A process for utilizing waste heat from magnesium reduction slag

Abstract

The present application provides a process for utilizing the waste heat of magnesium reduction slag, which comprises pouring the magnesium reduction slag from a slag box into a high-temperature slag bin; a heat exchange device is provided between the high-temperature slag bin and a scale conveying device, the heat exchange device receives the magnesium reduction slag output from the high-temperature slag bin, and takes away the heat of the magnesium reduction slag under the action of an airflow to form a first waste heat; the first waste heat is separated from the heat exchange device and acts on a component to be heated; the scale conveying device receives the magnesium reduction slag separated from the heat exchange device and conveys the magnesium reduction slag to a low-temperature slag bin, so as to facilitate secondary utilization of the magnesium reduction slag in the low-temperature slag bin; at this time, the heat exchange device receives the magnesium reduction slag output from the high-temperature slag bin, and takes away the heat of the magnesium reduction slag under the action of an airflow, so as to cool the magnesium reduction slag, and transfers the heat to the component to be heated, so as to fully utilize the first waste heat of the magnesium reduction slag, thereby improving the energy utilization rate of the magnesium reduction slag and avoiding waste of the first waste heat.

Description

Technical Field

[0001] The present application belongs to the technical field of magnesium reduction slag waste heat, and in particular relates to a process for utilizing magnesium reduction slag waste heat. Background Art

[0002] China has very rich reserves of magnesium resources and is also a major producer and exporter of metallic magnesium, ranking first in the world in magnesium production. China's magnesium production is mainly based on the Pidgeon process. The traditional Pidgeon process for magnesium smelting produces a lot of waste slag. For every ton of metallic magnesium produced using the Pidgeon process, 5 to 6 tons of reducing slag will be generated.

[0003] Magnesium reduction slag, when leaving the reduction tank, reaches a temperature of approximately 1000°C and contains a significant amount of heat energy. According to relevant data, the heat released during the cooling process from 1000°C to 25°C per ton of magnesium reduction slag is approximately equivalent to the heat released by burning 35kg of standard coal. The heat released during the cooling process of the magnesium reduction slag produced during the production of one ton of metallic magnesium is equivalent to 175-192.5kg of standard coal. Recycling 60% of the heat in the magnesium reduction slag would save 105-115.5kg of standard coal per ton of magnesium in magnesium production, significantly reducing production costs. However, in existing technologies, the waste heat from the magnesium reduction slag is directly discharged into the air, failing to achieve effective utilization. Summary of the Invention

[0004] The embodiments of the present application provide a process for utilizing the waste heat of magnesium reduction slag to solve the problem that the waste heat of the existing magnesium reduction slag is not effectively utilized.

[0005] In a first aspect, an embodiment of the present application provides a process for utilizing waste heat from magnesium reduction slag, comprising:

[0006] Pour the magnesium reduction slag from the slag box into the high-temperature slag bin;

[0007] A heat exchange device is provided between the high-temperature slag bin and the scale plate conveying device, wherein the heat exchange device receives the magnesium reduction slag outputted from the high-temperature slag bin and takes away the heat of the magnesium reduction slag under the action of airflow to form first waste heat;

[0008] Separating the first waste heat from the heat exchange device and applying it to the component to be heated;

[0009] The scale plate conveying device receives the magnesium reduction slag separated from the heat exchange device and conveys the magnesium reduction slag to the low-temperature slag bin, so as to facilitate secondary utilization of the magnesium reduction slag in the low-temperature slag bin.

[0010] Optionally, the component to be heated is arranged outside the heat exchange device and is transported to the heat exchange device through a pipeline. The first waste heat is transferred from the heat exchange device to the component to be heated along the pipeline, and the component to be heated is dried or preheated.

[0011] Optionally, in the heat exchange device, the heat exchange device receives low-temperature air, and the low-temperature air flows in the heat exchange device and takes away the heat of the magnesium reduction slag under the action of the airflow to reduce the temperature of the magnesium reduction slag.

[0012] Optionally, the low-temperature airflow is heat exchanged with the magnesium reduction slag, and the magnesium reduction slag after heat exchange is reduced from 1000° C. to below 100° C., and the magnesium reduction slag is discharged from a discharge port of the heat exchange device;

[0013] A large air intake volume is used to raise the air flow temperature to 150° C.-200° C., and then the first waste heat is transferred from the heating device to the silo of the component to be heated to dry the moisture of the material.

[0014] Optionally, in the heat exchange device, the low-temperature airflow is heat exchanged with the magnesium reduction slag, and the magnesium reduction slag after heat exchange is reduced from 1000° C. to below 100° C., and the magnesium reduction slag is discharged from a discharge port of the heat exchange device;

[0015] When the first waste heat rises to 200°C-300°C, the first waste heat then enters the silo of the component to be heated from the heat exchange device for preheating.

