A method of controlling a pelletizing process

Abstract

The present application relates to the technical field of metallurgical pellet production, and discloses a kind of pelletizing process control method, the method comprises: multiple green ball samples are dried;Measure the first average density of multiple green ball samples after drying;Based on the first average density, adjust the feed quantity of green ball manufacturing or the rotation speed of pelletizing disc.The scheme of the present application measures the average density of green ball sample, and adjusts the feed quantity of green ball manufacturing or the rotation speed of pelletizing disc through average density.Thereby, the green ball density and the closed-loop feedback of pelletizing parameter are formed, the production line real-time regulation and control demand is met, and the production work of pelletizing process is prospectively guided when material structure changes in production site.

Description

Technical Field

[0001] This invention relates to the field of metallurgical pellet production technology, specifically to a pelletizing process control method. Background Technology

[0002] In iron ore pellet production, the density of green pellets directly affects the oxygen diffusion rate and high-temperature consolidation efficiency during the oxidative roasting process. Too low a density leads to a loose pellet structure with numerous pore walls, reducing the compressive strength of the finished pellets and increasing the pulverization rate. Too high a density hinders oxygen diffusion into the interior, resulting in incomplete oxidation, poor high-temperature consolidation and crystallization strength, which also leads to low compressive strength in the finished pellets.

[0003] There are few reports on the measurement of iron concentrate pellet density. Green pellet density can reflect the pelletizing parameters and the quality of green pellets. When the pelletizing time is short, the green pellets have a short rolling and squeezing time in the pelletizing pan, resulting in a low green pellet density, and vice versa.

[0004] Therefore, how to control the pelletizing process and measure the density of green pellets using the corresponding equipment has become an urgent problem to be solved. Summary of the Invention

[0005] In view of this, the present invention provides a pelletizing process control method to solve the technical problem of how to control the pelletizing process and measure the density of green pellets using a matching device.

[0006] In a first aspect, the present invention provides a pelletizing process control method, the method comprising: drying multiple green pellet samples; measuring a first average density of the dried multiple green pellet samples; and adjusting the feed rate or pelletizing disc rotation speed of green pellet manufacturing based on the first average density.

[0007] In conjunction with the first aspect, in one possible implementation of the first aspect, adjusting the feed rate or pelletizing disc rotation speed based on the first average density includes: obtaining the standard density of the green pellets corresponding to the optimal compressive strength of the finished pellets; and adjusting the feed rate or pelletizing disc rotation speed based on the comparison result between the standard density and the first average density.

[0008] In conjunction with the first aspect, in one possible implementation of the first aspect, adjusting the feed rate or pelletizing disc rotation speed of green pellet manufacturing based on the comparison result of the standard density and the first average density includes: reducing the feed rate or pelletizing disc rotation speed of green pellet manufacturing when the first average density is less than the standard density, until the difference between the first average density and the standard density reaches a preset range; and increasing the feed rate or pelletizing disc rotation speed of green pellet manufacturing when the first average density is greater than the standard density, until the difference between the first average density and the standard density reaches a preset range.

[0009] In conjunction with the first aspect, in one possible implementation of the first aspect, the method further includes: Based on the adjusted feed rate, pelletizing disc rotation speed, and preset time interval, multiple test green pellets are produced within each preset time interval; the second average density of the multiple test green pellets is measured, and the performance of the multiple test green pellets is tested to determine the corresponding test results; based on the second average density and the corresponding test results, the green pellet manufacturing time interval is determined.

[0010] In conjunction with the first aspect, in one possible implementation of the first aspect, determining the green pellet manufacturing time interval based on the second average density and the corresponding detection results includes: comparing multiple second average densities with multiple detection results respectively; and using the corresponding preset time interval as the green pellet manufacturing time interval based on the comparison results.

[0011] In conjunction with the first aspect, in one possible implementation of the first aspect, measuring the first average density of a plurality of dried green pellet samples includes: measuring the first average density of the plurality of dried green pellet samples based on a green pellet density measuring device, wherein the green pellet density measuring device includes: a liquid container, a balance, and a liquid level change detector; the measurement steps of the first average density include: loading liquid into the liquid container, and setting the mass detected by the balance at the current moment and the volume detected by the liquid level change detector at the current moment to zero; sequentially placing the plurality of green pellet samples, and recording the corresponding mass ma and volume Va of each green pellet sample; and using the formula ρa i =ma i / Va i Calculate the density ρa corresponding to each of the green pellet samples. i The density ρa corresponding to all the green pellet samples. i The average density of the dried green pellets was determined by taking the average.

