CN110885064B - System and method for producing cement clinker and sulfuric acid by using calcium sulfate - Google Patents

System and method for producing cement clinker and sulfuric acid by using calcium sulfate Download PDF

Info

Publication number
CN110885064B
CN110885064B CN201811053062.3A CN201811053062A CN110885064B CN 110885064 B CN110885064 B CN 110885064B CN 201811053062 A CN201811053062 A CN 201811053062A CN 110885064 B CN110885064 B CN 110885064B
Authority
CN
China
Prior art keywords
kiln
cyclone
row
cyclone preheater
calcium sulfate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201811053062.3A
Other languages
Chinese (zh)
Other versions
CN110885064A (en
Inventor
李天贵
史楚翔
刘骁
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yunnan Chuangsen Environmental Protection Technology Co ltd
Original Assignee
Yunnan Chuangsen Environmental Protection Technology Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Yunnan Chuangsen Environmental Protection Technology Co ltd filed Critical Yunnan Chuangsen Environmental Protection Technology Co ltd
Priority to CN201811053062.3A priority Critical patent/CN110885064B/en
Publication of CN110885064A publication Critical patent/CN110885064A/en
Application granted granted Critical
Publication of CN110885064B publication Critical patent/CN110885064B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • C01B17/745—Preparation from sulfates
    • 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
    • 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
    • C04B7/43—Heat treatment, e.g. precalcining, burning, melting; Cooling
    • C04B7/44—Burning; Melting

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Curing Cements, Concrete, And Artificial Stone (AREA)
  • Furnace Details (AREA)

Abstract

The invention discloses a system for producing cement clinker and sulfuric acid by calcium sulfate, which comprises an N-grade kiln-row cyclone preheater and an M-grade kiln-row cyclone preheater, wherein the N-grade kiln-row cyclone preheater at least comprises two types of cyclone preheaters, one type is a cyclone cylinder for cement industry, and the other type is a lower exhaust cyclone separator; the M-level furnace row cyclone preheater comprises a lower exhaust cyclone separator; wherein N represents the stage number of a certain stage of the kiln row cyclone preheater, and is any natural number which is more than or equal to 3 and less than or equal to 7; m represents the stage number of the cyclone preheater of a certain stage of the furnace row, and M is any natural number which is more than or equal to 2 and less than or equal to 5. The invention also discloses a method for producing cement clinker and sulfuric acid by using the calcium sulfate. The invention realizes the smooth and stable operation of the whole production line with low resistance, high efficiency, low kiln tail frame height, less investment and low energy consumption by the combined connection of two cyclone preheaters with different structural forms.

