CN113480203A - Process for producing cement clinker by using papermaking waste residues (white mud) - Google Patents
Process for producing cement clinker by using papermaking waste residues (white mud) Download PDFInfo
- Publication number
- CN113480203A CN113480203A CN202110666727.3A CN202110666727A CN113480203A CN 113480203 A CN113480203 A CN 113480203A CN 202110666727 A CN202110666727 A CN 202110666727A CN 113480203 A CN113480203 A CN 113480203A
- Authority
- CN
- China
- Prior art keywords
- unit time
- amount
- per unit
- rotary kiln
- air
- 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.)
- Pending
Links
- 239000002699 waste material Substances 0.000 title claims abstract description 62
- 239000004568 cement Substances 0.000 title claims abstract description 52
- 238000000034 method Methods 0.000 title claims abstract description 43
- 230000008569 process Effects 0.000 title claims abstract description 32
- 239000002002 slurry Substances 0.000 claims abstract description 62
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims abstract description 39
- 229910052791 calcium Inorganic materials 0.000 claims abstract description 39
- 239000011575 calcium Substances 0.000 claims abstract description 39
- 150000001875 compounds Chemical class 0.000 claims abstract description 39
- 239000002994 raw material Substances 0.000 claims abstract description 37
- 239000000463 material Substances 0.000 claims abstract description 19
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 18
- 238000002485 combustion reaction Methods 0.000 claims abstract description 14
- 238000001354 calcination Methods 0.000 claims abstract description 13
- 239000004927 clay Substances 0.000 claims abstract description 12
- 238000012937 correction Methods 0.000 claims abstract description 11
- 239000000203 mixture Substances 0.000 claims abstract description 11
- 238000001704 evaporation Methods 0.000 claims abstract description 7
- 238000010438 heat treatment Methods 0.000 claims abstract description 7
- 238000002156 mixing Methods 0.000 claims abstract description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 74
- 239000001301 oxygen Substances 0.000 claims description 74
- 229910052760 oxygen Inorganic materials 0.000 claims description 74
- 239000003245 coal Substances 0.000 claims description 66
- 239000000843 powder Substances 0.000 claims description 65
- 239000007789 gas Substances 0.000 claims description 54
- 239000002912 waste gas Substances 0.000 claims description 22
- 230000001276 controlling effect Effects 0.000 claims description 20
- 238000009423 ventilation Methods 0.000 claims description 14
- 230000004044 response Effects 0.000 claims description 13
- 230000001105 regulatory effect Effects 0.000 claims description 12
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 claims description 8
- 230000004323 axial length Effects 0.000 claims description 6
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 claims description 5
- 239000000292 calcium oxide Substances 0.000 claims description 5
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 claims description 5
- 229910000019 calcium carbonate Inorganic materials 0.000 claims description 4
- 230000003247 decreasing effect Effects 0.000 claims description 4
- 238000001035 drying Methods 0.000 claims description 3
- 238000005303 weighing Methods 0.000 claims description 3
- 230000004907 flux Effects 0.000 claims description 2
- 238000003912 environmental pollution Methods 0.000 abstract description 12
- 238000004519 manufacturing process Methods 0.000 abstract description 12
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 24
- 239000000126 substance Substances 0.000 description 5
- 230000009471 action Effects 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 238000004537 pulping Methods 0.000 description 3
- 238000004064 recycling Methods 0.000 description 3
- 235000019738 Limestone Nutrition 0.000 description 2
- 238000005273 aeration Methods 0.000 description 2
- 239000006028 limestone Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000003673 groundwater Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
- 238000003900 soil pollution Methods 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
Images
Classifications
-
- 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
-
- 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
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/38—Concrete; Lime; Mortar; Gypsum; Bricks; Ceramics; Glass
- G01N33/383—Concrete or cement
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N5/00—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid
- G01N5/04—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid by removing a component, e.g. by evaporation, and weighing the remainder
- G01N5/045—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid by removing a component, e.g. by evaporation, and weighing the remainder for determining moisture content
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Organic Chemistry (AREA)
- Structural Engineering (AREA)
- Materials Engineering (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Thermal Sciences (AREA)
- Food Science & Technology (AREA)
- Medicinal Chemistry (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
The invention discloses a process for producing cement clinker by using papermaking waste residues (white mud), which comprises the following steps: measuring the mass of the calcium-containing compound in the papermaking waste residue; determining the mass of the argillaceous material corresponding to the mass of the calcium-containing compound and correcting the composition and mass of the material; crushing and mixing the papermaking waste residues, the clay raw materials and the correction raw materials to obtain raw slurry; measuring the moisture content in the raw slurry, judging whether the moisture content exceeds the preset content, and if so, heating and evaporating the raw slurry until the moisture content is equal to the preset content; if not, adding water into the raw slurry until the moisture content is equal to the preset content; and (4) transporting the raw slurry to a rotary kiln for calcining to obtain cement clinker. The invention improves the production quality of the cement clinker by controlling the proportion of the papermaking waste residues in the production of the cement clinker, and reduces the energy waste and the environmental pollution in the production process of the cement clinker by controlling the combustion mode.
Description
Technical Field
The invention relates to the field of cement production, in particular to a process for producing cement clinker by using papermaking waste residues (white mud).
