Single-stage water washing desalting process and system for sintered fly ash

Abstract

The application provides a sintering dust removal ash single-stage water washing desalination process and system. When the difference between the alkali metal salt concentration of the clear liquid in the clear liquid tank and the target concentration of the alkali metal salt is within a preset range, the clear liquid is sent to a subsequent evaporation crystallization desalination process, which can prevent the alkali metal salt concentration of the clear liquid from being too high to cause crystallization and block the pipeline when the clear liquid is transported in the pipeline, and can provide a higher concentration of clear liquid for the subsequent evaporation crystallization process. When the alkali metal salt concentration of the clear liquid is too high, the clear liquid is diluted by adding an appropriate amount of water to the clear liquid tank to control the alkali metal salt concentration of the clear liquid within a desired range, so as to avoid crystallization and block the pipeline when the clear liquid is transported in the pipeline. When the alkali metal salt concentration of the clear liquid is too low, the clear liquid is controlled to flow back to the slurry tank to participate in water washing again, so as to form a clear liquid salt enrichment cycle, effectively improve the alkali metal salt concentration of the clear liquid, and avoid the clear liquid from directly entering the evaporation crystallization desalination process, thereby effectively reducing energy consumption.

Description

Technical Field

[0001] This invention relates to the field of sintering dust disposal technology, and in particular to a single-stage water washing and desalination process and system for sintering dust. Background Technology

[0002] Sintering dust mainly comes from dust generated during the sintering machine head, tail, and environmental dust removal processes, especially the dust from the sintering machine head, which contains a relatively large amount of alkali metal elements such as K and Na.

[0003] Currently, the commonly used method is as follows: Figure 4 The typical water washing desalination system shown is used to remove alkali metal elements such as K and Na. The working principle of the water washing desalination system is mainly based on two core processes: water washing and evaporation crystallization. The water washing process separates soluble substances (such as K and Na) from the dust, and the evaporation crystallization technology is used to crystallize and separate the salt in the washing liquid, producing by-product salt, thus realizing the recycling of resources in the dust.

[0004] However, existing technologies typically use the same water washing process for all dust collector ash, for example, washing all the dust from the electrostatic precipitator head according to... Figure 4 The multi-stage or single-stage washing process shown can lead to uncertainties in the final washing liquid concentration due to the often uncertain source or composition of dust from sintering plants. This can result in a high concentration of the final washing liquid, such as when the concentration of alkali metal salts in the clear liquid is close to the saturation concentration. In this case, when the temperature decreases, KCl crystals in the clear liquid are prone to crystallization in the pipes, potentially causing blockages and hindering production. Alternatively, the final clear liquid concentration may be low, such as when the concentration of alkali metal salts in the clear liquid is far below the saturation concentration. In this case, more energy needs to be consumed in the subsequent evaporation, crystallization, and salt separation processes to evaporate the water in the washing liquid, thus increasing ineffective energy consumption.

[0005] Therefore, it is necessary to propose a single-stage water washing and desalination process and system for sintering dust removal to solve or at least alleviate the above-mentioned defects. Summary of the Invention

[0006] The main objective of this invention is to provide a single-stage water washing and desalination process and system for sintering dust, in order to solve the technical problems of existing technologies that use the same water washing process for dust, resulting in uncertain concentration of the washing liquid, which leads to pipe blockage due to excessively high concentration of washing liquid upon cooling and crystallization, or excessively low concentration of washing liquid, which requires additional ineffective energy consumption in subsequent evaporation, crystallization and salt separation processes.

[0007] To achieve the above objectives, the present invention provides a single-stage water washing and desalination process for sintering dust, comprising the following steps:

[0008] S1, during the initial production, the slurry outlet valve of the slurry tank is closed, and fresh water and dust removal ash are introduced into the slurry tank in proportion so that the fresh water and dust removal ash are mixed in the slurry tank to form slurry;

[0009] S2, after the slurry tank reaches the set liquid level, the feeding is stopped, and the slurry outlet valve is opened to allow the slurry to enter the solid-liquid separation device; wherein, the solid-liquid separation device is used to receive the slurry and generate clear liquid, the clear liquid enters the clear liquid tank, the clear liquid tank includes a first outlet valve and a second outlet valve, the first outlet valve and the second outlet valve are in a closed state before the clear liquid tank reaches the set liquid level;

[0010] S3, before the clear liquid tank reaches the set liquid level, determine the concentration of alkali metal salt in the clear liquid tank;

[0011] S4, when the difference between the concentration of the alkali metal salt in the clear liquid and the target concentration of the alkali metal salt is within a preset range, it is determined that the concentration of the alkali metal salt in the clear liquid is within the desired range. After the clear liquid tank reaches the set liquid level, the second liquid outlet valve is opened so that the clear liquid in the clear liquid tank can enter the subsequent evaporation, crystallization and salt separation process.

[0012] Preferably, step S3 is followed by the step:

[0013] When the difference between the concentration of the alkali metal salt in the clarified liquid and the target concentration of the alkali metal salt is greater than a first preset value, it is determined that the concentration of the alkali metal salt in the clarified liquid tank is in a high concentration range. The inlet valve of the clarified liquid tank is then opened, and the process is performed according to the formula... Adjust the flow rate of the inlet valve of the clear liquid tank to the added water flow rate. ;in: This represents the target concentration of alkali metal salts in the clarified solution Q1 in the clarified solution tank. The flow rate of the clear liquid Q1, This refers to the amount of water in the slurry tank when it reaches the set liquid level during initial production. This refers to the amount of dust collected in the slurry tank when it reaches the set liquid level during initial production. The content of alkali metal salts in dust B. The water content in dust collector B;

[0014] Continue to add fresh water and dust removal ash to the slurry tank in proportion. When the clear liquid tank reaches the set liquid level, open the second liquid outlet valve so that the clear liquid in the clear liquid tank can enter the subsequent evaporation, crystallization and salt separation process.

[0015] Preferably, step S3 is followed by the step:

[0016] S31, when the difference between the concentration of the alkali metal salt in the clear liquid and the target concentration of the alkali metal salt is less than the second preset value, it is determined that the concentration of the alkali metal salt in the clear liquid tank is in the low concentration range. Fresh water and dust removal ash are added to the slurry tank in proportion. When the clear liquid tank reaches the set liquid level, the first liquid outlet valve is opened to send the clear liquid in the clear liquid tank back to the slurry tank, and the flow rate of the first liquid outlet valve is controlled to be the same as the flow rate of the clear liquid generated by the solid-liquid separation device.