Description

System and method for producing cement clinker and sulfuric acid by using calcium sulfate
Technical Field
The invention relates to the technical field of producing portland cement clinker and sulfuric acid by calcium sulfate, in particular to a system and a method for producing cement clinker and sulfuric acid by calcium sulfate.
Background
The suspension preheating predecomposition technology is the core of the novel dry cement production technology and is also a key technology for producing the byproduct sulfuric acid of the portland cement clinker by using calcium sulfate. The method is characterized in that gas-solid heat exchange and mass transfer in the accumulation state in the original rotary kiln are transferred into a suspension preheater to be carried out, so that the drying, preheating and decomposition processes of the materials are rapidly completed in the suspension state outside the kiln.
In 1986, germany Lu Ji company developed technology for preparing sulfuric acid and co-producing cement by using energy-saving calcium sulfate thermal decomposition method, and a pilot-scale test was carried out to change the production mode of calcium sulfate reductive decomposition and cement calcination in a long kiln in the past into the production mode of preparing sulfur dioxide gas by using calcium sulfate decomposition in a circulating fluidized bed and cement calcination in a short kiln to obtain cement clinker, but no industrial application examples exist so far.
The preheating and predecomposition system consists of a suspension preheater and a decomposing furnace, wherein the suspension preheater adopts cyclones and connecting air pipes and blanking pipes between each stage of cyclone as heat exchange units. The suspension preheaters currently used in the industry are generally composed of five-stage or six-stage cyclone preheaters which are combined in series from top to bottom, and the height of a civil structure (a preheater tower) is in direct proportion to the stage number of the preheaters. The heat recovery efficiency of the preheater increases with the number of stages of the cyclone, but the increase in the number of stages increases the tower of the cyclone preheater. Along with the continuous upsizing of the pre-decomposition kiln device, the height of a suspension preheater, a heat exchange pipeline and a decomposing furnace support frame of the pre-decomposition kiln exceeds 100 meters, so that the energy consumption for lifting materials, the steel consumption of a kiln tail frame and the civil engineering investment of a kiln tail are increased.
With the increasingly mature suspension preheating and pre-decomposition technologies, the length-diameter ratio of the decomposing furnace also tends to rise. The height of the outlet of the decomposing furnace of the existing device is far higher than the height required by the last-stage suspension preheater material entering the kiln, and in order to reduce the height of a frame of the suspension preheater, a method of additionally arranging a gooseneck (U-shaped pipe) between the outlet of the top of the decomposing furnace and the last-stage suspension preheater is adopted at present, and the downward turning back of the gooseneck is utilized to reduce the arrangement elevation of the last-stage suspension preheater. Meanwhile, the waste gas pipe of the C1-stage suspension preheater is also a gooseneck pipe.
The Zhang Guanqing of Nanjing university of industry is pointed out in the text of the research on the law of gas flow test and numerical simulation in the gooseneck and waste gas pipeline of oxygen decomposition furnace: the gooseneck has a rather limited contribution to the increase of the retention time of the materials in the decomposing furnace for newly built cement production lines, and the effect is not ideal. The exhaust gas pipe and the gooseneck gas flow field are similar, and the resistance of the exhaust gas pipe and the gooseneck gas flow field is respectively equivalent to that of a cyclone preheater. The large resistance will result in the increase of the power consumption of the high temperature fan and higher operation cost.
In order to solve the problem caused by the overhigh frame of the cement preheater, the invention CN102954699A in China discloses a 'horizontal arrangement design of the cement preheater', and the horizontal arrangement of a cyclone in a suspension preheater system is adopted to replace the vertical arrangement adopted at present. The pipeline between adjacent preheaters is designed in a U shape, raw materials are added from the position near the bottom of the U shape, and are blown away under the action of hot airflow in the pipeline and are brought to the next stage of cyclone. But the resistance of the "U" shaped duct is comparable to the resistance of a cyclone preheater. Resulting in a multiple increase in the resistance of the overall preheating system. The air pressure of a high-temperature fan of a kiln system is increased more, the large fan is difficult to manufacture, the power consumption is obviously increased, and no industrialized device is applied until now.
In conclusion, the system for producing cement clinker and sulfuric acid by using calcium sulfate in the prior art has the defects of overhigh support frame of the cyclone preheater, high civil engineering investment cost, high system running resistance and high energy consumption.