[0012] In conjunction with the first aspect, in one possible implementation of the first aspect, the liquid contained in the liquid container is mercury.

[0013] In conjunction with the first aspect, in one possible implementation of the first aspect, the green pellet density measuring device further includes: a sample filter basket. Before loading the liquid into the liquid container, the step of measuring the first average density further includes: installing the sample filter basket in the liquid container; sequentially placing a plurality of green pellet samples and recording the corresponding mass ma and volume Va for each green pellet sample, comprising: sequentially placing a plurality of green pellet samples in the sample filter basket and recording the corresponding mass ma and volume Va for each green pellet sample.

[0014] In conjunction with the first aspect, in one possible implementation of the first aspect, the green pellet density measuring device further includes: a balance protective cover, the top surface of which is provided with an upper sample placement protective cover handle; multiple green pellet samples are sequentially placed in the sample filter basket, and the mass ma and volume Va corresponding to each green pellet sample are recorded respectively; the method includes: opening the balance protective cover through the upper sample placement protective cover handle; sequentially placing multiple green pellet samples in the sample filter basket; and recording the mass ma and volume Va corresponding to each green pellet sample respectively.

[0015] In conjunction with the first aspect, in one possible implementation of the first aspect, measuring the second average density of the plurality of test green pellets includes: measuring the second average density of the plurality of test green pellets based on a green pellet density measuring device, wherein the green pellet density measuring device includes: a liquid container, a balance, and a liquid level change detector; the measurement steps of the second average density include: loading liquid into the liquid container, and setting the mass detected by the balance at the current time and the volume detected by the liquid level change detector at the current time to zero; sequentially placing the plurality of test green pellets, and recording the mass mb and volume Vb corresponding to each green pellet sample respectively; and using the formula ρb i =mb i / Vb i Calculate the density ρb corresponding to each of the test pellets. i Based on each preset time interval, the test pellets are grouped, and the density ρb corresponding to the pellets belonging to the same group is determined. i Take the average and measure the second average density of multiple test pellets.

[0016] The technical solution of this invention has the following advantages: This invention provides a pelletizing process control method. The method involves drying multiple green pellet samples; measuring the first average density of the dried green pellet samples; and adjusting the feed rate or pelletizing disc rotation speed based on the first average density. In this process, the average density of the green pellet samples is measured, and the feed rate or pelletizing disc rotation speed is adjusted accordingly. This controls the pelletizing process, forming a closed-loop feedback between green pellet density and pelletizing parameters. This meets the real-time control requirements of the production line and proactively guides the pelletizing process when the material structure changes on the production floor. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic flowchart of a pelletizing process control method provided according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a green pellet density measuring device provided according to an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures: 1-Sample filter basket; 2-Balance protective cover; 3-Liquid container; 4-Balance; 5-Liquid level change detector; 6-Upper sampling and placement protective cover handle. Detailed Implementation

[0020] 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.

[0021] These embodiments are provided to make the disclosure thorough and complete, and to fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0022] It should be noted that, in the description of this disclosure, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationship, are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0023] Furthermore, the terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Terms such as "including" or "contains" mean that the element preceding the word encompasses the element listed after the word, and do not exclude the possibility of encompassing other elements as well.

[0024] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this disclosure depending on the specific circumstances. When a particular device is described as being located between a first device and a second device, an intermediary device may or may not be present between the particular device and the first or second device.

[0025] According to an embodiment of the present invention, a method for controlling a pelletizing process is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0026] This embodiment provides a method for controlling the pelletizing process, such as... Figure 1 As shown, the method includes the following steps: S101. Dry multiple green pellet samples.

[0027] Specifically, drying multiple green bulb samples refers to drying multiple intact green bulbs of similar size at 105±5℃ to constant weight to eliminate interference from free moisture. The number of green bulb samples can be 10, 5, or other quantities; this embodiment does not impose a specific limitation on this.

[0028] S102. Measure the first average density of the dried green pellet samples.

[0029] Specifically, the first average density of the dried green pellet samples is measured using the green pellet density measuring device described in the following embodiment. The specific operation procedure includes: placing multiple green pellet samples into the liquid container 3 at fixed intervals, and recording the mass of each sample on the balance 4. m The detector is set to zero, and the volume is recorded by detector 5 for each liquid level change. V And set to zero, thus according to the formula r i =m i / V i Calculate the density of each ball. Obtain multiple sets of raw ball density data based on the sequentially placed raw balls, and calculate the average density through statistical analysis. r That is, the first average density.