[0017] S32, then follow the formula Adjust the flow rate of the inlet valve of the slurry tank to the water addition flow rate. This allows the slurry tank, the solid-liquid separation device, and the clarified liquid tank to form a clarified liquid enrichment salt cycle; wherein, The water flow rate for adding water to the slurry tank when it reaches the set liquid level after initial production;

[0018] S33, determine the real-time alkali metal salt concentration of the clear liquid in the clear liquid tank during the circulation process, and determine whether the difference between the real-time alkali metal salt concentration of the clear liquid and the target concentration of the alkali metal salt is within a preset range;

[0019] S34, when the difference between the real-time alkali metal salt concentration of the clear liquid and the target concentration of the alkali metal salt is within a preset range, it is determined that the real-time alkali metal salt concentration of the clear liquid is within the desired range. After the clear liquid tank reaches the set liquid level, the second liquid outlet valve is opened so that the clear liquid in the clear liquid tank can enter the subsequent evaporation, crystallization and salt separation process.

[0020] Preferably, after determining whether the difference between the real-time alkali metal salt concentration of the clarified liquid and the target concentration of the alkali metal salt is within a preset range in step S33, the method further includes the following step:

[0021] If the difference between the real-time alkali metal salt concentration of the clarified liquid and the target concentration of the alkali metal salt is not within a preset range, it is determined that the real-time alkali metal salt concentration of the clarified liquid is not within the expected range, and the process returns to the step of determining the real-time alkali metal salt concentration of the clarified liquid in the clarified liquid tank during the circulation process.

[0022] Preferably, step S33, determining the real-time alkali metal salt concentration of the clarified liquid in the clarified liquid tank during the circulation process, specifically includes the following steps: according to the formula: Determine the real-time alkali metal salt concentration in the clarified liquid tank during the circulation process. ;in, To accumulate the amount of new water entering the slurry tank, To accumulate the amount of dust entering the slurry tank, This refers to the total amount of filter cake produced by the solid-liquid separation device. The content of alkali metal salts in dust B. The reference alkali metal salt concentration for circulating supernatant; The water content in dust B is... This represents the water content in filter cake B1.

[0023] Preferably, step S34 is followed by the step:

[0024] Production enters a continuous phase, and the flow rates of new water and dust removal ash added to the slurry tank are calculated according to the formula. Control; among which, To add flow to continuously produce fresh water, Add flow rate to continuously producing dust collector ash.

[0025] Preferably, the target concentration of the alkali metal salt is obtained through the following steps:

[0026] Obtain the current temperature T1 of the clarified liquid in the clarified liquid tank, and obtain the saturation concentration of KCl at temperature T1. ;

[0027] According to the formula Determine the target concentration of the alkali metal salt ;in, The coefficient is used for calculation, and is taken as 0.5~0.8.

[0028] Preferably, step S1, which involves introducing fresh water and dust removal ash into the slurry tank in a specific ratio, includes the following steps: fresh water and dust removal ash are mixed according to a static fresh water-ash ratio CK. AB The slurry enters the slurry tank; wherein the static new water-cement ratio CK AB The value range is 2 to 4.

[0029] This invention also provides a single-stage water washing and desalination system for sintering machine head electrostatic precipitator ash, comprising a slurry tank, a solid-liquid separation device, and a clarified liquid tank, wherein...

[0030] The slurry tank includes a slurry tank body, a first water inlet assembly for receiving external fresh water, an ash inlet assembly for receiving external dust collector ash, a return liquid assembly for receiving clean liquid returned from the clean liquid tank, and a slurry outlet assembly. The first water inlet assembly is equipped with a first water inlet valve, and the slurry outlet assembly is equipped with a slurry outlet valve. Water enters the slurry tank body through the first water inlet assembly, and the dust collector ash enters the slurry tank body through the ash inlet assembly. The water and dust collector ash mix in the slurry tank body to form a slurry.

[0031] The solid-liquid separation device is used to receive slurry from the slurry outlet assembly and produce a first clear liquid and filter cake;

[0032] The clarified liquid tank includes a clarified liquid tank body, a second water inlet assembly for receiving external fresh water, a liquid inlet assembly for receiving the first clarified liquid, a first liquid outlet assembly, and a second liquid outlet assembly. The second water inlet assembly is equipped with a second water inlet valve, the first liquid outlet assembly is equipped with a first liquid outlet valve, and the second liquid outlet assembly is equipped with a second liquid outlet valve. The first clarified liquid enters the clarified liquid tank body through the liquid inlet assembly. The clarified liquid in the clarified liquid tank body is transported to the subsequent evaporation, crystallization, and salt separation process through the second liquid outlet assembly. The clarified liquid in the clarified liquid tank body is transported to the slurry tank body through the first liquid outlet assembly and the return liquid assembly.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] This invention provides a single-stage water washing and desalination process and system for sintering dust removal. The system sends the alkali metal salt concentration in the sintering liquid to the subsequent evaporation, crystallization and salt separation process only when the difference between the alkali metal salt concentration in the sintering liquid and the target alkali metal salt concentration is within a preset range. At this time, the alkali metal salt concentration in the sintering liquid is within a suitable range, neither too high nor too low. This can prevent the problem of excessively high alkali metal salt concentration in the sintering liquid causing crystallization and blockage of the conveying pipeline when it encounters cold, and can also provide a higher concentration of sintering liquid for the subsequent evaporation and crystallization process, thereby minimizing ineffective energy consumption.

[0035] Secondly, when the difference between the concentration of alkali metal salt in the clarified liquid and the target concentration of alkali metal salt is greater than a first preset value, the clarified liquid is diluted by adding an appropriate amount of water to the clarified liquid tank to control the concentration of alkali metal salt in the clarified liquid within the desired range, thus preventing the clarified liquid from clogging the pipeline due to excessive cooling and crystallization during pipeline transportation. When the difference between the concentration of alkali metal salt in the clarified liquid and the target concentration of alkali metal salt is less than a second preset value, the clarified liquid is controlled to flow back to the slurry tank to re-participate in water washing, thereby forming a clarified liquid salt enrichment cycle, which effectively increases the concentration of alkali metal salt in the clarified liquid. Only when the difference between the concentration of alkali metal salt in the clarified liquid and the target concentration of alkali metal salt is within the preset range is the clarified liquid controlled to enter the subsequent evaporation, crystallization and salt separation process, avoiding the clarified liquid from directly entering the evaporation, crystallization and salt separation process, thus effectively reducing energy consumption. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0037] Figure 1 This is a schematic flowchart of one embodiment of the present invention;

[0038] Figure 2This is a schematic diagram of an electrostatic precipitator system for sintering machine heads in the prior art.

[0039] Figure 3 This is a schematic diagram of a typical ash removal sequence for a four-field electrostatic precipitator in an existing sintering machine head.

[0040] Figure 4 This is a flow chart of a typical water washing and desalination method in the prior art;

[0041] Figure 5 This is a schematic diagram of the system structure in one embodiment of the present invention.