Disclosure of Invention
The invention aims to solve the technical problem of providing a system and a method for producing cement clinker and sulfuric acid by calcium sulfate, which have the advantages of low investment, low energy consumption, capability of arranging more stages of cyclone preheaters and high heat energy utilization rate.
In order to solve the technical problems, the technical scheme of the invention is as follows:
a system for producing cement clinker and sulfuric acid by calcium sulfate comprises an N-grade kiln-row cyclone preheater and an M-grade kiln-row cyclone preheater, wherein the N-grade kiln-row cyclone preheater at least comprises two types of cyclone preheaters, one type of cyclone preheater is a cyclone cylinder for cement industry, and the other type of cyclone preheater is a lower exhaust cyclone separator; the M-level furnace row cyclone preheater comprises a lower exhaust cyclone separator; wherein N represents the stage number of a certain stage of the kiln row cyclone preheater, and is any natural number which is more than or equal to 3 and less than or equal to 7; m represents the stage number of the cyclone preheater of a certain stage of the furnace row, and M is any natural number which is more than or equal to 2 and less than or equal to 5.
Preferably, at least P stages in the N-stage kiln-row cyclone preheater are lower exhaust cyclone separators, and the value range of P is as follows: 1 ≦ P ≦ N-1.
Preferably, the kiln row cyclone preheater positioned at the top end in the N-stage kiln row cyclone preheater is a lower exhaust cyclone separator, and at least one stage in the other kiln row cyclone preheaters is the cyclone cylinder for the cement industry.
Preferably, M is 2, and the 2-stage furnace row cyclone preheaters are all lower exhaust cyclone separators.
The system for producing cement clinker and sulfuric acid by using calcium sulfate further comprises a reduction furnace, a rotary kiln, a breaking-up dryer, an air flow dryer, a clinker cooler, a grate exhaust fan and a dust collector; wherein a discharge pipe of the 1 st-stage kiln row cyclone preheater is connected with an air inlet pipe of the 1 st-stage kiln row cyclone preheater, and an air outlet is connected with a kiln row exhaust fan; an air outlet pipe of the 1 st-level kiln row cyclone preheater is connected with a dust collector; a discharge pipe of the N-stage kiln row cyclone preheater is connected with the reduction furnace, and an air inlet pipe of the N-stage kiln row cyclone preheater is connected with a smoke chamber at the tail of the rotary kiln; between the other kiln rows of cyclone preheaters, the air outlet of the kiln rows of cyclone preheaters is connected with the air inlet of the previous stage through an air inlet pipe, and the discharge port is connected with the air inlet pipe of the next stage through a discharge pipe;
an air outlet of the reduction furnace is connected with the M-level furnace row cyclone preheater, and a discharge pipe of the M-level furnace row cyclone preheater is respectively connected to the reduction furnace and the rotary kiln through a material distributing valve; the other furnace row cyclone preheaters of each stage are sequentially connected according to the sequence of the M-th furnace row cyclone preheater, the M-1 st furnace row cyclone preheater. The kiln head of the rotary kiln is connected with a clinker cooler.
Preferably, a heat exchanger is further arranged between the 1 st-stage kiln row cyclone preheater and the dust collector; and a connecting air pipe of the 1 st-level kiln row cyclone preheater is connected with a heat exchanger, and the heat exchanger is connected with an air inlet of the dust collector through a fan.
Preferably, the dust collector is a bag type dust collector.
Preferably, a gas pipeline is connected between the reduction furnace and the heat exchanger, and a control valve is arranged on the gas pipeline.
The invention also provides a method for producing cement clinker and sulfuric acid by using calcium sulfate, and the system for producing cement clinker and sulfuric acid by using calcium sulfate comprises the following steps:
(1) Drying and dehydrating: after scattering the calcium sulfate raw material, drying the calcium sulfate raw material by an airflow dryer and an M-level furnace-series cyclone preheater;
(2) Preheating, reduction and decomposition: the dried calcium sulfate raw material is preheated through an N-grade kiln cyclone preheater in turn, the preheated calcium sulfate material enters a reduction furnace (15), pulverized coal and/or natural gas are added, and the oxygen content of combustion is controlled to generate CO and H 2 One and/or two of the two are used as reducing agents to carry out reduction reaction to obtain a gas-solid mixture; the chemical reaction formula in the process is as follows:
CaS0 4 +4CO＝CaS+4C0 2
CaS0 4 +4H 2 ＝CaS+4H 2 O
(3) Calcining and cooling: after gas-solid separation of the gas-solid mixture, introducing the gas into a scattering dryer to dry the calcium sulfate raw material, and calcining the solid material in a rotary kiln to obtain SO 2 And the cement clinker is stored and sold after being cooled by a clinker cooler. The chemical reaction formula in the process is as follows:
