CN113683321A - Method for producing sulfate-resistant silicate cement by using phosphogypsum - Google Patents
Method for producing sulfate-resistant silicate cement by using phosphogypsum Download PDFInfo
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- CN113683321A CN113683321A CN202110906429.7A CN202110906429A CN113683321A CN 113683321 A CN113683321 A CN 113683321A CN 202110906429 A CN202110906429 A CN 202110906429A CN 113683321 A CN113683321 A CN 113683321A
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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
- C04B7/00—Hydraulic cements
- C04B7/24—Cements from oil shales, residues or waste other than slag
- C04B7/26—Cements from oil shales, residues or waste other than slag from raw materials containing flue dust, i.e. fly ash
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B17/00—Sulfur; Compounds thereof
- C01B17/69—Sulfur trioxide; Sulfuric acid
- C01B17/74—Preparation
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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
- C04B7/00—Hydraulic cements
- C04B7/02—Portland cement
- C04B7/04—Portland cement using raw materials containing gypsum, i.e. processes of the Mueller-Kuehne type
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- C04B7/00—Hydraulic cements
- C04B7/24—Cements from oil shales, residues or waste other than slag
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
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- C04B7/00—Hydraulic cements
- C04B7/36—Manufacture of hydraulic cements in general
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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
- C04B7/00—Hydraulic cements
- C04B7/36—Manufacture of hydraulic cements in general
- C04B7/38—Preparing or treating the raw materials individually or as batches, e.g. mixing with fuel
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
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- C04B7/00—Hydraulic cements
- C04B7/36—Manufacture of hydraulic cements in general
- C04B7/38—Preparing or treating the raw materials individually or as batches, e.g. mixing with fuel
- C04B7/40—Dehydrating; Forming, e.g. granulating
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- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding
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Abstract
The invention discloses a method for producing sulfate-resistant and silicate cement by using phosphogypsum, which comprises the following steps: firstly, drying materials, namely feeding dihydrate phosphogypsum into a scattering dryer for scattering and drying; secondly, cooling the materials, crushing and drying the materials by a scattering dryer, then feeding the materials into a tubular cooler, and cooling the phosphogypsum with the temperature of about 120 ℃ to 70-80 ℃; thirdly, dedusting, namely cooling the materials, then feeding the cooled materials into a multi-tube deduster for dedusting, and collecting dust into a round bin through a low-pressure pulse bag deduster; fourthly, calcining and decomposing; fifthly, collecting decomposition products; sixthly, preparing a finished product; the method for producing sulfate-resistant and silicate cement by using phosphogypsum changes the traditional production method by using limestone and utilizes the existing common solid waste phosphogypsum to produce special cement, thereby not only saving the cost and resources for grinding the limestone, but also achieving the requirement of environmental protection.
Description
Technical Field
The invention relates to a method for producing sulfate-resistant and silicate cement by using phosphogypsum, belonging to the technical field of production of sulfate-resistant and silicate cement.
Background
The sulfate-resistant portland cement is classified into a sulfate-resistant portland cement and a high-sulfate-resistant portland cement according to the degree of sulfate erosion resistance. The moderate sulfate ion corrosion resistant hydraulic cementing material is made by adding a proper amount of gypsum into portland cement clinker with proper components and grinding, and is called as moderate sulfate resistant portland cement, which is called as moderate sulfate resistant cement for short and has the code P.MSR; the hydraulic cementing material which is made by adding a proper amount of gypsum into portland cement clinker with proper components and grinding the mixture to resist the corrosion of sulfate ions with higher concentration is called high sulfate-resistant portland cement, which is called high sulfur-resistant cement for short and has the code P.HSR. The raw materials for producing the cement are limestone which can be utilized only after being mined and is a non-renewable resource.
Phosphogypsum is a solid waste generated in a wet-process phosphoric acid process, and the components of the phosphogypsum are mainly calcium sulfate dihydrate; the composition of the phosphogypsum is complex, and besides calcium sulfate, the phosphogypsum also contains incompletely decomposed phosphorite, residual phosphoric acid, fluoride, acid insoluble substances, organic matters and the like; the random discharge and accumulation of the phosphogypsum seriously damage the ecological environment, not only pollutes underground water resources, but also causes the waste of land resources.
