A suspension roasting desulfurization system for laterite leaching residue

Abstract

The utility model provides a kind of laterite ore leaching residue suspension roasting desulfurization system, including suspension roasting furnace, its feed inlet, top, discharge outlet are respectively equipped with second temperature transmitter, third temperature transmitter, fourth temperature transmitter, bottom air inlet is connected with the air outlet of hot blast furnace;Hot blast furnace air inlet is further connected with gas pipeline and combustion-supporting air fan, the side of hot blast furnace close to air outlet is further connected with air distribution pipeline, second regulating valve is further equipped on air distribution pipeline;First controller input end connects second temperature transmitter, third temperature transmitter, fourth temperature transmitter on suspension roasting furnace, output end is connected combustion-supporting air fan, second regulating valve respectively.The present application adopts PID controller to accurately control temperature in suspension roasting furnace, and control reducing atmosphere and air pressure in furnace;It can realize the automatic stable operation of suspension roasting desulfurization system, to ensure that material realizes target desulfurization effect under as low as possible energy consumption, reduce energy consumption, improve production efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of laterite ore leaching residue suspension roasting desulfurization technology, specifically relating to a laterite ore leaching residue suspension roasting desulfurization system. Background Technology

[0002] The hydrometallurgical process for laterite ore produces a large amount of leaching residue with an iron content of approximately 30-60%. Currently, the main method for handling leaching residue is tailings dam storage, which not only wastes iron resources but also causes significant environmental damage. Therefore, implementing resource utilization of leaching residue can not only bring economic benefits but also mitigate its environmental impact.

[0003] In the laterite ore refining process, the leaching step requires the addition of a 98% concentrated sulfuric acid solution, which results in a high sulfur content in the leaching residue. Desulfurization is an essential step in realizing the resource utilization of the leaching residue. From a metallurgical perspective, suspension roasting can achieve rapid and efficient desulfurization of the leaching residue. However, controlling this process presents two major challenges: precise temperature control and maintaining a consistently sufficient reducing atmosphere within the suspension roasting furnace.

[0004] Currently, suspension roasting technology is mainly used in bauxite desulfurization, bauxite desilication, and molybdenite desulfurization. Due to significant differences in raw materials and process design across various projects and applications, differences also exist in control systems and methods. Current mainstream suspension roasting applications typically only control the reaction temperature to achieve the desired reaction effect. For example, in bauxite desulfurization, the reaction temperature is usually around 550 degrees Celsius, far lower than the approximately 900 degrees Celsius required for laterite desulfurization. The furnace temperature is relatively uniform, and the furnace top temperature is usually used as the target temperature for control. However, in laterite desulfurization, due to the higher reaction temperature, there are large temperature fluctuations within the furnace and significant temperature differences at different locations. Therefore, multiple temperature sensors are needed for overall temperature control of the suspension roasting furnace. For laterite nickel ore leaching residue, the sulfur element in the material mainly exists in the form of ferric sulfate, aluminum sulfate, magnesium sulfate, and sodium sulfate. Among them, magnesium sulfate and aluminum sulfate have relatively stable physicochemical properties and high reaction temperatures. If the reaction atmosphere is not controlled, the reaction is difficult to complete in a short time, and the process design of flash reaction cannot be realized. Therefore, the desulfurization suspension roasting process of laterite nickel ore needs to control the reaction temperature and reaction atmosphere, and maintain good power in the furnace by controlling the pressure inside the furnace.

[0005] To address the aforementioned problems, this utility model provides a laterite ore leaching residue suspension roasting desulfurization system, which can achieve precise control of various parameters in the leaching residue suspension roasting desulfurization process, ensuring stable operation of the entire industrial process. Utility Model Content

[0006] The purpose of this invention is to provide a suspension roasting desulfurization system for laterite leaching residue, which aims to solve the problem of precise control of the temperature, airflow pressure and internal reducing atmosphere of the roasting furnace during the suspension roasting process.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A suspension roasting desulfurization system for laterite leaching residue includes a suspension roasting furnace and a first controller. The suspension roasting furnace is equipped with a second temperature transmitter at the feed inlet, a third temperature transmitter at the top, and a fourth temperature transmitter at the discharge outlet. The bottom air inlet is connected to the air outlet of a hot blast stove. The air inlet of the hot blast stove is also connected to a gas pipeline and a combustion air blower. An air distribution pipeline is also connected to the side of the hot blast stove near the air outlet, and a second regulating valve is also provided on the air distribution pipeline.