CaS+2O 2 ＝CaS0 4
3CaS0 4 +CaS＝4Ca0+4S0 2
CaS+O 2 ＝Ca0+S0 2
preferably, when the reduction reaction of calcium sulfate is performed in step (2), calcium sulfate accounting for 36% -98% of the total sulfur content in calcium sulfate is reduced to calcium sulfide by controlling the reducing agent.
The invention has the beneficial effects that:
(1) The lower exhaust cyclone separator is matched with the cyclone cylinder for the cement industry for use, and the discharge port and the gas outlet of the lower exhaust cyclone separator are arranged at the bottom, while the gas outlet of the cyclone cylinder for the cement industry is arranged at the top and the discharge port is arranged at the bottom; through the cyclone with above-mentioned two kinds of forms use that combines, can reduce kiln tail frame height, and then reduce kiln tail frame and use steel volume and civil engineering investment, traditional "U" shape structural design modes such as "gooseneck" are compared to above-mentioned compound mode simultaneously, and system resistance is little, and the energy consumption is low, can arrange the cyclone preheater of more progression, and heat utilization rate is high.
(2) Calcium sulfate is dried by the waste heat of the reducing furnace in a suspension state through an airflow dryer, so that the heat energy utilization rate is improved.
(3) The calcium sulfate reduction reaction in the reduction furnace generates carbon dioxide and carbon dioxide generated by burning fuel for providing heat required by the reaction, the generated carbon dioxide and the carbon dioxide are separated from the rotary kiln smoke from the decomposition furnace and do not enter the rotary kiln smoke containing sulfur dioxide for acid making, and the volume ratio concentration of the sulfur dioxide in the rotary kiln smoke is improved. The flue gas of the rotary kiln exchanges heat with gas needing to enter the reduction furnace through the heat exchanger, the waste heat of the flue gas of the rotary kiln is more fully recovered, and the energy consumption is saved.
(4) The cloth bag type dust collector has high dust collection efficiency and creates better conditions for sulfuric acid purification and conversion.
(5) The kiln is in an oxidizing atmosphere state, so that the influence of produced CO, hydrocarbon and sulfur hydride on a sulfuric acid conversion system when the weak oxidizing atmosphere is controlled by the traditional process can be eliminated.
(6) When solid coke is not used as a reducing agent and raw materials of main components of calcium sulfate, such as phosphogypsum, desulfurized gypsum, fluorgypsum and the like, are used, the traditional procedures of grinding, drying and storing raw materials are avoided, and the production flow is short.
(7) Short process flow, easy control of reaction atmosphere, high reduction and decomposition efficiency, and SO 2 The smoke concentration is high.
Drawings
Fig. 1 is a schematic structural view of the present invention when N =6 and M = 2.
In the figure, 1-2 nd-stage kiln row cyclone preheater, 2-1 st-stage kiln row cyclone preheater, 3-kiln row waste gas exhaust fan, 4-1 st-stage kiln row cyclone preheater, 5-4 th-stage kiln row cyclone preheater, 6-air locking valve, 7-heat exchanger, 8-3 rd-stage kiln row cyclone preheater, 9-dust collector, 10-5 th-stage kiln row cyclone preheater, 11-6 th-stage kiln row cyclone preheater, 12-2 nd-stage kiln row cyclone preheater, 13-material distributing valve, 14-coal powder feeding port for reducing furnace, 15-reducing furnace, 16-calcium sulfate feeding device, 17-scattering dryer, 18-rotary kiln, 19-clinker cooler, 20-air flow dryer, 21-smoke chamber, 22-gas pipeline, 23-air locking valve.
Detailed Description
The following further describes embodiments of the present invention with reference to the drawings. It should be noted that the description of the embodiments is provided to help understanding of the present invention, and is not intended to limit the present invention. In addition, the technical features involved in the respective embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
As shown in FIG. 1, a system for producing cement clinker and sulfuric acid from calcium sulfate comprises a multi-stage kiln train cyclone preheater and a multi-stage kiln train cyclone preheater; the multi-stage kiln row cyclone preheater comprises a 2 nd-stage kiln row cyclone preheater 1, a 1 st-stage kiln row cyclone preheater 4, a 3 rd-stage kiln row cyclone preheater 8, a 4 th-stage kiln row cyclone preheater 5, a 5 th-stage kiln row cyclone preheater 10 and a 6 th-stage kiln row cyclone preheater 11 from top to bottom in sequence so as to form a 6 th-stage kiln row cyclone preheater; the multi-stage furnace row cyclone preheater is a 2-stage furnace row cyclone preheater consisting of a 1 st-stage furnace row cyclone preheater 2 and a 2 nd-stage furnace row cyclone preheater 12 from top to bottom in sequence. Wherein, between each stage of cyclone preheater, the air outlet of the next stage of cyclone preheater is connected with the air inlet of the previous stage through an air inlet pipe, and the discharge port of the next stage of cyclone preheater is connected with the air inlet pipe of the next stage of cyclone preheater. Taking the 2 nd-level kiln row cyclone preheater 12 as an example, the air outlet of the 2 nd-level kiln row cyclone preheater 12 is connected to the air inlet of the 1 st-level kiln row cyclone preheater 2 through an air inlet pipe, and the discharge outlet of the 2 nd-level kiln row cyclone preheater 1 is connected to the air inlet pipe of the 3 rd-level kiln row cyclone preheater through a discharge pipe.
