Low-water sintering method for laterite-nickel ore

Abstract

A low-water sintering method for laterite-nickel ore comprises the following steps that S1, the laterite-nickel ore, flux and fuel are sequentially subjected to the procedures of batching, even mixing and granulation, and a sintering mixture is obtained; s2, the sintering mixture is arranged on a sintering machine trolley, and after material distribution is completed, the sintering mixture enters a pre-drying section to be subjected to pre-drying treatment; and S3, the pre-dried sintering mixture sequentially passes through an ignition section and a sintering section, and the ignition sintering process is completed. According to the method, the hot air pre-drying section is arranged at the position after sintering and distribution and before ignition, and part of moisture in the sintering mixture is removed in advance, so that the moisture content in the laterite-nickel ore sintering flue gas is reduced to meet the requirement of an activated carbon method flue gas purification technology for moisture; therefore, the application of an activated carbon method flue gas purification technology in laterite-nickel ore sintering is promoted, and the flue gas purification cost is greatly reduced.

Description

Technical Field

[0001] The invention relates to a sintering method for laterite nickel ore, in particular to a low-water sintering method for laterite nickel ore, and belongs to the technical field of sintering and energy conservation and emission reduction. Background Art

[0002] Laterite nickel ore sinter is the main charge for blast furnace production of nickel iron. In the sintering process of laterite nickel ore, a multi-carbon method is generally used to ensure the smooth sintering process. However, laterite nickel ore has a high moisture content, especially a high crystal water content, and a high sulfur content. The sulfur content and moisture content in the sintering flue gas are high, and the moisture content of the flue gas reaches about 18%, which is much higher than the moisture content of the sintering flue gas of ordinary iron ore. The sintering flue gas emission temperature is between 110-170℃, and it contains SO2, NO x Laterite nickel ore sintering flue gas is typically desulfurized using a wet process. The flue gas is cooled to around 50°C, then heated to around 300°C before undergoing SCR denitrification. This repeated cooling and heating of the flue gas increases energy consumption and purification costs.

[0003] Activated carbon flue gas purification technology is just suitable for the sintering flue gas temperature emission range, and can achieve synergistic and efficient purification of multiple pollutants. It can remove multiple pollutants simultaneously on one set of equipment, realizing the resource utilization of by-product SO2. In addition, this technology has the advantages of high pollutant removal efficiency, basically no water consumption, and no secondary pollution. The activated carbon flue gas purification device is equipped with multiple subsystems such as adsorption system, analysis system, and acid production system. The flue gas is purified after passing through the activated carbon adsorption unit, and the activated carbon particles circulate between the adsorption unit and the analysis unit to achieve the recycling of activated carbon in the process of "adsorbing pollutants → heating and decomposition activation (to make pollutants escape) → cooling → adsorbing pollutants". However, the activated carbon flue gas purification requires that the moisture content in the flue gas be controlled to not exceed 15%. The moisture content of the flue gas from laterite nickel ore sintering exceeds the moisture requirement for activated carbon flue gas purification. Furthermore, sintering flue gas recirculation is a new process for energy conservation and emission reduction in sintering, reducing waste gas emissions and widely used in conventional iron ore sintering. However, flue gas recirculation in laterite nickel ore sintering can increase the moisture content of the sintering flue gas to as high as 20% or more, further limiting the application of activated carbon flue gas purification in this process. Therefore, the use of activated carbon flue gas purification in laterite nickel ore sintering requires that the high moisture content in the flue gas be addressed first. Summary of the Invention

[0004] To address the problem in the prior art that the high moisture content of laterite nickel ore makes its sintering flue gas unsuitable for activated carbon flue gas purification technology, the present invention proposes a low-moisture sintering method for laterite nickel ore. In this technical solution, a hot air pre-drying section is installed after the sintering material is distributed and before ignition to pre-dehydrate the sintering mixture. This reduces the moisture content of the laterite nickel ore sintering flue gas to a level that meets the moisture requirements of activated carbon flue gas purification technology. This promotes the application of activated carbon flue gas purification technology in laterite nickel ore sintering and significantly reduces flue gas purification costs.

[0005] The present invention also uses the hot air generated during the cooling process of the sintered ore to pre-dry the sintered mixture, thereby fully utilizing the waste heat of the hot air generated during the cooling of the sintered ore.

[0006] Furthermore, the present invention establishes a dynamic relationship model to monitor key process parameters such as the initial moisture content of the sintering mix and the moisture content of the flue gas in real time. Based on this information, the hot air temperature and volume entering the pre-drying stage are adjusted online. This control strategy not only significantly improves the stability of the production process, but also effectively reduces the negative impact of raw material moisture fluctuations on the sintering process, thereby optimizing overall production efficiency.