Therefore, in order to solve the problems, the invention utilizes the byproduct phosphogypsum for producing ammonium phosphate as a raw material to recycle the phosphogypsum and produce high-sulfate-resistance portland cement, thereby saving the limestone grinding cost and resources and achieving the requirement of environmental protection.
Disclosure of Invention
In order to solve the problems, the invention provides a method for producing sulfate-resistant portland cement by using phosphogypsum, which changes the traditional production method by using limestone and utilizes the existing common solid waste phosphogypsum to produce special cement, thereby saving the cost and resources for grinding the limestone and meeting the requirement of environmental protection.
The method for producing sulfate-resistant silicate cement by using phosphogypsum comprises the following steps:
firstly, drying materials, namely feeding dihydrate phosphogypsum into a scattering dryer for scattering and drying, so that the moisture is dried to 8-10% within 2-5 s;
secondly, cooling the materials, crushing and drying the materials by a scattering dryer, then feeding the materials into a tubular cooler, and cooling the phosphogypsum with the temperature of about 120 ℃ to 70-80 ℃;
thirdly, dedusting, namely cooling the materials, then feeding the cooled materials into a multi-tube deduster for dedusting, and collecting dust into a round bin through a low-pressure pulse bag deduster;
fourthly, calcining and decomposing, namely proportioning the dried phosphogypsum, clay, iron tailings and kiln dust, then sequentially conveying the mixture to a firing kiln tail preheater through a conveyor, a bucket elevator and a mixer, and calcining at the high temperature of 750-900 ℃ in a rotary kiln to decompose the mixture into solid sulfate, silicate clinker and SO2A gas;
the fifth step, collecting the decomposition product, and decomposing SO2Sending the mixture into a sulfuric acid workshop for producing sulfuric acid after passing through an electric dust removal and purification tower; cooling the solid anti-sulfate and silicate clinker by a cooling cylinder and then conveying the cooled solid anti-sulfate and silicate clinker to a cement workshop;
and sixthly, preparing a finished product, namely mixing the produced clinker with a small amount of desulfurized gypsum, and then sending the mixture to a cement grinding machine for grinding, wherein the ground material is sulfate-resistant and silicate cement.
Further, the weight percentage of the phosphogypsum, the clay, the iron tailings and the kiln dust in the fourth step is phosphogypsum (CaO: 33%, SO)3: 45%) 75%, clay (SiO)265%) 7% of iron tailings (Fe)2O3: 35%) 3% and kiln dust (collected by a rotary kiln) 15%.
Further, SO decomposed in the fifth step2The gas concentration is 7-9%.
Further, the addition amount of the desulfurized gypsum in the sixth step accounts for 2 percent of the amount of the clinker.
Furthermore, the scattering dryer comprises a drying chamber, and a feeding channel and a discharging channel which are arranged above the drying chamber; the feeding channel is vertically arranged above the drying chamber, and a feeding hole is formed in the top of the feeding channel; the side surface of the feeding channel is provided with a hot air inlet; the discharging channel is obliquely arranged above the drying chamber, and the top of the discharging channel is provided with an air outlet and a discharging hole; a rotor with a suspension hammer is arranged in the drying chamber; the suspension hammer is made of manganese steel; the rotor is of a disc structure; a rotor shaft of the rotor is in transmission connection with the driving mechanism through a transmission mechanism, and the rotor is driven to rotate through the driving mechanism and the transmission mechanism; the rotor shaft is hollow structure, and rotor shaft and bearing frame all are equipped with water-cooling structure, and water cooling system passes through water-cooling structure with the leading-in rotor shaft of cooling water and bearing frame in for rotor shaft and bearing frame cooling, wherein, water cooling system is the common system that utilizes the cooling water to cool down to equipment among the prior art, does not detailed its concrete structure here and constitutes and theory of operation again.