[0009] The input terminals of the first controller are respectively connected to the second temperature transmitter, the third temperature transmitter, and the fourth temperature transmitter on the suspension roasting furnace, and the output terminals are respectively connected to the combustion air blower and the second regulating valve.

[0010] The first controller obtains the calculated temperature value of the suspension roasting furnace based on the detection values ​​of the second, third, and fourth temperature transmitters. Based on the deviation between the calculated temperature value and the set temperature value, it controls the air volume of the combustion air blower and the opening degree of the second regulating valve.

[0011] Preferably, the system also includes a second controller, the input of which is connected to an online gas analyzer installed at the outlet of the suspension roasting furnace, and the output of which is connected to a first regulating valve installed on the gas pipeline.

[0012] Preferably, the feed inlet of the suspension roasting furnace is connected to the bottom outlet of the preheater, the top air outlet of the preheater is connected to the dust collector, and the air outlet of the dust collector is connected to the variable frequency centrifugal fan.

[0013] Preferably, a third controller is also included, wherein the input end of the third controller is connected to the second pressure transmitter installed at the feed inlet of the suspension roasting furnace, and the output end is connected to the variable frequency centrifugal fan.

[0014] Preferably, the first controller, the second controller, and the third controller are PID controllers.

[0015] Preferably, when the calculated temperature value is less than the set temperature value, the first controller controls the combustion air blower to turn on and the second regulating valve to close; when the calculated temperature value is greater than the set temperature value, the first controller controls the combustion air blower to turn off and the second regulating valve to open; and the first controller calculates the actual output based on the control quantity, and controls the air volume of the combustion air blower or the opening degree of the second regulating valve based on the actual output quantity.

[0016] Preferably, the hot blast stove is also equipped with a first pressure transmitter; the top of the suspension roasting furnace is equipped with a third pressure transmitter, and the outlet of the suspension roasting furnace is equipped with a fourth pressure transmitter.

[0017] Preferably, the input terminal of the third controller is also connected to the first pressure transmitter, the third pressure transmitter, and the fourth pressure transmitter, respectively, and the output terminal is also connected to an alarm.

[0018] Preferably, the feed inlet at the top of the preheater is connected to a feed pipe.

[0019] Compared with the prior art, the present invention has the following beneficial technical effects:

[0020] This invention employs a PID controller to precisely control the temperature inside the suspension roasting furnace, as well as the reducing atmosphere and pressure within the furnace. It can remove sulfur content from the leaching residue to below 0.2%, while simultaneously enabling automated and stable operation of the suspension roasting system. The furnace's central temperature is controlled at 900-950 degrees Celsius, maintaining a suitable reducing atmosphere. Through flash suspension roasting of powdered materials, the invention ensures that the target desulfurization effect is achieved with the lowest possible energy consumption, reducing energy consumption during the suspension roasting desulfurization process and improving production efficiency. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the suspension roasting desulfurization structure according to an embodiment of the present invention.

[0022] Figure 2 This is a temperature control structure diagram of the control system according to an embodiment of the present invention.

[0023] Figure 3 This is a diagram of the pressure control structure of the control system according to an embodiment of this utility model.

[0024] Figure 4 This is a structural diagram of the atmosphere control system of the embodiment of this utility model.

[0025] Figure 5 This is a schematic diagram of the temperature control principle of the control system in an embodiment of this utility model.

[0026] Figure 6 This is a schematic diagram of the gas composition control principle of the control system according to an embodiment of this utility model.

[0027] Figure 7 This is a schematic diagram of the pressure control principle of the control system in an embodiment of this utility model.

[0028] Reference numerals in the attached diagram: 1-Gas pipeline; 2-First regulating valve; 3-Flow meter; 4-Variable frequency combustion fan; 5-Hot air furnace; 6-First temperature transmitter; 7-First pressure transmitter; 8-Second regulating valve; 9-Air distribution pipeline; 10-Hot air pipeline; 11-Second temperature transmitter; 12-Second pressure transmitter; 13-Suspension roasting furnace; 14-Third temperature transmitter; 15-Third pressure transmitter; 16-Fourth temperature transmitter; 17-Fourth pressure transmitter; 18-Online gas analyzer; 19-Feed pipeline; 20-Preheater; 21-Discharge pipeline; 22-Dust-laden gas conveying pipeline; 23-Dust collector; 24-Exhaust pipeline; 25-Variable frequency centrifugal fan; 26-Temperature controller; 27-Pressure controller; 28-Atmosphere controller. Detailed Implementation

