Furnace baking method of bauxite suspension roasting system

Abstract

The invention discloses a furnace baking method of a bauxite suspension roasting system, and belongs to the technical field of efficient upgrading metallurgy of bauxite. The furnace baking method comprises the steps that the hot blast stove, the suspension roasting furnace, the suspension preheating mechanism and the suspension cooling mechanism are subjected to staged stable heating furnace baking, furnace baking of the bauxite suspension roasting system is completed, the furnace baking time can be shortened, the furnace baking quality is guaranteed, water in the furnace is completely evaporated, attached water of castable in the bauxite suspension roasting system is rapidly and stably removed, and the quality of the castable is improved. And the method is simple in process, enables the bauxite suspension roasting system to achieve an expected effect, and is suitable for wide popularization and application.

Description

Technical Field

[0001] The present application relates to the technical field of metallurgy for efficiently improving the quality of bauxite, and in particular to a furnace baking method for a bauxite suspension roasting system. Background Art

[0002] The existing bauxite suspension roasting system can realize the dilute phase fluidized roasting method of high-sulfur bauxite. While efficiently removing impurities, this method produces a significant spillover effect, not only turning the previously unusable ore into high-quality effective resources, but also reducing the comparable production cost of alumina by 30 yuan / ton to 50 yuan / ton, achieving better use results.

[0003] When manufacturing a bauxite suspension roasting system, some parts need to be poured with castables such as cement. After the castable is poured, it takes time to evaporate the moisture in the castable. The oven can reduce the evaporation time. However, if a suitable oven drying method is not used, the castable of the bauxite suspension roasting system will be greatly affected, thereby affecting the strength and wear resistance of the bauxite suspension roasting system. However, there is currently no oven drying method for the bauxite suspension roasting system. Summary of the invention

[0004] The embodiment of the present application provides a baking method for a bauxite suspension roasting system, which can solve the problem that failure to adopt a suitable baking method will have a significant impact on the castable of the bauxite suspension roasting system, thereby affecting the strength and wear resistance indicators of the bauxite suspension roasting system, while there is currently no baking method for a bauxite suspension roasting system.

[0005] In order to achieve the above object, the technical solution of the embodiment of the present invention is:

[0006] The embodiment of the present invention provides a furnace baking method of a bauxite suspension roasting system, comprising:

[0007] Input fuel and air from the primary fan inlet at the entrance of the hot blast furnace, and open the primary fan valve;

[0008] Turning on the primary fan and atomizing air of the hot blast stove to purge the inner cavity of the hot blast stove;

[0009] Ignite the hot blast stove, open the first valve and the first blower, then adjust the opening of the primary blower valve, the flow rate of the fuel and the oxygen content of the inner cavity of the hot blast stove to keep the outlet pressure of the hot blast stove less than or equal to the first pressure value, keep the outlet of the hot blast stove heated to the first temperature at a first heating rate, and keep the first temperature constant for the first preset time;

[0010] Adjusting the opening of the primary fan valve, the opening of the first valve, the frequency of the first fan, and the flow rate of the fuel so that the pressure of the outlet flue of the suspension preheating mechanism is maintained at the second pressure value;

[0011] When the temperature of the middle part of the inner cavity of the hot blast stove is increased to be greater than or equal to the second temperature, feeding coal into the hot blast stove at the initial coal feeding amount;

[0012] Multi-stage constant temperature baking furnace for suspension roasting furnace;

[0013] When the temperature at the connection point between the suspension roasting furnace and the hot blast stove reaches the sixth temperature, the coal feeding amount, the opening degree of the first valve, and the frequency of the first fan are adjusted to keep the temperature at the connection point between the suspension roasting furnace and the hot blast stove at the sixth temperature;

[0014] Raising the temperature at the outlet of the suspension roasting furnace to a seventh temperature, and maintaining the seventh temperature for a fourth constant temperature and a fourth preset time;

[0015] Open the flap valve of the cyclone separator, start and adjust the frequency of the second fan, and adjust the opening of the second valve of the air inlet pipe of the cyclone separator, so that a part of the hot flue gas of the suspension roasting furnace enters the inlet of the suspension cooling mechanism along the discharge pipe of the cyclone separator;

[0016] The multi-stage constant temperature baking furnace of the suspension cooling mechanism completes the baking furnace of the bauxite suspension roasting system.

[0017] In a possible implementation, opening the primary fan valve further includes: adjusting the opening of the primary fan valve to 10% to 20%.

[0018] In a possible implementation, during the first constant temperature operation, a heat tightening operation is performed.

[0019] In a possible implementation, the first pressure value is 120 Pa, the first heating rate is 15° C. / h to 25° C. / h, the first temperature is 150° C. to 250° C., and the first preset time is 25h to 35h;

[0020] And / or, the second pressure value is -400Pa to -600Pa;

[0021] And / or, the second temperature is 550°C.