[0030] S103. Based on the first average density, adjust the feed rate or the rotation speed of the pelletizing disc for green pellet production.

[0031] This invention provides a pelletizing process control method. The method involves drying multiple green pellet samples; measuring the first average density of the dried green pellet samples; and adjusting the feed rate or pelletizing disc rotation speed based on the first average density. In this process, the average density of the green pellet samples is measured, and the feed rate or pelletizing disc rotation speed is adjusted accordingly. This controls the pelletizing process, forming a closed-loop feedback between green pellet density and pelletizing parameters. This meets the real-time control requirements of the production line and proactively guides the pelletizing process when the material structure changes on the production floor.

[0032] In one alternative embodiment, adjusting the feed rate or pelletizing disc rotation speed based on the first average density includes: Obtain the standard density of green pellets corresponding to the optimal compressive strength of the finished pellets; based on the comparison between the standard density and the first average density, adjust the feed rate or the rotation speed of the pelletizing disc for green pellet production.

[0033] Specifically, obtaining the standard density of green pellets corresponding to the optimal compressive strength of the finished pellets refers to using the density of green pellets at the optimal compressive strength of the finished pellets as the standard density, denoted as . r s The pelletizing parameters under these conditions are used as a benchmark. The pelletizing time is set to time T by default, which is the pelletizing time corresponding to the standard density.

[0034] In one optional implementation, adjusting the feed rate or pelletizing disc rotation speed for green pellet production based on the comparison between the standard density and the first average density includes: If the first average density is less than the standard density, reduce the feed rate or the rotation speed of the pelletizing disc in green pellet manufacturing until the difference between the first average density and the standard density reaches a preset range; if the first average density is greater than the standard density, increase the feed rate or the rotation speed of the pelletizing disc in green pellet manufacturing until the difference between the first average density and the standard density reaches a preset range.

[0035] Specifically, let 'a' represent the feed rate for green pellet production, and 'b' represent the rotational speed of the pelletizing disc. The preset range can be set according to actual working conditions; for ease of explanation, ±0.1 is used here. r i < r At that time, appropriately reduce a or b ,until r i and r Approaching r i ∈[ r -0.1, r +0.1]. When r i > r At that time, appropriately increase a or b until... r i and r Approaching r i ∈[ r -0.1, r +0.1].

[0036] In the pelletizing process, the green pellet manufacturing time is also a crucial factor. If the pelletizing time is too long, the pellets roll in the pelletizing disc for an extended period, becoming denser and increasing the green pellet density. However, green pellet density is not directly proportional to the compressive strength of the finished pellets. Therefore, after determining the feed rate and pelletizing disc rotation speed for green pellet manufacturing, the green pellet manufacturing time still needs to be determined. In one optional embodiment, the method further includes: Based on the adjusted feed rate, pelletizing disc rotation speed, and preset time interval, multiple test green pellets are produced within each preset time interval; the second average density of the multiple test green pellets is measured, and the performance of the multiple test green pellets is tested to determine the corresponding test results; based on the second average density and the corresponding test results, the green pellet manufacturing time interval is determined.

[0037] Specifically, the preset time interval can be 5 minutes, 3 minutes, or other times; for ease of explanation, 5 minutes will be used here. For example, after adjusting the feed rate and the pelletizing disc rotation speed, test pellets are taken at time intervals of 5 minutes, 10 minutes, 15 minutes, and 20 minutes. It should be understood that the process for determining the second average density is detailed in the following embodiments.

[0038] In one optional implementation, determining the green pellet manufacturing time interval based on the second average density and the corresponding detection result includes: The second average density is compared with multiple detection results respectively; based on the comparison results, the corresponding preset time interval is used as the green pellet manufacturing time interval.

[0039] Specifically, Table 1 below exemplarily illustrates multiple second average densities and multiple detection results.

[0040] Table 1

[0041] The comparative results show that the density of green pellets increases with increasing pelletizing time, while the number of green pellet drops and the compressive strength of the green pellets also show an increasing trend, mainly related to the increasing densification of the pellets. Analysis of the compressive strength of the finished pellets after roasting for green pellets of different densities reveals that the compressive strength of the finished pellets first increases and then decreases with increasing pellet density. When the pelletizing time is short, the pellet structure is loose, and the mechanical strength of the green pellets is low. Although this facilitates oxygen diffusion during roasting, the compressive strength after roasting is still relatively low. Conversely, when the pelletizing time is too long, the pellets roll in the pelletizing pan for too long, becoming more dense, and the mechanical strength of the green pellets is significantly improved. However, this hinders oxygen diffusion during roasting, resulting in poor consolidation and low compressive strength. Overall, a pelletizing time of 10-15 minutes yields qualified green pellets and the best finished pellet quality, with a corresponding green pellet density of 2.96 g / cm³-3.12 g / cm³. Therefore, we can judge and predict the quality of the pellets by detecting the green pellet density.