[0029] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0030] In the description of this utility model, it should be noted that the terms "upper," "inner," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In one embodiment, such as Figure 1 As shown, gas pipeline 1 is connected to the air inlet of hot blast stove 5. A first regulating valve 2 is installed on gas pipeline 1 to regulate the gas flow rate, and a flow meter 3 is installed on gas pipeline 1 to measure the flow rate. A variable frequency combustion fan 4 is connected to the air inlet of hot blast stove 5, and the motor frequency of the variable frequency combustion fan 4 can be adjusted to control the combustion air volume. The roasting furnace uses gas as its main energy source and also as a reducing gas. Depending on the type of air intake, the air inlet on hot blast stove 5 connected to gas pipeline 1 can be called the gas inlet, and the air inlet connected to variable frequency combustion fan 4 can be called the combustion air inlet. Both air inlets are located on the left side of hot blast stove 5. An air outlet is also provided on the right side of hot blast stove 5. Air distribution pipeline 9 is connected to the air distribution inlet on the side of hot blast stove 5 near the air outlet, and a second regulating valve 8 is installed on air distribution pipeline 9 to regulate the air distribution volume. A first temperature transmitter 6 and a first pressure transmitter 7 are installed on the body of hot blast stove 5 to measure the furnace temperature and pressure, respectively.

[0032] The air inlet at the bottom of the suspension roasting furnace 13 is connected to the air outlet on the right side of the hot blast stove 5 to ensure that the hot air flowing from the hot blast stove 5 circulates throughout the suspension roasting furnace 13. Hot air is supplied via a hot air duct 10. The suspension roasting furnace 13 also has a feed inlet at its bottom, which is higher than the air inlet, allowing the hot air to blow up the leaching residue entering the furnace, achieving suspension roasting. A second temperature transmitter 11 and a second pressure transmitter 12 are installed at the feed inlet of the furnace 13 to measure the temperature and pressure inside the furnace. After entering through the feed inlet, the leaching residue falls towards the bottom of the suspension roasting furnace 13 under gravity. Simultaneously, the leaching residue is also affected by the buoyancy of the hot air. Therefore, the measurements taken by the second temperature transmitter 11 and the second pressure transmitter 12 indicate the initial mixing of the leaching residue and the hot air. The third temperature transmitter 14 and the third pressure transmitter 15 are installed at the top of the roasting furnace 13 to measure the temperature and pressure at the top of the furnace, respectively. The measurement results are the results after the leaching residue is suspended and roasted. The fourth temperature transmitter 16, the fourth pressure transmitter 17, and the online gas analyzer 18 are installed at the outlet of the suspension roasting furnace 13 to measure the outlet temperature, pressure, and gas composition, respectively.

[0033] The bottom outlet of the preheater 20 is connected to the bottom inlet of the suspension roasting furnace 13 via the discharge pipe 21, and the top inlet of the preheater 20 is connected to one end of the feed pipe 19. The leaching residue enters the preheater 20 through the feed pipe 19 for preheating, and after preheating, it enters the inlet of the suspension roasting furnace 13 through the discharge pipe 21. The top of the preheater 20 is also equipped with an air outlet.

[0034] The dust-laden gas inlet of the dust collector 23 is connected to the air outlet of the preheater 20 via the dust-laden gas conveying pipe 22. The variable frequency centrifugal fan 25 is connected to the exhaust port of the dust collector 23 via the exhaust pipe 24. The dust of the entire system is sent to the dust collector 23 for centralized dust collection via the dust-laden gas conveying pipe 22, and the variable frequency centrifugal fan 25, in conjunction with the dust collector 23, provides the power for the dust flow.

[0035] Example 1;

[0036] Please see Figure 1-2 5. This embodiment provides a laterite ore leaching residue suspension roasting desulfurization system for precise temperature control within the suspension roasting furnace 13.

[0037] Specifically, the system also includes a first controller 26. The input terminals of the first controller 26 are respectively connected to the second temperature transmitter 11, the third temperature transmitter 14, and the fourth temperature transmitter 16 on the suspension roasting furnace 13, and the output terminals are respectively connected to the combustion air fan 4 and the second regulating valve 8. The first controller 26 calculates the temperature calculation value of the suspension roasting furnace 13 based on the detection values ​​of the second temperature transmitter 11, the third temperature transmitter 14, and the fourth temperature transmitter 16, and controls the air volume of the combustion air fan 4 and the opening degree of the second regulating valve 8 based on the deviation between the temperature calculation value and the temperature set value.