[0022] In a possible implementation, after maintaining the first temperature for the first time for the first preset time, the method further includes:

[0023] Start the flue gas desulfurization device.

[0024] In a possible implementation, the multi-stage constant temperature baking furnace of the suspension roasting furnace includes:

[0025] Adjust the valve opening of the primary fan, the coal feeding amount, the opening of the first valve and the frequency of the first fan, so that the temperature at the outlet of the hot blast furnace is increased to a third temperature at a second heating rate, and the temperature at the outlet of the suspension roasting furnace is increased to a fourth temperature, and the third temperature and the fourth temperature are maintained at a second constant temperature for a second preset time;

[0026] The coal feeding amount, the opening of the first valve, and the frequency of the first fan are adjusted to heat the outlet of the suspension roasting furnace to a fifth temperature at a third heating rate, and the fifth temperature is maintained at a third constant temperature for a third preset time.

[0027] In a possible implementation, the second heating rate is 25°C / h to 35°C / h, the third temperature is 220°C to 250°C, the second preset time is 18h to 24h, and the fourth temperature is 180°C to 250°C;

[0028] And / or, the third heating rate is 25°C / h to 35°C / h, the fifth temperature is 400°C to 500°C, and the third preset time is greater than or equal to 12 hours.

[0029] In a possible implementation, the sixth temperature is 700° C. to 1100° C.;

[0030] And / or, the seventh temperature is 400° C. to 600° C., and the fourth preset time is 8 h to 12 h.

[0031] In a possible implementation, the multi-stage constant temperature oven for the suspended cooling mechanism includes:

[0032] adjusting the coal feeding amount, the frequency of the first fan, the frequency of the second fan, and the opening of the second valve, so that the outlet of the suspension cooling mechanism is heated to an eighth temperature at a fourth heating rate, and the eighth temperature is kept constant for a fifth preset time;

[0033] Adjust the coal feeding amount, the frequency of the first fan, the frequency of the second fan, and the opening of the second valve, so that the outlet of the cyclone separator is heated to a ninth temperature at a fifth heating rate, and the ninth temperature is kept constant for a sixth preset time.

[0034] In a possible implementation, the fourth heating rate is 15°C / h to 25°C / h, the eighth temperature is 150°C to 300°C, and the fifth preset time is 20h to 30h;

[0035] And / or, the fifth heating rate is 15°C / min to 25°C / min, the ninth temperature is 400°C to 500°C, and the sixth preset time is 10h to 15h.

[0036] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0037] The baking method of the bauxite suspension roasting system provided in the embodiment of the present invention completes the baking of the bauxite suspension roasting system by stably heating up the hot blast furnace, the suspension roasting furnace, the suspension preheating mechanism and the suspension cooling mechanism in stages, which can shorten the baking time, ensure the baking quality, completely evaporate the water in the furnace, realize the rapid and stable removal of attached water from the castable in the bauxite suspension roasting system, achieve the strength and wear resistance indicators that meet the operation of the bauxite suspension roasting system, and extend the service life of the hot blast furnace. The method has a simple process, enables the baking of the bauxite suspension roasting system to achieve the expected effect, and is suitable for wide promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0039] Figure 1 A flow chart of a furnace method for a bauxite suspension roasting system provided in an embodiment of the present application;

[0040] Figure 2 This is a schematic diagram of the structure of the bauxite suspension roasting system provided in the embodiment of the present application.

[0041] Icons: 1-hot air furnace; 2-suspension roasting furnace; 3-cyclone separator; 4-suspension preheating mechanism; 5-dust collector; 6-first valve; 7-first fan; 8-flap valve; 9-suspension cooling mechanism; 10-second fan; 11-flue gas desulfurization device. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] In the description of the embodiments of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limitations on the present invention. The terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to the specific circumstances.

[0044] Please refer to Figure 2 As shown, the existing bauxite suspension roasting system includes a hot blast furnace 1, a suspension roasting furnace 2, a cyclone separator 3, a suspension preheating mechanism 4, a dust collector 5, a flue gas desulfurization device 11, a first valve 6, a first fan 7, a suspension cooling mechanism 9 and a second fan 10. A primary fan valve is provided at the inlet of the hot blast furnace 1. The outlet of the hot blast furnace 1 is connected to the suspension roasting furnace 2. The outlet of the suspension roasting furnace 2 is connected to the inlet of the cyclone separator 3. The first outlet of the cyclone separator 3 is connected to the suspension preheating mechanism 4, and the second outlet is connected to the suspension cooling mechanism 9.

[0045] The outlet of the suspension preheating mechanism 4 is connected to the inlet of the dust collector 5. The outlet of the dust collector 5 is connected to the first fan 7. A first valve 6 and a flue gas desulfurization device 11 are sequentially arranged between the outlet of the dust collector 5 and the first fan 7. The flap valve 8 is arranged between the second outlet of the cyclone separator 3 and the suspension cooling mechanism 9. The outlet of the suspension cooling mechanism 9 is connected to the second fan 10.