[0042] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0043] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0044] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0045] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0046] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0047] Those skilled in the art should know that with the rapid development of modern industry, the scale of steel production is increasing, and energy consumption is also increasing. Energy conservation and environmental protection indicators are becoming increasingly important factors to consider in the steel production process. In steel production, iron-containing raw materials need to be processed by a sintering system before entering the blast furnace for smelting. That is, various powdered iron-containing raw materials are mixed with appropriate amounts of fuel (coal powder, coke powder) and flux, and an appropriate amount of fresh water is added. After mixing and pelletizing, they are placed on a sintering trolley for roasting, causing a series of physicochemical changes to form easily smelted sinter. This process is called sintering.

[0048] In sintering production, the dust-laden flue gas from the main flue must undergo purification processes such as dust removal, desulfurization, and denitrification before being discharged. The mainstream method for dust removal in sintering flue gas is the use of an electrostatic precipitator (ESP) at the machine head to treat the dust in the flue gas. The amount of dust collected by the ESP accounts for approximately 2% to 4% of the sinter production. A company with an annual steel production of 10 million tons requires approximately 16 million tons of sinter, generating about 500,000 tons of dust annually. A schematic diagram of an existing large-scale sintering machine's ESP is shown below. Figure 2 As shown.

[0049] like Figure 2 As shown, the electric fields of the electrostatic precipitator at the sintering machine head are arranged in series. After the dust-laden flue gas is treated by each electric field, it enters the next process after meeting the entry standard. The dust collected by each electric field enters the ash storage bin of each electric field. The ash unloading system of each electric field's ash storage bin operates according to the set program / ash unloading sequence cycle. The dust collected by all electric fields is collected into the dust buffer bin by the dust conveying system. The dust collected in the dust buffer bin will be disposed of by the subsequent dust disposal process.

[0050] It is important to note that many ore raw materials contain high levels of alkali metal elements such as K and Na. The compounds formed by these alkali metal elements have low boiling points and can directly volatilize into the flue gas during high-temperature sintering, or be reduced by coke to the corresponding elemental metal gases, escaping and condensing in the electrostatic precipitator system. These gases then combine with Cl elements present in the raw materials and are subsequently captured and collected in the dust collector ash. The dust collector ash mainly contains various elements such as TFe, K, and Na (K and Na exist in the form of KCl and NaCl). It should be noted that existing sintering dust collector ash disposal methods generally involve:

[0051] (1) Stockpiling (transportation is considered solid waste). The problem with stockpiling is that it requires a lot of storage space, and as production continues, the accumulated dust will accumulate more and more, eventually forcing a solution to be found. Currently, all steel companies have a large amount of dust from the electrostatic precipitator at the machine head that needs to be disposed of.

[0052] (2) It is directly used as a sintering raw material and re-enters the sintering batching process to participate in the sintering process again. Fe element in dust is required for the sintering process, but the re-entry of alkali metals such as K and Na into the sintering process is detrimental to subsequent sintering production and the quality of sintered ore. In addition, it will form a closed-loop dust cycle, which will increase the ineffective load of the sintering system.

[0053] (3) After removing K and Na elements from the dust, it is then used in the sintering process. The dust from which K and Na elements have been removed can be used as raw material in sintering production without adversely affecting the sintering process. Currently, the commonly used K and Na removal process is water washing and desalination. A typical water washing and desalination process flow chart is shown below. Figure 4 As shown:

[0054] like Figure 4 As shown, sintering dust from the dust collector buffer silo and fresh production water are mixed in a slurry tank to form a slurry. The slurry undergoes solid-liquid separation in a solid-liquid separation unit. KCl and NaCl dissolve in the clear liquid and are carried away by the clear liquid to the subsequent evaporation, crystallization, and salt separation process. The filter cake enters a secondary fresh water washing process or is sent to sintering. Because the dust collector ash has a high K and Na content, multi-stage fresh water washing is required. Figure 4 (A single-stage water washing desalination system) to meet the requirements for removing K and Na elements;

[0055] like Figure 4 As shown, the primary clear liquid is sent to the evaporation, crystallization and salt separation process. The KCl and NaCl separated in the evaporation, crystallization and salt separation process can be sold as commodities. Therefore, the high content of KCl and NaCl in the filter cake is also a waste of raw materials.

[0056] It is worth noting that, as shown in Table 1 below, Table 1 is a table of the composition (mass fraction) of the dust collected by the electrostatic precipitator in each electric field of the sintering machine head of Ansteel.

[0057]

[0058] Table 1 lists the composition (mass fraction) of the dust from the electrostatic precipitators in each field of the sintering machine heads of the No. 2 and No. 3 sintering machines at Ansteel. This technical solution focuses on four components: TFe, FeO, NaCl, and KCl (highlighted in rectangular boxes in Table 1). TFe represents total iron, which is the sum of iron elements in all iron-containing components of the ore (here referring to the blast furnace head dust). It is calculated from all iron elements in metallic iron (Fe), magnetite (Fe3O4), iron oxide (Fe2O3), and ferrous oxide (FeO) in the ore. FeO is listed separately because FeO content is an important indicator for blast furnace production, hence its separate listing to assess ore quality. The iron elements in the FeO column are already included in the TFe column.

[0059] As can be seen from the rectangular boxes in Table 1, the composition of the dust from the electrostatic precipitators at the sintering machine heads varies due to differences in the raw material composition of each sintering machine. However, a common characteristic is that the Fe content (TFe + FeO) is high and the alkali metal salt (NaCl + KCl) content is low in the first electric field; the Fe content (TFe + FeO) gradually decreases in subsequent electric fields, while the alkali metal salt (NaCl + KCl) content gradually increases; and there are significant differences in the composition of the dust from each electric field. This table is representative, and the composition distribution of the dust from the electrostatic precipitators at the sintering machine heads of steel enterprises is similar to that of Ansteel.

[0060] It should be noted that the single-field dust removal efficiency of an electrostatic precipitator is ~80%. Considering that the airflow moving backward from the first field carries away some of the falling dust, the dust removed by the first field accounts for about 60% of the total dust removed, and the dust removed by the second field accounts for about 60% of the remaining 40%, or 24%, and so on for the other fields.

[0061] like Figure 3 The electrostatic precipitator shown is a four-field type sintering electrostatic precipitator. The typical ash discharge logic of each field's ash storage bin is as follows: Figure 3 As shown, specifically, the electrostatic precipitator at the dust collector head continuously discharges ash periodically during operation. T1 in the diagram represents one standard ash discharge cycle, and subsequent ash discharges can be considered as repetitions of multiple similar standard ash discharge cycles. Figure 3 As shown, the T1 ash unloading cycle can be divided into 5 segments, namely:

[0062] TT0: The ash accumulation section of each electric field ash storage bin of the dust collector head. The ash unloading equipment of each dust removal electric field in the TT0 section is not working. The ash storage bins of each dust removal electric field store the electrostatic precipitator ash collected to form a ash storage bin material seal.