[0007] According to an embodiment of the present invention, a low-water sintering method for laterite nickel ore is provided.

[0008] A low-water sintering method for laterite nickel ore, comprising the following steps: S1. The laterite nickel ore, flux and fuel are subjected to batching, mixing and granulation steps in sequence to obtain a sintering mixture.

[0009] S2. The sintering mixture is placed on the sintering machine trolley. After the placement is completed, the sintering mixture enters the pre-drying section for pre-drying treatment.

[0010] S3. The sintering mixture after pre-drying passes through the ignition section and the sintering section in sequence to complete the ignition and sintering process.

[0011] In the present invention, the method further comprises: After sintering is completed, the high-temperature sintered ore is unloaded into the cooler for cooling. The sintering flue gas discharged from the sintering section enters the sintering flue and is then discharged after dust removal and purification.

[0012] In the present invention, in step S2, the sintered mixture enters the pre-drying section for pre-drying treatment, specifically: the sintered mixture enters the pre-drying section, and at the same time, hot air is transported into the pre-drying section, and the hot air pre-dries the sintered mixture, and the pre-drying flue gas discharged from the pre-drying section (through the pre-drying flue) is discharged after dust removal.

[0013] Preferably, the hot air delivered to the pre-drying section is a mixed hot air composed of the hot air discharged from each section of the cooler.

[0014] In the present invention, the method further comprises the step of controlling the moisture content of the sintering flue gas, specifically comprising: a. Construct a relationship between the initial moisture content of the sintering mixture and the maximum temperature of the hot air delivered to the pre-drying section, and calculate and adjust the temperature of the hot air entering the pre-drying section.

[0015] b. Construct a relationship between the initial moisture content of the sintering mixture, the air volume of the sintering section, the moisture content of the pre-drying flue gas, the target moisture content of the sintering flue gas, and the minimum air volume of the hot air delivered to the pre-drying section, and calculate and adjust the hot air volume entering the pre-drying section.

[0016] c. Perform real-time moisture detection on the sintering flue gas discharged from the sintering section. When the real-time moisture content of the sintering flue gas is detected to be greater than the target moisture content, repeat steps a and b. When the real-time moisture content of the sintering flue gas is detected to be less than or equal to the target moisture content, maintain the existing parameters and stabilize the sintering operation.

[0017] In the present invention, step a is specifically: Construct a relationship between the initial moisture content of the sintering mixture and the maximum temperature of the hot air delivered to the pre-drying section. Detect the initial moisture content W0 of the sintering mixture. Calculate the maximum temperature T of the hot air delivered to the pre-drying section. max , ℃.

[0018] T max = 10836×W0 2 - 6356.8×W0+ 1120.7………… (Ⅰ).

[0019] Adjust the temperature of the hot air delivered to the pre-drying section so that the hot air temperature entering the pre-drying section is ≤T max .

[0020] In the present invention, step b is specifically: Construct a relationship between the initial moisture content of the sintering mix, the air volume of the sintering section, the moisture content of the pre-drying flue gas, the target moisture content of the sintering flue gas, and the minimum air volume of the hot air delivered to the pre-drying section. Detect the initial moisture content W0 of the sintering mix. Detect the air volume Q per ton of sintering mix in the sintering section. s , Nm 3 / t. Detect the moisture content GW of the pre-drying flue gas discharged from the pre-drying section d According to the moisture requirements of activated carbon flue gas purification, the target moisture content of sintering flue gas is set to W 目标 Calculate the minimum air volume Q per ton of sintered mixture delivered to the pre-drying section d , Nm 3 / t.

[0021] Q d =(1000×W0-0.6×Q s ×W 目标 ) / (0.6×GW d )…………(Ⅱ).

[0022] Adjust the hot air velocity entering the pre-drying section so that the hot air volume entering the pre-drying section is ≥Q d .

[0023] In the present invention, step c is specifically: Perform real-time moisture detection on the sintering flue gas discharged from the sintering section to obtain the real-time moisture content W of the sintering flue gas. 实时 The target moisture content of sintering flue gas is set to W 目标 .

[0024] When W 实时 >W 目标 , it is judged that the moisture content of the sintering flue gas discharged from the sintering section exceeds the standard, and steps ab are repeated to adjust the hot air temperature and / or hot air volume entering the pre-drying section until W 实时 ≤W 目标 .

[0025] When W 实时 ≤W 目标 , indicating that the moisture content of the sintering flue gas discharged from the sintering section meets the requirements, keeping the hot air temperature and hot air volume entering the pre-drying section unchanged, and sintering operation stable.

[0026] In the present invention, the target moisture content of the sintering flue gas is in the range of W 目标 ≤15%, preferably W 目标 ≤13%.

