Carbon forming process dust collection powder accurate back matching system

Abstract

This invention discloses a precise dust collection and reprocessing system for the carbon forming process, belonging to the field of electrolytic aluminum anode production technology, to solve the problem of insufficiently scientific and reasonable dust collection and reprocessing in the forming process. The system includes a post-calcination coke dust collection and reprocessing system, an anode slotting dust collection and reprocessing system, a batching scale, and a host computer control system. This invention is rationally designed, simple to modify, and inexpensive. After modification, the cost reduction, efficiency improvement, and product quality enhancement effects are significant, making it highly practical and worthy of promotion in relevant enterprises.

Description

Technical Field

[0001] This invention belongs to the field of electrolytic aluminum anode production technology, specifically relating to a precise dust collection and remixing system for the carbon forming process. Background Technology

[0002] Prebaked anode carbon blocks for electrolytic aluminum are a type of carbon material that is gradually consumed during the electrolysis process. In the carbon system forming process, the main raw material is granular calcined coke, which generates a large amount of dust during production. As a core product of the entire carbon production process (crushing, grinding, mixing, forming, and calcining), this dust is a recyclable "hidden raw material reservoir." Its treatment directly determines the raw material utilization rate, anode quality stability, and environmental compliance, making it a crucial link in carbon production where "a single change affects the entire process."

[0003] Currently, in the carbon industry, the dust collected during the forming process is mostly collected after calcination and fed into the grinding system, while the dust collected from the residual anode is discharged from the system.

[0004] like Figure 1 The process flow diagram of the dust collection system for the 500kA molding process in our carbon plant No. 2 is shown. The dust collection powder is divided into three categories: calcined coke dust collection powder, residual anode dust collection powder, and anode slotting dust collection powder.

[0005] Among these processes, directly re-blending the calcined coke dust into the ball mill has been found over many years of production to easily lead to the accumulation of dust within the system, creating a vicious cycle of "the more you grind, the finer it becomes," directly causing fluctuations in powder quality. The current Blaine content of the powder is 5500-7500 cm⁻¹. 2 / g, with a fluctuation range of up to 3000cm 2 / g, far exceeding the process control range, which may cause anode quality risks; The residual dust collected from the anode is directly discharged due to excessive impurities. The sales price of the discharged residual dust is low, and its utilization rate has not been fully developed. When the calcined anode grooving powder flows into the residual anode storage tank, it is very easy for it to stratify in the silo due to the large particle size difference. The stratified powder cannot provide stable raw materials for the batching process, which will further aggravate the anode quality risk.

[0006] Based on the problems mentioned above, the researchers proposed a precise dust collection and remixing system for the carbon forming process. Summary of the Invention

[0007] The purpose of this invention is to provide a precise dust collection and recycling system for the carbon forming process, so as to solve the problem that the dust collection and recycling in the forming process is not scientific and reasonable enough.

[0008] To solve the above problems, the technical solution of the present invention is as follows: A precise dust collection and reprocessing system for carbon forming process includes a calcined coke dust collection and reprocessing system, an anode slotting dust collection and reprocessing system, a batching scale, and a host computer control system. The post-calcined coke dust collection and recycling system includes a pre-milling chamber, a ball mill, a particle classifier, and a powder silo connected in sequence; it also includes a dust collection silo, a black process purification device, a dust collector, and a purification silo connected in sequence; the particle classifier is connected to the purification silo. The residual anode dust collection and recycling system includes a residual anode bin, a crushing device, and a screening device connected in sequence; the under-screen space of the screening device is connected to an external discharge bin via a pipeline. The anode slotting dust collection powder recycling system includes a dust collector, an intermediate silo, and a buffer silo connected in sequence; the intermediate silo is connected to a coarse material silo; the intermediate silo is also connected to the screen space of the screening device through a pipeline; the buffer silo is connected to the pre-milling silo of the calcined coke dust collection powder recycling system. The coarse material silo, powder material silo, and purification silo are all connected to the batching scale, which is also connected to the host computer.

[0009] The entire system exists independently of the post-calcination coke system, and the dust collected from the carbon forming process is independently graded and reused.

[0010] Furthermore, level gauges are installed in the coarse particle silo, powder silo, purification silo, residual electrode silo, external discharge silo, intermediate silo, buffer silo, pre-milling silo, and dust collection silo. Each of these silos is equipped with a discharge valve, and each level gauge and discharge valve is connected to a host computer. This enables automatic control of material discharge, feeding, and batching.