In the present embodiment, the 1 st-stage kiln-row cyclone preheater 4, the 2 nd-stage kiln-row cyclone preheater 1, the 4 th-stage kiln-row cyclone preheater 5, the 1 st-stage kiln-row cyclone preheater 2, and the 2 nd-stage kiln-row cyclone preheater 12 are all lower-discharge cyclone preheaters, and the remaining kiln-row cyclone preheaters and the kiln-row cyclone preheaters are cyclone cylinders for cement industry. Wherein, the air outlet and the discharge outlet of the lower exhaust cyclone preheater are both arranged at the bottom of the cyclone preheater, and the air inlet is arranged at the side part of the cyclone preheater; the air outlet of the cyclone cylinder for the cement industry is arranged at the top of the cyclone preheater, and the discharge port is arranged at the bottom of the cyclone preheater.
Of course, the system for producing sulfuric acid and cement clinker from calcium sulfate in the invention can be freely combined by the multi-stage kiln-train cyclone preheater and the multi-stage kiln-train cyclone preheater, for example, the kiln-train cyclone preheater in the invention is not limited to 6 stages, and can also be 3 stages, 4 stages, 5 stages or 7 stages; the train cyclone preheater is not limited to 2 stages, but may be 3 stages, 4 stages or 5 stages. The combination only needs to meet the requirement that the multi-stage kiln cyclone preheater at least comprises two types of cyclone preheaters, one type is a cyclone cylinder for cement industry, and the other type is a lower exhaust cyclone separator; the multi-stage furnace row cyclone preheater comprises a lower exhaust cyclone separator.
In addition, under the condition that the requirement on the separation efficiency of the calcium sulfate is not particularly high, for example, the separation efficiency of the calcium sulfate is less than eighty percent, a lower exhaust cyclone preheater can be replaced by a horizontal cyclone preheater with lower resistance in the cyclone preheaters of the 3 rd, 4 th and 5 th kiln columns, the height of a kiln tail frame can still be reduced, the steel consumption of the kiln tail frame and the civil engineering investment are further reduced, and meanwhile, the system resistance is small.
The key points of the invention are as follows: on the basis of the existing system for producing cement clinker and sulfuric acid by calcium sulfate and producing cement clinker by calcium carbonate, the lower exhaust cyclone separator is matched with the cyclone cylinder for the cement industry for use, and because the discharge port and the air outlet of the lower exhaust cyclone separator are both arranged at the bottom, and the air outlet of the cyclone cylinder for the cement industry is arranged at the top and the discharge port is arranged at the bottom; by combining the two types of cyclone separators, the number of stages of the cyclone preheater can be increased for the existing production line under the condition of not increasing the height of the kiln tail frame; or reduce kiln tail frame height on newly-built device, and then reduce for the kiln tail frame steel volume and civil engineering investment, above-mentioned compound mode compares "U" shape structural design modes such as traditional "gooseneck" simultaneously, and system resistance is little, can arrange the cyclone preheater of more progression, and the heat utilization rate is high. The invention is not only suitable for producing cement clinker and sulfuric acid by using calcium sulfate; and is suitable for producing cement clinker by using calcium carbonate, when the cement clinker is produced by using calcium carbonate, the stage number of the kiln-row cyclone preheater is the same as that of the kiln-row cyclone preheater, and the process of scattering by a scattering dryer can be cancelled.
The system for producing cement clinker and sulfuric acid by using calcium sulfate further comprises a reduction furnace 15, a rotary kiln 18, a scattering dryer 17, an airflow dryer 20, a clinker cooler 19, a furnace row exhaust fan 3, a feeding device 16 and a dust collector 9, wherein a wind locking valve 23 is arranged on a connecting pipeline of a feed opening of each stage of the kiln row cyclone preheater and the furnace row cyclone preheater; wherein, a discharge pipe of the cyclone preheater 2 of the 1 st-stage kiln row is connected with a connecting air pipe of the cyclone preheater 4 of the 1 st-stage kiln row, and an air outlet is connected with a kiln row exhaust fan 3; a connecting air pipe of the 1 st-level kiln row cyclone preheater 4 is connected with an air inlet of a dust collector 9; a discharge pipe of the 6 th-stage kiln row cyclone preheater is connected with the reduction furnace 15, and an air inlet pipe of the 6 th-stage kiln row cyclone preheater is connected with a smoke chamber 21 at the kiln tail of the rotary kiln 18; an air outlet of the reduction furnace 15 is connected