[0063] TT1: Ash discharge section of the first electric field. At this time, the ash storage bin of the first electric field is close to or reaches the high material level. The ash discharge equipment of the first electric field is working and the first electric field discharges ash. The duration of the ash discharge is TT1. The start time of the ash discharge is t1. When the ash storage bin of the first electric field is close to or reaches the low material level, the ash discharge of the first electric field ends. The end time of the ash discharge is t2.

[0064] TT2: Ash discharge section of the second electric field. At this time, the ash storage bin of the second electric field is close to or reaches the high material level. The ash discharge equipment of the second electric field is working and the second electric field discharges ash. The duration of ash discharge is TT2. The start time of ash discharge is t2. When the ash storage bin of the second electric field is close to or reaches the low material level, the ash discharge of the second electric field ends. The end time of ash discharge is t3.

[0065] TT3: Ash discharge section of the third electric field. At this time, the ash storage bin of the third electric field is close to or reaches the high material level. The ash discharge equipment of the third electric field works and the third electric field discharges ash. The duration of ash discharge is TT3. The start time of ash discharge is t3. When the ash storage bin of the third electric field is close to or reaches the low material level, the ash discharge of the second electric field ends. The end time of ash discharge is t4.

[0066] TT4: Ash discharge section of the fourth electric field. At this time, the ash storage bin of the fourth electric field is close to or reaches the high material level. The ash discharge equipment of the fourth electric field works and the fourth electric field discharges ash. The duration of ash discharge is TT4. The start time of ash discharge is t4. When the ash storage bin of the fourth electric field is close to or reaches the low material level, the ash discharge of the fourth electric field ends. The end time of ash discharge is t5.

[0067] T2 is the second ash unloading cycle, and the dust collector at the head of the machine repeats the above cycles for ash unloading.

[0068] like Figure 2 and Figure 3 As shown, in actual production, each dust removal electric field has the same ash unloading capacity. The dust removal ash conveying system is configured with conveying capacity according to the ash unloading amount of a single dust removal electric field. That is, the dust removal ash conveying system usually only allows one dust removal electric field to unload ash, and does not allow two dust removal electric fields to unload ash at the same time.

[0069] Those skilled in the field should understand that Figure 2 The dust in the dust removal buffer bin is the dust removal ash. Figure 4 The raw materials for the water washing and desalination process shown. If based on... Figure 3 The existing electrostatic precipitator ash removal method shown will cause the dust collected in the dust removal ash buffer bin to be discharged according to the following conditions: Figure 1 The pattern shown indicates that the dust collected in the first electric field ash storage bin of the electrostatic precipitator at the head of the machine (approximately from the high material level) is precipitated as dust. (Low material level), then receive the dust from the second electrostatic precipitator's ash storage bin at the head of the machine, and so on. Take a typical 360m³ machine as an example. 2 Calculated using a sintering machine, one 360m 2 The sintering machine produces 10,000 tons of sintered ore daily. The dust removal ash is calculated at 3%, which is 300 tons. The ash removal cycle of the electrostatic precipitator at the machine head is 8 hours, so the ash removal volume in one ash removal cycle is 100 tons. If the normal ash storage capacity of the dust removal ash storage silo is 100 tons, then in the ash storage silo, there are ~60 tons of first-field dust removal ash in the continuous space of the dust removal ash storage silo, and ~24 tons of second-field dust removal ash immediately following it. The remaining electric field ash is stored in the dust removal ash storage silo in the same way.

[0070] As shown in Table 1, the composition of dust collected by the electrostatic precipitator varies significantly across different electric fields. If we consider... Figure 3 The existing electrostatic precipitator dust removal method shown will lead to the entry of dust into the machine head. Figure 4The raw material composition of the water washing desalination method shown fluctuates greatly. Figure 4 Taking the water washing and desalination process shown as an example, as described above, the 360m... 2 The sintering machine head dust will first receive ~60t of dust from the first electric field dust collector within 8 hours, followed by ~24t of dust from the second electric field dust collector, and so on. However, due to the influence of many interfering factors during the production process, the composition of the raw materials in the subsequent water washing and desalination process is difficult to determine.

[0071] Because the dust collected in the first electric field has high TFe and FeO content and low NaCl and KCl content, while the TFe and FeO content decreases sequentially and the NaCl and KCl content increases sequentially in subsequent electric fields, the large fluctuations and uncertainties in the raw material composition will obviously lead to large fluctuations in the filter cake yield, TFe and FeO content in the filter cake, and KCl and NaCl content in the clarified liquid of the water washing desalination method. Ultimately, this will lead to instability in the water washing desalination process. This is also the main factor causing large production fluctuations, frequent equipment failures, high production costs, and production interruptions in the existing single-stage water washing desalination process for sintering machine head electrostatic precipitator dust.

[0072] Please refer to Figures 1 to 5 The present invention provides a single-stage water washing and desalination process for sintering dust, comprising the following steps:

[0073] S1, during the initial production, the slurry outlet valve of the slurry tank is closed, and fresh water and dust removal ash are introduced into the slurry tank in proportion so that the fresh water and dust removal ash are mixed in the slurry tank to form slurry;

[0074] Preferably, step S1, which involves introducing fresh water and dust removal ash into the slurry tank in a specific ratio, includes the following steps: fresh water and dust removal ash are mixed according to a static fresh water-ash ratio CK. AB The slurry enters the slurry tank; wherein the static new water-cement ratio CK AB The value range is 2 to 4. It is worth noting that the static water-cement ratio CK... AB The determining principle is that water and cement can be fully mixed to form a slurry with good fluidity, and the static water-cement ratio CK is... AB The static water-cement ratio CK can be obtained through water-cement mixing experiments and production experience. AB The commonly used value range is 2 to 4.

[0075] S2, after the slurry tank reaches the set liquid level, feeding is stopped, and the slurry outlet valve is opened to allow the slurry to enter the solid-liquid separation device; wherein, the solid-liquid separation device is used to receive the slurry and generate clear liquid, the clear liquid enters the clear liquid tank, the clear liquid tank includes a first outlet valve and a second outlet valve, the first outlet valve and the second outlet valve are in a closed state before the clear liquid tank reaches the set liquid level; the set liquid level can be preset, for example, the slurry tank reaches 85% of its capacity.