[0011] Furthermore, the under-screen space of the particle grading device is connected to the purification chamber via a conveying device; the over-screen space of the particle grading device is connected to the powder silo via a pneumatic chute.

[0012] Furthermore, an iron remover and a silo pump are installed on the connecting pipeline between the screening device and the intermediate silo.

[0013] Furthermore, a silo pump is installed between the dust collector and the intermediate silo; a silo pump is installed at the outlet of the intermediate silo, and the material conveying between the intermediate silo and the residual electrode silo, coarse particle silo, and buffer silo is achieved by the silo pump.

[0014] Furthermore, the black fumes purification device is also connected to the asphalt fume pipes of the mixer, the asphalt fume pipe of the forced refrigeration unit, and the asphalt fume pipe of the molding machine, which simultaneously collects other asphalt fumes from the molding process and integrates them into the black fumes purification device for unified treatment, thus saving costs.

[0015] The beneficial effects of this invention are as follows: (1) The present invention divides the dust collection powder of the carbon forming process into a calcined coke dust collection powder recycling system, a residual anode dust collection powder recycling system and an anode slotting dust collection powder recycling system. Each system operates independently but is interconnected. As a supplementary system for the batching of coarse coke, medium coke and fine coke in the calcined coke storage tank, it not only solves the problem of large fluctuations in the Blaine of powder caused by the circulation and enrichment of calcined coke dust collection powder in the ball mill, but also rationally classifies various dust collection powders and participates in the batching in different silos.

[0016] From a technological perspective, the dust collected during the carbon forming process is fully recycled and utilized, with only a very small amount of ultrafine powder unusable for external sales. From a cost perspective, the increased recycling volume completely eliminates the over-grinding mode of the dust collected within the grinding system, inevitably leading to cost reduction and efficiency improvement. In terms of the quality of the prebaked anode products produced after the raw materials enter the production process, the narrowing of the fluctuation range of the Blaine powder allows for flexible adjustment of the materials at each particle size distribution, resulting in a high degree of consistency between the theoretical formula and the actual raw materials for the three-grade distribution. Ultimately, this leads to a 5 μΩ·m decrease in the average anode resistivity and a 20% increase in the first-grade yield of prebaked anodes.

[0017] In summary, this system is reasonably designed, easy to modify, and inexpensive. After modification, the effects of cost reduction, efficiency improvement, and product quality enhancement are very significant. It is highly practical and worth promoting among relevant enterprises. Attached Figure Description

[0018] Figure 1 This is a diagram of the dust collection system for the 500kA molding process in our carbon plant No. 2; Figure 2 This is a schematic diagram of the system of the present invention; Figure 3 This is a schematic diagram of the control structure of the host computer in this invention; Figure 4 This is a control chart of Blaine values ​​for the modified powder in Example 2 (values ​​randomly selected from March 2025 to April 2025). Figure 5 This is a monthly trend chart of the resistivity index of the modified prebaked anode in Example 2 (August 2024 - September 2025). Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Therefore, the following detailed description of embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0021] Example 1

[0022] A precise dust collection and reprocessing system for carbon forming process includes a post-calcined coke dust collection and reprocessing system, an anode slotting dust collection and reprocessing system, a residual anode dust collection and reprocessing system, a host computer control system, and a batching scale.

[0023] Each system will be described in detail below: like Figure 2 As shown: 1. Calcination coke dust recycling system; The post-calcined coke dust collection and recycling system includes a pre-milling chamber, a ball mill, a particle classification device, a pneumatic chute, and a powder silo connected in sequence. It also includes a dust collection bin, a black filtration purification device, a dust collector, and a purification bin connected in sequence; The undersize material from the particle grading device is connected to the purification chamber via a conveying device; the oversize material from the particle grading device directly enters the pneumatic chute.

[0024] The dust collection bin is connected to all dust collectors in the entire molding process, including: to collect dust from all stages of the molding process, and to use the dust collected in the bin as raw material for black process purification, which is then transported to the black process purification device; the black process purification device is connected to the asphalt smoke pipe of the mixing machine, the asphalt smoke pipe of the forced cooling machine, and the asphalt smoke pipe of the molding machine.