Further, the rotating speed of the rotor and the water content of the material have the following relation:
in the formula, phi is the rotating speed of the rotor and the unit is r/min; t is the temperature of hot air, and the unit is; h is the water content of the material, L is the hot air quantity, and the unit is m3Min; n is an adjusting system, the value range is 200-300, and the preference is 240; a is a water content index, and the value range is 0.5-0.8, preferably 0.65.
As a preferred embodiment, the high temperature part of the housing of the scattering dryer is made of heat resistant steel; a refractory material is arranged at the hot air inlet; the scattering dryer is internally provided with a lining plate with an anti-abrasion effect.
As a preferred embodiment, the rotor shaft is of a hollow structure, and the rotor shaft and the bearing seat are both provided with water cooling structures.
Further, the tube array cooler comprises a cooling cylinder, a cooling tube arranged in the cooling cylinder and a shell arranged outside the cooling cylinder; a circulating air duct is formed between the shell and the cooling cylinder; a material inlet is formed in the upper part of the cooling cylinder body; the lower part of the cooling cylinder body is provided with a conical material outlet with a gradually reduced cross section; the lower part of the side surface of the circulating air duct is provided with an air inlet; the air inlet is connected with a cold air fan through an air pipe; and an air outlet is formed in the upper part of the side surface of the circulating air duct.
In a preferred embodiment, the middle section of the tubular cooler is also provided with a vibrating screen.
Compared with the prior art, the method for producing sulfate-resistant and silicate cement by using phosphogypsum adopts a scattering dryer as drying and crushing equipment of the phosphogypsum, provides the optimal relation about the water content and the rotating speed by analyzing various factors influencing the drying and crushing effects of materials, obviously improves the drying and crushing effects, has high thermal efficiency and reduces the power consumption; meanwhile, the rotary kiln for calcination is researched, reasonable process parameters such as kiln drying, rotary kiln, kiln coating hanging and the like are provided, and the long-period, stable and safe operation of the rotary kiln is guaranteed.
Drawings
Fig. 1 is a schematic view of the structure of the scattering dryer of the present invention.
FIG. 2 is a schematic diagram of the shell and tube cooler configuration of the present invention.
The components in the drawings are labeled as: 1-a feeding channel, 2-a hot air inlet, 3-a feeding hole, 4-a rotor, 5-a driving mechanism, 6-a transmission mechanism, 7-a discharging channel, 8-an air outlet and a discharging hole, 9-a material inlet, 10-a material outlet, 11-a cooling fan, 12-an air inlet, 13-an air outlet, 14-a drying chamber, 15-a cooling cylinder and 16-a circulating air duct.
Detailed Description
The method for producing sulfate-resistant silicate cement by using phosphogypsum comprises the following steps:
firstly, drying materials, namely feeding dihydrate phosphogypsum into a scattering dryer for scattering and drying, so that the moisture is dried to 8-10% within 2-5 s;
secondly, cooling the materials, crushing and drying the materials by a scattering dryer, then feeding the materials into a tubular cooler, and cooling the phosphogypsum with the temperature of about 120 ℃ to 70-80 ℃;
thirdly, dedusting, namely cooling the materials, then feeding the cooled materials into a multi-tube deduster for dedusting, and collecting dust into a round bin through a low-pressure pulse bag deduster;
fourthly, calcining and decomposing, namely proportioning the dried phosphogypsum, clay, iron tailings and kiln dust, then sequentially conveying the mixture to a firing kiln tail preheater through a conveyor, a bucket elevator and a mixer, and calcining at the high temperature of 750-900 ℃ in a rotary kiln to decompose the mixture into solid sulfate, silicate clinker and SO2A gas; wherein the weight percentage of the phosphogypsum, the clay, the iron tailings and the kiln dust is phosphogypsum (CaO: 33%, SO)3: 45%) 75%, clay (SiO)265%) 7% of iron tailings (Fe)2O3: 35%) 3% and kiln dust (rotary kiln dust collection) 15%;
the fifth step, collecting the decomposition product, and decomposing SO2The gas concentration is 7-9%, and the gas is sent into a sulfuric acid workshop to produce sulfuric acid after passing through an electric precipitation and purification tower; cooling the solid anti-sulfate and silicate clinker by a cooling cylinder and then conveying the cooled solid anti-sulfate and silicate clinker to a cement workshop;
sixthly, preparing a finished product, namely mixing the produced clinker with a small amount of desulfurized gypsum (about 2 percent), and then sending the mixture to a cement mill for grinding, wherein the ground material is sulfate-resistant and portland cement.
As shown in fig. 1, the scattering dryer comprises a drying chamber 14, and a feeding channel 1 and a discharging channel 7 which are arranged above the drying chamber 14; the feeding channel 1 is vertically arranged above the drying chamber 14, and the top of the feeding channel 1 is provided with a feeding hole 3; a hot air inlet 2 is formed in the side surface of the feeding channel 1; the discharging channel 7 is obliquely arranged above the drying chamber 14, and an air outlet and a discharging hole 8 are formed in the top of the discharging channel 7; the drying chamber 14 is internally provided with a rotor 4 with a suspension hammer, and under the action of the rotor, materials are immediately scattered after entering the drying chamber and exchange heat with hot air in a suspension state, so that the materials are rapidly heated and dried; the suspension hammer is made of manganese steel; the rotor is of a disc structure; and a rotor shaft of the rotor is in transmission connection with a driving mechanism 5 through a transmission mechanism 6, and the rotor is driven to rotate through the driving mechanism and the transmission mechanism. Wherein, the high-temperature part of the shell of the scattering dryer is made of heat-resistant steel; a refractory material is arranged at the hot air inlet; the scattering dryer is internally provided with a lining plate with an anti-abrasion effect. The rotor shaft is hollow structure, and rotor shaft and bearing frame all are equipped with water-cooling structure, and water cooling system passes through water-cooling structure with the leading-in rotor shaft of cooling water and bearing frame in for rotor shaft and bearing frame cooling, wherein, water cooling system is the common system that utilizes the cooling water to cool down to equipment among the prior art, does not detailed its concrete structure here and constitutes and theory of operation again.
In the process of preparing sulfate and silicate by phosphogypsum, crushing and drying by a dryer is the first process and one of the most important processes, because the water content of the material has large fluctuation, some materials are even in a slurry state, after the material enters the dryer, the water is required to be evaporated to 8-10% within 2-5s, and simultaneously the material is crushed under the impact of a rotor with a suspension hammer and is taken out of the dryer under the resultant force of centrifugal force and hot air; for materials with large water content, if the design of the rotating speed of the rotor is unreasonable, the water content is high, agglomerated materials cannot be effectively crushed, the drying of the materials is further influenced, the materials cannot rapidly leave the drying furnace, the phenomena of material piling and blocking are caused, the rotating speed needs to be increased, and the hot air quantity needs to be adaptively increased; if the parameters are adopted for the material with smaller water content, serious waste is caused, and the cost is too high; therefore, how to select proper rotating speed and wind amount becomes a key element for materials with different water contents.
Through the long-term research at production one-line, various factors that influence material stoving and crushing effect analyze, the discovery is along with the increase of material water content, should improve rotor speed, the material can be broken up more effectively in the improvement of rotor speed, make the material and hot-blast area of contact increase, improve heat exchange efficiency, but the improvement of rotational speed also makes centrifugal force bigger simultaneously, the dwell time that can make the material is shorter, lead to not fully drying, can suitably reduce hot-blast wind speed this moment, improve hot-blast wind pressure, make the time of material in the drying-machine suitably prolong, but discover in practice, the water content of material improves and the rotational speed increases and should not be simple linear relation, after the parameter of optimizing is fitted, the discovery adopts the rotational speed and the water content contrast of following relation to have the effect of optimization:
in the formula, phi is the rotating speed of the rotor and the unit is r/min; t is the temperature of hot air, and the unit is; h is the water content of the material, L is the hot air quantity, and the unit is m3Min; n is an adjusting system, the value range is 200-300, and the preference is 240; a is a water content index, and the value range is 0.5-0.8, preferably 0.65;
according to the above relationship, if the water content of the material is 25%, the hot air temperature is 500 ℃, and the air quantity is 85m3B, a is 0.65, the rotating speed of the rotor is 482 and 732r/min, preferably about 580 r/min; after the design of the parameters is adopted, the dryer saves energy by about 20-30% compared with the prior dryer, the heat efficiency is up to 70%, the heat loss is less, and the power consumption is reduced.
As shown in fig. 2, the shell-and-tube cooler includes a cooling cylinder 15, a cooling tube installed inside the cooling cylinder 15, and a housing installed outside the cooling cylinder 15; a circulating air duct 16 is formed between the shell and the cooling cylinder 15; the upper part of the cooling cylinder body 15 is provided with a material inlet 9; the lower part of the cooling cylinder body 15 is provided with a conical material outlet 10 with a gradually reduced cross section; the lower part of the side surface of the circulating air duct 16 is provided with an air inlet 12; the air inlet 12 is connected with the cold air fan 11 through an air pipe; and an air outlet 13 is arranged at the upper part of the side surface of the circulating air duct 16. The middle section of the tube still has vibrating screens; when the tubular cooler works, the phosphogypsum with the temperature of about 120 ℃ is conveyed into the material inlet at the upper part by the conveyor and passes through the cooling sections sequentially, the vibrating screen is arranged at the middle section of the tubular cooler, the material with the granularity of less than 2mm flows to the material outlet at the bottom in a zigzag mode through the vibrating screen, and meanwhile, a part of agglomerated material is scattered under the action of the vibrating screen and flows to the material outlet; the agglomerated materials with larger granularity and insufficient drying degree are sent back to the drying furnace for drying again; the cooling medium of the tubular cooler adopts natural air, after the cooling medium is pumped into the air inlet by the cooling fan and enters the cooling pipe, the cooling medium absorbs heat released by the heat medium through heat exchange of the pipe wall in the flowing process in the pipe and is finally discharged from the air outlet, the phosphogypsum is cooled, the natural air is heated, and the whole cooling process is reverse heat exchange.
The rotary kiln is a heart for preparing sulfate and silicate by using the phosphogypsum, is very important in operation and management, keeps long-period, stable and safe operation of the rotary kiln, and is the key point of production; according to the invention, through research on the rotary kiln for calcination, reasonable process parameters such as kiln drying, rotary kiln, kiln coating hanging and the like are provided, so that the long-period, stable and safe operation of the rotary kiln is ensured; the method comprises the following specific steps:
the new kiln building method is that a pile of firewood is piled 2m away from the kiln tail, and the firewood is added after ignition; then, the firewood is put into a shape of a Chinese character 'jing' every 5m, the height is about 2/3 of the diameter of the kiln, the last pile is 2.5-3m away from the kiln head, the firewood is sequentially ignited, the next pile is ignited after each pile of firewood is burnt, the rotary kiln rotates about 1/4, and the kiln drying time is 2-3 days; the preheater is cleaned after being dried and can be executed according to the kiln drying method of the cement kiln; generally, 25-35t of firewood is used for a kiln with the diameter of 3 multiplied by 100m, and then ignition can be carried out;
when in ignition, a starter enters the kiln through a working hole at the kiln head, is poured on the firewood through the priming substance (waste oil), and the firewood is ignited for a plurality of places, namely the firewood can be withdrawn out of the kiln, and a working door is closed; when the firewood is burnt by about 60 percent, a small amount of coal powder can be blown into the kiln; at the moment, the primary air is used as little as possible, so that pulverized coal is prevented from being blown to a fire point, and the fire is blown out; the coal powder and the primary air can not be gradually increased until the coal powder is normally combusted, and a kiln tail fan is properly started to increase the kiln tail air exhaust amount;
when the pulverized coal is completely combusted and forms flame with a stable shape, the rotary kiln 1/4 can be rotated; then, the kiln is rotated once every 10-15min according to the conditions in the kiln, and 1/2 rotations can be rotated each time; gradually increasing the kiln tail exhaust amount according to the temperature rise condition of the burning zone; adding raw materials when the temperature of the kiln tail reaches 350-; at the moment, the temperature in the kiln is still low, and according to experience,the blanking amount is 60-80% of the specified yield; the temperature of a burning zone and the condition of pulverized coal combustion are strictly controlled after raw materials enter a kiln, and the atmosphere in the kiln is a weak oxidation atmosphere; timely detecting kiln gas components and increasing detection frequency when the kiln gas contains SO2When the process is carried out, a sulfuric acid purification washing tower and a sulfuric acid dry absorption tail absorption tower are immediately started to prevent SO2Gas is discharged to pollute the surrounding environment;
when the materials enter a burning zone, the temperature of the burning zone is increased, a certain amount of liquid phase is generated, and meanwhile, the surface of the refractory brick reaches a certain temperature and the liquid phase exists on the surface; when the refractory bricks are turned to the lower part of the material, the material and the refractory bricks are bonded together and have chemical reaction; the temperature of the material is lower than the surface temperature of the refractory bricks, so that the material absorbs certain heat from the refractory bricks, the temperature of the refractory bricks is reduced, and the adhesion is condensed due to the reduction of the temperature of the refractory bricks; when the refractory bricks adhered with the materials are rotated out from the material layer, the refractory bricks are continuously heated by flame to form a layer of kiln coating; the kiln coating plays an important role in protecting the refractory bricks of the firing zone and realizing long-term safe operation; according to the method, a thicker kiln skin can be formed along with the continuous operation of the kiln; when the kiln skin is hung to a certain thickness (generally 100 and 200mm), normal operation can be carried out; the stable operation is needed for hanging the kiln skin, especially for a new kiln, the kiln speed, the kiln temperature, the raw material rate and the atmosphere in the kiln need to be stable, and the kiln skin needs to be hung layer by layer for a long time, generally about 3 days, so that the kiln skin is smooth and firm.
The above-described embodiments are merely preferred embodiments of the present invention, and all equivalent changes or modifications of the structures, features and principles described in the claims of the present invention are included in the scope of the present invention.
Claims (10)
1. A method for producing sulfate-resistant silicate cement by using phosphogypsum is characterized by comprising the following steps:
firstly, drying materials, namely feeding dihydrate phosphogypsum into a scattering dryer for scattering and drying, so that the moisture is dried to 8-10% within 2-5 s;
secondly, cooling the materials, crushing and drying the materials by a scattering dryer, then feeding the materials into a tubular cooler, and cooling the phosphogypsum with the temperature of about 120 ℃ to 70-80 ℃;
thirdly, dedusting, namely cooling the materials, then feeding the cooled materials into a multi-tube deduster for dedusting, and collecting dust into a round bin through a low-pressure pulse bag deduster;
fourthly, calcining and decomposing, namely proportioning the dried phosphogypsum, clay, iron tailings and kiln dust, then sequentially conveying the mixture to a firing kiln tail preheater through a conveyor, a bucket elevator and a mixer, and calcining at the high temperature of 750-900 ℃ in a rotary kiln to decompose the mixture into solid sulfate, silicate clinker and SO2A gas;
the fifth step, collecting the decomposition product, and decomposing SO2Sending the mixture into a sulfuric acid workshop for producing sulfuric acid after passing through an electric dust removal and purification tower; cooling the solid anti-sulfate and silicate clinker by a cooling cylinder and then conveying the cooled solid anti-sulfate and silicate clinker to a cement workshop;
and sixthly, preparing a finished product, namely mixing the produced clinker with a small amount of desulfurized gypsum, and then sending the mixture to a cement grinding machine for grinding, wherein the ground material is sulfate-resistant and silicate cement.
2. The method for producing sulfate-resistant portland cement by using phosphogypsum according to claim 1, wherein the weight percentage of the phosphogypsum to the clay, the iron tailings and the kiln dust in the fourth step is 75%, 7%, 3% and 15%.
3. The process for producing sulfate-resistant portland cement using phosphogypsum according to claim 1, wherein the SO decomposed in the fifth step2The gas concentration is 7-9%.
4. The method for producing sulfate-resistant portland cement by using phosphogypsum according to claim 1, wherein the addition amount of the desulfurized gypsum in the sixth step is 2% of the amount of the clinker.
5. The method for producing sulfate-resistant portland cement by using phosphogypsum according to claim 1, wherein the scattering dryer comprises a drying chamber, and a feeding channel and a discharging channel which are arranged above the drying chamber; the feeding channel is vertically arranged above the drying chamber, and a feeding hole is formed in the top of the feeding channel; the side surface of the feeding channel is provided with a hot air inlet; the discharging channel is obliquely arranged above the drying chamber, and the top of the discharging channel is provided with an air outlet and a discharging hole; a rotor with a suspension hammer is arranged in the drying chamber; the suspension hammer is made of manganese steel; the rotor is of a disc structure; and a rotor shaft of the rotor is in transmission connection with the driving mechanism through a transmission mechanism.
6. The method for producing sulfate-resistant portland cement by using phosphogypsum according to claim 5, wherein the rotation speed of the rotor and the water content of the material have the following relationship:
in the formula, phi is the rotating speed of the rotor and the unit is r/min; t is the temperature of hot air, and the unit is; h is the water content of the material, L is the hot air quantity, and the unit is m3Min; n is an adjusting system, the value range is 200-300, and the preference is 240; a is a water content index, and the value range is 0.5-0.8, preferably 0.65.
7. The method for producing sulfate-resistant portland cement using phosphogypsum according to claim 5, wherein the high-temperature part of the housing of the scattering dryer is made of heat-resistant steel; a refractory material is arranged at the hot air inlet; the scattering dryer is internally provided with a lining plate with an anti-abrasion effect.
8. The method for producing sulfate-resistant portland cement by using phosphogypsum according to claim 5, wherein the rotor shaft is of a hollow structure, and the rotor shaft and the bearing seat are both provided with water cooling structures.
9. The method for producing sulfate-resistant portland cement by using phosphogypsum according to claim 1, wherein the shell-and-tube cooler comprises a cooling cylinder, a cooling tube arranged inside the cooling cylinder and a shell arranged outside the cooling cylinder; a circulating air duct is formed between the shell and the cooling cylinder; a material inlet is formed in the upper part of the cooling cylinder body; the lower part of the cooling cylinder body is provided with a conical material outlet with a gradually reduced cross section; the lower part of the side surface of the circulating air duct is provided with an air inlet; the air inlet is connected with a cold air fan through an air pipe; and an air outlet is formed in the upper part of the side surface of the circulating air duct.
10. The method for producing sulfate-resistant portland cement by using phosphogypsum according to claim 1 or 9, wherein a vibrating screen is further arranged at the middle section of the tube cooler.
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| CN102531441A (en) * | 2012-02-28 | 2012-07-04 | 云南新龙矿物质饲料有限公司 | Production method and product of cement retarder from ardealite |
| CN106630703A (en) * | 2016-09-23 | 2017-05-10 | 金正大生态工程集团股份有限公司 | Method for preparing high-strength sulfate aluminum cement co-production sulfuric acid through calcining by steps |
| CN109052438A (en) * | 2018-07-12 | 2018-12-21 | 山东汇泰再生资源有限公司 | It is a kind of to prepare method of magnesium oxide using magnesium sulfite |
| CN110803878A (en) * | 2019-11-25 | 2020-02-18 | 江苏一夫科技股份有限公司 | Device and method for producing II type anhydrous gypsum by using phosphogypsum |
| CN112028511A (en) * | 2020-09-10 | 2020-12-04 | 合肥水泥研究设计院有限公司 | Calcination dehydration method of phosphogypsum |
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2021
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102531441A (en) * | 2012-02-28 | 2012-07-04 | 云南新龙矿物质饲料有限公司 | Production method and product of cement retarder from ardealite |
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| CN109052438A (en) * | 2018-07-12 | 2018-12-21 | 山东汇泰再生资源有限公司 | It is a kind of to prepare method of magnesium oxide using magnesium sulfite |
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