Background
China is a big country for pulping and papermaking, and most of the countries adopt a chemical pulping method at present. Chemical pulping produces a large amount of paper mill sludge. A
At present, the main treatment process of papermaking waste residue (white mud) in China is incineration and landfill. The incineration cost is very expensive, the equipment investment amount is large, the energy consumption is high, the common paper making enterprises in China cannot bear the incineration cost, a large amount of waste gas is generated, and the atmospheric pollution is easily caused. Landfill is the process that is generally adopted at present, but owing to lack the fund and establish seepage prevention water quality monitoring system, landfill can cause land resource waste and groundwater resources to pollute, has become one of the main pollution sources of water resource pollution and soil pollution in our country.
The process for producing cement by replacing part of limestone with papermaking waste residues is an existing environment-friendly papermaking waste residue treatment process, but the quality of produced cement is low due to the fact that the proportion of the papermaking waste residues and other cement raw materials is not well controlled in the prior art, and energy waste and pollution are increased due to the fact that a good combustion control mode is not provided in the calcining process.
Disclosure of Invention
In view of a part of the above-mentioned defects in the prior art, the technical problem to be solved by the present invention is to provide a process for producing cement clinker by using papermaking waste residues (white mud), which aims to control the proportion of the papermaking waste residues in the production of the cement clinker, improve the production quality of the cement clinker, and reduce the energy waste and the environmental pollution.
Therefore, the invention provides a process for producing cement clinker by using papermaking waste (white mud), which measures the mass of calcium-containing compounds in the papermaking waste; wherein the calcium-containing compound comprises calcium carbonate and calcium oxide;
determining the mass of the argillaceous material corresponding to the mass of the calcium-containing compound and the composition and mass of the calibration material;
crushing and mixing the papermaking waste residues, the clay raw materials and the correction raw materials to obtain raw slurry;
measuring the moisture content in the raw slurry, judging whether the moisture content exceeds a preset content, and if so, heating and evaporating the raw slurry until the moisture content is equal to the preset content; if not, adding water into the raw slurry until the moisture content is equal to the preset content;
and transporting the raw slurry to a rotary kiln for calcining to obtain cement clinker.
Optionally, the measuring the amount of the calcium-containing compound in the papermaking waste residue comprises:
taking a part of a sample of the papermaking waste residue;
performing material analysis on the sample of the papermaking waste residue to obtain a first content of calcium-containing compounds in the sample;
and obtaining the quality of the calcium-containing compound in the papermaking waste residue according to the first content.
Optionally, the determining the mass of the argillaceous material corresponding to the mass of the calcium-containing compound and the correcting the composition and mass of the material comprises:
determining the mass of the corresponding clay raw material according to the component ratio of the required cement clinker and the mass of the calcium-containing compound;
and determining the components and the quality of the correction raw material according to the component ratio of the required cement clinker, the quality of the calcium-containing compound and the quality of the clay raw material.
Optionally, the measuring the moisture content in the raw slurry comprises:
taking a partial sample of the raw slurry;
drying and weighing the sample of the raw slurry to obtain a first moisture content of the sample;
and obtaining the moisture content in the raw slurry according to the first moisture content.
Optionally, the transporting the raw slurry to a rotary kiln for calcination to obtain cement clinker includes:
collecting a first temperature of the burning zone in the rotary kiln in response to the raw slurry entering the rotary kiln, and determining the flux of the pulverized coal in unit time according to the first temperature;
determining the total ventilation amount of the ventilation end of the rotary kiln to the rotary kiln in unit time according to the length of the burning zone and the powder ventilation amount in unit time; wherein the total amount of gas aerated in unit time pushes the pulverized coal and the axial length of a flame tongue formed by combustion just covers the burning zone;
determining the air amount per unit time for introducing air to ensure that the pulverized coal is just fully combusted according to the pulverized coal passing amount per unit time of the pulverized coal;
determining the total introduced amount of the introduced air and the introduced waste gas to reach the waste gas amount per unit time required by the waste gas corresponding to the total introduced amount per unit time according to the total introduced amount per unit time and the air amount per unit time;
regulating and controlling a powder outlet valve of a coal powder bin, a first valve of a first air blower and a second valve of a second air blower to calcine the raw slurry according to the powder passing amount, the air amount and the waste gas amount in unit time to obtain the cement clinker; the coal powder bin is used for storing coal powder, the first air blower is used for introducing air, and the second air blower is used for introducing waste gas produced by the rotary kiln.
Optionally, the acquiring the first temperature of the burning zone in the rotary kiln includes:
collecting a first temperature of a burning zone in the rotary kiln through a temperature sensor; and at least one temperature sensor is arranged on the inner wall of the burning zone of the rotary kiln.
Optionally, the adjusting and controlling a powder outlet valve of the pulverized coal bunker, a first valve of the first blower and a second valve of the second blower according to the powder passing amount per unit time, the air amount per unit time and the exhaust gas amount per unit time includes:
regulating and controlling a powder outlet valve of the pulverized coal bin according to the difference value between the powder passing amount in unit time and the standard powder passing amount;
regulating and controlling the first valve of the first air blower according to the difference value between the air amount per unit time and the air standard inlet amount;
and regulating and controlling the second valve of the second blower according to the waste gas amount per unit time.
Optionally, the process further comprises:
collecting the oxygen content in the rotary kiln to obtain the oxygen content in the rotary kiln;
and adjusting the air quantity per unit time and the exhaust gas quantity per unit time according to the oxygen quantity in the rotary kiln.