[0038] The first controller 26 employs a PID controller. When the calculated temperature value is less than the set temperature value, the first controller 26 controls the combustion air blower 4 to turn on and the second regulating valve 8 to close; when the calculated temperature value is greater than the set temperature value, the first controller 26 controls the combustion air blower 4 to turn off and the second regulating valve 8 to open; furthermore, the first controller 26 calculates the actual output based on the control quantity, and controls the air volume of the combustion air blower 4 or the opening degree of the second regulating valve 8 based on the actual output quantity.

[0039] In this embodiment, the operation of the suspension roasting system is divided into two stages: a heating stage and a working stage. The first controller 26 described in this embodiment performs automated control for the working stage of the roasting system. During the heating stage of the roasting system, the operator mainly relies on comprehensive consideration of the specifications of the roasting system and, based on experience, controls the opening degree of the first regulating valve 2, the opening degree of the second regulating valve 8, and the air volume of the variable frequency combustion fan 4 to ensure that the temperature steadily rises to the required temperature. The heating process will not be described in detail here.

[0040] In this embodiment, after the heating stage of the suspension roasting furnace is completed, the system enters the working stage. The displayed values ​​of the first temperature transmitter 6, the second temperature transmitter 11, the third temperature transmitter 14, and the fourth temperature transmitter 16 are 850~1200℃.

[0041] In this embodiment, after the heating process of the suspension roasting furnace 13 is completed, the leaching residue can be fed into the feed pipe 19. At this time, the first controller 26 is switched to automatic mode. The first controller 26 can accurately adjust the temperature of the suspension roasting furnace 13 according to the set temperature value. The control principle diagram is shown below. Figure 2 As shown below, the control method will be described in detail:

[0042] 1) Obtain the calculated temperature value ;

[0043] Obtain the detection value from the second temperature transmitter. The detected value of the third temperature transmitter and the detection value of the fourth temperature transmitter The calculated temperature value of the suspension roasting furnace 13 is obtained based on the three temperature detection values. Calculation is performed according to weighted function operation 3: ,in: , , , It is a positive real number, and its value ranges from 0 to 1. The specific value is determined according to the actual operation of the suspension roasting furnace 13, and will not be described in detail here.

[0044] 2) Establish a PID control function based on the temperature deviation. ;

[0045] Calculated temperature value after calculation With temperature setpoint Deviation set as The proportional (P), integral (I), and derivative (D) of the deviation are linearly combined to form the control quantity, thus constructing a PID control function. The expression is:

[0046]

[0047] in, , , The values ​​after inference from the fuzzy control model represent the proportional gain, integral time constant, and derivative time constant of the temperature control process of the calcination system, respectively; t is time.

[0048] 3) Based on the control quantity Determine the execution volume;

[0049] The control quantity is positively correlated with the air volume of the variable frequency fan and the opening degree of the regulating valve, respectively. This embodiment provides two proportional functions. When the calculated temperature value is less than the set temperature value, the execution quantity of the variable frequency combustion fan 4 is determined according to proportional function 1. When the calculated temperature value is greater than the set temperature value, the execution quantity of the second regulating valve 8 is determined according to proportional function 2.

[0050] Proportional function 1: ,

[0051] Proportional function 2: ,

[0052] in, It is a positive real number, with a value range of 0 to 1. The specific value is determined based on the actual operation of the hot blast stove 5, and will not be detailed here.

[0053] The output value (execution quantity 1) is converted into an electrical signal and output to the variable frequency combustion fan 4 to control the size of the combustion air. The larger the combustion air, the higher the hot air temperature at the outlet of the hot air furnace 5, and the more the temperature of the suspension roasting furnace 13 rises. The output value (execution quantity 2) is converted into an electrical signal and output to the second regulating valve 8 to control the amount of gas distribution. The larger the opening of the second regulating valve 8, the more gas is distributed, the lower the outlet temperature of the hot air furnace 5, and the greater the temperature drop of the suspension roasting furnace.

[0054] The detection value of the second temperature transmitter The detected value of the third temperature transmitter and the detection value of the fourth temperature transmitter The calculated temperature value is obtained after weighted function calculation. , setting value Calculated temperature value Obtain the deviation value Fuzzy control model and The PID control function performs fuzzy inference on the input values. , , and The calculation is performed on the input value, and the result is used to obtain the final output value through proportional function 1 and proportional function 2. The output value is converted into an electrical signal and then transmitted to the actuator (second regulating valve 8 and variable frequency combustion fan 4).

[0055] By setting up a second temperature transmitter 11, a third temperature transmitter 14, and a fourth temperature transmitter 16, overall temperature monitoring of the suspension roasting furnace can be achieved. The second temperature transmitter measures the inlet hot air temperature of the roasting furnace, which is the highest temperature point inside the furnace and also the starting point of the reaction process. This effectively measures the temperature of the most stable and difficult-to-reduce portion of the material. The third temperature transmitter measures the top inlet temperature of the roasting furnace, which is the midpoint of the material transport path within the furnace and roughly represents the average temperature of the main reaction zone. The fourth temperature transmitter measures the flue gas temperature at the outlet, which is the roasting furnace outlet and represents the material temperature after the reaction is complete. The determination of the calculated temperature values ​​is related to the specific structure of the suspension roasting furnace 13, and the coefficients... , , This can be obtained based on the measured data of the suspension roasting furnace 13. Different suspension roasting furnaces 13 have different coefficients. These three measured values ​​and their corresponding coefficients can effectively characterize the furnace temperature, thereby achieving precise control of the desulfurization temperature.

[0056] Example 2;

[0057] Please see Figure 1 , 3 6. This embodiment provides a laterite ore leaching residue suspension roasting desulfurization system to regulate the reducing atmosphere in the suspension roasting furnace.

[0058] Specifically, based on Embodiment 1, the system further includes a second controller 27. The input of the second controller 27 is connected to an online gas analyzer 18 installed at the outlet of the suspension roasting furnace 13, and the output is connected to a first regulating valve 2 installed on the gas pipeline 1. The second controller 27 also adopts a PID controller.

[0059] In this embodiment, a certain reducing atmosphere should always be maintained inside the suspension roasting furnace 13 to ensure that the sulfate reduction reaction proceeds in the forward direction and has a good reaction rate. The reducing atmosphere mainly uses carbon monoxide as the reducing agent. The reducing atmosphere inside the furnace is controlled by online analysis of the gas composition at the outlet of the suspension roasting furnace 13 and adjustment of the first regulating valve 2 on the gas pipeline 1. The control of the continuous reducing atmosphere adopts a single-loop feedback control model. The control principle diagram is shown below. Figure 3 As shown below, the control method will be described in detail:

[0060] The control loop consists of the second controller 27, the online gas analyzer 18, and the first regulating valve 2. The online gas analyzer 18 collects the measured values ​​of the gas composition at the calcining furnace outlet. Gas composition set value The deviation is set as The PID control function of the second controller 27 is... For control model enter:

[0061]

[0062] in, , , The proportional gain, integral time constant, and derivative time constant are used to calculate the final output value, which is then converted into an electrical signal and transmitted to the first regulating valve 2.

[0063] Example 3;

[0064] Please see Figure 1 , 4 7. This embodiment provides a laterite ore leaching residue suspension roasting desulfurization system to regulate the working pressure inside the suspension roasting furnace.

[0065] Specifically, based on Embodiment 2, the system also includes a third controller 28. The input of the third controller 28 is connected to the second pressure transmitter 12 installed at the feed inlet of the suspension roasting furnace 13, and the output is connected to the variable frequency centrifugal fan 25. The third controller 28 also adopts a PID controller.

[0066] In this embodiment, a certain negative pressure should be maintained inside the suspension roasting furnace 13 to ensure good power conditions within the furnace. The pressure control during the roasting process adopts a single-loop feedback control model. The control principle diagram is shown below. Figure 4 As shown below, the control method will be described in detail:

[0067] The control loop consists of the third controller 28, the second pressure transmitter 12, and the variable frequency centrifugal fan 25. The second pressure transmitter 12 collects the pressure measurement value at the feed inlet of the suspension roasting furnace 13. With pressure set value The deviation is set as The PID control function of the third controller 28 is as follows: The input is the control model. enter:

[0068]

[0069] in, , , The proportional gain, integral time constant, and derivative time constant are used to calculate the final output value, which is then converted into an electrical signal and transmitted to the variable frequency centrifugal fan 25.