[0016] Optionally, a bucket elevator is provided between the scale conveying device and the low-temperature slag bin, and the bucket elevator transfers the magnesium reduction slag conveyed by the scale conveying device to the low-temperature slag bin in a vertical direction and dumps the magnesium reduction slag into the low-temperature slag bin.

[0017] Optionally, the low-temperature slag bin contains cooled magnesium reduction slag, and the magnesium reduction slag is transported to a cement processing device, which performs secondary utilization of the magnesium reduction slag.

[0018] Optionally, a dust collector is applied to the high-temperature slag bin, the bucket elevator, and the low-temperature slag bin, and performs dust removal on the high-temperature slag bin, the bucket elevator, and the low-temperature slag bin.

[0019] Optionally, dust in the high-temperature slag bin, the bucket elevator, and the low-temperature slag bin is input into the dust collector along a dust channel and is purified in the dust collector.

[0020] The embodiment of the present application provides a process for utilizing the waste heat of magnesium reduction slag, which pours the magnesium reduction slag from a slag box into a high-temperature slag bin; a heat exchange device is provided between the high-temperature slag bin and a scale conveying device, the heat exchange device receives the magnesium reduction slag output through the high-temperature slag bin, and takes away the heat of the magnesium reduction slag under the action of an airflow to form a first waste heat; the first waste heat is separated from the heat exchange device and acts on a component to be heated; the scale conveying device receives the magnesium reduction slag separated from the heat exchange device and conveys the magnesium reduction slag to a low-temperature slag bin, so as to facilitate secondary utilization of the magnesium reduction slag in the low-temperature slag bin; at this time, the heat exchange device receives the magnesium reduction slag output through the high-temperature slag bin, and takes away the heat of the magnesium reduction slag under the action of an airflow, so as to cool the magnesium reduction slag, and transfer the heat to the component to be heated, so as to fully utilize the first waste heat of the magnesium reduction slag, improve the energy utilization rate of the magnesium reduction slag, and avoid waste of the first waste heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] To more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0022] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings. In the following description, the same reference numerals represent the same parts.

[0023] Figure 1 This is a schematic flow chart of the process for utilizing waste heat from magnesium reduction slag provided in an embodiment of the present application.

[0024] Figure 2 This is a structural schematic diagram of the process for utilizing waste heat from magnesium reduction slag provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0026] Example

[0027] See also Figure 1 and Figure 2 A process for utilizing waste heat from magnesium reduction slag, comprising:

[0028] S11: Pour the magnesium reduction slag from the slag box 1 into the high-temperature slag bin 2;

[0029] Among them, magnesium reduction slag is formed when magnesium is in the reduction process and exists in the form of waste slag. The magnesium reduction slag is driven by the slag box 1 and tilts toward the high-temperature slag bin 2, so that the magnesium reduction slag enters the high-temperature slag bin 2 under the action of its own gravity. At this time, the slag box 1 has a flipping and tilting device, and the flipping direction of the magnesium reduction slag is adjusted by the flipping and tilting device, so that the magnesium reduction slag enters the high-temperature slag bin 2 along the tilting direction.

[0030] S12: A heat exchange device 3 is provided between the high-temperature slag bin 2 and the scale plate conveying device 4. The heat exchange device 3 receives the magnesium reduction slag output from the high-temperature slag bin 2 and removes the heat of the magnesium reduction slag under the action of the airflow to form the first waste heat;

[0031] Among them, the component to be heated is arranged outside the heat exchange device 3 and is transported to the heat exchange device 3 through a pipeline. The first waste heat is transferred from the heat exchange device 3 to the component to be heated along the pipeline, and the moisture of the component to be heated is dried or preheated. Therefore, the first waste heat is used to dry or preheat the moisture of the component to be heated and is effectively reused for a second time. At this time, the heat exchange device 3 receives the magnesium reduction slag output through the high-temperature slag bin 2, and takes away the heat of the magnesium reduction slag under the action of the airflow, so as to cool the magnesium reduction slag and transfer the heat to the component to be heated, so as to make full use of the first waste heat of the magnesium reduction slag, thereby improving the energy utilization rate of the magnesium reduction slag and avoiding the waste of the first waste heat.

[0032] Specifically, in the heat exchange device 3, the heat exchange device 3 receives low-temperature air, and the low-temperature air flows in the heat exchange device 3 and takes away the heat of the magnesium reduction slag under the action of the airflow to reduce the temperature of the magnesium reduction slag. At this time, the low-temperature air takes away the heat of the magnesium reduction slag during the flow process and effectively cools the magnesium reduction slag, so as to reduce the temperature of the magnesium reduction slag and facilitate the subsequent secondary utilization of the magnesium reduction slag. It can also take away the peripheral heat of the magnesium reduction slag to facilitate the continuous supply of the first waste heat.

