Method for utilizing iron-containing dust sludge with high moisture content

Abstract

The application belongs to the field of comprehensive utilization of resources, and a utilization method of high-moisture iron-containing dust sludge is provided. The high-moisture iron-containing dust sludge is mixed with high-temperature ash and steel particles containing high CaO, and is layered and stacked and laid flat, and finally is mixed uniformly by a strong stirring mixer, so that the moisture content of the high-moisture iron-containing dust sludge is reduced, the material is gradually dried and loosened, and the mixing uniformity of the sintering burden is met, thereby achieving the purpose of returning the iron-containing dust sludge to the sintering production.

Description

Technical Field

[0001] This invention belongs to the field of comprehensive resource utilization and relates to a method for utilizing iron-containing dust and sludge with high moisture content. Background Technology

[0002] The hot rolling water treatment system in steel mills generates a certain amount of iron-containing dust and sludge during operation. This iron-containing dust and sludge is an byproduct formed during the rolling production line. It enters subsequent processes with high-pressure water. Large particles are iron scale, which is generally returned to the sintering process. The finer powdery material enters a horizontal flow tank for secondary sedimentation, and then is grabbed by a grab bucket and sent to a buffer tank for water control treatment. The buffer tank has no dehydration or rain protection facilities, and only relies on natural drying for simple dehydration. This material is the iron-containing dust and sludge with high moisture content. It contains 61-66% TFe and has high utilization value. However, because the dust and sludge has fine particles, high hydrophilicity (moisture content above 30%), and forms clumps, it has high viscosity and toughness, making loading and unloading extremely difficult. Without dehydration measures, it cannot be returned to production.

[0003] Analysis revealed that this type of dust with high moisture content contains 61-66% TFe, indicating high utilization value. Research is needed on recycling and utilizing this iron-containing dust with high moisture content.

[0004] The purpose of this invention is to reduce the moisture content of iron-containing dust and sludge by mixing it with high-temperature ash and high-CaO steel particles, stacking and spreading it in layers, and finally mixing it with a high-powered mixer. This process gradually dries the iron-containing dust and sludge, making the material loose and meeting the mixing conditions for sintering batching, thereby achieving the purpose of recycling iron-containing dust and sludge for sintering production. Summary of the Invention

[0005] The purpose of this invention is to address the above-mentioned problems by providing a method for utilizing iron-containing dust and sludge with high moisture content.

[0006] The objective of this invention is achieved as follows: A method for utilizing iron-containing dust with high moisture content, comprising the following steps: Step 1: Mixing iron-containing dust with high-temperature converter evaporation ash, steel particles, and blast furnace gravity ash: The high-temperature converter evaporation ash, iron-containing dust, steel particles, and blast furnace gravity ash are arranged in layers according to a mass ratio of 3:1:2:2: First, the high-temperature converter evaporation ash produced by the steel plant is used as the first layer of bottom material; the iron-containing dust with high moisture content is evenly spread using a loader as the second layer covering the evaporation ash; the steel particles directly transported from the slag yard to the batching station are used as the third layer covering the iron-containing dust; the blast furnace gravity ash is then placed on top of the steel particles to form the fourth layer, and then these materials are stirred and mixed evenly; Step 2: Layered stacking: After stirring... The mixed material is stacked in layers into a ladder shape with a height of 2-3 meters using a loader. The water absorption and cooling process lasts for 7-10 hours, and the material gradually dries. The third step is flat spreading and direct extraction: During the process of loading the mixed material into the silo, a loader equipped with a weighing scale is used to spread it flat and extract it directly. The mixed and water-absorbed material enters the batching station through a high-level silo. At this time, the material is in a semi-dry state with a moisture content of 12-16%. The material is loose and meets the conditions for preliminary mixing for sintering. The fourth step is strong mixing and quality improvement: The batching station is equipped with a strong mixing machine with a processing capacity of 500-600 tons / hour. After strong mixing, the mixture of iron dust and sludge with high moisture content, evaporation cold ash, steel particles, and gravity ash is controlled at 8%-10% of the finished product moisture content, which meets the conditions for sintering batching.

[0007] In the first step, the high-temperature converter evaporates cold ash with a heat of 100~140℃.

[0008] In the first step, the steel particles contain 30-39% CaO, which can release heat and absorb some moisture.

[0009] In the first step, the blast furnace gravity ash has residual heat of 80-120℃.

[0010] The beneficial effects of this invention are: by mixing iron-containing dust with high moisture content with high-temperature ash and steel particles with high CaO content, the moisture content of the iron-containing dust can be reduced, gradually dried, and the material becomes loose, meeting the mixing conditions for sintering batching, thereby achieving the purpose of re-sintering and utilizing iron-containing dust. Attached Figure Description

[0011] The present invention will now be further described with reference to the accompanying drawings.

[0012] Figure 1 This is a schematic diagram of a strongly mixed field involved in the present invention.