[0027] In the present invention, during the batching of laterite nickel ore, flux and fuel in step S1, iron ore and / or miscellaneous materials are optionally added together for batching, and then the mixture is mixed and granulated to obtain a sintered mixture.

[0028] Preferably, the iron ore is one or more of hematite, magnetite, limonite, siderite, specularite, goethite, ilmenite, chromite, ferromanganese ore, vanadium-titanium magnetite, and sintering return ore. The miscellaneous materials are one or more of iron-containing dust and mud, iron oxide scale, iron-containing oil sludge, pellet return material, red mud, copper slag, nickel slag, sulfuric acid slag, steel slag, and other iron-containing slag and return materials generated in the steel, nonferrous metals, chemical, new energy and other industries.

[0029] Generally speaking, laterite nickel ore has a high moisture content. Especially in regions and times of humid weather, such as rain, the moisture content of laterite nickel ore raw materials can fluctuate significantly, introducing instability into the sintering process. Consequently, the flue gas from laterite nickel ore sintering has a high moisture content, making it unsuitable for activated carbon flue gas purification technology. Wet desulfurization and SCR denitrification are often used, requiring a cycle of cooling and then heating the ore, which repeatedly results in excessive energy consumption and increased purification costs. To address this issue, pre-drying the laterite nickel ore before blending and sintering is commonly used to reduce and stabilize the moisture content during the sintering process. However, this method requires the construction of a dedicated laterite nickel ore drying production line, which requires significant equipment investment and complicates the entire process.

[0030] In response to the problems existing in the above-mentioned prior art, the present invention adds a pre-drying section to the existing sintering machine. There is no need to pre-dry the laterite nickel ore. The sintering mixture granulated from the laterite nickel ore, flux, fuel, etc. is pre-dried and dehydrated directly after the sintering distribution and before ignition. This can ensure stable production during the sintering process and reduce the moisture content of the sintering flue gas to meet the moisture requirements of the activated carbon flue gas purification technology (for example, the moisture content of the sintering flue gas is ≤15%), thereby ensuring the normal use of the activated carbon flue gas purification technology in the laterite nickel ore sintering process and reducing the flue gas purification cost.

[0031] Specifically, such as Figure 1 As shown, along the running direction of the sintering trolley, the sintering machine is equipped with a distribution section, a pre-drying section, an ignition section (or an ignition and heat preservation section), and a sintering section in sequence. The main steps of the process flow of the present invention are as follows: S1. The laterite nickel ore, flux and fuel are subjected to batching, mixing and granulation steps in sequence to obtain a sintering mixture.

[0032] Wherein, flux is not limited, for example, limestone, dolomite, quicklime, slaked lime, etc. can be selected. Fuel can be selected from coal powder, coke powder, etc. In the process of batching the above-mentioned laterite nickel ore, flux and fuel, iron ore and / or miscellaneous materials can also be selectively added together for batching, and then mixed and granulated to obtain a sintered mixture. Wherein, the iron ore that can be added to the batching mainly includes hematite, magnetite, limonite, siderite, specularite, goethite, ilmenite, chromite, ferromanganese ore, vanadium-titanium magnetite, sintering return ore, etc., and one or more of the above can be selected. The miscellaneous materials that can be added to the batching mainly include iron-containing dust mud, iron oxide scale, iron-containing oil mud, pellet return material, red mud, copper slag, nickel slag, sulfuric acid slag, steel slag, and iron-containing slag dust and return material generated by other steel, nonferrous metals, chemicals, new energy and other industries, and one or more of the above can be selected.

[0033] S2. The sintering mixture is placed on the sintering machine trolley. After the placement is completed, the sintering mixture enters the pre-drying section for pre-drying treatment.

[0034] In the pre-drying section, hot air can be drawn in from above the material bed to pre-dry the sintering mix. The pre-drying flue gas from the pre-drying section passes through a pre-drying flue, undergoes dust removal, and is then directly discharged. The control requirement for removing moisture from the sintering mix in the pre-drying section is to ensure that the moisture content of the subsequent sintering flue gas does not exceed 15%, preferably not more than 13%.

[0035] S3. The sintering mixture after pre-drying passes through the ignition section and the sintering section in sequence to complete the ignition and sintering process.

[0036] After sintering is completed, the high-temperature sintered ore is unloaded into the cooler for cooling. The sintering flue gas discharged from the sintering section enters the sintering flue and is then discharged after dust removal and purification.

[0037] Preferably, based on the above implementation steps, the present invention transports mixed hot air composed of hot air discharged from each section of the cooler (such as a ring cooler) to the pre-drying section, and the mixed hot air pre-removes moisture from the sintered mixture entering the pre-drying section.