[0033] S13: The first waste heat is separated from the heat exchange device 3 and acts on the component to be heated;

[0034] In the first embodiment, the low-temperature airflow is heat exchanged with the magnesium reduction slag. After the heat exchange, the temperature of the magnesium reduction slag is reduced from 1000°C to below 100°C, and the magnesium reduction slag is discharged from the discharge port of the heat exchange device 3. A large air intake volume is used to raise the airflow temperature to 150°C-200°C, and then the first waste heat is transferred from the heating device to the silo of the component to be heated to dry the moisture of the material.

[0035] In the second embodiment, in the heat exchange device 3, the low-temperature airflow exchanges heat with the magnesium reduction slag, and the magnesium reduction slag after heat exchange is reduced from 1000°C to below 100°C, and the magnesium reduction slag is discharged from the discharge port of the heat exchange device 3; when the first waste heat rises to 200°C-300°C, the first waste heat then enters the silo of the component to be heated from the heat exchange device 3 for preheating.

[0036] S14: The scale conveying device 4 receives the magnesium reduction slag separated from the heat exchange device 3 and conveys the magnesium reduction slag to the low-temperature slag bin 6 so as to facilitate secondary utilization of the magnesium reduction slag in the low-temperature slag bin 6;

[0037] Among them, a bucket elevator 5 is provided between the scale conveying device 4 and the low-temperature slag bin 6. The bucket elevator 5 transfers the magnesium reduction slag conveyed by the scale conveying device 4 to the low-temperature slag bin 6 in the vertical direction, and dumps the magnesium reduction slag into the low-temperature slag bin 6, so as to facilitate the transfer of the cooled magnesium reduction slag to the work station through the scale conveying device 4.

[0038] The low-temperature slag bin 6 contains the cooled magnesium reduction slag and transports the magnesium reduction slag to the cement processing device, which reuses the magnesium reduction slag. At this time, the cooled and transferred magnesium reduction slag can be used as a raw material for cement secondary utilization, thereby improving the utilization rate of the magnesium reduction slag.

[0039] In addition, the dust collector 7 is applied to the high-temperature slag bin 2, the bucket elevator 5, and the low-temperature slag bin 6, and the high-temperature slag bin 2, the bucket elevator 5, and the low-temperature slag bin 6 are dust-removed. The dust in the high-temperature slag bin 2, the bucket elevator 5, and the low-temperature slag bin 6 is input into the dust collector 7 along the dust channel and purified in the dust collector 7.

[0040] In the actual application environment:

[0041] Example 1:

[0042] Slag box 1, containing high-temperature magnesium reduction slag, is placed on the slag box 1 dumping device. The tilting device is turned, and the high-temperature magnesium reduction slag is poured into high-temperature slag bin 2. The magnesium reduction slag in high-temperature slag bin 2 enters heat exchange device 3 from the feed port through a chute. Low-temperature airflow enters heat exchange device 3 from heat exchange device 3, and the airflow direction is opposite to the flow direction of the solid reduction slag.

[0043] In the heat exchange device 3, the low-temperature airflow exchanges heat with the high-temperature magnesium reduction slag. After the heat exchange, the magnesium reduction slag is reduced from about 1000°C to below 100°C and discharged from the discharge port of the heat exchange device 3. A large air intake volume is used to raise the airflow temperature to 150°C-200°C, and then it enters the silo from the heat exchange device 3 to dry the moisture in the material.

[0044] The low-temperature magnesium reduction slag discharged from the heat exchange device 3 is conveyed to the low-temperature slag bin 6 through the scale conveyor and bucket elevator 5 for temporary storage, and then transported to the cement plant to be used as a secondary resource for cement production raw materials.

[0045] During the material handling and transportation process, the dust generated in the high-temperature slag bin 2, the low-temperature slag bin 6, and the bucket elevator 5 is purified by the dust collector 7 and the gas is discharged.

[0046] Example 2:

[0047] Slag box 1, containing high-temperature magnesium reduction slag, is placed on a tilting and tilting device. The device is tilted, and the high-temperature magnesium reduction slag is poured into high-temperature slag bin 2. The magnesium reduction slag in high-temperature slag bin 2 flows through a chute from the feed port into heat exchanger 3. Low-temperature airflow enters heat exchanger 3 from heat exchanger 3, flowing in the opposite direction of the solid reduction slag.