[0042] This embodiment also provides a green bulb density measuring device, which is used to implement the above embodiments and preferred embodiments, and will not be repeated as already described. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0043] This embodiment provides a device for measuring the density of green bulbs, such as... Figure 2 As shown, it includes: Liquid container 3, balance 4, liquid level change detector 5, among which, The liquid container 3 is placed on the balance 4 to detect the mass of the raw balls placed in the liquid container 3; the liquid level change detector 5 is connected to the liquid container 3 to detect changes in the liquid level in the liquid container 3.

[0044] Specifically, the measurement steps for the first average density include: The liquid is loaded into the liquid container, and the mass detected by the balance at the current moment and the volume detected by the liquid level change detector at the current moment are both set to zero. Multiple green pellet samples are placed in sequence, and the mass ma and volume Va corresponding to each green pellet sample are recorded respectively; Using the formula ρa i =ma i / Va i Calculate the density ρa corresponding to each of the green pellet samples. i ; The density ρa corresponding to all the green pellet samples i The average density of the dried green pellets was determined by taking the average.

[0045] In one alternative embodiment, the liquid container 3 contains mercury.

[0046] Specifically, to obtain the density of an object, its mass and volume are usually known, and then calculated using the density formula. The mass of green pellets can be obtained by weighing, but because green pellets vary in shape and are spherical, they cannot be obtained through parameter measurement. If the traditional displacement method is used to measure the volume of green pellets, the porous medium of the green pellets and the capillary action of the mineral powder cause a certain degree of water absorption, leading to deviations in the volume measurement. Therefore, mercury is placed in liquid container 3 to avoid errors caused by water absorption.

[0047] In one alternative embodiment, the device further includes a sample filter basket 1, wherein the sample filter basket 1 is placed inside the liquid container 3 for holding green pellets.

[0048] Specifically, the green pellet density measuring device further includes: a sample filter basket; and the first average density measurement step, prior to loading the liquid into the liquid container, further includes: Install the sample filter basket in the liquid container; Multiple green pellet samples are sequentially placed in the container, and the mass ma and volume Va corresponding to each green pellet sample are recorded, including: Multiple green pellet samples are placed sequentially in the sample filter basket, and the corresponding mass ma and volume Va of each green pellet sample are recorded.

[0049] In one alternative embodiment, the device further includes a balance protection cover 2, wherein the balance protection cover 2 is placed on the balance 4 and the liquid container 3 and the liquid level change detector 5 are placed inside the cover.

[0050] In one alternative embodiment, the top surface of the balance protective cover 2 is provided with an upper sampling protective cover handle 6.

[0051] Specifically, the upper sampling protective cover handle 6 facilitates the taking / placing of the balance protective cover 2, thereby facilitating the placement and removal of raw balls.

[0052] Specifically, multiple green pellet samples are sequentially placed in the sample filter basket, and the corresponding mass ma and volume Va of each green pellet sample are recorded, including: Open the balance protective cover by taking out the upper sample protective cover handle, put multiple green pellet samples into the sample filter basket in sequence, and record the corresponding mass ma and volume Va for each green pellet sample.

[0053] In one optional embodiment, measuring the second average density of the plurality of test green pellets includes: measuring the second average density of the plurality of test green pellets based on a green pellet density measuring device, wherein the green pellet density measuring device includes: a liquid container, a balance, and a liquid level change detector; the measurement step of the second average density includes: The liquid is loaded into the liquid container, and the mass detected by the balance at the current moment and the volume detected by the liquid level change detector at the current moment are both set to zero. Multiple test green pellets are placed in sequence, and the mass mb and volume Vb corresponding to each green pellet sample are recorded respectively; Using the formula ρb i =mb i / Vb i Calculate the density ρb corresponding to each of the test pellets. i ; Based on each preset time interval, the test pellets are grouped, and the density ρb corresponding to the pellets belonging to the same group is determined. i Take the average and measure the second average density of multiple test pellets.

