus generating the power for the deformation of the metal elastic sheet 4. If the dust removal net 3 is not blocked or is blocked to a small extent, it will not cause the deformation of the metal elastic sheet 4;

[0051] The metal elastic sheet 4 is preferably set in a hollow shape, such as Figure 5 the regular hexagon hollow structure shown, or as Figure 6 the equilateral triangle hollow structure shown. Its shape is not limited. By adopting the hollow method, it avoids occupying too much cross-sectional space and thus affecting the air flow outflow of the dust removal net 3;

[0052] A reset mechanism is provided at one side of the metal spring 4 which is concave in the initial state. The reset mechanism may be composed of a telescopic rod and a sensor. The sensor detects the deformation of the metal spring 4. After the deformation, the metal spring 4 is pushed to reset by the telescopic rod. The metal spring 4 may also be reset by rotating a cam. The form is not limited.

[0053] A dust collecting chamber 5 is also provided in the separation tube 1. The dust collecting chamber 5 is arranged on one side of the dust removing net 3 which is affected by the metal shrapnel 4 and is close to the dust removing net 3. The dust falling down due to the elastic action of the dust removing net 3 caused by the deformation of the metal shrapnel 4 is collected, and an outlet is opened for regular transportation and discharge. The dust collecting chamber 5 is in a detachable state and can be disassembled and replaced after collecting for a certain period of time. Furthermore, the dust collecting chamber 5 is a tubular cavity with a wide mouth facing the separation tube 1 and the other end extending downward. The wide mouth and the inclined state are more conducive to the dust in the separation tube 1 falling into the dust collecting chamber 5, and the downward extension of the dust collecting chamber 5 can prevent the dust from being carried away again by the airflow.

[0054] Furthermore, a venturi tube 6 is installed on the air inlet side of the dust removal net 3 in the separation tube 1, which can increase the air flow velocity by reducing the cross-sectional area, thereby making the air flow flow quickly and generate turbulence, which is then agitated in the space between the venturi tube 6 and the dust removal net 3 in the separation tube 1, and the dust is quickly captured by the dust removal net 3.

[0055] See also Figure 3 and Figure 8 The dust removal net 3 has two configuration modes, namely, it can protrude toward the inlet end of the separation tube 1 or toward the outlet end of the separation tube 1. Figure 3 The metal spring 4 is protruded toward the inlet end of the separation tube 1. This arrangement is relatively simple. The deformation of the metal spring 4 only requires an increase in pressure, and the reset only requires a push. The outer peripheral surface of the metal spring 4 can be directly fixed on the inner wall of the separation tube 1. Figure 8 As shown, the metal spring piece 4 protrudes toward the outlet end of the separation tube 1. Because its deformation needs to be reversed, the outer circumferential edge of the metal spring piece 4 cannot be directly fixed to the inner wall of the separation tube 1. The outer circumferential side edge of the metal spring piece 4 slides with the inner wall of the separation tube 1. The outer circumferential side edge of the metal spring piece 4 in the initial state is close to the direction of the inlet of the separation tube 1, and a baffle 7 is fixed in the separation tube 1. The baffle 7 is on the side of the metal spring piece 4 close to the outlet end of the separation tube and fits with the surface of the metal spring piece 4 in the initial state. The fitting position is limited to the middle part of the metal spring piece 4, so that the airflow is restricted in the middle part of the metal spring piece 4. The pressure mainly acts on the edge of the metal spring piece 4. As the dust removal net 3 is blocked, the force increases, causing the metal spring piece to appear as shown in the figure. Figure 8 In the state shown by the dotted line in FIG, the outer circumference moves toward the outlet end of the separation tube 1;

[0056] See also Figure 9, as shown above, although the initial state of the metal elastic sheet 4 is arranged in a more complex way protruding towards the outlet end of the separation tube 1, it also has better effects. In Figure 9 , a1 shown in Figure 9 is a partially enlarged structure of the planar dust removal net 3, which is planar, and the pore diameters of its material are relatively balanced. When it is attached to the spherical surface of the metal elastic sheet 4, due to the curved surface deformation of the planar dust removal net 3, the pores on the left and right sides of the dust removal net 3 change. As shown in Figure 9 , a2 in Figure 9 , the pores on the air inlet side will become smaller due to compression, and the right side is the opposite. After dust adheres and blocks in this state, due to the pressure effect, the dust removal net 3 deforms into the state shown in Figure 9 , a3 in Figure 9 . The pore diameters on the left side become larger, and in this state, due to the deformation of the metal elastic sheet 4, the dust can be better bounced out, enabling the dust removal net 3 to recover closer to the initial state, thereby improving the subsequent dust removal effect.