with a 2 nd-level furnace row cyclone preheater; a discharge pipe of the 2 nd-stage furnace row cyclone preheater is respectively connected to a reduction furnace 15 and a rotary kiln 18 through a material distributing valve 13, and an air outlet pipe is connected with an air inlet of a scattering dryer 17; the scattering dryer 17 is provided with a feeding device 16, and a discharge hole of the scattering dryer is connected with an airflow dryer 20; the airflow dryer 20 is connected with a 1 st-stage furnace row cyclone preheater; between the other kiln row cyclone preheaters of each stage and the kiln row cyclone preheaters, the air outlets of the kiln row cyclone preheaters and the kiln row cyclone preheaters of the stage are connected with the air inlet of the previous stage through air inlet pipes, and the discharge openings are connected with the air inlet pipe of the next stage through discharge pipes; the kiln head of the rotary kiln 18 is connected with a clinker cooler 19.
Preferably, a heat exchanger 7 is further arranged between the 1 st-stage kiln row cyclone preheater 4 and the dust collector 9; and a connecting air pipe of the 1 st-level kiln row cyclone preheater 4 is connected with a heat exchanger 7, and the heat exchanger 7 is connected with an air inlet of a dust collector 9 through a fan. As a further preference, the dust collector 9 is a bag type dust collector.
Preferably, a gas pipe 22 is connected between the reduction furnace 15 and the heat exchanger 7, and a control valve is provided on the gas pipe 22. The heat of the rotary kiln flue gas is exchanged with the gas needing to enter the reduction furnace 15 through the heat exchanger 7, so that the waste heat of the rotary kiln flue gas is more fully recovered, and the energy consumption is saved.
Preferably, an air pipe (not shown) may be connected to the outlet pipe of the 2 nd-stage cyclone preheater 12, and a control valve may be provided on the air pipe. By adopting the design, the residual carbon monoxide in the reduction furnace 15 is fully and completely combusted through the introduced air, so that the combustion heat release of the carbon monoxide is fully utilized, and the harm of the carbon monoxide to the subsequent process steps is eliminated.
The system for producing cement clinker and sulfuric acid by using calcium sulfate in the embodiment is a method for producing cement clinker and sulfuric acid, and the method comprises the following process steps:
(1) Drying and dehydrating: calcium sulfate raw materials are added into a scattering dryer 17 through a feeding device 16, are scattered under the action of a hammer head of the scattering dryer, are mixed with hot gas from a 2 nd-stage furnace line cyclone preheater 12, and enter an airflow dryer 20 and a 1 st-stage furnace line cyclone preheater 2 in sequence after being temporarily stopped, so that free water and crystal water in the calcium sulfate raw materials are removed, gas-solid separation is carried out in the 1 st-stage furnace line cyclone preheater 2, and the gas enters a furnace line waste exhaust fan 3 through a pipeline and is discharged into a waste gas treatment system;
(2) Preheating, reduction and decomposition: the materials obtained by separation in the step (1) enter a cyclone preheater 4 of a kiln row of the level 1, after the materials are heated and separated by the cyclone preheater 4 of the kiln row of the level 1, the gas enters a heat exchanger 7 through a pipeline for further cooling, then the gas is sent into a dust collector 9 through a fan for removing most of dust and then is sent into a sulfuric acid purification system for producing sulfuric acid, the materials obtained by separation sequentially pass through the cyclone preheats of the kiln row of the other level 5, the preheated calcium sulfate materials finally enter a reduction furnace 15, pulverized coal and/or natural gas are added into the reduction furnace 15 through a pulverized coal adding port 14 for the reduction furnace, and the oxygen content of combustion is controlled to generate CO and H 2 One and/or two of the calcium sulfide and the calcium sulfate are/is used as reducing agents to carry out reduction reaction to obtain gas-solid mixtures such as calcium sulfide, unreacted calcium sulfate and unreacted gas;
(3) And (3) calcining and cooling: after the gas-solid mixture is subjected to gas-solid separation by a 2 nd stage cyclone preheater 12, the gasA scattering dryer 17 is introduced to dry the calcium sulfate raw material, and the solid material enters a rotary kiln 18 to be calcined to obtain SO 2 And the cement clinker is stored and sold after being cooled by the clinker cooler 19.
Preferably, in the step (2), during the reduction reaction of calcium sulfate, the reducing agent is controlled to reduce calcium sulfate accounting for 36% -98% of the total sulfur content in the calcium sulfate into calcium sulfide, so that the material is calcined in the rotary kiln under wider control conditions, and meanwhile, the excess of the calcium sulfate is ensured, so that sulfur dioxide with higher concentration can be obtained.
The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in the embodiments without departing from the principles and spirit of the invention, and these embodiments are still within the scope of the invention.