[0046] When the baking of the bauxite suspension roasting system is actually carried out, a coal feeder is arranged at the entrance of the hot blast stove 1. The measurement structures such as pressure sensors, temperature sensors and oxygen monitors are arranged at appropriate positions of each mechanism of the bauxite suspension roasting system.

[0047] Please refer to Figure 1 As shown, a method for baking a bauxite suspension roasting system provided by an embodiment of the present invention includes the following steps, and the sequence numbers after the steps do not represent the order of execution.

[0048] Step 1: Input fuel and air from the primary fan input port at the entrance of the hot blast furnace 1, and open the primary fan valve.

[0049] Among them, opening the primary fan valve also includes: adjusting the primary fan valve opening to 10% to 20%, which can be 10%, 12%, 14%, 16%, 18%, 20% and other typical but non-limiting openings. Thus, the appropriate amount of fuel and air can be input according to demand. The fuel can be liquid fuel such as diesel.

[0050] Step 2: Turn on the primary fan and atomizing air of the hot blast stove 1 to purge the inner cavity of the hot blast stove 1 , so that the fuel and air are evenly distributed in the inner cavity of the hot blast stove 1 .

[0051] Step 3: Ignite the hot blast stove 1 (when the ignition is successful through flame detection, the fuel and air input ratio and the opening of the primary fan valve are adjusted by monitoring the pressure value and temperature of the inner cavity of the hot blast stove 1 to maintain the heating of the hot blast stove 1), open the first valve 6 and the first fan 7, and then adjust the opening of the primary fan valve, the flow rate of the fuel and the oxygen content of the inner cavity of the hot blast stove 1 to keep the outlet pressure of the hot blast stove 1 less than or equal to the first pressure value, and keep the outlet of the hot blast stove 1 heated to the first temperature at a first heating rate, and keep the first temperature constant for the first preset time.

[0052] During the first constant temperature, thermal tightening is performed. In practice, the system is at room temperature before heating. During the first constant temperature, the connectors of the equipment, such as nuts, are checked and tightened if loose, to improve the safety of the system.

[0053] Among them, the first pressure value is 120Pa, the first heating rate is 15℃ / h~25℃ / h (it can be 15℃ / h, 16℃ / h, 17℃ / h, 18℃ / h, 19℃ / h, 20℃ / h, 21℃ / h, 22℃ / h, 23℃ / h, 24℃ / h, 25℃ / h and other typical but non-limiting heating rates), the first temperature is 150℃~250℃ (it can be 150℃, 170℃, 190℃, 200℃, 210℃, 230℃, 250℃ and other typical but non-limiting temperatures), and the first preset time is 25h~35h (it can be 25h, 26h, 27h, 28h, 29h, 30h, 31h, 32h, 33h, 34h, 35h and other typical but non-limiting times), so as to avoid excessive local temperature of the system caused by excessive heating rate.

[0054] Step 3 can ensure that the attached water of the castable in the hot blast furnace 1 is stably removed.

[0055] Step 4: Start the flue gas desulfurization device 11 to remove sulfur and the like in the flue gas and also dry the flue gas desulfurization device 11 .

[0056] Step 5: Adjust the opening of the primary fan valve, the opening of the first valve 6, the frequency of the first fan 7 (the combustion air volume can be adjusted by adjusting the opening of the first valve 6 and the frequency of the first fan 7), and the flow rate of the fuel to maintain the pressure of the outlet flue of the suspension preheating mechanism 4 at the second pressure value.

[0057] The second pressure value is -400Pa to -600Pa, and may be typical but non-limiting pressure values ​​such as -400Pa, -450Pa, -500Pa, -550Pa, and -600Pa.

[0058] like Figure 2 As shown, the suspension preheating mechanism 4 includes four preheaters, namely C1A, C1B, C2A, and C2B. In practice, the flue gas pressure at the outlets of C1A and C1B is maintained at the second pressure value to ensure that the hot air delivered to the suspension preheating mechanism 4 by the hot blast furnace 1 crosses and rises in the heat exchange pipe of the suspension preheating mechanism 4.

[0059] Step 6: When the temperature of the middle part of the inner cavity of the hot blast stove 1 is raised to be greater than or equal to the second temperature, coal is fed into the hot blast stove 1 at the initial coal feeding amount.

[0060] The second temperature is 550° C. The initial coal feeding rate is 0.5 t / h to 0.7 t / h, and can be 0.5 t / h, 0.6 t / h, 0.7 t / h, and other typical but non-limiting coal feeding rates.

[0061] Step 7: 2 multi-stage constant temperature baking furnace for suspension roasting furnace.

[0062] Wherein, step 7 comprises:

[0063] Step 71: Adjust the primary fan valve opening, coal feeding amount, the opening of the first valve 6 and the frequency of the first fan 7, so that the outlet of the hot blast furnace 1 is heated to the third temperature at the second heating rate, and the temperature at the outlet of the suspension roasting furnace 2 is heated to the fourth temperature, and the third and fourth temperatures are maintained at a constant temperature for a second preset time.