[0057] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0058] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A steel slag treatment process, comprising the following steps: Step 1, raw material crushing: The steel slag enters the pair-roller machine from the raw material bin for crushing to make the raw material into granular form; Step 2, screening: The particles crushed in Step 1 enter the screening drum. The screening drum has a double-layer screening structure and screens the crushed particles into three parts, namely particles with a diameter of more than 4.5 mm, particles with a diameter of more than 1.0 mm and less than 4.5 mm, and particles with a diameter of less than 1.0 mm; Step 3, magnetic separation of the particles with a diameter of more than 4.5 mm: The steel separated by magnetic separation enters the iron material bin, and the non-steel particles form semi-finished aggregate or enter the raw material bin to form smaller particles by circulation; Step 4, sand making: A parallel step to Step 3. The particles with a diameter of more than 1.0 mm and less than 4.5 mm after screening in Step 2 enter the sand making machine for sand making, and after sand making, they enter the next step, while the particles with a diameter of less than 1.0 mm directly enter the next step; Step 5, powder selection: The dust in the particles after sand making is discharged by wind force. The dust enters the cyclone dust collector, and the remaining aggregate particles are subjected to secondary magnetic separation. The steel after secondary magnetic separation enters the iron material bin, and the non-steel particles enter the special fine aggregate bin for storage as concrete or cement additives; Step 6, secondary dust removal: The inlet of the secondary dust collector is docked with the outlet of the cyclone dust collector. The dust enters the secondary dust collector to separate the air flow and the dust. The dust enters the dust bin for storage as raw materials for commercial concrete; 2. A steel slag treatment device, characterized in that, The secondary dust collector for Claim 1, comprising a separation pipe (1) arranged at the outlet of the cyclone dust collector. A pressurizing part (2) is arranged between the separation pipe (1) and the outlet of the cyclone dust collector. The pressurizing part (2) cuts off and pressurizes the air flow at the outlet of the cyclone dust collector and conveys it into the separation pipe (1). Inside the separation pipe (1), a dust removal net (3) with a spherical surface and a metal elastic sheet (4) are successively arranged in the air flow direction. The dust removal net (3) and the metal elastic sheet (4) are in contact, and the circumferential side walls of both are fixed to the inner wall of the separation pipe (1). When the air flow passes through the dust removal net (3), the dust is intercepted. And after the dust removal net (3) is blocked, the air pressure in the separation pipe (1) increases, causing the metal elastic sheet (4) to bend reversely and shake off the dust on the dust removal net (3). A dust collection cavity (5) is arranged on the air inlet side of the separation pipe (1) where the dust removal net (3) is located, and a one-way valve that only allows air to pass through is arranged at the outlet end of the separation pipe (1).

3. A steel slag treatment device according to claim 2, characterized in that: A Venturi tube (6) is arranged on the air inlet side of the separation pipe (1) where the dust removal net (3) is located.

4. The steel slag treatment equipment according to claim 2, wherein: The metal elastic sheet (4) and the dust removal net (3) are spherical surfaces protruding towards the air inlet side.

5. The steel slag treatment equipment according to claim 2, wherein: The metal elastic sheet (4) and the dust removal net (3) are spherical surfaces protruding towards the air outlet side, and the circumferential side wall of the metal elastic sheet (4) is arranged in a limited sliding manner with the separation pipe (1), and a baffle (7) in contact with the middle position of the metal elastic sheet (4) is arranged inside the separation pipe (1).

6. A steel slag treatment device according to claim 2, characterized in that: The metal elastic sheet (4) is a hollow frame elastic sheet.

7. A steel slag treatment device according to claim 2, characterized in that: Multiple groups of separation pipes (1) can be arranged for alternating air supply.

8. A steel slag treatment device according to claim 5, characterized in that: The initial state of the dust prevention net is a plane and adheres to one side of the metal elastic sheet (4).

9. A steel slag treatment device according to claim 2, characterized in that: The dust collection cavity (5) is a tubular cavity with a wide mouth facing the inside of the separation pipe (1) and extending downward at the other end.

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