[0076] S3, before the clear liquid tank reaches the set liquid level, determine the concentration of alkali metal salt in the clear liquid tank;

[0077] Preferably, the target concentration of the alkali metal salt is obtained through the following steps:

[0078] Obtain the current temperature T1 of the clarified liquid in the clarified liquid tank, and obtain the saturation concentration of KCl at temperature T1. , unit; according to the formula Determine the target concentration of the alkali metal salt , in %, of which , The coefficients are dimensionless and range from 0.5 to 0.8.

[0079] It is worth noting that, as shown in Table 1, KCl is the main alkali metal salt in the dust, with NaCl accounting for 5.6% and KCl accounting for 94.4%. In the preferred embodiment, KCl concentration is used as the criterion for determining the concentration of alkali metal salts. It is also worth noting that the solubility (i.e., saturation concentration) of each substance differs at different temperatures. For KCl, its solubility in water increases with increasing temperature. The saturation concentration of KCl at temperature T1 can be determined by consulting relevant solubility tables or using empirical formulas. After determining the saturation concentration of KCl, the coefficient is calculated using the aforementioned formula. The formula is used to calculate the target concentration of alkali metals in the clear liquid, and the calculation coefficient is used. It is a value between 0.5 and 0.8, which can be determined based on experimental data or engineering experience.

[0080] Specifically, according to this formula, if the concentration of alkali metal salts in the clarified liquid is close to the saturation concentration, then when the temperature decreases, KCl crystals in the clarified liquid are prone to crystallizing in the pipes, which can easily clog the pipes and hinder production. If the concentration of alkali metal salts in the clarified liquid is far below the saturation concentration, then more energy needs to be consumed to evaporate the water in the subsequent evaporation, crystallization, and salt separation process, which is also detrimental to the subsequent evaporation, crystallization, and salt separation process. Therefore, it is appropriate to use 50% to 80% of the saturation concentration of the clarified liquid as the control target for the clarified liquid concentration. The specific coefficient can be determined based on production experience. Alternatively, in another preferred example, the clarified liquid concentration can be controlled to fluctuate within a certain range, such as 75% to 80%, which is more conducive to production adjustment.

[0081] This embodiment considers the effect of temperature on KCl solubility and determines the target concentration of alkali metal in the clarified solution accordingly, thereby achieving precise control of the concentration of alkali metal salt in the clarified solution. Controlling the concentration of alkali metal salt in the clarified solution according to this target can avoid problems such as crystallization of pipelines when the concentration is too high or too low, or increased ineffective energy consumption.

[0082] S4, when the difference between the concentration of the alkali metal salt in the clear liquid and the target concentration of the alkali metal salt is within a preset range, it is determined that the concentration of the alkali metal salt in the clear liquid is within the desired range. After the clear liquid tank reaches the set liquid level, the second liquid outlet valve is opened so that the clear liquid in the clear liquid tank can enter the subsequent evaporation, crystallization and salt separation process.

[0083] Specifically, such as Figure 5 As shown, during the initial production, the slurry tank's outlet valve is closed to ensure the slurry preparation process within the tank is sealed. Fresh water and dust collector ash are added to the slurry tank in a specific ratio, causing the liquid level to gradually rise. Through mixing, the soluble components in the dust collector ash (mainly K and Na) dissolve in the water, forming a slurry with a certain concentration of alkali metal salts. When the liquid level in the slurry tank reaches the set value, the addition of fresh water and dust collector ash is stopped to prevent slurry overflow. The outlet valve is then opened, sending the slurry into a solid-liquid separation device (e.g., a plate and frame filter press), producing a relatively pure clear liquid and filter cake. The clear liquid then continues to flow into the clear liquid tank, which is equipped with a first outlet valve and a second outlet valve. Both valves remain closed until the clear liquid tank reaches the set liquid level. Before the clear liquid tank reaches the set liquid level, the concentration of alkali metal salts in the clear liquid is detected or calculated, for example, by using a concentration meter. If the difference between the concentration of alkali metal salts in the clear liquid and the target concentration of alkali metal salts is within the allowable range, the concentration of the clear liquid is considered to be within the expected range. After the clear liquid tank reaches the set liquid level, the second outlet valve is opened, and the clear liquid is sent to the evaporation crystallization and salt separation process. The clear liquid removes water through evaporation, causing the alkali metal salts to crystallize and precipitate, thereby realizing the separation and recovery of salts, realizing the resource utilization of industrial waste, and reducing environmental pollution.

[0084] In this application, the clarified liquid is only sent to the subsequent evaporation, crystallization, and salt separation process when the difference between the alkali metal salt concentration in the clarified liquid tank and the target alkali metal salt concentration is within a preset range. At this time, the alkali metal salt concentration in the clarified liquid is within a suitable range, neither too high nor too low. This can prevent the problem of excessively high alkali metal salt concentration in the clarified liquid causing crystallization and blockage of the conveying pipeline when it encounters cold, and can also provide a higher concentration of clarified liquid for the subsequent evaporation and crystallization process, thereby minimizing ineffective energy consumption.

[0085] In a preferred embodiment, step S3 is followed by the following step:

[0086] When the difference between the concentration of the alkali metal salt in the clarified liquid and the target concentration of the alkali metal salt is greater than a first preset value, it is determined that the concentration of the alkali metal salt in the clarified liquid tank is in a high concentration range. The inlet valve of the clarified liquid tank is then opened, and the process is performed according to the formula... Adjust the flow rate of the inlet valve of the clear liquid tank to the added water flow rate. ;in: This represents the target concentration of alkali metal salts in the clarified solution Q1 in the clarified solution tank. The flow rate of the clear liquid Q1, This refers to the amount of water in the slurry tank when it reaches the set liquid level during initial production. This refers to the amount of dust collected in the slurry tank when it reaches the set liquid level during initial production. The content of alkali metal salts in dust B. The water content in dust collector B;

[0087] Continue to add fresh water and dust removal ash to the slurry tank in proportion. When the clear liquid tank reaches the set liquid level, open the second liquid outlet valve so that the clear liquid in the clear liquid tank can enter the subsequent evaporation, crystallization and salt separation process.

[0088] Specifically, when the difference between the concentration of the alkali metal salt in the clarified liquid and the target concentration of the alkali metal salt is greater than a first preset value, it indicates that the concentration of the alkali metal salt in the clarified liquid is too high. This means the concentration of the alkali metal salt in the clarified liquid tank is in a high concentration range. If the clarified liquid is directly sent to the subsequent evaporation, crystallization, and salt separation process at this time, crystallization is likely to occur in the conveying pipeline, easily causing blockages and thus hindering production. Therefore, this embodiment dilutes the clarified liquid by adding an appropriate amount of water to the clarified liquid tank to control the concentration of the alkali metal salt within the desired range. The water flow rate of the inlet valve is adjusted according to the above formula, which considers the target concentration and flow rate of the clarified liquid, as well as factors such as the amount of water in the slurry tank during initial production, the amount of dust collected, and the alkali metal salt and water content in the dust collected, ensuring that the concentration of the diluted clarified liquid is within the desired range. During the dilution process, fresh water and dust removal ash are continuously added to the slurry tank in proportion to maintain production activities in the slurry tank. When the liquid level in the clear liquid tank reaches the set value again, the inlet valve is closed and the second outlet valve is opened to bring the concentration of alkali metal salts in the diluted and adjusted clear liquid to the desired range, and it can then be sent to the subsequent evaporation, crystallization and salt separation process for further processing.