[0054] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for controlling the pelletizing process, characterized in that, The method includes: Multiple green pellet samples were dried; Measure the first average density of multiple dried green pellet samples; Based on the first average density, adjust the feed rate or the rotation speed of the pelletizing disc for green pellet production.

2. The method according to claim 1, characterized in that, The step of adjusting the feed rate or pelletizing disc rotation speed based on the first average density includes: Obtain the standard density of green pellets corresponding to the optimal compressive strength of the finished pellets; Based on the comparison between the standard density and the first average density, the feed rate or the rotation speed of the pelletizing disc in green pellet production is adjusted.

3. The method according to claim 2, characterized in that, The adjustment of the feed rate or pelletizing disc rotation speed in green pellet production based on the comparison between the standard density and the first average density includes: If the first average density is less than the standard density, reduce the feed rate or the rotation speed of the pelletizing disc in green pellet production until the difference between the first average density and the standard density reaches a preset range. If the first average density is greater than the standard density, increase the feed rate or the rotation speed of the pelletizing disc in the green pellet manufacturing process until the difference between the first average density and the standard density reaches a preset range.

4. The method according to claim 1, characterized in that, The method further includes: Based on the adjusted feed rate, pelletizing disc rotation speed, and preset time interval, multiple test pellets are produced within each preset time interval. The second average density of multiple test green pellets is measured, and the performance of the multiple test green pellets is tested to determine the corresponding test results; Based on the second average density and the corresponding detection results, the time interval for green pellet manufacturing is determined.

5. The method according to claim 4, characterized in that, The step of determining the green pellet manufacturing time interval based on the second average density and the corresponding detection result includes: Each of the second average densities is compared with the multiple detection results; Based on the comparison results, the corresponding preset time interval is used as the time interval for raw pellet manufacturing.

6. The method according to claim 1, characterized in that, The measurement of the first average density of the multiple dried green bulb samples includes: measuring the first average density of the multiple dried green bulb samples based on a green bulb density measuring device, wherein the green bulb density measuring device includes: a liquid container, a balance, and a liquid level change detector; the measurement steps of the first average density include: The liquid is loaded into the liquid container, and the mass detected by the balance at the current moment and the volume detected by the liquid level change detector at the current moment are both set to zero. Multiple green pellet samples are placed in sequence, and the mass ma and volume Va corresponding to each green pellet sample are recorded respectively; Using the formula ρa i =ma i / Va i Calculate the density ρa corresponding to each of the green pellet samples. i ; The density ρa corresponding to all the green pellet samples i The average density of the dried green pellets was determined by taking the average.

7. The method according to claim 6, characterized in that, The liquid contained in the liquid container is mercury.

8. The method according to claim 7, characterized in that, The green pellet density measuring device further includes: a sample filter basket; and the first average density measurement step, prior to loading the liquid into the liquid container, further includes: Install the sample filter basket in the liquid container; Multiple green pellet samples are sequentially placed in the container, and the mass ma and volume Va corresponding to each green pellet sample are recorded, including: Multiple green pellet samples are placed sequentially in the sample filter basket, and the corresponding mass ma and volume Va of each green pellet sample are recorded.

9. The method according to claim 8, characterized in that, The green pellet density measuring device further includes: a balance protective cover, the top surface of which is provided with an upper sample placement protective cover handle. Multiple green pellet samples are sequentially placed in the sample filter basket, and the corresponding mass ma and volume Va for each green pellet sample are recorded, including: Open the balance protective cover by taking out the upper sample protective cover handle, put multiple green pellet samples into the sample filter basket in sequence, and record the corresponding mass ma and volume Va for each green pellet sample.

10. The method according to claim 4, characterized in that, The measurement of the second average density of the plurality of test green pellets includes: measuring the second average density of the plurality of test green pellets based on a green pellet density measuring device, wherein the green pellet density measuring device includes: a liquid container, a balance, and a liquid level change detector; the measurement steps of the second average density include: The liquid is loaded into the liquid container, and the mass detected by the balance at the current moment and the volume detected by the liquid level change detector at the current moment are both set to zero. Multiple test green pellets are placed in sequence, and the mass mb and volume Vb corresponding to each green pellet sample are recorded respectively; Using the formula ρb i =mb i / Vb i Calculate the density ρb corresponding to each of the test pellets. i ; Based on each preset time interval, the test pellets are grouped, and the density ρb corresponding to the pellets belonging to the same group is determined. i Take the average and measure the second average density of multiple test pellets.

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