[0038] The present invention aims to solve the problem of high moisture content in sintering flue gas during the sintering process of laterite nickel ore. To ensure that the moisture content of the sintering flue gas discharged from the sintering section after sintering is completed meets the requirements for activated carbon flue gas purification, the present invention also includes a step of controlling the moisture content of the sintering flue gas. This is mainly achieved by controlling the hot air temperature and hot air volume entering the pre-drying section, and combining a feedback adjustment strategy for real-time detection of the moisture content of the sintering flue gas to achieve pre-removal of some moisture from the sintering mixture, ultimately achieving the purpose of controlling the moisture content of the sintering flue gas. The main steps include: a. Construct a relationship between the initial moisture content of the sintering mixture and the maximum temperature of the hot air delivered to the pre-drying section, and calculate and adjust the temperature of the hot air entering the pre-drying section.

[0039] During the pre-drying process, in order to ensure that the water-containing pellets do not explode in large quantities and cause the air permeability of the material layer to decrease, the hot air temperature must be adjusted and controlled so that the hot air temperature does not exceed the maximum temperature requirement of the hot air in the pre-drying section. The specific maximum temperature requirement for hot air control must meet Figure 2 The law shown is the following relationship: T max = 10836×W0 2 - 6356.8×W0+ 1120.7………… (Ⅰ); Where: W0 is the initial moisture content of the sintering mixture; T max The maximum temperature of the hot air delivered to the pre-drying section; Adjust the temperature of the hot air delivered to the pre-drying section so that the hot air temperature entering the pre-drying section is ≤T maxTo ensure that during the pre-drying process of the sintering mixture, there will be no large-scale explosion of the granulated balls due to excessive wind temperature.

[0040] If the hot air delivered to the pre-drying section is a mixed hot air composed of the hot air discharged from each section of the cooler, the temperature of the mixed hot air can be controlled by adjusting the proportion of the hot air discharged from each section of the cooler in the mixed hot air.

[0041] b. Construct a relationship between the initial moisture content of the sintering mixture, the air volume of the sintering section, the moisture content of the pre-drying flue gas, the target moisture content of the sintering flue gas, and the minimum air volume of the hot air delivered to the pre-drying section, and calculate and adjust the hot air volume entering the pre-drying section.

[0042] To achieve the desired pre-drying effect, while maintaining the same length of the pre-drying section, it's crucial not only to use hot air at higher temperatures but also to adjust the volume of hot air passing through the pre-drying section. Excessive hot air volume delivered to the pre-drying section can lead to over-compaction of the material layer, reducing its air permeability. Therefore, to ensure smooth production, the hot air volume in the pre-drying section should be the minimum required to meet pre-drying requirements. Based on experimental and engineering applications, the following relationship was obtained: Q d =(1000×W0-0.6×Q s ×W 目标 ) / (0.6×GW d )…………(Ⅱ); Where: Q d is the minimum air volume per ton of sintering mixture transported to the pre-drying section; W0 is the initial moisture content of the sintering mixture; Q s W is the air volume per ton of sintering mixture in the sintering section; 目标 GW is the target moisture content of sintering flue gas; d is the moisture content of the pre-drying flue gas discharged from the pre-drying section; Adjust the hot air velocity entering the pre-drying section so that the hot air volume entering the pre-drying section is ≥Q d During the adjustment process, try to control the hot air volume to a lower level within this range to ensure that during the pre-drying of the sintering mixture, the material layer will not be overly compacted or the air permeability of the material layer will not be reduced due to excessive hot air volume.

[0043] c. Perform real-time moisture detection on the sintering flue gas discharged from the sintering section to obtain the real-time moisture content W of the sintering flue gas. 实时 The target moisture content of sintering flue gas is set to W 目标 (For example, W 目标 ≤15%, preferably W 目标 ≤13%).

[0044] When the real-time moisture content of the sintering flue gas is detected to be greater than the target moisture content, that is, W 实时 >W 目标 , it is judged that the moisture content of the sintering flue gas discharged from the sintering section exceeds the standard, and the moisture content of the sintering flue gas does not meet the requirements of activated carbon flue gas purification, and steps ab are repeated to adjust the hot air temperature and / or hot air volume entering the pre-drying section until W 实时 ≤W 目标 .

[0045] When the real-time moisture content of the sintering flue gas is detected to be less than or equal to the target moisture content, that is, W 实时 ≤W 目标 , indicating that the moisture content of the sintering flue gas discharged from the sintering section meets the requirements, keeping the hot air temperature and hot air volume entering the pre-drying section unchanged, and sintering operation stable.