[0025] The entire post-calcination coke dust recycling system provides two materials to the batching system: The purification chamber contains fine dust collected by the dust collector and fine material undersize from the particle grading device, which provides fine material for the batching system. The powder silo contains intermediate-fineness materials after grinding and classification. The fineness of the material can be dynamically adjusted by the mill and particle classification device to meet the needs of the batching system.

[0026] 2. Waste dust collection and recycling system; The residual electrode dust collection and distribution system includes a residual electrode bin, a crushing device, and a screening device connected in sequence. The material oversize from the screening device is connected to the intermediate silo of the anode slotted dust collection and distribution system via a pipeline; a magnetic separator and a silo pump are installed on this pipeline. The undersize material from the screening device is connected to an external discharge bin via a pipeline.

[0027] The materials in the residual dust collection and distribution system have a high iron content and cannot be directly fed into the batching system. Therefore, an iron remover is installed to remove iron and screen out some of the extremely fine materials that cannot be fed into the batching system. These unusable extremely fine materials are stored in the external discharge silo and packaged for sale at an opportune time. The materials that have been screened and have had their iron removed enter the intermediate silo as one of the supplementary materials for the intermediate silo.

[0028] 3. Anode trenching dust collection and recycling system; The anode slotting dust collection and distribution system includes a dust collector, an intermediate silo, and a buffer silo connected in sequence. The dust collector is located above the grooving machine; an air intake fan is connected to the top of the dust collector. The intermediate silo serves as a storage silo and is also connected to the coarse material silo, providing a path for the coarse material to directly enter the batching system.

[0029] The buffer chamber is connected to the pre-mill chamber of the calcined coke dust collection and reprocessing system.

[0030] The anode trough dust collection and recycling system provides a large amount of raw materials for the batching system. The coarse material silo provides the system with coarse particle raw materials; The buffer bin serves as a raw material replenishment buffer point before grinding. After being processed by the calcined coke dust recovery and distribution system, it provides the batching system with fine materials and intermediate-fineness materials with adjustable fineness.

[0031] 4. Host computer control system; like Figure 3 As shown: All silos are equipped with level gauges, and each silo has a discharge valve at the bottom. The level gauges and discharge valves are connected to the host computer in the central control room, which allows the host computer to monitor the level of each silo at any time and adjust the infeed and discharge of each silo. At the same time, it can open and close various relevant valves according to process and formula requirements, so as to realize the automatic control of the system.

[0032] 5. Batching scale; The coarse material silo, powder silo, and purification silo are all connected to the batching scale, which is also connected to the host computer for easy weighing according to the formula. The batching scale is connected to the batching screw at the rear end to send the material into the batching system.

[0033] Example 2

[0034] The difference from Example 1 is that: Taking the actual upgrade and technological transformation of the dust collection and recycling system of the 500kA molding process in our carbon plant No. 2 as an example: 1. In the calcined coke dust recycling system: A belt conveyor is installed between the pre-grinding chamber and the ball mill; A variable frequency unloader and a screw conveyor are installed sequentially between the dust collection bin and the black bleaching purification device. The dust collection bins are connected to the dust collection devices of the raw material storage bins, molding system, various conveyor belts, and various bucket elevators in the molding process. The modification in this embodiment makes the dust collection powder conveying channel of the calcined coke dust collection powder recycling system clear and independent, which can bypass the ball milling process and directly quantitatively feed the powder into the kneading process through the feeding screw, avoiding the accumulation of fine powder in the ball mill and dust collection cycle; and can realize a graded utilization mode in which the intermediate particle material comes from the powder silo of the ball mill during the feeding before kneading, and the fine powder is directionally supplemented from the dust collection powder purification silo.

[0035] 2. In the residual dust collection and distribution system: The magnetic separator uses the CBZ-5 fully automatic drawer-type magnetic separator, with a maximum surface magnetic field strength of ≥12000gs for the magnetic rods. It has 17 magnetic rods in 5 layers, a processing capacity of ≥3T / h, and is equipped with a 1m... 3 The ground-level iron collection box collects iron slag, and the inlet and outlet of the iron remover are equipped with fully automatic electric valves (a manual slide valve is added upstream for easy maintenance). The third type of silo pump adopts the ATP-500 / 100 silo pump, with a conveying capacity of ≥2T / h, a vertical height of ≥40m, and a horizontal distance of ≥120m; After passing through the iron remover, the material on the screen is pumped to the intermediate silo by the ATP-500 / 100 silo pump.

[0036] 3. In the anode trenching dust collection and recycling system: The grooving machine dust collector is topped with an 800mm wide steel platform (1200mm high railing); Build 90m 3 The intermediate silo, based on a daily requirement of 450 anodes for electrolysis, a single anode producing 20 kg of slotted powder, and a storage capacity for 10 days of shutdown, has a bulk density of 1.0 g / cm³. 3 Due to space constraints, the column spacing is 4.5 meters. The intermediate warehouse is equipped with a standard staircase conforming to GB4503.2-2009. Due to space limitations during construction, the capacity of the intermediate warehouse is limited. Therefore, a separate pipeline is installed to connect the intermediate warehouse with the residual electrode warehouse to prevent insufficient capacity in the intermediate warehouse. This pipeline can supply a portion of the residual electrode to the residual electrode warehouse when needed and serves as a backup line during normal operation.

[0037] Simultaneously build 2m 3 Buffer bay.

[0038] Both silos are equipped with 600×600mm manholes on the top; each silo bottom cone is equipped with two sets of silo wall vibrators.

[0039] A silo pump is installed between the dust collector and the intermediate silo; A second silo pump is installed at the outlet of the intermediate silo. The material conveying between the intermediate silo and the residual electrode silo, coarse particle silo, and buffer silo is entirely achieved by the second silo pump.

[0040] All the chamber pumps used in the above systems utilize dual air sources: an air compressor and factory-compressed air, equipped with 3m³ / h. 3 gas tank; All silos are equipped with top dust collectors to prevent dust from spilling out; the model should be selected according to the silo capacity. In this embodiment of the modification: The newly built intermediate silo is equipped with a DMC-112B dust collector (air volume 4500m³ / h). 3 / h, filtration area ≥90㎡, 7.5kW motor); The buffer chamber is equipped with a DMC-112A dust collector (air volume 4500m³ / h). 3 / h, filtration area ≥90㎡, 7.5kW motor); 5. Batching scale: The batching scale uses a Hasler batching scale, which utilizes its high-precision loss-in-weight batching system (metering accuracy ±1%). By dynamically monitoring the mass flow rate of the collected dust in real time, and combining it with the batching system, it achieves closed-loop quantitative control of batching, solving the problem of fluctuation in the original batching amount and realizing accurate metering of the collected dust. Moreover, the collected dust used in batching can be switched between the powder silo and the purification silo at any time, so that the collected dust can be added as a controllable component according to the powder particle size requirements.

[0041] In this embodiment of the modification: By dynamically monitoring the material level in each silo in real time, and combining the material valve and batching scale to achieve closed-loop control, the problem of fluctuation in the original batching amount (unpredictable fluctuations of 2.1-5.7t / h before the transformation) can be solved, and the amount of dust collected can be accurately controlled within the formula ratio of 6%-7%.

[0042] The overall implementation effect of this modified embodiment: 1. The dust collection powder circulating and over-grinding mode within the grinding system is completely eliminated, and the overall power consumption of the molding process is reduced from the original 66kWh / t to 60kWh / t, a reduction of 10%, saving 1.2 million kWh of electricity per year. Calculated at an electricity price of 0.4 yuan / kWh, this translates to an annual saving of 480,000 yuan.

[0043] 2. The quality indicators of the powder have improved significantly, such as... Figure 4 As shown, the Blaine value of the modified powder has decreased from 5500-7000 before the modification to 3500-4000 at the current stage, meeting the process standards and narrowing the fluctuation range to within 500.

[0044] Furthermore, after the calcined coke dust is removed, two sets of particle size distribution raw materials are formed in the batching system: One of the systems is the original calcined coke tipper system, which separates the coke, medium coke, and fine coke after they enter the calcined coke storage tank. Figure 1 The middle part remains unchanged. Figure 2(No duplicate drawings). The proportion of medium and coarse particles (0.075-0.15mm) has recovered from 25% before stripping to 38%, and the proportion of coarse particles (≥0.15mm) has increased from 5% to 15%. The particle size distribution has returned to the theoretical ratio of "coarse 15% - medium 40% - fine 45%", which significantly reduces the excessive adsorption of asphalt by fine powder. This makes the specific surface area of ​​fine particles controllable after the ingredients enter the mixing system, and the asphalt content has been reduced from 16% to 15%, thus reducing asphalt consumption.

[0045] The other one is Figure 2 The coarse material bin, powder bin, and purification bin provided by the coarse material bin, powder bin, and purification bin can be mixed into the kneading system in proportion, or added as an additional supplement to any granular material if the three-stage distribution of calcined coke is not ideal, further ensuring the accurate fit between the batching and the theory.

[0046] 3. The stability of the kneading system has been greatly improved, the accuracy of dust collection and powder metering has been increased by 15 times, the material feeding obstruction effect of the powder scale has disappeared, the number of times the kneading system stops due to powder fluctuations has been reduced from 3-10 times per month to 0 times, and the operational stability of the molding system has been improved by more than 70%.

[0047] 4. The residual powder discharged from the anode is incorporated into the batching system, enabling quantitative reuse back to the production line. The reprocessing volume is 200t / month, and material consumption is optimized by 0.013t / t. Based on the price difference between the sales price of the fine residual powder discharged from the anode and the price of its use as residual powder, it is estimated that the molding process achieves a cost reduction of 271,000 yuan / month, and an annual cost reduction of 3,252,000 yuan.

[0048] 5. The homogeneity of the prebaked anode has been steadily improved since August 2024 after the implementation of the modification, such as... Figure 5 As shown, the average anode resistivity decreased by 5 μΩ·m, the first-grade rate of prebaked anodes increased by 20%, and the annual loss of defective products was reduced by approximately 7.21 million yuan.

Claims

1. A precise dust collection and recycling system for carbon forming processes, characterized in that, The system includes a post-calcination coke dust collection powder recycling system, an anode slotting dust collection powder recycling system, a residual anode dust collection powder recycling system, a batching scale, and a host computer control system; The post-calcined coke dust collection and recycling system includes a pre-milling chamber, a ball mill, a particle classifier, and a powder silo connected in sequence; it also includes a dust collection silo, a black process purification device, a dust collector, and a purification silo connected in sequence; the particle classifier is connected to the purification silo. The residual anode dust collection and recycling system includes a residual anode bin, a crushing device, and a screening device connected in sequence; the under-screen space of the screening device is connected to an external discharge bin via a pipeline. The anode slotting dust collection powder recycling system includes a dust collector, an intermediate silo, and a buffer silo connected in sequence; the intermediate silo is connected to a coarse material silo; the intermediate silo is also connected to the screen space of the screening device through a pipeline; the buffer silo is connected to the pre-milling silo of the calcined coke dust collection powder recycling system. The coarse material silo, powder material silo, and purification silo are all connected to the batching scale, which is also connected to the host computer.

2. The carbon forming process dust collection powder precise recycling system as described in claim 1, characterized in that: The coarse particle silo, powder silo, purification silo, residual electrode silo, external discharge silo, intermediate silo, buffer silo, pre-grinding silo, and dust collection silo are all equipped with level gauges. Each of the coarse particle silo, powder silo, purification silo, residual electrode silo, external discharge silo, intermediate silo, buffer silo, pre-grinding silo, and dust collection silo is equipped with a discharge valve. Each level gauge and discharge valve is connected to the host computer.

3. A precise dust collection and remixing system for carbon forming process as described in claim 1 or 2, characterized in that: The under-screen space of the particle grading device is connected to the purification chamber via a conveying device; the over-screen space of the particle grading device is connected to the powder silo via a pneumatic chute.

4. The carbon forming process dust collection powder precise recycling system as described in claim 3, characterized in that: The screening device and the intermediate silo are connected by an iron remover and a silo pump.

5. The carbon forming process dust collection powder precise recycling system as described in claim 4, characterized in that: The intermediate compartment and the residual electrode compartment are connected by a pipeline.

6. The carbon forming process dust collection powder precise recycling system as described in claim 5, characterized in that: A silo pump is installed between the dust collector and the intermediate silo; a second silo pump is installed at the outlet of the intermediate silo.

7. The carbon forming process dust collection powder precise recycling system as described in claim 6, characterized in that: The black fumes purification device is also connected to the asphalt smoke pipe of the mixer, the asphalt smoke pipe of the forced cooling machine, and the asphalt smoke pipe of the molding machine.

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