[0064] Among them, the second heating rate is 25℃ / h~35℃ / h (it can be typical but non-limiting heating rates such as 25℃ / h, 26℃ / h, 27℃ / h, 28℃ / h, 29℃ / h, 30℃ / h, 31℃ / h, 32℃ / h, 33℃ / h, 34℃ / h, 35℃ / h, etc.), the third temperature is 220℃~250℃ (it can be typical but non-limiting temperatures such as 220℃, 230℃, 240℃, 250℃, etc.), the second preset time is 18h~24h (it can be typical but non-limiting time such as 18h, 19h, 20h, 21h, 22h, 23h, 24h, etc.), and the fourth temperature is 180℃~250℃ (it can be typical but non-limiting temperatures such as 180℃, 200℃, 230℃, 250℃, etc.).

[0065] Through step 71, the water attached to the castable in the suspension roasting furnace 2 can be stably removed.

[0066] Step 72: adjust the coal feeding amount, the opening of the first valve 6, and the frequency of the first fan 7 to heat the outlet of the suspension roasting furnace 2 to a fifth temperature at a third heating rate, and maintain the fifth temperature for a third constant temperature for a third preset time.

[0067] The third heating rate is 25℃ / h~35℃ / h (it can be typical but non-limiting heating rates such as 25℃ / h, 26℃ / h, 27℃ / h, 28℃ / h, 29℃ / h, 30℃ / h, 31℃ / h, 32℃ / h, 33℃ / h, 34℃ / h, 35℃ / h, etc.), the fifth temperature is 400℃~500℃ (it can be typical but non-limiting temperatures such as 400℃, 420℃, 440℃, 450℃, 460℃, 480℃, 500℃, etc.), and the third preset time is greater than or equal to 12h.

[0068] The suspension roasting furnace 2 can be dried well through step 72. Step 7 utilizes the dried hot air furnace 1 to output stable high-temperature hot air to dry the suspension roasting furnace 2. Moreover, the multi-stage constant temperature drying furnace of the suspension roasting furnace 2 can better match the drying curve of the castable.

[0069] Step 8: When the temperature at the connection point between the suspension roasting furnace 2 and the hot blast stove 1 (i.e., the bottom of the suspension roasting furnace 2) is increased to the sixth temperature, the coal feeding amount, the opening degree of the first valve 6, and the frequency of the first fan 7 are adjusted to keep the temperature at the connection point between the suspension roasting furnace 2 and the hot blast stove 1 at the sixth temperature.

[0070] Among them, the sixth temperature is 700℃~1100℃, and can be typical but non-limiting temperatures such as 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, 1000℃, 1050℃, 1100℃, etc.

[0071] Step 9: Raise the temperature so that the temperature at the outlet of the suspension roasting furnace 2 reaches the seventh temperature, and maintain the seventh temperature for the fourth constant temperature for the fourth preset time.

[0072] Among them, the seventh temperature is 400℃~600℃ (it can be typical but non-limiting temperatures such as 400℃, 450℃, 500℃, 550℃, 600℃, etc.), and the fourth preset time is 8h~12h (it can be typical but non-limiting time such as 8h, 9h, 10h, 11h, 12h, etc.).

[0073] The drying of the suspension preheating mechanism 4 can be achieved through step 6 and step 7. At this time, the drying work of the hot air furnace 1, the suspension roasting furnace 2 and the suspension preheating mechanism 4 is completed through the above steps.

[0074] Step 10: Open the flap valve 8 of the cyclone separator 3, start and adjust the frequency of the second fan 10, and adjust the opening of the second valve of the air inlet pipe of the cyclone separator 3, so that a part of the hot flue gas of the suspension roasting furnace 2 enters the inlet of the suspension cooling mechanism 9 along the discharge pipe of the cyclone separator 3.

[0075] Step 11: The suspension cooling mechanism 9 is used for a multi-stage constant temperature baking furnace to complete the baking furnace of the bauxite suspension roasting system.

[0076] Wherein, step 11 comprises:

[0077] Step 111: adjust the coal feeding amount, the frequency of the first fan 7, the frequency of the second fan 10, and the opening of the second valve, so that the outlet of the suspension cooling mechanism 9 is heated to the eighth temperature at the fourth heating rate, and the eighth temperature is kept constant for the fifth preset time.

[0078] Among them, the fourth heating rate is 15℃ / h~25℃ / h (it can be typical but non-limiting heating rates such as 15℃ / h, 16℃ / h, 17℃ / h, 18℃ / h, 19℃ / h, 20℃ / h, 21℃ / h, 22℃ / h, 23℃ / h, 24℃ / h, 25℃ / h, etc.), the eighth temperature is 150℃~300℃ (it can be typical but non-limiting temperatures such as 150℃, 200℃, 250℃, 300℃, etc.), and the fifth preset time is 20h~30h (it can be typical but non-limiting time such as 20h, 21h, 22h, 23h, 24h, 25h, 26h, 27h, 28h, 29h, 30h, etc.).

[0079] Step 112: Adjust the coal feeding amount, the frequency of the first fan 7, the frequency of the second fan 10, and the opening of the second valve, so that the outlet of the cyclone separator 3 is heated to the ninth temperature at the fifth heating rate, and the ninth temperature is kept constant for the sixth preset time. The multi-stage constant temperature drying furnace of the suspension cooling mechanism 9 can better match the drying curve of the castable.

[0080] Among them, the fifth heating rate is 15℃ / min~25℃ / min (it can be typical but non-limiting heating rates such as 15℃ / h, 16℃ / h, 17℃ / h, 18℃ / h, 19℃ / h, 20℃ / h, 21℃ / h, 22℃ / h, 23℃ / h, 24℃ / h, 25℃ / h, etc.), the ninth temperature is 400℃~500℃ (it can be typical but non-limiting temperatures such as 400℃, 420℃, 440℃, 450℃, 460℃, 480℃, 500℃, etc.), and the sixth preset time is 10h~15h (it can be typical but non-limiting time such as 10h, 11h, 12h, 13h, 14h, 15h, etc.).

[0081] The baking method of the bauxite suspension roasting system provided in the embodiment of the present invention can shorten the baking time, ensure the baking quality, completely evaporate the water in the furnace, realize the rapid and stable removal of attached water from the castable in the bauxite suspension roasting system, achieve the strength and wear resistance indicators that meet the operation of the bauxite suspension roasting system, and extend the service life of the hot blast furnace 1. The method has a simple process, enables the baking of the bauxite suspension roasting system to achieve the expected effect, and is suitable for wide promotion and application.

[0082] The baking method provided by the embodiment of the present invention can solve the problem that there is no baking method for bauxite suspension roasting system at present, and realize the baking of bauxite suspension roasting system before the start of the bauxite suspension roasting quality improvement process technology. It can realize the bauxite dilute phase fluidized roasting quality improvement process technology, reduce the heat loss and energy consumption of the bauxite suspension roasting system, reduce production costs and increase the stability of the bauxite suspension roasting system. It ensures the stable operation of the bauxite suspension roasting system, solves the technical problems of baking the bauxite suspension roasting system that have long plagued my country's alumina industry, and creates a new situation for the healthy and sustainable development of the alumina industry.

[0083] In order to enable the above implementation details and operations of the present application to be clearly understood by those skilled in the art, and to significantly demonstrate the progressiveness of the baking method of the bauxite suspension roasting system in the embodiment of the present application, the above technical scheme is illustrated by means of multiple embodiments below.

[0084] Embodiment 1

[0085] Step 1: Input fuel and air from the primary fan input port at the entrance of the hot blast furnace 1, and open the primary fan valve. Adjust the primary fan valve opening to 16%.

[0086] Step 2: Turn on the primary fan and atomizing air of the hot blast stove 1 to purge the inner cavity of the hot blast stove 1 .

[0087] Step 3: Ignite the hot blast furnace 1, open the first valve 6 and the first fan 7, and then adjust the opening of the primary fan valve, the flow rate of the fuel and the oxygen content of the inner cavity of the hot blast furnace 1 to keep the outlet pressure of the hot blast furnace 1 less than or equal to 120Pa, and keep the outlet of the hot blast furnace 1 heated to 220℃ at 22℃ / h, and keep the first constant temperature of 220℃ for 28h. During the first constant temperature, perform heat tightening work.

[0088] Step 4: Start the flue gas desulfurization device 11.

[0089] Step 5: Adjust the opening of the primary fan valve, the opening of the first valve 6 (20%), the frequency of the first fan 7 (the combustion air volume can be adjusted by adjusting the opening of the first valve 6 and the frequency of the first fan 7), and the flow rate of the fuel to maintain the pressure of the outlet flue of the suspension preheating mechanism 4 at -500Pa.

[0090] Step 6: When the temperature of the middle part of the inner cavity of the hot blast stove 1 is raised to be greater than or equal to 550° C., coal is fed into the hot blast stove 1 at an initial coal feeding rate of 0.6 t / h.

[0091] Step 7: 2 multi-stage constant temperature baking furnace for suspension roasting furnace.

[0092] Step 71: Adjust the primary fan valve opening, coal feeding amount, the opening of the first valve 6 and the frequency of the first fan 7, so that the temperature at the outlet of the hot blast furnace 1 is raised to 230°C at 30°C / h, and the temperature at the outlet of the suspension roasting furnace 2 is raised to 215°C, and maintain the second constant temperature of 230°C and 215°C for 21 hours.

[0093] Step 72: Adjust the coal feeding amount, the opening of the first valve 6, and the frequency of the first fan 7 to raise the temperature at the outlet of the suspension roasting furnace 2 to 450° C. at 32° C. / h, and maintain the temperature at 450° C. for the third time for 15 hours.

[0094] Step 8: When the temperature at the connection between the suspension roasting furnace 2 and the hot blast stove 1 reaches 950°C, adjust the coal feeding amount, the opening of the first valve 6, and the frequency of the first fan 7 to maintain the temperature at the connection between the suspension roasting furnace 2 and the hot blast stove 1 at 950°C.

[0095] Step 9: Raise the temperature at the outlet of the suspension roasting furnace 2 to 500° C. and maintain the temperature at 500° C. for the fourth time for 10 hours.

[0096] Step 10: Open the flap valve 8 of the cyclone separator 3, start and adjust the frequency of the second fan 10, and adjust the opening of the second valve of the air inlet pipe of the cyclone separator 3, so that a part of the hot flue gas of the suspension roasting furnace 2 enters the inlet of the suspension cooling mechanism 9 along the discharge pipe of the cyclone separator 3.

[0097] Step 11: The suspension cooling mechanism 9 is used for a multi-stage constant temperature baking furnace to complete the baking furnace of the bauxite suspension roasting system.

[0098] Step 111: Adjust the coal feeding amount, the frequency of the first fan 7, the frequency of the second fan 10, and the opening of the second valve to raise the temperature at the outlet of the suspension cooling mechanism 9 to 225°C at a rate of 20°C / h and maintain a constant temperature of 225°C for 25h.

[0099] Step 112: Adjust the coal feeding amount, the frequency of the first fan 7, the frequency of the second fan 10, and the opening of the second valve, so that the outlet of the cyclone separator 3 is heated to 450°C at a rate of 20°C / h and maintained at a constant temperature of 450°C for 12.5h.

[0100] Embodiment 2

[0101] Step 1: Input fuel and air from the primary fan input port at the entrance of the hot blast furnace 1, and open the primary fan valve. Adjust the primary fan valve opening to 10%.

[0102] Step 2: Turn on the primary fan and atomizing air of the hot blast stove 1 to purge the inner cavity of the hot blast stove 1 .

[0103] Step 3: Ignite the hot blast furnace 1, open the first valve 6 and the first fan 7, and then adjust the opening of the primary fan valve, the flow rate of the fuel and the oxygen content of the inner cavity of the hot blast furnace 1 to keep the outlet pressure of the hot blast furnace 1 less than or equal to 120Pa, and keep the outlet of the hot blast furnace 1 heated to 150°C at a rate of 15°C / h, and keep the first constant temperature of 150°C for 35h.

[0104] Step 4: Start the flue gas desulfurization device 11.

[0105] Step 5: Adjust the opening of the primary fan valve, the opening of the first valve 6, the frequency of the first fan 7 (the combustion air volume can be adjusted by adjusting the opening of the first valve 6 and the frequency of the first fan 7), and the flow rate of the fuel to maintain the pressure of the outlet flue of the suspension preheating mechanism 4 at -400Pa.

[0106] Step 6: When the temperature of the middle part of the inner cavity of the hot blast stove 1 is raised to be greater than or equal to 550° C., coal is fed into the hot blast stove 1 at an initial coal feeding rate of 0.5 t / h.

[0107] Step 7: 2 multi-stage constant temperature baking furnace for suspension roasting furnace.

[0108] Step 71: Adjust the primary fan valve opening, coal feeding amount, the opening of the first valve 6 and the frequency of the first fan 7, so that the temperature at the outlet of the hot blast furnace 1 is raised to 220°C at 25°C / h, and the temperature at the outlet of the suspension roasting furnace 2 is raised to 180°C, and maintain a second constant temperature of 220°C and 180°C for 24 hours.

[0109] Step 72: Adjust the coal feeding amount, the opening of the first valve 6, and the frequency of the first fan 7 to raise the temperature at the outlet of the suspension roasting furnace 2 to 400° C. at 25° C. / h, and maintain the third constant temperature of 400° C. for 18 hours.

[0110] Step 8: When the temperature at the connection between the suspension roasting furnace 2 and the hot blast stove 1 reaches 700°C, adjust the coal feeding amount, the opening of the first valve 6, and the frequency of the first fan 7 to maintain the temperature at the connection between the suspension roasting furnace 2 and the hot blast stove 1 at 700°C.

[0111] Step 9: Raise the temperature at the outlet of the suspension roasting furnace 2 to 400° C. and maintain the temperature at 400° C. for the fourth time for 12 hours.

[0112] Step 10: Open the flap valve 8 of the cyclone separator 3, start and adjust the frequency of the second fan 10, and adjust the opening of the second valve of the air inlet pipe of the cyclone separator 3, so that a part of the hot flue gas of the suspension roasting furnace 2 enters the inlet of the suspension cooling mechanism 9 along the discharge pipe of the cyclone separator 3.

[0113] Step 11: The suspension cooling mechanism 9 is used for a multi-stage constant temperature baking furnace to complete the baking furnace of the bauxite suspension roasting system.

[0114] Step 111: Adjust the coal feeding amount, the frequency of the first fan 7, the frequency of the second fan 10, and the opening of the second valve to raise the temperature at the outlet of the suspension cooling mechanism 9 to 150°C at a rate of 15°C / h and maintain a constant temperature of 150°C for 30 hours.

[0115] Step 112: Adjust the coal feeding amount, the frequency of the first fan 7, the frequency of the second fan 10, and the opening of the second valve, so that the outlet of the cyclone separator 3 is heated to 400°C at a rate of 15°C / min and maintained at a constant temperature of 400°C for 15 hours.

[0116] Embodiment 3

[0117] Step 1: Input fuel and air from the primary fan input port at the entrance of the hot blast furnace 1, and open the primary fan valve. Adjust the primary fan valve opening to 20%.

[0118] Step 2: Turn on the primary fan and atomizing air of the hot blast stove 1 to purge the inner cavity of the hot blast stove 1 .

[0119] Step 3: Ignite the hot blast furnace 1, open the first valve 6 and the first fan 7, and then adjust the opening of the primary fan valve, the flow rate of the fuel and the oxygen content of the inner cavity of the hot blast furnace 1 to keep the outlet pressure of the hot blast furnace 1 less than or equal to 120Pa, and keep the outlet of the hot blast furnace 1 heated to 250℃ at 25℃ / h, and keep the first constant temperature of 250℃ for 25h. During the first constant temperature, perform heat tightening.

[0120] Step 4: Start the flue gas desulfurization device 11.

[0121] Step 5: Adjust the opening of the primary fan valve, the opening of the first valve 6, the frequency of the first fan 7 (the combustion air volume can be adjusted by adjusting the opening of the first valve 6 and the frequency of the first fan 7), and the flow rate of the fuel to maintain the pressure of the outlet flue of the suspension preheating mechanism 4 at -600Pa.

[0122] Step 6: When the temperature of the middle part of the inner cavity of the hot blast stove 1 is raised to be greater than or equal to 550° C., coal is fed into the hot blast stove 1 at an initial coal feeding rate of 0.7 t / h.

[0123] Step 7: 2 multi-stage constant temperature baking furnace for suspension roasting furnace.

[0124] Step 71: Adjust the primary fan valve opening, coal feeding amount, the opening of the first valve 6 and the frequency of the first fan 7, so that the temperature at the outlet of the hot blast furnace 1 is raised to 250°C at 35°C / h, and the temperature at the outlet of the suspension roasting furnace 2 is raised to 230°C, and maintain a second constant temperature of 250°C and 230°C for 18 hours.

[0125] Step 72: Adjust the coal feeding amount, the opening of the first valve 6, and the frequency of the first fan 7 to raise the temperature at the outlet of the suspension roasting furnace 2 to 500° C. at 35° C. / h, and maintain the third constant temperature of 500° C. for 12 hours.

[0126] Step 8: When the temperature at the connection between the suspension roasting furnace 2 and the hot blast stove 1 reaches 1100°C, adjust the coal feeding amount, the opening of the first valve 6, and the frequency of the first fan 7 to maintain the temperature at the connection between the suspension roasting furnace 2 and the hot blast stove 1 at 1100°C.

[0127] Step 9: Raise the temperature at the outlet of the suspension roasting furnace 2 to 600° C. and maintain the temperature at 600° C. for the fourth time for 8 hours.

[0128] Step 10: Open the flap valve 8 of the cyclone separator 3, start and adjust the frequency of the second fan 10, and adjust the opening of the second valve of the air inlet pipe of the cyclone separator 3, so that a part of the hot flue gas of the suspension roasting furnace 2 enters the inlet of the suspension cooling mechanism 9 along the discharge pipe of the cyclone separator 3.

[0129] Step 11: The suspension cooling mechanism 9 is used for a multi-stage constant temperature baking furnace to complete the baking furnace of the bauxite suspension roasting system.

[0130] Step 111: Adjust the coal feeding amount, the frequency of the first fan 7, the frequency of the second fan 10, and the opening of the second valve to raise the temperature at the outlet of the suspension cooling mechanism 9 to 300°C at 25°C / h, and maintain the cyclone separator 3 at a constant temperature of 300°C for 20 hours.

[0131] Step 112: Adjust the coal feeding amount, the frequency of the first fan 7, the frequency of the second fan 10, and the opening of the second valve, so that the temperature at the outlet of the cyclone separator 3 is raised to 500°C at 25°C / h and maintained at a constant temperature of 500°C for 10 hours.