[0046] It should be noted that all formulas in the present invention are obtained by fitting by the inventors based on experiments and engineering applications, and all calculations are obtained by substituting the converted values into the formulas according to the given units (after converting the units, only the values are substituted into the formulas for calculation, without substituting the units; the units are only used to adjust the size of the values).

[0047] In this application, "optionally" means to perform or not perform.

[0048] Compared with the prior art, the present invention has the following beneficial technical effects: 1. The present invention sets a hot air pre-drying section after sintering the material and before ignition to remove part of the moisture in the sintering mixture in advance, so that the moisture content in the flue gas from the laterite nickel ore sintering is reduced to meet the moisture requirements of the activated carbon flue gas purification technology, thereby promoting the application of the activated carbon flue gas purification technology in the sintering of laterite nickel ore and greatly reducing the flue gas purification cost.

[0049] 2. The present invention uses the hot air generated during the cooling process of the sintered ore to pre-dry the sintered mixture, making full use of the waste heat of the hot air from the cooling of the sintered ore.

[0050] 3. Based on experimental and engineering applications, this invention constructs a dynamic relationship model to monitor key process parameters such as the initial moisture content of the sintering mix and the moisture content of the flue gas in real time. Based on this information, the hot air temperature and volume entering the pre-drying stage are adjusted online. This control strategy not only significantly improves the stability of the production process, but also effectively reduces the negative impact of raw material moisture fluctuations on the sintering process, thereby optimizing overall production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 4 is a process flow chart of the low-water sintering method of laterite nickel ore in Example 4 of the present invention; Figure 2 Graph showing the relationship between the initial moisture content of the sintering mixture and the maximum temperature of the hot air delivered to the pre-drying section in Example 7 of the present invention; Figure 3 This is a flow chart for controlling the moisture content of sintering flue gas in Example 7 of the present invention. DETAILED DESCRIPTION

[0052] The technical solutions of the present invention are illustrated below with examples, and the scope of protection requested by the present invention includes but is not limited to the following embodiments. Example 1

[0053] A low-water sintering method for laterite nickel ore, comprising the following steps: S1. The laterite nickel ore, flux and fuel are subjected to batching, mixing and granulation steps in sequence to obtain a sintering mixture.

[0054] S2. The sintering mixture is placed on the sintering machine trolley. After the placement is completed, the sintering mixture enters the pre-drying section for pre-drying treatment.

[0055] S3. The sintering mixture after pre-drying passes through the ignition section and the sintering section in sequence to complete the ignition and sintering process. Example 2

[0056] A low-water sintering method for laterite nickel ore, comprising the following steps: S1. The laterite nickel ore, flux and fuel are subjected to batching, mixing and granulation steps in sequence to obtain a sintering mixture.

[0057] S2. The sintering mixture is placed on the sintering machine trolley. After the placement is completed, the sintering mixture enters the pre-drying section for pre-drying treatment.

[0058] S3. The sintering mixture after pre-drying passes through the ignition section and the sintering section in sequence to complete the ignition and sintering process.

[0059] After sintering is completed, the high-temperature sintered ore is unloaded into the cooler for cooling. The sintering flue gas discharged from the sintering section enters the sintering flue and is then discharged after dust removal and purification. Example 3

[0060] A low-water sintering method for laterite nickel ore, comprising the following steps: S1. The laterite nickel ore, flux and fuel are subjected to batching, mixing and granulation steps in sequence to obtain a sintering mixture.

[0061] S2. The sintering mixture is placed on the sintering machine trolley. After the placement is completed, the sintering mixture enters the pre-drying section for pre-drying treatment.

[0062] Among them, the sintered mixture enters the pre-drying section for pre-drying treatment, specifically: the sintered mixture enters the pre-drying section, and at the same time, hot air is transported into the pre-drying section, and the hot air pre-dries the sintered mixture. The pre-drying flue gas discharged from the pre-drying section is discharged after dust removal through the pre-drying flue.

[0063] S3. The sintering mixture after pre-drying passes through the ignition section and the sintering section in sequence to complete the ignition and sintering process.

[0064] After sintering is completed, the high-temperature sintered ore is unloaded into the cooler for cooling. The sintering flue gas discharged from the sintering section enters the sintering flue and is then discharged after dust removal and purification. Example 4

[0065] like Figure 1 As shown, a low-water sintering method for laterite nickel ore comprises the following steps: S1. The laterite nickel ore, flux and fuel are subjected to batching, mixing and granulation steps in sequence to obtain a sintering mixture.

[0066] The flux is a mixture of limestone and dolomite, and the fuel is a mixture of coal powder and coke powder.

[0067] S2. The sintering mixture is placed on the sintering machine trolley. After the placement is completed, the sintering mixture enters the pre-drying section for pre-drying treatment.