[0048] In the heat exchange device 3, the low-temperature airflow exchanges heat with the high-temperature magnesium reduction slag. After the heat exchange, the magnesium reduction slag is reduced from about 1000°C to below 100°C and discharged from the discharge port of the heat exchange device 3; while the airflow temperature rises to 200°C-300°C, and then enters the silo from the heat exchange device 3 to preheat the material.

[0049] The low-temperature magnesium reduction slag discharged from the heat exchange device 3 is conveyed to the low-temperature slag bin 6 through the scale conveyor and bucket elevator 5 for temporary storage, and then transported to the cement plant to be used as a secondary resource for cement production raw materials.

[0050] During the material handling and transportation process, the dust generated in the high-temperature slag bin 2, the low-temperature slag bin 6, and the bucket elevator 5 is purified by the dust collector 7 and the gas is discharged.

[0051] The embodiment of the present application provides a process for utilizing the waste heat of magnesium reduction slag, which pours the magnesium reduction slag from the slag box 1 into the high-temperature slag bin 2; a heat exchange device 3 is provided between the high-temperature slag bin 2 and the scale conveyor 4, and the heat exchange device 3 receives the magnesium reduction slag output through the high-temperature slag bin 2 and takes away the heat of the magnesium reduction slag under the action of airflow to form a first waste heat; the first waste heat is separated from the heat exchange device 3 and acts on the component to be heated; the scale conveyor 4 receives the magnesium reduction slag separated from the heat exchange device 3 and conveys the magnesium reduction slag to the low-temperature slag bin 6, so as to facilitate the secondary utilization of the magnesium reduction slag in the low-temperature slag bin 6. At this time, the heat exchange device 3 receives the magnesium reduction slag output through the high-temperature slag bin 2 and takes away the heat of the magnesium reduction slag under the action of airflow to cool the magnesium reduction slag and transfer the heat to the component to be heated, so as to fully utilize the first waste heat of the magnesium reduction slag, improve the energy utilization rate of the magnesium reduction slag, and avoid waste of the first waste heat.

[0052] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0053] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more features.

[0054] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for technical personnel in this field, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on this application.

Claims

1. A process for utilizing waste heat from magnesium reduction slag, characterized in that: include: Pour the magnesium reduction slag from the slag box into the high-temperature slag bin; A heat exchange device is provided between the high-temperature slag bin and the scale plate conveying device, wherein the heat exchange device receives the magnesium reduction slag outputted from the high-temperature slag bin and takes away the heat of the magnesium reduction slag under the action of airflow to form first waste heat; Separating the first waste heat from the heat exchange device and applying it to the component to be heated; The scale plate conveying device receives the magnesium reduction slag separated from the heat exchange device and conveys the magnesium reduction slag to the low-temperature slag bin, so as to facilitate the secondary utilization of the magnesium reduction slag in the low-temperature slag bin; In the heat exchange device, the heat exchange device receives low-temperature air, and the low-temperature air flows in the heat exchange device, and the airflow direction of the low-temperature air is opposite to the flow direction of the solid reduction slag; The low-temperature air exchanges heat with the magnesium reduction slag, and the magnesium reduction slag is reduced from 1000°C to below 100°C after the heat exchange, and the magnesium reduction slag is discharged from the discharge port of the heat exchange device; the temperature of the low-temperature controlled air flow is raised to 150°C-200°C; A bucket elevator is provided between the scale plate conveying device and the low-temperature slag bin, and the bucket elevator transfers the magnesium reduction slag conveyed by the scale plate conveying device to the low-temperature slag bin in a vertical direction, and dumps the magnesium reduction slag into the low-temperature slag bin; The low-temperature slag bin contains cooled magnesium reduction slag and transports the magnesium reduction slag to a cement processing device, which performs secondary utilization on the magnesium reduction slag.

2. The process for utilizing waste heat from magnesium reducing slag according to claim 1, characterized in that: The component to be heated is arranged outside the heat exchange device and is transported to the heat exchange device through a pipeline. The first waste heat is transferred from the heat exchange device to the component to be heated along the pipeline, and moisture is dried or preheated on the component to be heated.

3. The process for utilizing waste heat from magnesium reducing slag according to claim 1, characterized in that: After the first waste heat rises to 200° C.-300° C., the first waste heat then enters the silo of the component to be heated from the heat exchange device for preheating.

4. The process for utilizing waste heat from magnesium reducing slag according to claim 1, characterized in that: The dust collector is applied to the high-temperature slag bin, the bucket elevator, and the low-temperature slag bin, and performs dust removal on the high-temperature slag bin, the bucket elevator, and the low-temperature slag bin.

5. The process for utilizing waste heat of magnesium reducing slag according to claim 4, characterized in that: The dust in the high-temperature slag bin, the bucket elevator, and the low-temperature slag bin is input into the dust collector along the dust channel and is purified in the dust collector.

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