Claims (8)

1. A system for producing cement clinker and sulfuric acid by calcium sulfate comprises an N-grade kiln-series cyclone preheater and a 2-grade kiln-series cyclone preheater, and is characterized in that: the N-stage kiln row cyclone preheater at least comprises two types of cyclone preheaters, one type is a cyclone cylinder for cement industry, and the other type is a lower exhaust cyclone separator; the 2-stage furnace row cyclone preheater comprises a lower exhaust cyclone separator; wherein N represents the stage number of a certain stage of the kiln row cyclone preheater, and is any natural number which is more than or equal to 3 and less than or equal to 7; the kiln row cyclone preheater positioned at the top end in the N-stage kiln row cyclone preheater is a lower exhaust cyclone separator, and at least one stage in the other kiln row cyclone preheaters is the cyclone cylinder for the cement industry;
the system also comprises a reduction furnace (15), a rotary kiln (18), a breaking-up dryer (17), an airflow dryer (20), a clinker cooler (19), a furnace row waste gas exhaust fan (3), a calcium sulfate feeding device (16) and a dust collector (9); wherein a discharge pipe of the 1 st-stage kiln row cyclone preheater (2) is connected with an air inlet pipe of the 1 st-stage kiln row cyclone preheater (4), and an air outlet is connected with a kiln row waste gas exhaust fan (3); an air outlet pipe of the 1 st-level kiln row cyclone preheater (4) is connected with a dust collector (9); a discharge pipe of the N-stage kiln row cyclone preheater is connected with the reduction furnace (15), and an air inlet pipe of the N-stage kiln row cyclone preheater is connected with a smoke chamber (21) at the kiln tail of the rotary kiln (18); among other kiln row cyclone preheaters at all levels, the air outlet of the kiln row cyclone preheater is connected with the air inlet of the previous level through an air inlet pipe, and the discharge port is connected with the air inlet pipe of the next level through a discharge pipe;
an air outlet of the reduction furnace (15) is connected with a 2 nd-level furnace row cyclone preheater, and a discharge pipe of the 2 nd-level furnace row cyclone preheater is respectively connected to the reduction furnace (15) and the rotary kiln (18) through a material distributing valve (13); the other cyclone preheaters of all the furnace rows are sequentially connected according to the sequence of the cyclone preheater of the 2 nd furnace row, the scattering dryer (17), the airflow dryer (20) and the cyclone preheater (2) of the 1 st furnace row; the kiln head of the rotary kiln (18) is connected with a clinker cooler (19).
2. The system for producing cement clinker and sulfuric acid from calcium sulfate according to claim 1, wherein: at least P stages in the N-stage kiln row cyclone preheater are lower exhaust cyclone separators, and the value range of P is as follows: 1 ≦ P ≦ N-1.
3. The system for producing cement clinker and sulfuric acid from calcium sulfate according to claim 1, wherein: the 2-stage furnace row cyclone preheaters are all lower exhaust cyclone separators.
4. The system for producing cement clinker and sulfuric acid from calcium sulfate according to claim 1, wherein: a heat exchanger (7) is also arranged between the 1 st-stage kiln row cyclone preheater (4) and the dust collector (9); and a connecting air pipe of the 1 st-level kiln row cyclone preheater (4) is connected with the heat exchanger (7), and the heat exchanger (7) is connected with an air inlet of the dust collector (9) through a fan.
5. The system for producing cement clinker and sulfuric acid from calcium sulfate according to claim 4, wherein: the dust collector (9) is a bag type dust collector.
6. The system for producing cement clinker and sulfuric acid from calcium sulfate according to claim 4, wherein: a gas pipeline (22) is connected between the reduction furnace (15) and the heat exchanger (7), and a control valve is arranged on the gas pipeline (22).
7. A method for producing cement clinker and sulfuric acid by calcium sulfate is characterized in that: a system for producing cement clinker and sulfuric acid from calcium sulfate according to claim 4, comprising the steps of:
(1) Drying and dehydrating: after the calcium sulfate raw material is scattered, drying the calcium sulfate raw material by an airflow dryer and a 2-stage furnace row cyclone preheater;
(2) Preheating, reduction and decomposition: the dried calcium sulfate raw material is preheated by an N-grade kiln cyclone preheater in turn, the preheated calcium sulfate material enters a reduction furnace (15), pulverized coal and/or natural gas are added, and the oxygen content of combustion is controlled to generate CO and H 2 One and/or two of the components are used as reducing agents to carry out reduction reaction to obtain gas-solid mixture;
(3) And (3) calcining and cooling: after gas-solid separation of the gas-solid mixture, the gas is introduced into a scattering dryer (17) to dry the calcium sulfate raw material, and the solid material enters a rotary kiln (18) to be calcined to prepare SO 2 And the cement clinker is stored and sold after being cooled by a clinker cooler (19).
8. The method for producing cement clinker and sulfuric acid from calcium sulfate according to claim 7, wherein: and (3) reducing the calcium sulfate accounting for 36-98% of the total sulfur content in the calcium sulfate into calcium sulfide by controlling a reducing agent during the reduction reaction of the calcium sulfate in the step (2).
CN201811053062.3A 2018-09-10 2018-09-10 System and method for producing cement clinker and sulfuric acid by using calcium sulfate Active CN110885064B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201811053062.3A CN110885064B (en) 2018-09-10 2018-09-10 System and method for producing cement clinker and sulfuric acid by using calcium sulfate