[0070] In this embodiment, the input terminal of the third controller 28 can also be connected to the first pressure transmitter 7, the third pressure transmitter 15, and the fourth pressure transmitter 17 respectively, and the output terminal is also connected to an alarm (not shown in the figure). After the entire airflow system stabilizes, the variation range of the difference between the data collected by the first pressure transmitter 7 and the second pressure transmitter 12, the difference between the data collected by the third pressure transmitter 15 and the second pressure transmitter 12, and the difference between the fourth pressure transmitter 17 and the third pressure transmitter 15 are all constant values. The third controller 28 can determine whether the system is operating stably based on whether the above differences are constant values. If the difference exceeds the constant value, the third controller 28 sends a command to the alarm, and the alarm issues an alarm signal.

[0071] The above description is only used to illustrate the technical solution of this utility model and is not intended to limit it. Any modifications or substitutions made to the technical solution by other people skilled in the art, as long as they do not depart from the connotation of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.

Claims

1. A suspension roasting desulfurization system for laterite ore leaching residue, characterized in that: The system includes a suspension roasting furnace (13) and a first controller (26). The suspension roasting furnace (13) is equipped with a second temperature transmitter (11) at the feed inlet, a third temperature transmitter (14) at the top, and a fourth temperature transmitter (16) at the discharge outlet. The bottom air inlet is connected to the air outlet of the hot blast stove (5). The air inlet of the hot blast stove (5) is also connected to a gas pipeline (1) and a combustion air blower (4). The side of the hot blast stove (5) near the air outlet is also connected to an air distribution pipeline (9). The air distribution pipeline (9) is also equipped with a second regulating valve (8). The input terminals of the first controller (26) are respectively connected to the second temperature transmitter (11), the third temperature transmitter (14), and the fourth temperature transmitter (16) on the suspension roasting furnace (13), and the output terminals are respectively connected to the combustion air blower (4) and the second regulating valve (8). The first controller (26) obtains the temperature calculation value of the suspension roasting furnace (13) based on the detection values ​​of the second temperature transmitter (11), the third temperature transmitter (14), and the fourth temperature transmitter (16). Based on the deviation between the temperature calculation value and the temperature set value, it controls the air volume of the combustion air blower (4) and the opening degree of the second regulating valve (8).

2. The laterite ore leaching residue suspension roasting desulfurization system according to claim 1, characterized in that: It also includes a second controller (27), the input end of which is connected to an online gas analyzer (18) installed at the outlet of the suspension roasting furnace (13), and the output end is connected to a first regulating valve (2) installed on the gas pipeline (1).

3. The laterite ore leaching residue suspension roasting desulfurization system according to claim 2, characterized in that: The feed inlet of the suspension roasting furnace (13) is connected to the bottom outlet of the preheater (20), the top outlet of the preheater (20) is connected to the dust collector (23), and the outlet of the dust collector (23) is connected to the variable frequency centrifugal fan (25).

4. The laterite ore leaching residue suspension roasting desulfurization system according to claim 3, characterized in that: It also includes a third controller (28), the input end of which is connected to a second pressure transmitter (12) installed at the feed inlet of the suspension roasting furnace (13), and the output end is connected to a variable frequency centrifugal fan (25).

5. The laterite ore leaching residue suspension roasting desulfurization system according to claim 4, characterized in that: The first controller (26), the second controller (27), and the third controller (28) are PID controllers.

6. The laterite ore leaching residue suspension roasting desulfurization system according to claim 5, characterized in that: When the calculated temperature value is less than the set temperature value, the first controller (26) controls the combustion air blower (4) to open and the second regulating valve (8) to close; when the calculated temperature value is greater than the set temperature value, the first controller (26) controls the combustion air blower (4) to close and the second regulating valve (8) to open; and the first controller (26) calculates the actual output based on the control quantity, and controls the air volume of the combustion air blower (4) or the opening degree of the second regulating valve (8) based on the actual output quantity.

7. The laterite ore leaching residue suspension roasting desulfurization system according to claim 5, characterized in that: The hot air furnace (5) is also equipped with a first pressure transmitter (7); the top of the suspension roasting furnace (13) is equipped with a third pressure transmitter (15), and the outlet of the suspension roasting furnace (13) is equipped with a fourth pressure transmitter (17).

8. The laterite ore leaching residue suspension roasting desulfurization system according to claim 7, characterized in that: The input terminal of the third controller (28) is also connected to the first pressure transmitter (7), the third pressure transmitter (15), and the fourth pressure transmitter (17), respectively, and the output terminal is also connected to an alarm.

9. The laterite ore leaching residue suspension roasting desulfurization system according to claim 5, characterized in that: The feed inlet at the top of the preheater (20) is connected to a feed pipe (19).

Images