Optionally, the adjusting the air amount per unit time and the exhaust gas amount per unit time according to the oxygen amount in the rotary kiln includes:
maintaining said amount of air per unit time and said amount of off-gas per unit time constant in response to said amount of oxygen within said rotary kiln being between a first threshold and a second threshold;
in response to the amount of oxygen in the rotary kiln being less than the first threshold, increasing the amount of air per unit time and decreasing the amount of exhaust gas per unit time;
in response to the amount of oxygen in the rotary kiln being greater than the second threshold, decreasing the amount of air per unit time and increasing the amount of exhaust gas per unit time; wherein the first threshold is less than or equal to the second threshold.
Optionally, adjusting the air amount per unit time and the exhaust gas amount per unit time according to the oxygen amount in the rotary kiln includes:
and adjusting the air quantity per unit time and the exhaust gas quantity per unit time according to the oxygen quantity in the rotary kiln so that the sum of the oxygen quantity in the air quantity per unit time and the oxygen quantity in the rotary kiln reaches the oxygen quantity required for just sufficient combustion with the powder passing quantity per unit time.
The invention has the beneficial effects that: 1. the method comprises the steps of measuring the mass of the calcium-containing compound in the papermaking waste residue, determining the mass of the argillaceous raw material corresponding to the mass of the calcium-containing compound and the components and mass of the correction raw material, crushing and mixing the papermaking waste residue, the argillaceous raw material and the correction raw material to obtain raw slurry. The invention determines the amount of other raw materials according to the mass of the calcium-containing compound which is the effective component of the cement clinker in the papermaking waste residue, thereby ensuring that the mixture ratio of various raw materials is proper and improving the quality of the produced cement clinker. 2. Measuring the moisture content in the raw slurry, judging whether the moisture content exceeds the preset content, and if so, heating and evaporating the raw slurry until the moisture content is equal to the preset content; if not, adding water into the raw slurry until the moisture content is equal to the preset content; and (4) transporting the raw slurry to a rotary kiln for calcining to obtain cement clinker. The invention utilizes the water in the papermaking waste residue to replace the water in the raw slurry, thereby reducing the use of water and saving resources. 3. In the invention, when raw slurry is calcined: collecting a first temperature of a burning zone in the rotary kiln in response to the raw slurry entering the rotary kiln, and determining the powder passing amount of the pulverized coal in unit time according to the first temperature; determining the total ventilation amount of the ventilation end of the rotary kiln to introduce gas into the rotary kiln in unit time according to the length of the burning zone and the powder introduction amount in unit time; determining the air quantity per unit time for introducing air to ensure that the pulverized coal is just fully combusted according to the pulverized coal introducing quantity per unit time of the pulverized coal; and determining the unit time exhaust gas amount required by the total introduced air and exhaust gas amount reaching the exhaust gas corresponding to the unit time total introduced air amount according to the unit time total introduced air amount and the unit time air amount. The combustion temperature is controlled by controlling the powder passing amount in unit time, the axial length of a flame tongue formed by pushing pulverized coal and combusting is just covered on a burning zone by the total air passing amount in unit time, and the powder passing amount in unit time can be just fully combusted by the air amount in unit time and the exhaust gas amount in unit time. This has the following benefits: firstly, the pulverized coal can be fully combusted, and the energy waste is reduced. And secondly, the oxygen can be ensured not to be excessive, the generation of nitrogen oxides is reduced, and the environmental pollution is reduced. And thirdly, ensuring that the materials in the whole burning zone can be calcined. And fourthly, the recycling of the waste gas is realized, the waste gas emission is reduced, and the environmental pollution is reduced. 4. The invention also collects the oxygen content in the rotary kiln to obtain the oxygen content in the rotary kiln; the air quantity per unit time and the exhaust gas quantity per unit time are adjusted according to the oxygen quantity in the rotary kiln. The invention also considers the oxygen amount in the rotary kiln, further ensures that the coal powder is fully combusted, reduces the generation of nitrogen oxides and reduces the environmental pollution. In conclusion, the invention improves the production quality of the cement clinker by controlling the proportion of the papermaking waste residues in the production of the cement clinker, and reduces the energy waste and the environmental pollution in the production process of the cement clinker by controlling the combustion mode.
Drawings
Fig. 1 is a schematic flow chart of a process for producing cement clinker by using papermaking waste (white mud) according to an embodiment of the present invention.
Detailed Description
The invention discloses a process for producing cement clinker by using papermaking waste residues (white mud), and a person skilled in the art can use the contents for reference and appropriately improve the technical details to realize the process. It is expressly intended that all such similar substitutes and modifications which would be obvious to one skilled in the art are deemed to be included in the invention. While the methods and applications of this invention have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations and modifications in the methods and applications described herein, as well as other suitable variations and combinations, may be made to implement and use the techniques of this invention without departing from the spirit and scope of the invention.
The process for producing cement by replacing part of limestone with papermaking waste residues is an existing environment-friendly papermaking waste residue treatment process, but the quality of produced cement is low due to the fact that the proportion of the papermaking waste residues and other cement raw materials is not well controlled in the prior art, and energy waste and pollution are increased due to the fact that a good combustion control mode is not provided in the calcining process.
Therefore, the embodiment of the present invention discloses a process for producing cement clinker by using papermaking waste (white mud), as shown in fig. 1, comprising:
step S101: and measuring the mass of the calcium-containing compound in the papermaking waste residue.
Wherein the calcium-containing compound comprises calcium carbonate and calcium oxide. The papermaking waste residue is a causticized product, most of calcium-containing compounds in the papermaking waste residue are calcium carbonate, and a small part of calcium oxide is changed into calcium oxide under the influence of external factors.
Optionally, the measuring the amount of the calcium-containing compound in the papermaking waste residue comprises:
taking a part of a sample of the papermaking waste residue;
performing material analysis on a sample of the papermaking waste residue to obtain a first content of a calcium-containing compound in the sample;
and obtaining the mass of the calcium-containing compound in the papermaking waste residue according to the first content.
It is noted that it is much quicker and easier to estimate the total calcium-containing compound mass by the sample calcium-containing compound content. The content of each substance in a part of samples of the papermaking waste residue can be determined by substance analysis.
Step S102: determining the mass of the argillaceous material corresponding to the mass of the calcium-containing compound and correcting the composition and mass of the material.
The clay raw material at least comprises one of clay, loess, shale, siltstone, marl and river mud.
Optionally, determining the mass of the argillaceous material corresponding to the mass of the calcium-containing compound and correcting the composition and mass of the material comprises:
determining the quality of the corresponding clay raw material according to the component ratio of the required cement clinker and the quality of the calcium-containing compound;
and determining the components and the quality of the correction raw material according to the component ratio of the required cement clinker, the quality of the calcium-containing compound and the quality of the clay raw material.
The calibration raw material is used for fine adjustment of the mixture ratio of the components of each substance of the raw slurry, and the components and the mass thereof are determined based on the other raw materials. The amount of other raw materials is determined according to the mass of the calcium-containing compound which is an effective component of the cement clinker in the papermaking waste residue, so that the mixture ratio of various raw materials is proper, and the quality of the produced cement clinker is improved.
Step S103: and crushing and mixing the papermaking waste residues, the clay raw materials and the correction raw materials to obtain raw slurry.
The pulverization and mixing are intended to distribute the various raw materials evenly for subsequent calcination and reaction.
Step S104: measuring the moisture content in the raw slurry, judging whether the moisture content exceeds the preset content, and if so, heating and evaporating the raw slurry until the moisture content is equal to the preset content; if not, adding water into the raw slurry until the moisture content is equal to the preset content.
Optionally, measuring the moisture content of the raw slurry comprises:
taking a part of sample of the raw slurry;
drying and weighing a sample of the raw slurry to obtain a first moisture content of the sample;
and obtaining the moisture content in the raw slurry according to the first moisture content.
It should be noted that water in the papermaking waste residue is used for replacing water in raw slurry, so that the use of water is reduced, and resources are saved. Comparing the moisture content in the raw slurry with the moisture content of the raw slurry to be calcined, and heating and evaporating or adding water to make the moisture content in the raw slurry reach the moisture content during calcination.
Step S105: and (4) transporting the raw slurry to a rotary kiln for calcining to obtain cement clinker.
Optionally, in a specific embodiment, the raw slurry is transported to a rotary kiln for calcination to obtain cement clinker, including:
step S201: and responding to the raw slurry entering the rotary kiln, collecting a first temperature of a burning zone in the rotary kiln, and determining the powder passing amount of the pulverized coal in unit time according to the first temperature.
Optionally, collecting a first temperature of a burning zone in the rotary kiln includes:
collecting a first temperature of a burning zone in the rotary kiln through a temperature sensor; wherein, the inner wall of the burning zone of the rotary kiln is provided with at least one temperature sensor.
In a specific embodiment, a plurality of temperature sensors are arranged on the inner wall of the burning zone of the rotary kiln, and the average value of the temperatures sensed by the plurality of temperature sensors is taken as the first temperature. The temperature measurement is carried out through a plurality of temperature sensors, so that the first temperature can be ensured to be more suitable for the actual temperature of the burning zone of the rotary kiln.
It should be noted that the burning zone temperature is directly related to the amount of pulverized coal. The more the amount of pulverized coal, the higher the burning zone temperature. The detected first temperature is inversely related to the required powder passing amount per unit time. If the first temperature exceeds the temperature required by the burning zone of the rotary kiln, the coal powder amount in the rotary kiln is excessive, and the powder passing amount in unit time needs to be reduced. If the first temperature does not reach the temperature required by the burning zone of the rotary kiln, the coal powder amount in the rotary kiln is too small, and the coal powder passing amount in unit time needs to be increased. The corresponding relation between the first temperature and the powder passing amount in unit time can be obtained according to a first temperature-unit time powder passing amount model. The model was obtained from preliminary experiments.
Step S102: and determining the total ventilation amount of the ventilation end of the rotary kiln to the rotary kiln in unit time according to the length of the burning zone and the powder ventilation amount in unit time.
Wherein, the axial length of the flame tongue formed by the total amount of air per unit time pushing the coal powder and burning just covers the burning zone.
It should be noted that, under the condition that the length of the burning zone is not changed, the powder passing amount in unit time is in positive correlation with the total aeration amount in unit time, and the more the powder passing amount in unit time, the greater the total aeration amount in unit time is needed, so that the flaming tongue formed by burning the pulverized coal just covers the burning zone.
In addition, the axial length of the flame tongue formed by burning the pulverized coal just covers the burning zone, and the pulverized coal burner has the following advantages: firstly, the materials on the burning zone are all guaranteed to be burnt. And secondly, avoiding the influence of the excessively long flame tongue on the unmixed and uniform materials outside the burning zone.
Step S203: and determining the air amount per unit time for introducing air to ensure that the pulverized coal is just fully combusted according to the pulverized coal passing amount per unit time of the pulverized coal.
Optionally, the components of the pulverized coal are determined, the amount of oxygen required for enabling the pulverized coal with the pulverized coal passing amount in unit time to be just fully combusted is determined according to the components of the pulverized coal, and the amount of air in unit time is determined according to the amount of oxygen and the oxygen content in the air. It should be noted that if the oxygen and the pulverized coal are just completely combusted, not only can the pulverized coal be fully utilized, but also the emission of nitrogen oxides can be reduced.
It is worth mentioning that the nitrogen oxides are produced under conditions of oxygen enrichment and high temperature.
Step S204: and determining the unit time exhaust gas amount required by the total introduced air and exhaust gas amount reaching the exhaust gas corresponding to the unit time total introduced air amount according to the unit time total introduced air amount and the unit time air amount.
The sum of the air amount per unit time and the exhaust gas amount per unit time is equal to the total ventilation amount per unit time. The amount of oxygen in the air per unit time is sufficient for the amount of the introduced powder per unit time to be sufficiently combusted, and it is necessary to introduce a gas containing no or very little oxygen so that the both are mixed to the total amount of the introduced gas per unit time. The embodiment of the present invention rotates the tail gas (exhaust gas) generated from the rotary kiln to serve as the gas. Not only because the oxygen content of the waste gas generated by the rotary kiln is low, but also the effects of recycling tail gas, reducing emission and lightening environmental pollution can be achieved.
Step S205: and (3) regulating and controlling a powder outlet valve of the coal powder bin, a first valve of the first air blower and a second valve of the second air blower according to the powder passing amount per unit time, the air amount per unit time and the waste gas amount per unit time to calcine the raw slurry to obtain the cement clinker.
The coal powder bin is used for storing coal powder, the first air blower is used for introducing air, and the second air blower is used for introducing waste gas produced by the rotary kiln.
Optionally, the powder outlet valve of the pulverized coal bunker, the first valve of the first blower and the second valve of the second blower are controlled according to the powder passing amount per unit time, the air amount per unit time and the exhaust gas amount per unit time, and the method includes:
regulating and controlling a powder outlet valve of the pulverized coal bin according to the difference value between the powder passing amount in unit time and the standard powder passing amount;
regulating and controlling a first valve of a first air blower according to the difference value between the air amount per unit time and the air standard inlet amount;
and regulating and controlling a second valve of the second blower according to the waste gas amount in unit time.
It should be noted that the standard powder passing amount per unit time and the standard air passing amount per unit time are required to be passed through at the beginning of combustion, so the opening degrees of the powder outlet valve of the coal powder bin and the first valve of the first air blower at the beginning of combustion correspond to the standard powder passing amount and the standard air passing amount. Therefore, the powder outlet valve and the first valve can be adjusted to be larger or smaller by comparing the two valves. The exhaust gas is not combusted at the beginning, so that the comparison is not needed, and the adjustment can be directly carried out.
Optionally, the embodiment further includes:
collecting the oxygen content in the rotary kiln to obtain the oxygen content in the rotary kiln;
the air quantity per unit time and the exhaust gas quantity per unit time are adjusted according to the oxygen quantity in the rotary kiln.
It should be noted that the oxygen content in the rotary kiln may be too high or too low due to the initially introduced air and coal powder. Therefore, the invention considers the oxygen amount in the rotary kiln, and adjusts the air amount per unit time and the exhaust gas amount per unit time according to the oxygen amount, thereby further ensuring that the pulverized coal is fully combusted, reducing the generation of nitrogen oxides and reducing the environmental pollution.
Optionally, the acquiring the oxygen content in the rotary kiln to obtain the oxygen content in the rotary kiln includes:
collecting the oxygen content in the rotary kiln through an oxygen sensor; wherein, the inner wall of the rotary kiln is provided with at least one oxygen sensor;
and obtaining the oxygen amount in the rotary kiln according to the oxygen content and the volume of the rotary kiln.
It should be noted that, a plurality of oxygen sensors may be set to take the average value of the collected data, so as to ensure the accuracy of the collected data.
Optionally, adjusting the amount of air per unit time and the amount of exhaust gas per unit time according to the amount of oxygen in the rotary kiln includes:
keeping the air amount per unit time and the exhaust gas amount per unit time constant in response to the oxygen amount in the rotary kiln being between a first threshold value and a second threshold value;
in response to the oxygen amount in the rotary kiln being smaller than a first threshold value, increasing the air amount per unit time and reducing the exhaust gas amount per unit time;
in response to the oxygen amount in the rotary kiln being larger than a second threshold value, reducing the air amount per unit time and increasing the exhaust gas amount per unit time; wherein the first threshold is less than or equal to the second threshold.
The oxygen amount in the rotary kiln is between the first threshold and the second threshold, and it is explained that the oxygen amount in the rotary kiln and the air amount per unit time can sufficiently burn the pulverized coal having the powder flow amount per unit time, and therefore the air amount per unit time and the exhaust gas amount per unit time are kept unchanged. If the oxygen amount in the rotary kiln is less than the first threshold value, the oxygen amount in the rotary kiln is insufficient, and the air amount per unit time enables the pulverized coal with the powder passing amount per unit time to be fully combusted, so that the air amount per unit time is increased, and the exhaust gas amount per unit time is reduced. If the oxygen amount in the rotary kiln is larger than the second threshold value, the oxygen amount in the rotary kiln and the air amount per unit time can enable the pulverized coal of the powder passing amount per unit time to be fully combusted, and excess oxygen is also generated, so that excessive nitrogen oxides are generated, the air amount per unit time is reduced, and the exhaust gas amount per unit time is increased. This embodiment is convenient, simple and effective.
Optionally, adjusting the amount of air per unit time and the amount of exhaust gas per unit time according to the amount of oxygen in the rotary kiln includes:
according to the oxygen amount in the rotary kiln, the air amount per unit time and the waste gas amount per unit time are adjusted, so that the sum of the oxygen amount in the air amount per unit time and the oxygen amount in the rotary kiln reaches the oxygen amount which is just enough to be burnt with the powder passing amount per unit time.
It should be noted that, in this embodiment, the amount of oxygen and the amount of air per unit time in the rotary kiln are more precisely controlled, so that the pulverized coal passing through the amount per unit time can be just fully combusted.
In normal conditions, the temperature change in the rotary kiln is not too large, so that the oxygen required to be introduced into the rotary kiln to dilute the air amount introduced into the rotary kiln per unit time by introducing the exhaust gas per unit time does not account for 10% of the total amount of the introduced air per unit time, and the total amount of the introduced air per unit time and the exhaust gas per unit time are nearly equal. Thus, in the present embodiment, it is generally sufficient to recycle 10% of the tail gas to control the overall combustion process.
It should be noted that the unit time in the same embodiment refers to a preset time duration with the same length.
The embodiment of the invention measures the mass of the calcium-containing compound in the papermaking waste residue, determines the mass of the argillaceous raw material corresponding to the mass of the calcium-containing compound and the components and mass of the correction raw material, and crushes and mixes the papermaking waste residue, the argillaceous raw material and the correction raw material to obtain raw slurry. The embodiment of the invention determines the amount of other raw materials according to the mass of the calcium-containing compound which is the effective component of the cement clinker in the papermaking waste residue, thereby ensuring that the mixture ratio of various raw materials is proper and improving the quality of the produced cement clinker. Measuring the moisture content in the raw slurry, judging whether the moisture content exceeds the preset content, and if so, heating and evaporating the raw slurry until the moisture content is equal to the preset content; if not, adding water into the raw slurry until the moisture content is equal to the preset content; and (4) transporting the raw slurry to a rotary kiln for calcining to obtain cement clinker. The embodiment of the invention utilizes the water in the papermaking waste residues to replace the water in the raw slurry, thereby reducing the use of water and saving resources. In the embodiment of the invention, when the raw slurry is calcined: collecting a first temperature of a burning zone in the rotary kiln in response to the raw slurry entering the rotary kiln, and determining the powder passing amount of the pulverized coal in unit time according to the first temperature; determining the total ventilation amount of the ventilation end of the rotary kiln to introduce gas into the rotary kiln in unit time according to the length of the burning zone and the powder introduction amount in unit time; determining the air quantity per unit time for introducing air to ensure that the pulverized coal is just fully combusted according to the pulverized coal introducing quantity per unit time of the pulverized coal; and determining the unit time exhaust gas amount required by the total introduced air and exhaust gas amount reaching the exhaust gas corresponding to the unit time total introduced air amount according to the unit time total introduced air amount and the unit time air amount. The combustion temperature is controlled by controlling the powder passing amount in unit time, the axial length of a flame tongue formed by pushing pulverized coal and combusting is just covered on a burning zone by the total air passing amount in unit time, and the powder passing amount in unit time can be just fully combusted by the air amount in unit time and the exhaust gas amount in unit time. This has the following benefits: firstly, the pulverized coal can be fully combusted, and the energy waste is reduced. And secondly, the oxygen can be ensured not to be excessive, the generation of nitrogen oxides is reduced, and the environmental pollution is reduced. And thirdly, ensuring that the materials in the whole burning zone can be calcined. And fourthly, the recycling of the waste gas is realized, the waste gas emission is reduced, and the environmental pollution is reduced. The embodiment of the invention also collects the oxygen content in the rotary kiln to obtain the oxygen content in the rotary kiln; the air quantity per unit time and the exhaust gas quantity per unit time are adjusted according to the oxygen quantity in the rotary kiln. The embodiment of the invention also considers the oxygen amount in the rotary kiln, further ensures that the coal powder is fully combusted, reduces the generation of nitrogen oxides and reduces the environmental pollution. In summary, the embodiment of the invention improves the production quality of the cement clinker by controlling the proportion of the papermaking waste residues in the production of the cement clinker, and reduces the energy waste and the environmental pollution in the production process of the cement clinker by controlling the combustion mode.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
All the embodiments in the present specification are described in a related manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.
The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.
Claims (10)
1. A process for producing cement clinker by using papermaking waste residues (white mud), which is characterized by comprising the following steps:
measuring the mass of the calcium-containing compound in the papermaking waste residue; wherein the calcium-containing compound comprises calcium carbonate and calcium oxide;
determining the mass of the argillaceous material corresponding to the mass of the calcium-containing compound and the composition and mass of the calibration material;
crushing and mixing the papermaking waste residues, the clay raw materials and the correction raw materials to obtain raw slurry;
measuring the moisture content in the raw slurry, judging whether the moisture content exceeds a preset content, and if so, heating and evaporating the raw slurry until the moisture content is equal to the preset content; if not, adding water into the raw slurry until the moisture content is equal to the preset content;
and transporting the raw slurry to a rotary kiln for calcining to obtain cement clinker.
2. The process of claim 1, wherein said measuring the amount of calcium-containing compounds in the papermaking waste comprises:
taking a part of a sample of the papermaking waste residue;
performing material analysis on the sample of the papermaking waste residue to obtain a first content of calcium-containing compounds in the sample;
and obtaining the quality of the calcium-containing compound in the papermaking waste residue according to the first content.
3. The process of claim 1, wherein said determining the mass of the argillaceous feedstock corresponding to the mass of the calcium-containing compound and correcting the composition and mass of the feedstock comprises:
determining the mass of the corresponding clay raw material according to the component ratio of the required cement clinker and the mass of the calcium-containing compound;
and determining the components and the quality of the correction raw material according to the component ratio of the required cement clinker, the quality of the calcium-containing compound and the quality of the clay raw material.
4. The process of claim 1, wherein said measuring the moisture content of said raw slurry comprises:
taking a partial sample of the raw slurry;
drying and weighing the sample of the raw slurry to obtain a first moisture content of the sample;
and obtaining the moisture content in the raw slurry according to the first moisture content.
5. The process of claim 1, wherein said transporting said raw slurry to a rotary kiln for calcination to obtain cement clinker comprises:
collecting a first temperature of the burning zone in the rotary kiln in response to the raw slurry entering the rotary kiln, and determining the flux of the pulverized coal in unit time according to the first temperature;
determining the total ventilation amount of the ventilation end of the rotary kiln to the rotary kiln in unit time according to the length of the burning zone and the powder ventilation amount in unit time; wherein the total amount of gas aerated in unit time pushes the pulverized coal and the axial length of a flame tongue formed by combustion just covers the burning zone;
determining the air amount per unit time for introducing air to ensure that the pulverized coal is just fully combusted according to the pulverized coal passing amount per unit time of the pulverized coal;
determining the total introduced amount of the introduced air and the introduced waste gas to reach the waste gas amount per unit time required by the waste gas corresponding to the total introduced amount per unit time according to the total introduced amount per unit time and the air amount per unit time;
regulating and controlling a powder outlet valve of a coal powder bin, a first valve of a first air blower and a second valve of a second air blower to calcine the raw slurry according to the powder passing amount, the air amount and the waste gas amount in unit time to obtain the cement clinker; the coal powder bin is used for storing coal powder, the first air blower is used for introducing air, and the second air blower is used for introducing waste gas produced by the rotary kiln.
6. The process as claimed in claim 5, wherein said collecting a first temperature of a burn zone in said rotary kiln comprises:
collecting a first temperature of a burning zone in the rotary kiln through a temperature sensor; and at least one temperature sensor is arranged on the inner wall of the burning zone of the rotary kiln.
7. The process of claim 5, wherein the controlling of the pulverized coal bunker discharge valve, the first blower valve, and the second blower valve according to the pulverized coal passing amount per unit time, the air amount per unit time, and the exhaust gas amount per unit time comprises:
regulating and controlling a powder outlet valve of the pulverized coal bin according to the difference value between the powder passing amount in unit time and the standard powder passing amount;
regulating and controlling the first valve of the first air blower according to the difference value between the air amount per unit time and the air standard inlet amount;
and regulating and controlling the second valve of the second blower according to the waste gas amount per unit time.
8. The process of claim 5, further comprising:
collecting the oxygen content in the rotary kiln to obtain the oxygen content in the rotary kiln;
and adjusting the air quantity per unit time and the exhaust gas quantity per unit time according to the oxygen quantity in the rotary kiln.
9. The process as claimed in claim 8, wherein said adjusting said air per unit time amount and said off-gas per unit time amount according to said oxygen amount in said rotary kiln comprises:
maintaining said amount of air per unit time and said amount of off-gas per unit time constant in response to said amount of oxygen within said rotary kiln being between a first threshold and a second threshold;
in response to the amount of oxygen in the rotary kiln being less than the first threshold, increasing the amount of air per unit time and decreasing the amount of exhaust gas per unit time;
in response to the amount of oxygen in the rotary kiln being greater than the second threshold, decreasing the amount of air per unit time and increasing the amount of exhaust gas per unit time; wherein the first threshold is less than or equal to the second threshold.
10. The process as claimed in claim 8, wherein adjusting the amount of air per unit time and the amount of offgas per unit time according to the amount of oxygen in the rotary kiln comprises:
and adjusting the air quantity per unit time and the exhaust gas quantity per unit time according to the oxygen quantity in the rotary kiln so that the sum of the oxygen quantity in the air quantity per unit time and the oxygen quantity in the rotary kiln reaches the oxygen quantity required for just sufficient combustion with the powder passing quantity per unit time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110666727.3A CN113480203A (en) | 2021-06-16 | 2021-06-16 | Process for producing cement clinker by using papermaking waste residues (white mud) |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110666727.3A CN113480203A (en) | 2021-06-16 | 2021-06-16 | Process for producing cement clinker by using papermaking waste residues (white mud) |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113480203A true CN113480203A (en) | 2021-10-08 |
Family
ID=77935019
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110666727.3A Pending CN113480203A (en) | 2021-06-16 | 2021-06-16 | Process for producing cement clinker by using papermaking waste residues (white mud) |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113480203A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1986472A (en) * | 2006-12-12 | 2007-06-27 | 广西贵糖（集团）股份有限公司 | Process of producing cement with papermaking white clay as material |
| CN105605584A (en) * | 2016-03-17 | 2016-05-25 | 北京建筑材料科学研究总院有限公司 | Method for processing solid waste through enriched oxygen in cement kiln |
| CN110345507A (en) * | 2019-06-11 | 2019-10-18 | 张家港优赛电子商务有限公司 | A kind of coal-fired boiler combustion Automatic Optimal control device |
| CN110963723A (en) * | 2018-09-30 | 2020-04-07 | 台山市翔隆纸业有限公司 | Method for producing cement clinker by using papermaking wastewater |
| CN111521004A (en) * | 2020-04-11 | 2020-08-11 | 芜湖海螺水泥有限公司 | Kiln tail temperature accurate control process |
| CN112500003A (en) * | 2020-11-26 | 2021-03-16 | 兰溪诸葛南方水泥有限公司 | Novel method for reducing emission of nitrogen oxides through preheating and calcining |
-
2021
- 2021-06-16 CN CN202110666727.3A patent/CN113480203A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1986472A (en) * | 2006-12-12 | 2007-06-27 | 广西贵糖（集团）股份有限公司 | Process of producing cement with papermaking white clay as material |
| CN105605584A (en) * | 2016-03-17 | 2016-05-25 | 北京建筑材料科学研究总院有限公司 | Method for processing solid waste through enriched oxygen in cement kiln |
| CN110963723A (en) * | 2018-09-30 | 2020-04-07 | 台山市翔隆纸业有限公司 | Method for producing cement clinker by using papermaking wastewater |
| CN110345507A (en) * | 2019-06-11 | 2019-10-18 | 张家港优赛电子商务有限公司 | A kind of coal-fired boiler combustion Automatic Optimal control device |
| CN111521004A (en) * | 2020-04-11 | 2020-08-11 | 芜湖海螺水泥有限公司 | Kiln tail temperature accurate control process |
| CN112500003A (en) * | 2020-11-26 | 2021-03-16 | 兰溪诸葛南方水泥有限公司 | Novel method for reducing emission of nitrogen oxides through preheating and calcining |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5888256A (en) | Managed composition of waste-derived fuel | |
| US5349910A (en) | Method and apparatus for incinerating waste in a cement kiln plant | |
| CN103739184B (en) | Method for drying and direct blending combustion of domestic sludge by using dry-process cement kiln waste heat | |
| US6439139B1 (en) | Method for recycling building materials | |
| CN103415483B (en) | Cement composition and manufacture method thereof | |
| AU2012361875B2 (en) | System for manufacturing cement clinker | |
| SG192920A1 (en) | Cement composition and process for producing same | |
| CN101723610B (en) | Clinker method calcining cement clinker by using predecomposition technology of completely replacing calcareous raw material with wet type acetylene sludge | |
| CN103130428B (en) | Method of utilizing dicyandiamide waste residues and carbide slag to produce lime | |
| CN105801067B (en) | A kind of grey material modified method applied to wall plastering material of flue gas desulfurization | |
| Li et al. | Influence of sugar filter mud on formation of portland cement clinker | |
| CN113480203A (en) | Process for producing cement clinker by using papermaking waste residues (white mud) | |
| US20030192461A1 (en) | Methods for controlling ignitability of organic waste with mineral by-products | |
| EP2807128B1 (en) | Use of organic fibre cement as a raw material in the production of cement clinker | |
| US6183244B1 (en) | Control of cement clinker production in a wet process rotary kiln by analysis of sulfur in the end product | |
| JP3999799B2 (en) | Method for producing inorganic particles | |
| CN1012579B (en) | Comprehensive utilization of cr dregs by detoxicated melting cr dregs | |
| CN113566563A (en) | Combustion control method of intelligent rotary kiln | |
| US3402225A (en) | Method of preparing vertical shaft kiln feed for production of portland cement | |
| US20040025753A1 (en) | Cement manufacturing processes with a view to reducing NOx emissions in particular | |
| KR20030067075A (en) | A Manufacturing method of Anhydrite using By-Product Gypsum | |
| CN217441656U (en) | Antibiotic dregs of a decoction processing system | |
| JP2020163318A (en) | Method for producing sewage sludge fermentation raw material | |
| CN103922623A (en) | Clinker sintering system taking dry acetylene sludge as calcium raw material | |
| CN103936310A (en) | Method used for improving cement raw material grindability and reducing TOC discharge with kitchen waste |
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 | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20211008 |
|
| RJ01 | Rejection of invention patent application after publication |