[0013] Among them: 1-Tail intermediate compartment, 2,3-Slide valve, 5,10-Star-type ash discharge valve, 4,8,9-Clubs, 6-Weighing hopper, 7-Strong mixer, 11-Belt conveyor, 12-Water tank, 13-Solenoid valve for water pump. Implementation

[0014] This invention mainly provides a method for utilizing iron-containing dust and sludge with high moisture content, and the specific technical solution is as follows.

[0015] This invention involves mixing high-moisture iron-containing dust with high-temperature ash and steel particles, then layering and stacking the mixture, spreading it evenly, and finally mixing it thoroughly with a high-powered mixer. This process reduces the moisture content of the high-moisture iron-containing dust, gradually dries it, and loosens the material, meeting the mixing requirements for sintering batching. This allows the iron-containing dust to be reused in sintering production. This method of utilizing high-moisture iron-containing dust can be summarized as a four-step process: "dry and wet mixing, layered stacking, flat spreading and direct extraction, and strong mixing for quality improvement." Specifically, the process is as follows: Step 1: Mixing iron-containing dust and sludge with high-temperature ash and steel particles with high CaO content: Because this iron-containing dust and sludge has a high moisture content, it cannot be dried under normal conditions. Based on the temperature of various materials, it is arranged in layers according to a mass ratio of 3:1:2:2: First, the high-temperature converter evaporation cold ash (100~140℃ heat) generated by the steel plant is used as the first layer of bottom material; the iron-containing dust and sludge with high moisture content is evenly spread on top of the evaporation cold ash using a loader as the second layer; the steel particles (CaO content 30-39%) directly sent from the slag yard to the batching station (which can release heat and absorb some moisture) are used as the third layer to cover the dust and sludge; the blast furnace gravity ash (100℃) is then used to cover the steel particles again, forming the fourth layer, so that the iron-containing dust and sludge is surrounded by a high-temperature material. Then, these materials are stirred and mixed evenly.

[0016] Step 2: Layered Stacking: After mixing, the material is stacked in layers into a trapezoidal shape using a loader, with a height of 2-3 meters. The water absorption and cooling process lasts for 7-10 hours, during which the material is in an evaporating state, with steam continuously escaping, and the material gradually dries.

[0017] Step 3: Spreading and Direct Extraction: During the process of loading the mixed material into the silo, a loader equipped with a weighing scale is used to spread and extract the material, similar to the operation mode of a stacker-reclaimer. The mixed and water-absorbed material enters the main system through the high-level silo. At this time, the material is in a semi-dry state with a moisture content of about 12-16%. The material is loose and has the conditions for initial mixing during sintering.

[0018] Step 4: Intensive mixing and quality improvement: The main system of the batching station is equipped with a powerful mixer. After the mixture of iron-containing dust and sludge with high moisture content, evaporation cold ash, steel particles, and gravity ash is strongly mixed, the moisture content of the finished product is controlled at about 8%-10%, which meets the sintering batching conditions.

[0019] After the above-mentioned processing, this dust with high moisture content can be reused in the sintering process.

[0020] The specific embodiments of the present invention will be described in detail below with reference to the examples, but the specific embodiments are not limited to the following examples. Example 1

[0021] (1) Mixing iron dust and sludge with high-temperature ash and steel particles with high CaO content: Weigh 90 tons of high-temperature converter evaporation cold ash and spread it flat as the first layer of bottom material. Use a loader to evenly spread 30 tons of iron dust and sludge with high moisture content as the second layer to cover the evaporation cold ash. Use 60 tons of steel particles (CaO content 33%, which can release heat and absorb some moisture) directly sent from the slag yard to the batching station as the third layer to cover the dust and sludge. Use 60 tons of blast furnace gravity ash (100℃) to cover the steel particles again to form the fourth layer. Then, stir and mix these materials evenly.

[0022] (2) Layered stacking: After mixing, the material is stacked in layers into a trapezoidal shape using a loader, with a height of 3 meters. The water absorption and cooling process lasts for 8 hours, and the material gradually dries.

[0023] (3) Flat and direct extraction: During the process of loading the mixed material into the silo, a loader with a weighing scale is used to flat and extract the material in accordance with the operation mode of the stacker-reclaimer. The mixed and water-absorbing material enters the main system through the high-level silo. At this time, the material moisture content is about 15%, the material is loose, and it has the conditions for initial mixing in sintering.

[0024] (4) Strong mixing and quality improvement: The main system of the batching station is equipped with a strong mixing machine. After the mixture of iron dust and sludge with high moisture content, evaporation cold ash, steel particles and gravity ash is mixed by the strong mixing machine, the moisture content of the finished product is about 10%, which meets the sintering batching conditions. Example 2

[0025] (1) Mixing iron dust and sludge with high-temperature ash and steel particles with high CaO content: Weigh 60 tons of high-temperature converter evaporation cold ash and spread it flat as the first layer of bottom material. Use a loader to evenly spread 20 tons of iron dust and sludge with high moisture content as the second layer to cover the evaporation cold ash. Use 40 tons of steel particles (CaO content 36%, which can release heat and absorb some moisture) directly sent from the slag yard to the batching station as the third layer to cover the dust and sludge. Use 40 tons of blast furnace gravity ash (100℃) to cover the steel particles again to form the fourth layer. Then stir and mix these materials evenly.

[0026] (2) Layered stacking: After mixing, the material is stacked in layers into a trapezoidal shape using a loader, with a height of 2.6 meters. The water absorption and cooling process lasts for 7 hours, and the material gradually dries.

[0027] (3) Flat and direct extraction: During the process of loading the mixed material into the silo, a loader with a weighing scale is used to carry out flat and direct extraction in accordance with the operation mode of the stacker-reclaimer. The mixed and water-absorbing material enters the main system through the high-level silo. At this time, the material moisture content is about 14%, the material is loose, and it has the conditions for initial mixing in sintering.

[0028] (4) Strong mixing and quality improvement: The main system of the batching station is equipped with a strong mixing machine. After the mixture of iron dust and sludge with high moisture content, evaporation cold ash, steel particles and gravity ash is mixed by the strong mixing machine, the moisture content of the finished product is about 9%, which meets the sintering batching conditions. Example 3

[0029] (1) Mixing iron dust and sludge with high-temperature ash and steel particles with high CaO content: Weigh 30 tons of high-temperature converter evaporation cold ash and spread it flat as the first layer of base material. Use a loader to evenly spread 10 tons of iron dust and sludge with high moisture content as the second layer to cover the evaporation cold ash. Use 20 tons of steel particles (CaO content 32%, which can release heat and absorb some moisture) directly sent from the slag yard to the batching station as the third layer to cover the dust and sludge. Use 20 tons of blast furnace gravity ash (100℃) to cover the steel particles again to form the fourth layer. Then stir and mix these materials evenly.

[0030] (2) Layered stacking: After mixing, the material is stacked in layers into a trapezoidal shape with a height of 2 meters using a loader. The water absorption and cooling process lasts for 7 hours, and the material gradually dries.

[0031] (3) Flat and direct extraction: During the process of loading the mixed material into the silo, a loader with a weighing scale is used to flat and extract the material in accordance with the operation mode of the stacker-reclaimer. The mixed and water-absorbing material enters the main system through the high-level silo. At this time, the material moisture content is about 12%, the material is loose, and it has the conditions for initial mixing in sintering.

[0032] (4) Strong mixing and quality improvement: The main system of the batching station is equipped with a strong mixing machine. After the mixture of iron dust and sludge with high moisture content, evaporation cold ash, steel particles and gravity ash is mixed by the strong mixing machine, the moisture content of the finished product is about 8%, which meets the sintering batching conditions.

[0033] The above description is only a specific embodiment of the present invention, but the structural features protected by the present invention are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the present invention are covered by the patent scope of the present invention.

Claims

1. A method for utilizing iron-containing dust with high moisture content, characterized in that: Includes the following steps: Step 1: Mixing iron-containing dust and sludge with high-temperature converter evaporation ash, steel particles, and blast furnace gravity ash: The high-temperature converter evaporation ash, iron-containing dust and sludge, steel particles, and blast furnace gravity ash are layered in a mass ratio of 3:1:2:2: First, the high-temperature converter evaporation ash produced by the steel plant is used as the first layer of bottom material; the iron-containing dust and sludge with high moisture content is evenly spread using a loader as the second layer covering the evaporation ash; the steel particles directly transported from the slag yard to the batching station are used as the third layer covering the iron-containing dust and sludge; the blast furnace gravity ash is then placed on top of the steel particles to form the fourth layer, and then these materials are stirred and mixed evenly. Step 2: Layered stacking: The mixed material after stirring is stacked in layers into a ladder shape using a loader, with a height of 2-3 meters. The water absorption and cooling process lasts for 7-10 hours, and the material gradually dries. Step 3: Spreading and taking directly: During the process of loading the mixed material into the silo, a loader with a weighing scale is used to spread and take directly. The mixed and water-absorbing material enters the batching station through the high-level silo. At this time, the material is in a semi-dry state with a moisture content of 12-16%. The material is loose and has the conditions for initial mixing in sintering. Step 4: Intensive mixing and quality improvement: The batching station is equipped with a high-intensity mixer with a processing capacity of 500-600 tons / hour. After the mixture of iron-containing dust and sludge with high moisture content, evaporation cold ash, steel particles, and gravity ash is subjected to intensive mixing, the moisture content of the finished product is controlled at 8%-10%, which meets the sintering batching conditions. In the first step, the steel particles contain 30-39% CaO, which can release heat and absorb some moisture.

2. The method for utilizing iron-containing dust with high moisture content according to claim 1, characterized in that: In the first step, the high-temperature converter evaporates cold ash with a heat of 100~140℃.

3. The method for utilizing iron-containing dust with high moisture content according to claim 1, characterized in that: In the first step, the gravity ash from the blast furnace has residual heat of 80~120℃.

Images