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201811053062.3A CN110885064B (en) 2018-09-10 2018-09-10 System and method for producing cement clinker and sulfuric acid by using calcium sulfate

Publications (2)

Publication Number Publication Date
CN110885064A CN110885064A (en) 2020-03-17
CN110885064B true CN110885064B (en) 2023-04-18

Family

ID=69745171

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201811053062.3A Active CN110885064B (en) 2018-09-10 2018-09-10 System and method for producing cement clinker and sulfuric acid by using calcium sulfate

Country Status (1)

Country Link
CN (1) CN110885064B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115140957B (en) * 2022-08-11 2023-10-03 中国中材国际工程股份有限公司 High-efficiency phosphogypsum acid-making co-production cement preheating and pre-decomposition method and device

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6637503B1 (en) * 1999-02-18 2003-10-28 Pospisil Jaroslav Lower cyclone heat exchanger
CN101811839A (en) * 2009-02-24 2010-08-25 成都建筑材料工业设计研究院有限公司 Method for producing cement clinker by calcining chalk
CN105152141A (en) * 2015-08-07 2015-12-16 天津水泥工业设计研究院有限公司 Thermal technology for making acid from gypsum as well as device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6637503B1 (en) * 1999-02-18 2003-10-28 Pospisil Jaroslav Lower cyclone heat exchanger
CN101811839A (en) * 2009-02-24 2010-08-25 成都建筑材料工业设计研究院有限公司 Method for producing cement clinker by calcining chalk
CN105152141A (en) * 2015-08-07 2015-12-16 天津水泥工业设计研究院有限公司 Thermal technology for making acid from gypsum as well as device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Increasing Pyro System Productivity through Innovative Preheater Upgrades;Sathish Krishnamoorthy et al.;《2018 IEEE-IAS/PCA Cement industry Conference》;20180510;第1-10页 *

Also Published As

Publication number Publication date
CN110885064A (en) 2020-03-17

Similar Documents

Publication Publication Date Title
CN101318632B (en) Method for decomposing phosphogypsum to produce sulphuric acid and cement with suspended state
CN101955166B (en) Method for decomposing semi-hydrated phosphogypsum
CN210922156U (en) Cement predecomposition kiln system
WO2011009321A1 (en) Predecomposition kiln tail system used outside of cement kiln for processing raw materials with combustible substances
WO2021026714A1 (en) Cement pre-calciner kiln system and method for preparing cement clinker
CN112142350A (en) Phosphogypsum desulfurization and calcination treatment system and treatment method
CN213865977U (en) Ardealite desulfurization calcination processing system
CN212669567U (en) Powder lime calcining and reforming system based on novel dry-process cement clinker calcining system
CN111825350B (en) Device with light burned magnesia preparation and carbon dioxide collection functions
CN211035717U (en) Cement predecomposition kiln system capable of realizing calcium circulation
CN110803876B (en) II type anhydrous gypsum thermal coupling production device and method
CN105152141B (en) A kind of gypsum relieving haperacidity thermal technology and device
CN101244811A (en) Method for improving SO2 concentration in acid making technique with decomposition of calcium sulphate
CN112390552A (en) Cement predecomposition kiln system capable of realizing calcium circulation and method for preparing cement clinker
CN110885064B (en) System and method for producing cement clinker and sulfuric acid by using calcium sulfate
WO2022099532A1 (en) Cement kiln system and method for preparing cement clinker
CN212504610U (en) Device for preparing light-burned magnesia and enriching carbon dioxide by self-circulation pyrolysis of flue gas
CN103241717A (en) Drying and calcining process and device for coproduction of sulfuric acid and cement from gypsum
CN108910836A (en) A kind of technique and device of gypsum Sulphuric acid coproduction lime
CN111777340A (en) Device for preparing light-burned magnesia and enriching carbon dioxide by self-circulation pyrolysis of flue gas
CN115259102B (en) Process and equipment for preparing sulfur dioxide concentrated flue gas and silicate clinker by flue gas diversion
CN203212332U (en) Drying and calcining device for sulfuric acid and cement production from gypsum
CN205023854U (en) Gypsum relieving haperacidity thermal technology device
CN115159876A (en) Low-energy-consumption carbon capture cement clinker production system and cement clinker preparation method
CN114772559A (en) Separated dual system and production method for preparing sulfuric acid and co-producing cement from phosphogypsum

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant