CN115448627A - Method for preparing semi-hydrated gypsum powder by dynamic roasting of purified phosphogypsum - Google Patents
Method for preparing semi-hydrated gypsum powder by dynamic roasting of purified phosphogypsum Download PDFInfo
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- CN115448627A CN115448627A CN202211157920.5A CN202211157920A CN115448627A CN 115448627 A CN115448627 A CN 115448627A CN 202211157920 A CN202211157920 A CN 202211157920A CN 115448627 A CN115448627 A CN 115448627A
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B11/00—Calcium sulfate cements
- C04B11/26—Calcium sulfate cements strating from chemical gypsum; starting from phosphogypsum or from waste, e.g. purification products of smoke
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B11/00—Calcium sulfate cements
- C04B11/02—Methods and apparatus for dehydrating gypsum
- C04B11/028—Devices therefor characterised by the type of calcining devices used therefor or by the type of hemihydrate obtained
- C04B11/036—Devices therefor characterised by the type of calcining devices used therefor or by the type of hemihydrate obtained for the dry process, e.g. dehydrating in a fluidised bed or in a rotary kiln, i.e. to obtain beta-hemihydrate
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Abstract
The invention provides a method for preparing semi-hydrated gypsum powder by purifying dynamic phosphogypsum roasting, which relates to the technical field of waste recovery, and adopts a dynamic roasting device to carry out dynamic roasting, and the method comprises the following steps: introducing purified phosphogypsum into a fully preheated dynamic roasting device from a feed inlet; adjusting the temperature of the dry reaction gas introduced into the dry reaction section to 180-220 ℃, and reacting for 10-30min to remove free water; adjusting the roasting reaction gas introduced into the roasting reaction section to the temperature of 120-160 ℃ in the roasting reaction section, and reacting for 30-60min to remove half of the crystal water; then adjusting the temperature of the cooling reaction gas introduced into the cooling reaction section to 60-120 ℃, and reacting for 15-30min to cool gypsum to prepare the semi-hydrated gypsum powder. The invention can establish a phosphogypsum efficient drying dehydration cooperative regulation and control mechanism, reduce energy consumption and increase the qualification rate of the hemihydrate gypsum product.
Description
Technical Field
The invention relates to the technical field of waste recovery, in particular to a method for preparing semi-hydrated gypsum powder by purifying dynamic roasting of phosphogypsum.
Background
Phosphogypsum is a byproduct generated in the production process of phosphate fertilizer, and the main component of the phosphogypsum is CaSO 4 ·2H 2 O, the mass fraction is more than 80 percent, and because the phosphogypsum contains a certain amount of SiO 2 Impurities such as F, P, organic matters and the like influence the comprehensive utilization of the phosphogypsum, the rapid development of the phosphate fertilizer industry produces and discharges a large amount of phosphogypsum, and the resource utilization rate of the phosphogypsum is low. The existing phosphogypsum treatment method mainly adopts stockpiling treatment, occupies a large amount of land and causes environmental pollution.
The building gypsum is also called plaster, is a powdery cementing material using semi-hydrated gypsum as main component, and is made up by using natural gypsum stone or industrial by-product gypsum (phosphogypsum) through the processes of breaking, grinding and low-temp. calcination, but the internal temp. difference of traditional dewatering equipment, such as rotary kiln, is large, and it is difficult to implement accurate regulation and control of thermal engineering system of roasting temp. and so on, and the semi-hydrated gypsum crystal produced is small, low in purity and poor in quality. The dehydration of dihydrate gypsum by fluidized roasting process has also been practiced by scholars. However, the dihydrate gypsum produced by the phosphogypsum after impurity removal has large water content, is easy to agglomerate after entering a roasting furnace, influences the suspension state of materials, and has high fluidized roasting speed, poor controllability, poor crystallization degree of the produced hemihydrate (anhydrous) gypsum, smaller crystal grains and low strength.
In view of this, the present application is specifically proposed.
Disclosure of Invention
The invention aims to provide a method for preparing semi-hydrated gypsum powder by purifying dynamic roasting of phosphogypsum, which can establish a high-efficiency drying and dewatering synergistic regulation and control mechanism of the phosphogypsum, reduce energy consumption and increase the qualification rate of semi-hydrated gypsum products.
The invention can be realized in the following way:
in a first aspect, the invention provides a method for preparing semi-hydrated gypsum powder by purifying dynamic roasting of phosphogypsum, which comprises the steps of carrying out dynamic roasting by adopting a dynamic roasting device, wherein the dynamic roasting device comprises a furnace body and a central rotating shaft rotationally connected to the furnace body; the furnace body is divided into a plurality of layers of reaction chambers by the furnace trays, and the furnace body is sequentially divided into a drying reaction section, a roasting reaction section and a cooling reaction section from top to bottom, wherein the drying reaction section comprises 2-4 reaction chambers, the roasting reaction section comprises 4-6 reaction chambers, and the cooling reaction section comprises 2-4 reaction chambers; the furnace plate comprises a central blanking plate and an edge blanking plate, a central blanking port is arranged at the position, close to the central rotating shaft, of the central blanking plate, an edge blanking port is arranged at the position, close to the inner wall of the furnace body, of the edge blanking plate, and the central blanking plate and the edge blanking plate are arranged at intervals; a plurality of stirring parts are arranged on the central rotating shaft, and the stirring parts extend into at least one reaction chamber for stirring materials; the top of the furnace body is provided with a feed inlet, a preheated gas inlet and a waste gas outlet, and the bottom of the furnace body is provided with a discharge outlet; a working gas inlet is formed in the side wall of the furnace body corresponding to the position of each reaction chamber;
the method comprises the following steps:
introducing purified phosphogypsum into the fully preheated dynamic roasting device from the feed inlet;
adjusting the temperature of the dry reaction gas introduced into the dry reaction section to 180-220 ℃, and reacting for 10-30min to remove free water;
regulating the roasting reaction gas introduced into the roasting reaction section to the temperature of 120-160 ℃ in the roasting reaction section, and reacting for 30-60min to remove half of crystal water;
and then adjusting the cooling reaction gas introduced into the cooling reaction section until the outlet temperature of the cooling reaction section is 60-80 ℃, and reacting for 15-30min to cool gypsum to prepare the semi-hydrated gypsum powder.
In an alternative embodiment, the rotation speed of the central rotating shaft is 4-10r/min when the purified phosphogypsum passes through the drying reaction section, the roasting reaction section and the cooling reaction section.
In an alternative embodiment, the central rotating shaft and the stirring part are both provided with cooling air channels, the central rotating shaft is provided with a cooling air inlet, and the tail end of the stirring part is provided with a cooling air outlet; and cooling air discharged from the cooling air outlet is used as combustion-supporting air for the drying reaction section, the roasting reaction section and the cooling reaction section.
In an optional embodiment, the central rotating shaft is provided with a wind shield, the wind shield divides the central rotating shaft into a plurality of cooling sections, and the cooling sections are communicated with the cooling air channels and are in one-to-one correspondence with the cooling air channels.
In an alternative embodiment, the stirring member includes a first stirring member and a second stirring member which are arranged in an overlapping manner, the first stirring member is located above the second stirring member, and an end of the first stirring member away from the central rotating shaft is provided with an arc-shaped material guiding surface which inclines downwards towards the furnace body.
In an alternative embodiment, the dry reactant gas is gas fired hot air;
preferably, the roasting reaction gas is natural gas, coke oven gas, artificial gas or has a heat value of 3000-4000kJ/Nm 3 Blast furnace gas of (2);
preferably, the cooled reactant gas is provided by a roots blower.
In an alternative embodiment, the preheating of the dynamic roasting apparatus uses a boiling furnace to burn raw coal to provide the preheated gas.
In an alternative embodiment, high temperature exhaust gas discharged from the exhaust gas outlet of the dynamic roasting apparatus is communicated with the boiling furnace for drying the raw coal.
In an alternative embodiment, the purified phosphogypsum is pneumatically conveyed into the dynamic roasting device at a speed of 1-200 tons/hour.
In an optional embodiment, the purified phosphogypsum is a phosphogypsum subjected to a decoloring, purifying and flotation process, the water content of the purified phosphogypsum is 15% -18%, the whiteness is 56% -62%, and the CaSO 4 ·2H 2 O content of 95-97%, siO 2 The content is 0.6-1.0%.
The beneficial effects of the embodiment of the invention include, for example:
the method for preparing the semi-hydrated gypsum powder by dynamically roasting the purified phosphogypsum adopts a dynamic roasting device to realize dynamic roasting, wherein a plurality of reaction chambers are adopted to synchronously regulate and control main process parameters such as roasting temperature, time, atmosphere and the like; the mineral powder is rolled and uniformly heated in the furnace body, the roasting time is shortened, and the roasting uniformity is greatly improved; the whole-grain-level mineral powder is directly roasted at medium temperature and low temperature; the method adopts a mode of preheating the mineral powder step by step and reacting step by step, so that the reaction is complete, the reduction rate can reach more than 90 percent, and blocky materials are avoided, so that the procedures of screening, grading, grinding and batching and pelletizing the ores are reduced, the method is suitable for the full-size mineral powder (0-15 mm), and the raw material adaptability is high; the temperature gradient in the furnace of the dynamic roasting device is obvious, the dehydration, drying, preheating, roasting and cooling are independently completed in one device, the roasting temperature can be controlled to be 150-850 ℃, the temperature field in each stage is uniform, the temperature and atmosphere controllability in different stages is strong, and the regulation and control are convenient; the application has low energy consumption and good fuel adaptability; the whole process has no high-temperature waste gas emission, and belongs to an environment-friendly new technology. The hemihydrate gypsum prepared by the method is stable in quality and convenient and fast to manage; the roasting device has stable and reliable operation, convenient operation and management, few easily-worn parts and simple maintenance.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
FIG. 1 is a schematic structural diagram of a dynamic roasting apparatus provided in an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of an edge blanking tray of the dynamic roasting apparatus according to an embodiment of the present invention;
FIG. 3 is a schematic flow chart of a method for preparing hemihydrate gypsum powder by dynamic roasting of purified phosphogypsum, which is provided by the embodiment of the invention.
Icon: 100-dynamic roasting device; 110-a furnace body; 111-a hob; 1111-central blanking plate; 1112-edge drop trays; 1113-central blanking port; 1114-edge blanking port; 1115-striker plates; 112-a reaction chamber; 113-a feed port; 114-inlet of preheated gas; 115-an exhaust gas outlet; 116-a discharge port; 117 — working gas inlet; 120-a central rotating shaft; 121-stirring members; 1211-a first stirring member; 1212-a second stirring member; 1213-arc-shaped material guiding surface; 122-cooling air channel; 1221-cooling air inlet; 1222-a cooling air outlet; 123-wind deflector.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined or explained in subsequent figures.
In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. indicate an orientation or a positional relationship based on that shown in the drawings or that the product of the present invention is used as it is, this is only for convenience of description and simplification of the description, and it does not indicate or imply that the device or the element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention.
Furthermore, the appearances of the terms "first," "second," and the like, if any, are only used to distinguish one description from another and are not to be construed as indicating or implying relative importance.
It should be noted that the features of the embodiments of the present invention may be combined with each other without conflict.
The application provides a method for preparing semi-hydrated gypsum powder by dynamic roasting of purified phosphogypsum, which comprises the steps of adopting a dynamic roasting device 100 to carry out dynamic roasting, and in order to facilitate the subsequent explanation of the method for preparing semi-hydrated gypsum powder by dynamic roasting of purified phosphogypsum, the specific structure of the dynamic roasting device 100 is explained firstly.
Referring to fig. 1 and 2, the dynamic roasting apparatus 100 includes a furnace body 110 and a central rotation shaft 120 rotatably coupled to the furnace body 110.
In the present application, the furnace body 110 is used as a reaction cavity to implement operations such as drying, dehydration and roasting of materials (for example, purifying phosphogypsum), specifically, in the present application, the furnace body 110 is of a vertical structure, a plurality of furnace trays 111 are arranged in the furnace body, the furnace body 110 is divided into a plurality of layers of reaction chambers 112 by the plurality of furnace trays 111, a feed inlet 113, a preheated gas inlet 114 and a waste gas outlet 115 are arranged at the top of the furnace body 110, and a discharge outlet 116 is arranged at the bottom of the furnace body 110. The material enters the furnace body 110 from the feed inlet 113, and undergoes preheating reaction, drying reaction, roasting reaction and cooling reaction layer by layer in the multilayer reaction chamber 112.
Specifically, the furnace body 110 is sequentially divided into a drying reaction section, a roasting reaction section and a cooling reaction section from top to bottom, wherein the drying reaction section comprises 2-4 reaction chambers 112, the roasting reaction section comprises 4-6 reaction chambers 112, and the cooling reaction section comprises 2-4 reaction chambers 112.
In the present application, in order to increase the retention time of the material in the furnace body 110, the motion trajectory of the material in the present application is "S" shape, specifically, in the present application, the furnace tray 111 includes a central blanking tray 1111 and an edge blanking tray 1112, the central blanking tray 1111 is provided with a central blanking port 1113 at a position close to the central rotating shaft 120, the edge blanking tray 1112 is provided with an edge blanking port 1114 at a position close to the inner wall of the furnace body 110, and the central blanking tray 1111 and the edge blanking tray 1112 are arranged at intervals; in this application, the central blanking tray 1111 and the edge blanking tray 1112 are both inclined, and one side close to the central rotation axis 120 is higher than one side close to the inner wall of the furnace body 110. The first layer of the furnace trays 111 and the last layer of the furnace trays 111 in the plurality of furnace trays 111 are both the central blanking tray 1111. Through the arrangement of the structure, the material enters the furnace body 110 from the feeding port 113, firstly falls onto the edge blanking disc 1112 in the next layer from the central blanking port 1113 of the central blanking disc 1111, and then falls off from the edge blanking port 1114 of the edge blanking disc 1112, and at this time, the movement track of the material is in an "S" shape. Further, because edge charging tray 1112 in this application is not directly connected with center axis of rotation 120, in order to avoid the material from the clearance blanking between edge charging tray 1112 and the center axis of rotation 120, consequently, edge charging tray 1112 is provided with the striker plate 1115 of avoiding the material to follow the unloading of middle part in one side that this application edge charging tray 1112 is close to center axis of rotation 120, and the setting of striker plate 1115 can avoid the material that should follow edge charging tray 1114 blanking from the middle part blanking, has guaranteed the motion trail of material.
Of furnace body 110The side wall is provided with an inlet 117 for a working gas, which may be, for example, natural gas, coke oven gas, artificial gas or a low heating value (3000-4000 kJ/Nm), at a position corresponding to each reaction chamber 112 3 ) The blast furnace gas is used as the working gas for drying and roasting, so that the raw material is dried and roasted, and meanwhile, the working gas can be cold air or normal-temperature air, so that the raw material in the bottom reaction chamber 112 is cooled by air, and the cold air or the normal-temperature air can be input into the reaction chamber 112 through the Roots blower.
Through adjusting the working gas that lets in every reaction chamber 112 in this application, can realize adjusting the temperature of every reaction chamber 112, and then realize carrying out drying, calcination and air-cooled operation in proper order in a furnace body 110. In this application, the working gas inlet 117 of each reaction chamber 112 is separately provided with a flow controller and a temperature controller. The provision of flow controllers and temperature controllers allows for better control of the temperature within the reaction chamber 112.
The central rotating shaft 120 can rotate relative to the furnace body 110, in the present application, a plurality of stirring members 121 are disposed on the central rotating shaft 120, and the stirring members 121 extend into the at least one reaction chamber 112 for stirring the material; the materials can be driven by the stirring member 121 to turn over, so that the materials can be uniformly heated in the reaction chamber 112, and the roasting time can be shortened.
Further, in the present application, the central rotating shaft 120 and the stirring member 121 are both provided with a cooling air channel 122, the central rotating shaft 120 is provided with a cooling air inlet 1221, and the end of the stirring member 121 is provided with a cooling air outlet 1222. Through setting up cooling air passageway 122, can make the temperature on stirring piece surface lower, avoid the raw materials caking, simultaneously, the export of cooling air directly sets up on stirring material 121, can utilize the cooling air as the combustion-supporting wind of dynamic furnace this moment, make full use of the energy to harmful gas's emission has been reduced.
In order to better control the cooling temperature of each cooling air channel 122, in the present application, a wind shield 123 is disposed in the central rotating shaft 120, the wind shield 123 divides the central rotating shaft 120 into a plurality of mutually independent cooling sections, and the cooling sections are communicated with the cooling air channels 122 and are in one-to-one correspondence. Therefore, the cooling air in each cooling interval can be independently controlled, and the control precision is higher. In the present application, the temperature in each reaction chamber 112 can be controlled cooperatively by the temperature and the amount of the introduced reaction gas, the rotation speed of the central rotating shaft 120, the temperature of the cooling air, etc., the calcination temperature can be controlled to be 150-850 ℃, the temperature fields in each stage are uniform, the temperature and the atmosphere controllability in different stages are strong, and the regulation and the control are convenient.
In this application, the stirring member 121 includes a first stirring member 1211 and a second stirring member 1212 that are overlapped, the first stirring member 1211 is located above the second stirring member 1212, and an end of the first stirring member 1211 that is away from the central rotation axis 120 is provided with an arc-shaped material guiding surface 1213 that inclines downward toward the furnace body 110. The arrangement of the overlapped first stirring member 1211 and the second stirring member 1212 can prolong the moving time of the cooling air in the stirring member 121, and is advantageous for ensuring that the upper or lower material in the reaction chamber 112 can be fully contacted with the first stirring member 1211 and the second stirring member 1212. Meanwhile, the arc-shaped material guiding surface 1213 enables the material on the upper surface of the first material stirring member 1211 to slide down along the surface of the first material stirring member 1211 more easily, which is beneficial to controlling the movement track of the material.
In the present application, one stirring member 121 may be disposed in each reaction chamber 112, or some of the reaction chambers 112 may be selectively disposed with the stirring members 121, and the others are not disposed. This application is preferred all to be provided with one in the top of every center blanking dish 1111 and stirs material 121, and stirring material 121 is not established to the top of edge blanking dish 1112, and the advantage that sets up like this lies in being favorable to guaranteeing that the material on the center blanking dish 1111 is discharged from center blanking mouth 1113 under the drive of stirring material 121 to be favorable to controlling the movement track of material.
The working principle of the dynamic roasting apparatus 100 is: preheating gas gets into furnace body 110 from furnace body 110's preheating gas import 114 and preheats furnace body 110 in advance, preheat the back of accomplishing, the material gets into furnace body 110 from furnace body 110's feed inlet 113, the material falls into on furnace body 110's the first central blanking dish 1111, stir material part 121 this moment and drive the material upset, realize the thermally equivalent, drive the material simultaneously from central blanking dish 1111's central blanking mouth 1113 blanking to the edge blanking dish 1112 of next layer, because the slope of edge blanking dish 1112 sets up, make the material more move towards edge blanking mouth 1114 easily. In addition, stir the cooling air passageway 122 that sets up on the material part 121 in this application not only can cool off stirring material part 121, can also let in the cooling air as combustion-supporting wind simultaneously, make full use of the energy to harmful gas's emission has been reduced. The temperature and the flow of the working gas introduced into each reaction chamber 112 of the dynamic roasting device 100 can be adjusted, so that the temperature of each reaction chamber 112 is adjusted, and further, the materials are gradually dried, roasted, cooled and the like from the reaction chamber 112 at the top to the reaction chamber 112 at the bottom, and the operation is simple and the practicability is strong.
Based on the dynamic roasting device 100, the application provides a method for preparing hemihydrate gypsum powder by dynamic roasting of purified phosphogypsum, please refer to fig. 3, which comprises the following steps:
s1, preheating.
The raw coal is combusted using a fluidized bed furnace to provide a preheating gas, which is in communication with the preheating gas inlet 114 to preheat the dynamic roasting apparatus 100.
S2, feeding.
Introducing purified phosphogypsum into the fully preheated dynamic roasting device 100 from a feeding hole 113; the purified phosphogypsum is conveyed into the dynamic roasting device 100 by a feeder in a pneumatic conveying speed of 1-200 tons/hour.
The purified phosphogypsum is obtained by a decolorization purification flotation process, the water content of the purified phosphogypsum is 15-18%, the whiteness is 56-62%, and the CaSO 4 ·2H 2 O content of 95-97%, siO 2 The content is 0.6-1.0%.
S3, drying and reacting.
Adjusting the temperature of the dry reaction gas introduced into the dry reaction section to 180-220 ℃, and reacting for 10-30min to remove free water; during the drying reaction, the rotation speed of the central rotating shaft 120 is 4-10r/min. Because in this application, before carrying out the drying, let in advance and carried out the wind that preheats to dynamic roasting device 100, consequently the dry reaction stage does not have the demand of intensification, dry reaction section only need let in cooling air in central axis of rotation 120 can, the cooling air that lets in central axis of rotation 120 mainly is used for guaranteeing to stir material piece 121 not overtemperature, and the cooling air that simultaneously cooling air export 1222 exhaust is as the preheated wind of dry reaction section, is favorable to retrieving heat energy, can adjust the temperature of dry reaction section. In addition, the flue gas in the drying reaction stage needs to be discharged after temperature reduction and desulfurization treatment.
S4, roasting reaction.
Adjusting the temperature of the roasting reaction gas introduced into the roasting reaction section to 120-160 ℃, and reacting for 30-60min to remove half of the crystal water.
The roasting reaction gas is natural gas, coke oven gas, artificial gas or has a heat value of 3000-4000kJ/Nm 3 The blast furnace gas of (1); the adaptability to fuel is strong, and the optimal balance between the system resistance and the temperature of the tail gas discharged from the system is achieved under the condition of reasonable temperature system and air flow matching.
During the roasting reaction, the rotation speed of the central rotating shaft 120 is 4-10r/min. The cooling air discharged from the cooling air outlet 1222 is used as combustion-supporting air of the roasting reaction section, so that energy is fully utilized, and the emission of harmful gas is reduced; the comprehensive fuel consumption of the roasting system is lower than 35kg standard coal/ton raw ore, and the whole process has no high-temperature waste gas emission, thereby belonging to an environment-friendly new technology.
It is worth noting that the temperature of the roasting reaction in the application is lower than the temperature of the drying stage, the temperature is controlled to be higher in the drying stage so as to enable the phosphogypsum to rapidly remove the external water, and the temperature is controlled to be lower in the roasting stage so as to ensure the semi-water loss of the phosphogypsum, the roasting temperature is gradually reduced, and meanwhile, the requirement of the subsequent cooling reaction is reduced.
Further, the application tests the roasting for 90min at different roasting temperatures, and the test results are as follows:
from the above table, it can be seen that at 130 ℃, the content of the hemihydrate gypsum can reach 80.482%, the temperature is continuously increased to 140 ℃, the content of the hemihydrate gypsum is hardly changed, at the moment, the whiteness of the hemihydrate gypsum product is 72.75%, and the result shows that the hemihydrate gypsum of the phosphogypsum flotation concentrate is suitable for the conversion temperature interval of 130-140 ℃. Therefore, the firing temperature is preferably 130 to 140 ℃ in the present application.
And S5, cooling and reacting.
Then adjusting the cooling reaction gas introduced into the cooling reaction section until the outlet temperature of the cooling reaction section is 60-80 ℃, and reacting for 15-30min to cool gypsum to prepare semi-hydrated gypsum powder.
The cooling reaction gas is provided by a Roots blower which can introduce air into the roasting reaction section so as to realize air cooling of the material in the roasting reaction section. During the cooling reaction, the rotation speed of the central rotating shaft 120 is 4-10r/min, and the cooling air discharged from the cooling air outlet 1222 is used as auxiliary cooling air for cooling the reaction section, thereby improving the cooling effect.
And S6, discharging waste gas.
On the other hand, for the drying and dehydration of the dihydrate gypsum, except for the dehydration of water, part of volatile impurities in the phosphogypsum can be removed in the drying and dehydration process and enter tail gas, and if the roasting equipment does not have tail gas purification treatment, the substances and the tiny gypsum dust enter the atmosphere, so that air pollution is easily caused. And the high temperature waste gas and the fluidized bed furnace intercommunication of the exhaust outlet 115 exhaust from dynamic roasting device 100 in this application are in order to be used for dry raw coal, are favorable to reducing high temperature exhaust emission, and the energy saving is adjusted according to actual conditions also conveniently simultaneously. The tail gas behind the dry raw coal is discharged up to standard after desulfurization and denitrification device handles, is favorable to the environmental protection, avoids causing air pollution.
And S7, collecting products.
The dust collector is communicated with the discharge hole 116, and the dust collector is communicated with the hemihydrate gypsum bin through a bucket elevator. The dust collector can realize the collection to the product to carry through the bucket and carry the machine and carry, finally carry to store in the hemihydrate gypsum storehouse.
The following is specifically described with reference to specific examples.
Example 1
The embodiment provides a method for preparing semi-hydrated gypsum powder by dynamic roasting of purified phosphogypsum, wherein Yichang purified gypsum is phosphogypsum with the water content of 15 percent and CaSO4.2HJ which are subjected to a decoloring, purifying and flotation process 2 The O content is 95.57 percent, the phosphogypsum whiteness is 59.45 percent, and SiO 2 The content is 0.68%. Referring to fig. 3, the process flow diagram includes the following steps:
preheating a dynamic roasting device 100 by high-temperature flue gas generated by a fluidized bed furnace, opening a switch of a feeding hole 113 after the temperature reaches 220 ℃, pneumatically conveying raw material purified phosphogypsum to the dynamic roasting device 100, and slowly feeding the phosphogypsum into a furnace body 110, wherein the first section is a drying reaction section for removing free water, the drying temperature of the drying reaction section is 210 ℃, and the drying time is 10min; the second section is a roasting reaction section for removing half of the crystal water, the roasting temperature of the roasting reaction section is 125 ℃, and the roasting time is 30min; the third section is a cooling reaction section, air cooling is adopted until the temperature of the outlet of the cooling reaction section is reduced to 70 ℃, and the temperature is maintained for 15min.
A gypsum phase analyzer is used for detecting a roasted sample, the compression strength and the flexural strength of the phosphogypsum are tested according to GB/T17669.3-1999 determination of mechanical properties of building gypsum, the content of the semi-hydrated gypsum of the product is 78.06 percent, the whiteness is 70.01 percent, the initial setting time is 4min, the final setting time is 11min, the 2h compression strength is 5.9Mpa, and the 2h flexural strength is 2.8Mpa.
Example 2
The embodiment provides a method for preparing semi-hydrated gypsum powder by dynamic roasting of purified phosphogypsum, wherein Yichang purified gypsum is phosphogypsum with the water content of 15 percent and CaSO subjected to a decoloring, purifying and flotation process 4 ·2H 2 95.57 percent of O content, 59.45 percent of phosphogypsum whiteness and SiO 2 The content is 0.68%. Referring to fig. 3, the process flow diagram includes the following steps:
preheating a dynamic roasting device 100 by high-temperature flue gas generated by a fluidized bed furnace, opening a switch of a feeding hole 113 after the temperature reaches 200 ℃, pneumatically conveying raw material purified phosphogypsum to the dynamic roasting device 100, and slowly feeding the phosphogypsum into a furnace body 110, wherein the first section is a drying reaction section for removing free water, the drying temperature of the drying reaction section is 190 ℃, and the drying time is 15min; the second section is a roasting reaction section for removing half of the crystal water, the roasting temperature of the roasting reaction section is 135 ℃, and the roasting time is 60min; the third section is a cooling reaction section, air cooling is adopted until the temperature of the outlet of the cooling reaction section is reduced to 80 ℃, and the temperature is maintained for 20min.
A gypsum phase component instrument is used for detecting a sample after roasting, the compression strength and the flexural strength of the phosphogypsum are tested according to GB/T17669.3-1999 determination of mechanical properties of building gypsum, the content of the semi-hydrated gypsum of the product is 87.45 percent, the whiteness is 74.04 percent, the initial setting time is 3min, the final setting time is 9min, the compression strength of 2h is 7.8Mpa, and the flexural strength of 2h is 3.5Mpa.
Example 3
This example provides a method for producing hemihydrate gypsum powder by dynamic calcination of purified phosphogypsum, wherein Yichang purified gypsum is phosphogypsum with water content of 15% and CaSO subjected to decolorization, purification and flotation processes 4 ·2H 2 95.57 percent of O content, 59.45 percent of phosphogypsum whiteness and SiO 2 The content is 0.68%. Referring to fig. 3, the process flow diagram includes the following steps:
preheating a dynamic roasting device 100 by high-temperature flue gas generated by a fluidized bed furnace, opening a switch of a feeding hole 113 after the temperature reaches 180 ℃, pneumatically conveying raw material purified phosphogypsum to the dynamic roasting device 100, and slowly feeding the phosphogypsum into a furnace body 110, wherein the first section is a drying reaction section for removing free water, the drying temperature of the drying reaction section is 170 ℃, and the drying time is 20min; the second section is a roasting reaction section for removing half of crystal water, the roasting temperature of the roasting reaction section is 145 ℃, and the roasting time is 90min; the third section is a cooling reaction section, the temperature of the outlet of the cooling reaction section is reduced to 65 ℃ by air cooling, and the temperature is maintained for 20min.
A gypsum phase component instrument is used for detecting a sample after roasting, the compression strength and the flexural strength of the phosphogypsum are tested according to GB/T17669.3-1999 determination of mechanical properties of building gypsum, the content of the semi-hydrated gypsum of the product is 81.47 percent, the whiteness is 71.56 percent, the initial setting time is 3min, the final setting time is 10min, the 2h compression strength is 6.6Mpa, and the 2h flexural strength is 3.1Mpa.
Comparative example 1
The purified gypsum in example 1 (Yichang purified gypsum is phosphogypsum with water content of 15% and CaSO obtained by decolorizing, purifying and flotation process) is roasted by adopting a rotary kiln 4 ·2H 2 95.57 percent of O content, 59.45 percent of phosphogypsum whiteness and SiO 2 Content 0.68%) were calcined to prepare hemihydrate gypsum.
The specific roasting process is that a fluidized bed hot blast stove is adopted to heat materials in the rotary kiln, and the temperature of hot blast in the kiln is controlled between 180 ℃ and 220 ℃ for 90min. And screening the gypsum powder by adopting a cloth bag dust removal and cyclone classifier.
A gypsum phase analyzer is used for detecting a sample after roasting, the compression strength and the flexural strength of the phosphogypsum are tested according to GB/T17669.3-1999 determination of mechanical properties of building gypsum, the content of the semi-hydrated gypsum of the product is 75.62%, the whiteness is 69.01%, the initial setting time is 4min, the final setting time is 11min, the 2h compression strength is 6.1Mpa, and the 2h flexural strength is 3.1Mpa.
Comparing example 1 with comparative example 1, it can be seen that the total content of hemihydrate gypsum in the rotary kiln dried product is low, mainly two times: 1. the material group condition exists in the rotary kiln, cyclone classification screening is needed, and the purity of the screened material is lower than that of a dynamic roasting product; 2. the phosphogypsum entering the rotary kiln is not uniformly contacted with flue gas or the feeding is not matched, so that the gypsum is over-burnt or under-burnt.
Comparative example 2
The purified gypsum in example 1 (Yichang purified gypsum is phosphogypsum with water content of 15% and CaSO obtained by decolorizing, purifying and flotation process) is subjected to fluidized roasting 4 ·2H 2 95.57 percent of O content, 59.45 percent of phosphogypsum whiteness and SiO 2 Content 0.68%) were calcined to prepare hemihydrate gypsum.
The fluidized roasting process generally adopts the steps of feeding hot combustion air of a heat-conducting oil central station into a primary crusher at a temperature of between 250 and 300 ℃, pre-drying materials, scattering, crushing and homogenizing the materials. Fluidizing the crushed materials by hot air, bringing the crushed materials into a main drying device, indirectly and uniformly heating the materials by introducing oil, controlling the heating temperature between 160 and 180 ℃, and then removing dust and collecting to produce qualified products.
A gypsum phase analyzer is used for detecting a roasted sample, the compression strength and the flexural strength of the phosphogypsum are tested according to GB/T17669.3-1999 determination of mechanical properties of building gypsum, the content of the semi-hydrated gypsum of the product is 78.23 percent, the whiteness is 70.12 percent, the initial setting time is 4min, the final setting time is 10min, the 2h compression strength is 5.9Mpa, and the 2h flexural strength is 2.8Mpa.
Comparing the embodiment 1 with the comparative example 2, it can be seen that the fluidized heat transfer oil heating process is complex, the material load is limited by the total amount of hot air, the process parameters are mutually influenced in the control process, the dynamic adjustment cannot be realized, the adjustment of hot air affects the feeding amount of the system, the introduction of oil is easy to exceed the temperature if the hot air is too much, and the control of the product quality is difficult to control compared with the dynamic roasting process.
In conclusion, the method for preparing the semi-hydrated gypsum powder by dynamically roasting the purified phosphogypsum adopts the dynamic roasting device 100 to realize dynamic roasting, wherein a plurality of reaction chambers 112 are combined to synchronously regulate and control main process parameters such as roasting temperature, time, atmosphere and the like; the mineral powder is rolled and uniformly heated in the furnace body 110, the roasting time is shortened, the defect that the stacking gas-solid heat transfer and mass transfer speed is low in the traditional roasting process such as a shaft furnace, a rotary kiln and a rotary hearth furnace is overcome, and the roasting uniformity is greatly improved; the technical bottlenecks of overburning (overburning), underfurning (burning-in-case), bonding and the like in other roasting processes are effectively avoided, and the ring formation and agglomeration phenomena are avoided all the year round in practical production. And the dynamic roasting device 100 preheats and reacts the raw materials step by step, and uses the central shaft cooling air as the combustion-supporting air of the dynamic furnace, thereby fully utilizing energy sources and reducing the emission of harmful gases. The gas producer is also a kind of artificial gas equipment which is started in recent years, and the burnout rate is high. The dynamic roasting device 100 is designed with a cooling mode in the furnace, thereby ensuring the recovery of waste heat and reducing the total energy consumption of the process. The whole-grain-level mineral powder is directly roasted at medium temperature and low temperature; the method adopts the mode of preheating the mineral powder step by step and reacting step by step, so that the reaction is complete, the reduction rate can reach more than 90 percent, and the generation of blocky materials is avoided, thereby reducing the oreThe stone screening, grading, grinding and batching and pelletizing process is applicable to full-size mineral powder (0-15 mm), and has strong raw material adaptability; the temperature gradient in the furnace of the dynamic roasting device 100 is obvious, the dehydration drying, the preheating, the roasting and the cooling are independently completed in one device, the roasting temperature can be controlled to be 150-850 ℃, the temperature field of each stage is uniform, the temperature and atmosphere controllability of different stages is strong, and the regulation and the control are convenient; the application has low energy consumption and good fuel adaptability; the application can use natural gas, coke oven gas, artificial gas or low heat value (3000-4000 kJ/Nm) 3 ) The blast furnace gas is used as roasting working gas, has strong adaptability to fuel, and achieves the optimal balance between the system resistance and the temperature of tail gas discharged from the system under the condition of reasonable temperature system and air flow matching; the waste gas discharged from the furnace top can be used for drying raw ores, so that the high-temperature waste gas emission is reduced, the energy is saved, and the adjustment is convenient according to the actual condition; the central shaft cooling air is used as combustion-supporting air of the dynamic furnace, so that energy is fully utilized, and the emission of harmful gas is reduced; the comprehensive fuel consumption of the roasting system is lower than 35kg standard coal/ton raw ore, and the whole process has no high-temperature waste gas emission, and belongs to an environment-friendly new technology. The semi-hydrated gypsum prepared by the method is stable in quality and convenient and fast to manage; the roasting device has stable and reliable operation, convenient operation and management, few easily-worn parts and simple maintenance.
The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (10)
1. A method for preparing semi-hydrated gypsum powder by dynamic roasting of purified phosphogypsum is characterized by comprising the steps of carrying out dynamic roasting by adopting a dynamic roasting device, wherein the dynamic roasting device comprises a furnace body and a central rotating shaft which is rotationally connected with the furnace body; the furnace body is divided into a plurality of layers of reaction chambers by the aid of the furnace discs, and the furnace body is sequentially divided into a drying reaction section, a roasting reaction section and a cooling reaction section from top to bottom, wherein the drying reaction section comprises 2-4 reaction chambers, the roasting reaction section comprises 4-6 reaction chambers, and the cooling reaction section comprises 2-4 reaction chambers; the furnace plate comprises a central blanking plate and an edge blanking plate, a central blanking port is arranged at the position, close to the central rotating shaft, of the central blanking plate, an edge blanking port is arranged at the position, close to the inner wall of the furnace body, of the edge blanking plate, and the central blanking plate and the edge blanking plate are arranged at intervals; a plurality of stirring parts are arranged on the central rotating shaft, and the stirring parts extend into at least one reaction chamber for stirring materials; the top of the furnace body is provided with a feed inlet, a preheated gas inlet and a waste gas outlet, and the bottom of the furnace body is provided with a discharge outlet; a working gas inlet is formed in the side wall of the furnace body corresponding to the position of each reaction chamber;
the method comprises the following steps:
introducing purified phosphogypsum into the fully preheated dynamic roasting device from the feeding hole;
adjusting the dry reaction gas introduced into the dry reaction section to the temperature of 180-220 ℃ in the dry reaction section, and reacting for 10-30min to remove free water;
regulating the roasting reaction gas introduced into the roasting reaction section to the temperature of 120-160 ℃ in the roasting reaction section, and reacting for 30-60min to remove half of crystal water;
and then adjusting the cooling reaction gas introduced into the cooling reaction section until the outlet temperature of the cooling reaction section is 60-80 ℃, and reacting for 15-30min to cool gypsum to prepare the semi-hydrated gypsum powder.
2. The method for preparing hemihydrate gypsum powder by dynamic roasting of purified phosphogypsum according to claim 1, wherein the rotating speed of the central rotating shaft is 4-10r/min when the purified phosphogypsum passes through the drying reaction section, the roasting reaction section and the cooling reaction section.
3. The method for preparing the hemihydrate gypsum powder by dynamic calcination of the purified phosphogypsum as claimed in claim 1, wherein the central rotating shaft and the stirring member are both provided with cooling air channels, the central rotating shaft is provided with a cooling air inlet, and the tail end of the stirring member is provided with a cooling air outlet; and cooling air discharged from the cooling air outlet is used as combustion-supporting air for the drying reaction section, the roasting reaction section and the cooling reaction section.
4. The method for preparing hemihydrate gypsum powder by dynamic calcination of phosphogypsum through purification according to claim 3, wherein the central rotating shaft is provided with a wind shield, the wind shield divides the central rotating shaft into a plurality of cooling intervals, and the cooling intervals are communicated with the cooling air channels and correspond to the cooling air channels one by one.
5. The method for preparing hemihydrate gypsum powder by dynamic calcination of phosphogypsum through purification according to claim 3, wherein the stirring members comprise a first stirring member and a second stirring member which are arranged in an overlapping manner, the first stirring member is positioned above the second stirring member, and one end of the first stirring member, which is far away from the central rotating shaft, is provided with an arc-shaped material guide surface which inclines downwards towards the furnace body.
6. The method for preparing the semi-hydrated gypsum powder by dynamically roasting the purified phosphogypsum according to claim 1, wherein the roasting reaction gas is natural gas, coke oven gas, artificial gas or has a heat value of 3000-4000kJ/Nm 3 The blast furnace gas of (1);
preferably, the cooled reactant gas is provided by a roots blower.
7. The method for preparing hemihydrate gypsum powder by dynamic calcination of purified phosphogypsum as claimed in claim 1, wherein the preheating of the dynamic calcination device is carried out by burning raw coal in a fluidized bed furnace to provide preheated gas.
8. The method for preparing hemihydrate gypsum powder by dynamic calcination of phosphogypsum according to claim 7, wherein high temperature exhaust gas discharged from the exhaust gas outlet of the dynamic calcination device is communicated with the fluidized bed furnace for drying the raw coal.
9. The method for preparing the hemihydrate gypsum powder by dynamically roasting the purified phosphogypsum according to claim 1, wherein the purified phosphogypsum is conveyed into the dynamic roasting device by air at a speed of 1-200 tons/hour.
10. The method for preparing the semi-hydrated gypsum powder by dynamically roasting the purified phosphogypsum according to any one of claims 1 to 9, wherein the purified phosphogypsum is the phosphogypsum subjected to a decoloring, purifying and flotation process, the water content of the purified phosphogypsum is 15-18%, the whiteness is 56-62%, and the CaSO 4 ·2H 2 O content of 95-97%, siO 2 The content is 0.6-1.0%.
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| CN202211157920.5A CN115448627B (en) | 2022-09-22 | 2022-09-22 | Method for preparing semi-hydrated gypsum powder by dynamic roasting of purified phosphogypsum |
| PCT/CN2023/082865 WO2024060552A1 (en) | 2022-09-22 | 2023-03-21 | Method for preparing semi-hydrated gypsum powder by dynamically roasting purified ardealite |
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| WO2024060552A1 (en) * | 2022-09-22 | 2024-03-28 | 宜昌邦普循环科技有限公司 | Method for preparing semi-hydrated gypsum powder by dynamically roasting purified ardealite |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ES307014A1 (en) * | 1963-12-12 | 1965-04-16 | Lambert Freres & Cie Soc Franc | Method and apparatus for calcining gypsum in two stages |
| GB994067A (en) * | 1960-09-21 | 1965-06-02 | Prerovske Strojirny Np | A method of and apparatus for thermally treating pulverulent or finely granulated materials |
| US4569831A (en) * | 1985-04-01 | 1986-02-11 | Fuller Company | Process and apparatus for calcining gypsum |
| RU2558569C1 (en) * | 2014-06-02 | 2015-08-10 | Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования Воронежский государственный университет инженерных технологий (ФГБОУ ВПО ВГУИТ) | Alpha-gypsum dehydration apparatus |
| CN111306934A (en) * | 2020-04-10 | 2020-06-19 | 绍兴合源环境科技有限公司 | Stove plate heating external heating type multi-hearth stove |
| CN114317945A (en) * | 2021-04-25 | 2022-04-12 | 赣州泽钰管理咨询有限公司 | Rare earth waste or reclaimed material oxidizing roasting system and process |
| CN114538801A (en) * | 2022-04-07 | 2022-05-27 | 广西大学 | Biofuel shaft kiln for firing calcium oxide and method for firing calcium oxide |
| CN114893960A (en) * | 2022-04-27 | 2022-08-12 | 河南郑矿机器有限公司 | Gypsum calcining rotary kiln production line system |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2689502B2 (en) * | 1988-07-28 | 1997-12-10 | 三菱マテリアル株式会社 | How to control gypsum firing equipment |
| CN112551925B (en) * | 2020-10-29 | 2022-08-05 | 中科南京绿色制造产业创新研究院 | Device and method for comprehensively utilizing gypsum raw material |
| CN115448627B (en) * | 2022-09-22 | 2023-10-20 | 宜昌邦普循环科技有限公司 | Method for preparing semi-hydrated gypsum powder by dynamic roasting of purified phosphogypsum |
-
2022
- 2022-09-22 CN CN202211157920.5A patent/CN115448627B/en active Active
-
2023
- 2023-03-21 WO PCT/CN2023/082865 patent/WO2024060552A1/en unknown
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB994067A (en) * | 1960-09-21 | 1965-06-02 | Prerovske Strojirny Np | A method of and apparatus for thermally treating pulverulent or finely granulated materials |
| ES307014A1 (en) * | 1963-12-12 | 1965-04-16 | Lambert Freres & Cie Soc Franc | Method and apparatus for calcining gypsum in two stages |
| US4569831A (en) * | 1985-04-01 | 1986-02-11 | Fuller Company | Process and apparatus for calcining gypsum |
| RU2558569C1 (en) * | 2014-06-02 | 2015-08-10 | Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования Воронежский государственный университет инженерных технологий (ФГБОУ ВПО ВГУИТ) | Alpha-gypsum dehydration apparatus |
| CN111306934A (en) * | 2020-04-10 | 2020-06-19 | 绍兴合源环境科技有限公司 | Stove plate heating external heating type multi-hearth stove |
| CN114317945A (en) * | 2021-04-25 | 2022-04-12 | 赣州泽钰管理咨询有限公司 | Rare earth waste or reclaimed material oxidizing roasting system and process |
| CN114538801A (en) * | 2022-04-07 | 2022-05-27 | 广西大学 | Biofuel shaft kiln for firing calcium oxide and method for firing calcium oxide |
| CN114893960A (en) * | 2022-04-27 | 2022-08-12 | 河南郑矿机器有限公司 | Gypsum calcining rotary kiln production line system |
Non-Patent Citations (1)
| Title |
|---|
| 李少华;王进伟;王启民;杨海瑞;: "应用流化床焙烧制备熟石膏的实验研究", 锅炉技术, no. 03, pages 64 - 67 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024060552A1 (en) * | 2022-09-22 | 2024-03-28 | 宜昌邦普循环科技有限公司 | Method for preparing semi-hydrated gypsum powder by dynamically roasting purified ardealite |
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