[0132] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0133] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A method for baking a bauxite suspension roasting system, characterized in that: include: Input fuel and air from the primary fan inlet at the entrance of the hot blast furnace, and open the primary fan valve; Turning on the primary fan and atomizing air of the hot blast stove to purge the inner cavity of the hot blast stove; Ignite the hot blast stove, open the first valve and the first blower, then adjust the opening of the primary blower valve, the flow rate of the fuel and the oxygen content of the inner cavity of the hot blast stove to keep the outlet pressure of the hot blast stove less than or equal to the first pressure value, keep the outlet of the hot blast stove heated to the first temperature at a first heating rate, and keep the first temperature constant for the first preset time; Adjusting the opening of the primary fan valve, the opening of the first valve, the frequency of the first fan, and the flow rate of the fuel so that the pressure of the outlet flue of the suspension preheating mechanism is maintained at the second pressure value; When the temperature of the middle part of the inner cavity of the hot blast stove is increased to be greater than or equal to the second temperature, feeding coal into the hot blast stove at the initial coal feeding amount; Multi-stage constant temperature baking furnace for suspension roasting furnace; When the temperature at the connection point between the suspension roasting furnace and the hot blast stove reaches the sixth temperature, the coal feeding amount, the opening degree of the first valve, and the frequency of the first fan are adjusted to keep the temperature at the connection point between the suspension roasting furnace and the hot blast stove at the sixth temperature; Raising the temperature at the outlet of the suspension roasting furnace to a seventh temperature, and maintaining the seventh temperature for a fourth constant temperature and a fourth preset time; Open the flap valve of the cyclone separator, start and adjust the frequency of the second fan, and adjust the opening of the second valve of the air inlet pipe of the cyclone separator, so that a part of the hot flue gas of the suspension roasting furnace enters the inlet of the suspension cooling mechanism along the discharge pipe of the cyclone separator; The multi-stage constant temperature baking furnace of the suspension cooling mechanism completes the baking furnace of the bauxite suspension roasting system.

2. The method for baking alumina suspension roasting system according to claim 1, characterized in that: Opening the primary fan valve also includes: adjusting the opening of the primary fan valve to 10% to 20%.

3. The method for baking alumina suspension roasting system according to claim 1, characterized in that: When the temperature is kept constant for the first time, heat tightening work is performed.

4. The method for baking alumina suspension roasting system according to claim 1, characterized in that: The first pressure value is 120 Pa, the first heating rate is 15° C. / h to 25° C. / h, the first temperature is 150° C. to 250° C., and the first preset time is 25h to 35h; And / or, the second pressure value is -400Pa to -600Pa; And / or, the second temperature is 550°C.

5. The method for baking alumina suspension roasting system according to claim 1, characterized in that: After the first temperature is maintained for the first time at a constant temperature for the first preset time, the method further comprises: Start the flue gas desulfurization device.

6. The method for baking alumina suspension roasting system according to claim 1, characterized in that: The multi-stage constant temperature baking furnace for the suspension roasting furnace comprises: Adjust the valve opening of the primary fan, the coal feeding amount, the opening of the first valve and the frequency of the first fan, so that the temperature at the outlet of the hot blast furnace is increased to a third temperature at a second heating rate, and the temperature at the outlet of the suspension roasting furnace is increased to a fourth temperature, and the third temperature and the fourth temperature are maintained at a second constant temperature for a second preset time; The coal feeding amount, the opening of the first valve, and the frequency of the first fan are adjusted to heat the outlet of the suspension roasting furnace to a fifth temperature at a third heating rate, and the fifth temperature is maintained at a third constant temperature for a third preset time.

7. The method for baking alumina suspension roasting system according to claim 6, characterized in that: The second heating rate is 25°C / h to 35°C / h, the third temperature is 220°C to 250°C, the second preset time is 18h to 24h, and the fourth temperature is 180°C to 250°C; And / or, the third heating rate is 25°C / h to 35°C / h, the fifth temperature is 400°C to 500°C, and the third preset time is greater than or equal to 12 hours.

8. The method for baking alumina suspension roasting system according to claim 1, characterized in that: The sixth temperature is 700° C. to 1100° C.; And / or, the seventh temperature is 400° C. to 600° C., and the fourth preset time is 8 h to 12 h.

9. The method for baking alumina suspension roasting system according to claim 1, characterized in that: The multi-stage constant temperature oven with suspended cooling mechanism comprises: adjusting the coal feeding amount, the frequency of the first fan, the frequency of the second fan, and the opening of the second valve, so that the outlet of the suspension cooling mechanism is heated to an eighth temperature at a fourth heating rate, and the eighth temperature is kept constant for a fifth preset time; Adjust the coal feeding amount, the frequency of the first fan, the frequency of the second fan, and the opening of the second valve, so that the outlet of the cyclone separator is heated to a ninth temperature at a fifth heating rate, and the ninth temperature is kept constant for a sixth preset time.

10. The method for baking alumina suspension roasting system according to claim 9, characterized in that: The fourth heating rate is 15°C / h to 25°C / h, the eighth temperature is 150°C to 300°C, and the fifth preset time is 20h to 30h; And / or, the fifth heating rate is 15°C / min to 25°C / min, the ninth temperature is 400°C to 500°C, and the sixth preset time is 10h to 15h.

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