[0068] Among them, the sintered mixture enters the pre-drying section for pre-drying treatment, specifically: the sintered mixture enters the pre-drying section, and at the same time, hot air is transported into the pre-drying section, and the hot air pre-dries the sintered mixture. The pre-drying flue gas discharged from the pre-drying section is discharged after dust removal through the pre-drying flue.

[0069] Furthermore, the hot air delivered to the pre-drying section is a mixed hot air composed of the hot air discharged from each section of the cooler. The cooler is a ring cooler. According to the direction of the sintered ore, the ring cooler is sequentially provided with ring cooling section 1, ring cooling section 2, and ring cooling section 3. That is, the hot air discharged from each of the ring cooling section 1, ring cooling section 2, and ring cooling section 3 corresponds to Figure 1 The mixed hot air composed of hot air 1, hot air 2 and hot air 3 performs pre-moisture removal treatment on the sintering mixture entering the pre-drying section.

[0070] S3. The sintering mixture after pre-drying passes through the ignition section and the sintering section in sequence to complete the ignition and sintering process.

[0071] After sintering is completed, the high-temperature sintered ore is unloaded into the cooler for cooling. The sintering flue gas discharged from the sintering section enters the sintering flue and is then discharged after dust removal and purification. Example 5

[0072] Example 4 was repeated, except that iron ore was added to the batching of laterite nickel ore, flux, and fuel in step S1, and then mixed and pelletized to obtain a sintered mixture. Specifically, the iron ore was hematite and magnetite. Example 6

[0073] Example 4 was repeated, except that during the batching of laterite nickel ore, flux, and fuel in step S1, iron ore and miscellaneous materials were added and batched together. The sintered mixture was then subjected to mixing and pelletizing steps to obtain the sintered mixture. Specifically, the iron ore was hematite and magnetite. Specifically, the miscellaneous materials were blast furnace dust and converter dust. Example 7

[0074] like Figure 3 As shown, Example 4 is repeated, except that the method further includes the step of controlling the moisture content of the sintering flue gas, specifically including: a. Construct a relationship between the initial moisture content of the sintering mixture and the maximum temperature of the hot air delivered to the pre-drying section, calculate and adjust the temperature of the hot air entering the pre-drying section. Specifically: The relationship between the initial moisture content of the sintering mixture and the maximum temperature of the hot air delivered to the pre-drying section (I) is constructed, and the corresponding relationship diagram is shown in FIG. Figure 2 As shown. The initial moisture content of the sintering mixture is detected to be W0=15%. The maximum temperature of the hot air delivered to the pre-drying section is calculated as T max , ℃.

[0075] T max = 10836×W0 2 - 6356.8×W0+ 1120.7=411℃………… (Ⅰ).

[0076] Adjust the proportion of hot air discharged from the first, second and third ring cooling sections in the mixed hot air so that the hot air temperature entering the pre-drying section is ≤T max Specifically, in this embodiment, the temperature of the hot air entering the pre-drying section is 350°C.

[0077] b. Construct a relationship between the initial moisture content of the sintering mixture, the air volume of the sintering section, the moisture content of the pre-drying flue gas, the target moisture content of the sintering flue gas, and the minimum air volume of the hot air delivered to the pre-drying section, and calculate and adjust the hot air volume entering the pre-drying section. Specifically: Construct the relationship formula (II) between the initial moisture content of the sintering mixture, the air volume of the sintering section, the moisture content of the pre-drying flue gas, the target moisture content of the sintering flue gas, and the minimum air volume of the hot air delivered to the pre-drying section. Detect the initial moisture content of the sintering mixture W0 = 15%. Detect the air volume Q per ton of sintering mixture in the sintering section. s =1400 Nm3 / t. Detect the moisture content GW of the pre-drying flue gas discharged from the pre-drying section d =12%. Set the target moisture content of sintering flue gas to W 目标 =15%. Calculate the minimum air volume Q per ton of sintered mixture delivered to the pre-drying section. d , Nm 3 / t.

[0078] Q d =(1000×W0-0.6×Q s ×W 目标 ) / (0.6×GW d )=333 Nm 3 / t…………(Ⅱ).

[0079] Adjust the hot air velocity entering the pre-drying section so that the hot air volume entering the pre-drying section is ≥Q d Specifically, in this embodiment, the hot air volume entering the pre-drying section is 340 Nm 3 / t.

[0080] c. Perform real-time moisture detection on the sintering flue gas discharged from the sintering section to obtain the real-time moisture content W of the sintering flue gas. 实时 =15.7%. The target moisture content of sintering flue gas is W 目标 =15%.

[0081] Obviously, W 实时 >W 目标 , it is judged that the moisture content of the sintering flue gas discharged from the sintering section exceeds the standard, and the above steps ab are repeated to adjust the hot air temperature and hot air volume entering the pre-drying section until W 实时 ≤W 目标 . Example 8

[0082] Example 6 was repeated, except that the method further included the step of controlling the moisture content of the sintering flue gas, specifically comprising: a. Construct a relationship between the initial moisture content of the sintering mixture and the maximum temperature of the hot air delivered to the pre-drying section, calculate and adjust the temperature of the hot air entering the pre-drying section. Specifically: Construct the relationship between the initial moisture content of the sintering mixture and the maximum temperature of the hot air delivered to the pre-drying section (I). Detect the initial moisture content of the sintering mixture W0 = 14%. Calculate the maximum temperature of the hot air delivered to the pre-drying section T max , ℃.

[0083] T max = 10836×W0 2 - 6356.8×W0+ 1120.7=443℃………… (Ⅰ).

[0084] Adjust the proportion of hot air discharged from the first, second and third ring cooling sections in the mixed hot air so that the hot air temperature entering the pre-drying section is ≤T max Specifically, in this embodiment, the temperature of the hot air entering the pre-drying section is 400°C.

[0085] b. Construct a relationship between the initial moisture content of the sintering mixture, the air volume of the sintering section, the moisture content of the pre-drying flue gas, the target moisture content of the sintering flue gas, and the minimum air volume of the hot air delivered to the pre-drying section, and calculate and adjust the hot air volume entering the pre-drying section. Specifically: Construct the relationship formula (II) between the initial moisture content of the sintering mixture, the air volume of the sintering section, the moisture content of the pre-drying flue gas, the target moisture content of the sintering flue gas, and the minimum air volume of the hot air delivered to the pre-drying section. Detect the initial moisture content of the sintering mixture W0 = 14%. Detect the air volume Q per ton of sintering mixture in the sintering section. s =1600 Nm 3 / t. Detect the moisture content GW of the pre-drying flue gas discharged from the pre-drying section d =12%. Set the target moisture content of sintering flue gas to W 目标 =13%. Calculate the minimum air volume Q per ton of sintered mixture delivered to the pre-drying section. d , Nm 3 / t.

[0086] Q d =(1000×W0-0.6×Q s ×W 目标 ) / (0.6×GW d )=211 Nm 3 / t…………(Ⅱ).

[0087] Adjust the hot air velocity entering the pre-drying section so that the hot air volume entering the pre-drying section is ≥Q d Specifically, in this embodiment, the hot air volume entering the pre-drying section is 300Nm 3 / t.

[0088] c. Perform real-time moisture detection on the sintering flue gas discharged from the sintering section to obtain the real-time moisture content W of the sintering flue gas. 实时 =11.2%. The target moisture content of sintering flue gas is W 目标 =13%.

[0089] Obviously, W 实时 ≤W 目标 , indicating that the moisture content of the sintering flue gas discharged from the sintering section meets the requirements, keeping the hot air temperature and hot air volume entering the pre-drying section unchanged, and sintering operation stable.

[0090] The present invention adds a pre-drying section to the existing sintering machine, and performs pre-drying and dehydration directly after sintering the material and before ignition, so as to ensure stable production during the sintering process, so that the moisture content of the sintering flue gas meets the requirements of activated carbon flue gas purification, ensure the normal use of activated carbon flue gas purification technology in the laterite nickel ore sintering process, and reduce the cost of flue gas purification.

[0091] The present invention also uses the hot air generated during the cooling process of sintered ore to pre-dry the sintered mixture, and detects key process parameters such as the moisture content of the sintered mixture and the moisture content of the flue gas in real time through the process, fits and constructs a dynamic relationship model, and adjusts the hot air temperature and air volume online to ensure the stability of the production process. It not only makes full use of the waste heat of the hot air from the cooling of the sintered ore, but also effectively reduces the negative impact of the fluctuation of the moisture content of the raw materials on the sintering process, thereby optimizing the overall production efficiency.

Claims

1. A low-water sintering method for laterite nickel ore, the method comprising the following steps: S1, subjecting laterite nickel ore, flux and fuel to batching, mixing and granulation steps in sequence to obtain a sintering mixture; S2. The sintering mixture is placed on the sintering machine trolley. After the placement is completed, the sintering mixture enters the pre-drying section for pre-drying treatment; S3. The sintering mixture after pre-drying passes through the ignition section and the sintering section in sequence to complete the ignition and sintering process.

2. The method according to claim 1, wherein: The method further includes: S4. After sintering is completed, the high-temperature sintered ore is unloaded into the cooler for cooling; the sintering flue gas discharged from the sintering section enters the sintering flue, and is then discharged after dust removal and purification.

3. The method according to claim 2, wherein: In step S2, the sintered mixture enters the pre-drying section for pre-drying treatment. Specifically, the sintered mixture enters the pre-drying section, and at the same time, hot air is transported into the pre-drying section. The hot air pre-dries the sintered mixture, and the pre-drying flue gas discharged from the pre-drying section (through the pre-drying flue) is discharged after dust removal.

4. The method according to claim 3, wherein: The hot air delivered to the pre-drying section is a mixed hot air composed of the hot air discharged from each section of the cooler.

5. The method according to claim 3 or 4, characterized in that: The method further includes the step of controlling the moisture content of the sintering flue gas, specifically comprising: a. Establish a relationship between the initial moisture content of the sintering mixture and the maximum temperature of the hot air delivered to the pre-drying section, and calculate and adjust the temperature of the hot air entering the pre-drying section; b. Establish a relationship between the initial moisture content of the sintering mixture, the air volume in the sintering section, the moisture content of the pre-drying flue gas, the target moisture content of the sintering flue gas, and the minimum air volume of the hot air delivered to the pre-drying section, and calculate and adjust the hot air volume entering the pre-drying section; c. Perform real-time moisture detection on the sintering flue gas discharged from the sintering section. When the real-time moisture content of the sintering flue gas is detected to be greater than the target moisture content, repeat steps a and b. When the real-time moisture content of the sintering flue gas is detected to be less than or equal to the target moisture content, maintain the existing parameters and stabilize the sintering operation.

6. The method according to claim 5, characterized in that: Step a is specifically as follows: Construct a relationship between the initial moisture content of the sintering mixture and the maximum temperature of the hot air delivered to the pre-drying section; detect the initial moisture content W0 of the sintering mixture; calculate the maximum temperature T of the hot air delivered to the pre-drying section max , ℃; T max = 10836×W0 2 - 6356.8×W0+ 1120.7………… (Ⅰ); Adjust the temperature of the hot air delivered to the pre-drying section so that the hot air temperature entering the pre-drying section is ≤T max .

7. The method according to claim 5 or 6, characterized in that: Step b is specifically as follows: Construct the relationship between the initial moisture content of the sintering mixture, the air volume of the sintering section, the moisture content of the pre-drying flue gas, the target moisture content of the sintering flue gas and the minimum air volume of the hot air delivered to the pre-drying section; detect the initial moisture content W0 of the sintering mixture; detect the air volume Q per ton of sintering mixture in the sintering section s , Nm 3 / t; Detect the moisture content GW of the pre-drying flue gas discharged from the pre-drying section d ; Set the target moisture content of sintering flue gas to W 目标 ; Calculate the minimum air volume Q per ton of sintered mixture delivered to the pre-drying section d , Nm 3 / t; Q d =(1000×W0-0.6×Q s ×W 目标 ) / (0.6×GW d )…………(Ⅱ); Adjust the hot air velocity entering the pre-drying section so that the hot air volume entering the pre-drying section is ≥Q d .

8. The method according to any one of claims 5 to 7, characterized in that: Step c is specifically as follows: Perform real-time moisture detection on the sintering flue gas discharged from the sintering section to obtain the real-time moisture content W of the sintering flue gas. 实时 ; Set the target moisture content of sintering flue gas to W 目标 ; When W 实时 >W 目标 , it is judged that the moisture content of the sintering flue gas discharged from the sintering section exceeds the standard, and steps ab are repeated to adjust the hot air temperature and / or hot air volume entering the pre-drying section until W 实时 ≤W 目标 ; When W 实时 ≤W 目标 , indicating that the moisture content of the sintering flue gas discharged from the sintering section meets the requirements, keeping the hot air temperature and hot air volume entering the pre-drying section unchanged, and sintering operation stable.

9. The method according to claim 8, characterized in that: The target moisture content of the sintering flue gas is in the range of W 目标 ≤15%, preferably W 目标 ≤13%.

10. The method according to any one of claims 1 to 9, characterized in that: During the batching of laterite nickel ore, flux and fuel in step S1, iron ore and / or miscellaneous materials are optionally added together for batching, and then mixed and granulated to obtain a sintered mixture; Preferably, the iron ore is one or more of hematite, magnetite, limonite, siderite, specularite, goethite, ilmenite, chromite, ferromanganese ore, vanadium-titanium magnetite, and sintered return ore; the miscellaneous materials are iron-containing dust, iron oxide scale, iron-containing oil sludge, pellet return material, red mud, copper slag, nickel slag, sulfuric acid slag, steel slag, and one or more of iron-containing slag dust and return materials generated by other steel, nonferrous metals, chemical industry, and new energy industries.

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