[0089] This embodiment also provides the process of obtaining the above formula, as detailed below:

[0090] Combination Figure 5 After the slurry valve JF1 is opened, water A and dust removal ash B are mixed in proportion CK. AB The total flow rate of water and cement entering the slurry tank JG1 is equal to the flow rate of slurry exiting the slurry tank. The slurry valve JF1 remains open to maintain the liquid level balance in the slurry tank JG1.

[0091] The concentration of alkali metal salts in the supernatant can be calculated as shown in Formula 1:

[0092] ;Formula 1

[0093] Wherein: CM A : The amount of water in the slurry tank when it reaches the set level during initial production, in kg; cm BND: The amount of dust collected in the slurry tank when it reaches the set liquid level during initial production, in kg; G1 : Alkali metal salt concentration in the clear liquid QG1 in the clear liquid tank after the initial production slurry tank reaches the set liquid level and water and ash are mixed, in % ND B The alkali metal salt content in dust collector B, expressed as a percentage, can be obtained through online instrument detection beforehand. (HS) B The water content in dust collector B, expressed as a percentage, can be obtained through online instrument detection.

[0094] Total material entering the clear liquid tank: CM QG1 =(LL Q1 +LL A2 ) t; where: CM QG1 The amount of material entering the clear liquid tank, in kg; LL Q1 The flow rate of the clear liquid is Q1, in kg / s; LL A2 The flow rate of water added into the clear liquid tank QG1 is expressed in kg / s; t is the duration, expressed in seconds.

[0095] Alkali metal content entering the clear liquid tank: CM JQG1 =LL Q1 ND G1 t; where: CM QG1 The amount of alkali metal entering the clear liquid tank, in kg; LL Q1 The flow rate of the clear liquid is Q1, in kg / s; ND G1 The concentration of the alkali metal salt in the clear liquid Q1 is %; t is the duration in seconds.

[0096] To achieve the controlled concentration of the clarified liquid, the following control targets must be met:

[0097] ;Formula 2

[0098] Wherein: ND K The target concentration of the clear liquid Q1 is expressed in % LL. Q1 The flow rate of the clear liquid is Q1, in kg / s; LL A2 The flow rate of water added into the clear liquid tank QG1 is expressed in kg / s; ND G1 The concentration of the alkali metal salt in the clear liquid Q1 is %; t is the duration in seconds.

[0099] From Formula 2, it can be deduced that by adjusting the regulating valve AF2 according to Formula 3, the clear liquid Q1 can reach the set concentration.

[0100] Formula 2a

[0101] Substituting Formula 1 into Formula 2a, we obtain the flow regulation method for regulating valve AF2 as shown in Formula 3:

[0102] ;Formula 3

[0103] Wherein: ND K The target concentration of the clear liquid Q1 is expressed in % LL. Q1 The flow rate of the clear liquid is Q1, in kg / s; LL A2 The flow rate of water added into the clear liquid tank QG1, in kg / s; CM A : The amount of water in the slurry tank when it reaches the set level during initial production, in kg; cm B ND: The amount of dust collected in the slurry tank when it reaches the set liquid level during initial production, in kg; B : Alkali metal salt content in dust collector B, unit: % HS B Moisture content in dust collector B, unit: %

[0104] In a preferred embodiment, step S3 is followed by the following step:

[0105] S31, when the difference between the concentration of the alkali metal salt in the clear liquid and the target concentration of the alkali metal salt is less than the second preset value, it is determined that the concentration of the alkali metal salt in the clear liquid tank is in the low concentration range. Fresh water and dust removal ash are added to the slurry tank in proportion. When the clear liquid tank reaches the set liquid level, the first liquid outlet valve is opened to send the clear liquid in the clear liquid tank back to the slurry tank, and the flow rate of the first liquid outlet valve is controlled to be the same as the flow rate of the clear liquid generated by the solid-liquid separation device.

[0106] S32, then follow the formula Adjust the flow rate of the inlet valve of the slurry tank to the water addition flow rate. This allows the slurry tank, the solid-liquid separation device, and the clarified liquid tank to form a clarified liquid enrichment salt cycle; wherein, The water flow rate for adding water to the slurry tank when it reaches the set liquid level after initial production;

[0107] S33, determine the real-time alkali metal salt concentration of the clear liquid in the clear liquid tank during the circulation process, and determine whether the difference between the real-time alkali metal salt concentration of the clear liquid and the target concentration of the alkali metal salt is within a preset range;

[0108] In a preferred embodiment, step S33, determining the real-time alkali metal salt concentration of the clarified liquid in the clarified liquid tank during the circulation process, specifically includes the following steps: According to the formula:

[0109]

[0110] Determine the real-time alkali metal salt concentration in the clarified liquid tank during the circulation process. ;in, To accumulate the amount of new water entering the slurry tank, To accumulate the amount of dust entering the slurry tank, This refers to the total amount of filter cake produced by the solid-liquid separation device. The content of alkali metal salts in dust B. The reference alkali metal salt concentration for circulating supernatant; The water content in dust B is... This represents the water content in filter cake B1.

[0111] S34, when the difference between the real-time alkali metal salt concentration of the clear liquid and the target concentration of the alkali metal salt is within a preset range, it is determined that the real-time alkali metal salt concentration of the clear liquid is within the desired range. After the clear liquid tank reaches the set liquid level, the second liquid outlet valve is opened so that the clear liquid in the clear liquid tank can enter the subsequent evaporation, crystallization and salt separation process.

[0112] Specifically, when the difference between the concentration of the alkali metal salt in the clarified liquid and the target concentration of the alkali metal salt is less than a second preset value, it indicates that the concentration of the alkali metal salt in the clarified liquid is low. Therefore, it is determined that the concentration of the alkali metal salt in the clarified liquid tank is in the low concentration range. If the clarified liquid is directly sent to the subsequent evaporation, crystallization and salt separation process at this time, the basic principle of the evaporation and crystallization process is to heat the KCl and NaCl mixed solution to evaporate the water in the KCl and NaCl mixed solution, so that the KCl and NaCl in the mixed solution are supersaturated, thereby forming KCl and NaCl crystals, and finally obtaining KCl and NaCl products. If the concentration of the alkali metal salt in the clarified liquid is lower, more water needs to be evaporated, which requires a large amount of ineffective energy consumption.

[0113] In this situation, fresh water and dust removal ash are continuously added to the slurry tank in proportion to maintain production and increase the concentration of the subsequent clarified liquid. Once the clarified liquid tank reaches the set level, it is not directly sent to the subsequent evaporation, crystallization, and salt separation process. Instead, the first outlet valve is opened to return the low-concentration clarified liquid to the slurry tank for re-participation in the washing process. Simultaneously, the flow rate of the first outlet valve is controlled to match the flow rate of the clarified liquid generated by the solid-liquid separation device, thus maintaining the stability and continuity of the system.

[0114] Adjust the water flow rate of the slurry tank's inlet valve according to the above formula to form a circulating system for salt enrichment in the clarified liquid among the slurry tank, solid-liquid separation device, and clarified liquid tank. Through multiple cycles of enrichment, the concentration of alkali metal salts in the clarified liquid is gradually increased. During the circulation process, the real-time concentration of alkali metal salts in the clarified liquid tank can be continuously monitored or calculated. When the difference between the real-time alkali metal salt concentration and the target concentration is within a preset range, it is determined that the real-time alkali metal salt concentration of the clarified liquid is within the desired range. After the clarified liquid tank reaches the set liquid level again, the second outlet valve is opened, and the qualified clarified liquid is sent to the subsequent evaporation, crystallization, and salt separation process for further processing.

[0115] In this embodiment, when the concentration of alkali metal salt in the clarified liquid is low, the clarified liquid is controlled to flow back to the slurry tank to re-participate in water washing, thereby forming a clarified liquid salt enrichment cycle, which effectively increases the concentration of alkali metal salt in the clarified liquid. Only when the difference between the concentration of alkali metal salt in the clarified liquid and the target concentration of alkali metal salt is within a preset range is the clarified liquid controlled to enter the subsequent evaporation crystallization and salt separation process, avoiding the clarified liquid from directly entering the evaporation crystallization and salt separation process, and effectively reducing energy consumption.

[0116] Furthermore, after determining whether the difference between the real-time alkali metal salt concentration of the clarified liquid and the target alkali metal salt concentration is within a preset range in step S33, the method further includes the following step:

[0117] If the difference between the real-time alkali metal salt concentration of the clarified liquid and the target concentration of the alkali metal salt is not within a preset range, it is determined that the real-time alkali metal salt concentration of the clarified liquid is not within the expected range, and the process returns to the step of determining the real-time alkali metal salt concentration of the clarified liquid in the clarified liquid tank during the circulation process.

[0118] Furthermore, step S34 is followed by the following step:

[0119] Production enters a continuous phase, and the flow rates of new water and dust removal ash added to the slurry tank are calculated according to the formula. Control; among which, The flow rate for adding fresh water to continuously produce water is expressed in kg / s. The flow rate of dust added for continuous production, in kg / s.

[0120] This invention also provides a single-stage water washing and desalination system for sintering machine head electrostatic precipitator ash, comprising a slurry tank, a solid-liquid separation device, and a clarified liquid tank, wherein...

[0121] The slurry tank includes a slurry tank body, a first water inlet assembly for receiving external fresh water, an ash inlet assembly for receiving external dust collector ash, a return liquid assembly for receiving clean liquid returned from the clean liquid tank, and a slurry outlet assembly. The first water inlet assembly is equipped with a first water inlet valve, and the slurry outlet assembly is equipped with a slurry outlet valve. Water enters the slurry tank body through the first water inlet assembly, and the dust collector ash enters the slurry tank body through the ash inlet assembly. The water and dust collector ash mix in the slurry tank body to form a slurry.

[0122] The solid-liquid separation device is used to receive slurry from the slurry outlet assembly and generate a first clear liquid and a filter cake; the clear liquid tank includes a clear liquid tank body, a second inlet assembly for receiving external fresh water, an inlet assembly for receiving the first clear liquid, a first outlet assembly, and a second outlet assembly, wherein the second inlet assembly is provided with a second inlet valve, the first outlet assembly is provided with a first outlet valve, and the second outlet assembly is provided with a second outlet valve. The first clear liquid enters the clear liquid tank body through the inlet assembly, and the clear liquid in the clear liquid tank body is transported to the subsequent evaporation, crystallization, and salt separation process through the second outlet assembly. The clear liquid in the clear liquid tank body is transported back to the slurry tank body through the first outlet assembly and the return assembly.

[0123] Specifically, during initial production, fresh external water enters the slurry tank body through the first water inlet assembly, while sintering dust enters through the dust inlet assembly. Inside the slurry tank body, water and dust mix to form a slurry. The mixed slurry is then output to the solid-liquid separation device through the slurry outlet valve of the slurry outlet assembly. The solid-liquid separation device receives the slurry from the slurry tank and produces a filter cake and a clear liquid. The first clear liquid can enter the clear liquid tank body through the liquid inlet assembly. In the clear liquid tank, the clear liquid can be transported to the subsequent evaporation, crystallization, and salt separation process for further treatment through the second liquid outlet assembly. Alternatively, the clear liquid can be returned to the slurry tank body through the first liquid outlet assembly and the return assembly for circulating water washing to increase the clear liquid concentration. When the amount of clear liquid in the clear liquid tank is insufficient or the clear liquid concentration needs to be adjusted, fresh external water can enter the clear liquid tank body through the second water inlet valve of the second water inlet assembly.

[0124] Compared to traditional water washing and desalination systems, this system has advantages such as simple structure, convenient operation, and low maintenance cost.

[0125] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A single-stage water washing and desalination process for sintering dust, characterized in that, Including the following steps: S1, during the initial production, the slurry outlet valve of the slurry tank is closed, and fresh water and dust removal ash are introduced into the slurry tank in proportion so that the fresh water and dust removal ash are mixed in the slurry tank to form slurry; S2, after the slurry tank reaches the set liquid level, the feeding is stopped, and the slurry outlet valve is opened to allow the slurry to enter the solid-liquid separation device; wherein, the solid-liquid separation device is used to receive the slurry and generate clear liquid, the clear liquid enters the clear liquid tank, the clear liquid tank includes a first outlet valve and a second outlet valve, the first outlet valve and the second outlet valve are in a closed state before the clear liquid tank reaches the set liquid level; S3, before the clear liquid tank reaches the set liquid level, determine the concentration of alkali metal salt in the clear liquid tank; S4, when the difference between the concentration of the alkali metal salt in the clear liquid and the target concentration of the alkali metal salt is within a preset range, it is determined that the concentration of the alkali metal salt in the clear liquid is within the desired range. When the clear liquid tank reaches the set liquid level, the second liquid outlet valve is opened so that the clear liquid in the clear liquid tank can enter the subsequent evaporation, crystallization and salt separation process. The step S3 is followed by the following step: When the difference between the concentration of the alkali metal salt in the clarified liquid and the target concentration of the alkali metal salt is greater than a first preset value, it is determined that the concentration of the alkali metal salt in the clarified liquid tank is in a high concentration range. The inlet valve of the clarified liquid tank is then opened, and the process is performed according to the formula... Adjust the flow rate of the inlet valve of the clear liquid tank to the added water flow rate. ;in: This represents the target concentration of alkali metal salts in the clarified solution Q1 in the clarified solution tank. The flow rate of the clear liquid Q1, This refers to the amount of water in the slurry tank when it reaches the set liquid level during initial production. This refers to the amount of dust collected in the slurry tank when it reaches the set liquid level during initial production. The content of alkali metal salts in dust B. The water content in dust collector B; Continue to add fresh water and dust removal ash to the slurry tank in proportion. When the clear liquid tank reaches the set liquid level, open the second liquid outlet valve so that the clear liquid in the clear liquid tank can enter the subsequent evaporation, crystallization and salt separation process.

2. The single-stage water washing and desalination process for sintering dust removal according to claim 1, characterized in that, The step S3 is followed by the following step: S31, when the difference between the concentration of the alkali metal salt in the clear liquid and the target concentration of the alkali metal salt is less than the second preset value, it is determined that the concentration of the alkali metal salt in the clear liquid tank is in the low concentration range. Fresh water and dust removal ash are added to the slurry tank in proportion. When the clear liquid tank reaches the set liquid level, the first liquid outlet valve is opened to send the clear liquid in the clear liquid tank back to the slurry tank, and the flow rate of the first liquid outlet valve is controlled to be the same as the flow rate of the clear liquid generated by the solid-liquid separation device. S32, then follow the formula Adjust the flow rate of the inlet valve of the slurry tank to the water addition flow rate. This allows the slurry tank, the solid-liquid separation device, and the clarified liquid tank to form a clarified liquid enrichment salt cycle; wherein, The water flow rate for adding water to the slurry tank when it reaches the set liquid level after initial production; S33, determine the real-time alkali metal salt concentration of the clear liquid in the clear liquid tank during the circulation process, and determine whether the difference between the real-time alkali metal salt concentration of the clear liquid and the target concentration of the alkali metal salt is within a preset range; S34, when the difference between the real-time alkali metal salt concentration of the clear liquid and the target concentration of the alkali metal salt is within a preset range, it is determined that the real-time alkali metal salt concentration of the clear liquid is within the desired range. After the clear liquid tank reaches the set liquid level, the second liquid outlet valve is opened so that the clear liquid in the clear liquid tank can enter the subsequent evaporation, crystallization and salt separation process.

3. The single-stage water washing and desalination process for sintering dust removal according to claim 2, characterized in that, After determining whether the difference between the real-time alkali metal salt concentration of the clarified liquid and the target concentration of the alkali metal salt is within a preset range in step S33, the following step is also included: If the difference between the real-time alkali metal salt concentration of the clarified liquid and the target concentration of the alkali metal salt is not within a preset range, it is determined that the real-time alkali metal salt concentration of the clarified liquid is not within the expected range, and the process returns to the step of determining the real-time alkali metal salt concentration of the clarified liquid in the clarified liquid tank during the circulation process.

4. The single-stage water washing and desalination process for sintering dust removal according to claim 2, characterized in that, The step S33, determining the real-time alkali metal salt concentration of the clarified liquid in the clarified liquid tank during the circulation process, specifically includes the following steps: According to the formula: Determine the real-time alkali metal salt concentration in the clarified liquid tank during the circulation process. ;in, To accumulate the amount of new water entering the slurry tank, To accumulate the amount of dust entering the slurry tank, This refers to the total amount of filter cake produced by the solid-liquid separation device. The content of alkali metal salts in dust B. The reference alkali metal salt concentration for circulating supernatant; The water content in dust B is... This represents the water content in filter cake B1.

5. The single-stage water washing and desalination process for sintering dust removal according to claim 4, characterized in that, The step S34 is followed by the following step: Production enters a continuous phase, and the flow rates of new water and dust removal ash added to the slurry tank are calculated according to the formula. Control; among which, To add flow to continuously produce fresh water, Add flow rate to continuously producing dust collector ash.

6. The single-stage water washing and desalination process for sintering dust removal according to claim 1, characterized in that, The target concentration of the alkali metal salt is obtained through the following steps: Obtain the current temperature T1 of the clarified liquid in the clarified liquid tank, and obtain the saturation concentration of KCl at temperature T1. ; According to the formula Determine the target concentration of the alkali metal salt ;in, The coefficient is set to 0.5 to 0.

8.

7. The single-stage water washing and desalination process for sintering dust removal according to claim 1, characterized in that, Step S1, which involves introducing fresh water and dust removal ash into the slurry tank in a specific ratio, includes the following steps: Fresh water and dust removal ash are mixed according to a static fresh water-ash ratio CK. AB The slurry enters the slurry tank; wherein the static new water-cement ratio CK AB The value range is 2 to 4.

8. A single-stage water washing and desalination system for electrostatic precipitator dust in sintering machine heads, characterized in that, It includes a slurry tank, a solid-liquid separation device, and a clear liquid tank, among which, The slurry tank includes a slurry tank body, a first water inlet assembly for receiving external fresh water, an ash inlet assembly for receiving external dust collector ash, a return liquid assembly for receiving clean liquid returned from the clean liquid tank, and a slurry outlet assembly. The first water inlet assembly is equipped with a first water inlet valve, and the slurry outlet assembly is equipped with a slurry outlet valve. Water enters the slurry tank body through the first water inlet assembly, and the dust collector ash enters the slurry tank body through the ash inlet assembly. The water and dust collector ash mix in the slurry tank body to form a slurry. The solid-liquid separation device is used to receive slurry from the slurry outlet assembly and produce a first clear liquid and filter cake; The clarified liquid tank includes a clarified liquid tank body, a second water inlet assembly for receiving external fresh water, a liquid inlet assembly for receiving the first clarified liquid, a first liquid outlet assembly, and a second liquid outlet assembly. The second water inlet assembly is equipped with a second water inlet valve, the first liquid outlet assembly is equipped with a first liquid outlet valve, and the second liquid outlet assembly is equipped with a second liquid outlet valve. The first clarified liquid enters the clarified liquid tank body through the liquid inlet assembly. The clarified liquid in the clarified liquid tank body is transported to the subsequent evaporation, crystallization, and salt separation process through the second liquid outlet assembly. The clarified liquid in the clarified liquid tank body is transported to the slurry tank body through the first liquid outlet assembly and the return liquid assembly.

Images