CN-117602961-B - Production process and system for preparing high-performance lightweight aggregate by using floor sludge and pyrolysis slag

CN117602961BCN 117602961 BCN117602961 BCN 117602961BCN-117602961-B

Abstract

The invention discloses a production process and a system for preparing high-performance lightweight aggregate by using floor oil sludge and pyrolysis slag, which comprises the following steps of metering the floor oil sludge and/or pyrolysis slag, fly ash and bentonite powder as raw materials according to a proportion, sequentially feeding the raw materials into two double-shaft mixers in series for mixing and sectionally adding water, extruding and granulating ceramsite raw materials out of the double-shaft mixers, and shaping to obtain ceramsite raw material balls; the raw material balls of the ceramsite are sent into a rotary indirect dryer to be dried indirectly until the water content is 12-17%, then sent into a belt dryer to be dried until the water content is less than or equal to 4%, then sent into a ceramsite rotary kiln to be calcined at high temperature, cooled by a grate cooler, screened and stored, and cooled to obtain the oil sludge ceramsite product. The invention solves the problems of drying safety, flue gas treatment and emission caused by volatile petroleum hydrocarbon components in ceramsite raw material balls by utilizing the combined process technology of a kiln tail heat recovery system, a kiln head heat recovery system, a firing system and a flue gas treatment system, improves the heat efficiency of the system and reduces the energy consumption of the system.

Inventors

HAN HUI
FAN QINGSHUAI
WU XILIN
DONG TAO
PENG XUEPING
Fan Daorong
FAN YULIN
JIANG BING
XIE ZHIYING
LIN MINYAN

Assignees

天津水泥工业设计研究院有限公司
榆林锋利悦环保科技有限公司
天津中材工程研究中心有限公司

Dates

Publication Date: 20260505
Application Date: 20231129

Claims (14)

1. The production process for preparing the high-performance lightweight aggregate by using the floor sludge and the pyrolysis slag is characterized by comprising the following steps of: Metering the raw materials of the floor sludge and/or pyrolysis slag, fly ash and bentonite according to the proportion of ingredients, sequentially feeding the raw materials into two double-shaft mixers in series for mixing and sectionally adding water, feeding the ceramsite raw materials out of the double-shaft mixers into an oil sludge ceramsite granulating system for extrusion granulating, and feeding the raw materials into a shaping machine for shaping treatment to obtain ceramsite raw material balls which contain volatile petroleum hydrocarbon; The method comprises the steps of feeding raw ceramsite pellets from an oil sludge ceramsite granulating system into a rotary indirect dryer for indirect drying until the water content is 12-17%, wherein a drying medium of the rotary indirect dryer is heat conducting oil, a drying heat source is kiln tail smoke of a ceramsite rotary kiln, then feeding the raw ceramsite pellets into a belt dryer for continuous drying until the water content is less than or equal to 4%, solving the drying safety problem caused by volatile petroleum hydrocarbon components in the raw ceramsite pellets, feeding the raw ceramsite pellets into a ceramsite rotary kiln for high-temperature calcination, cooling the calcined raw ceramsite pellets by a grate cooler, screening and storing, and cooling to obtain an oil sludge ceramsite product with the bulk density of 800-1100kg/m 3 , the cylinder pressure of 10-23MPa and the water absorption rate of 2.14-9.8%; The ceramsite rotary kiln is a ceramsite roasting rotary kiln and comprises a kiln body, wherein a fire-resistant layer is arranged on the inner wall of the kiln body, a material blocking check area and a quick roasting area are sequentially arranged from a kiln tail to a kiln head of the kiln body, a material feeding shrinkage cavity is arranged on the material inlet side of the material blocking check area, a material blocking boss is arranged in the middle of the material blocking check area, a high-temperature SNCR denitration device is arranged at the center of the material feeding end of the material blocking check area, three or more camber parts with curved structures are arranged on the inner wall of the kiln body of the quick roasting area along the circumferential direction of the kiln body, a material discharging shrinkage cavity is arranged on the material outlet side of the quick roasting area, and diversion slopes towards the inner sides of the areas where the material feeding shrinkage cavity and the material discharging shrinkage cavity are respectively arranged.
2. The production process for preparing high-performance lightweight aggregate by using the floor sludge and the pyrolysis slag, which is disclosed in claim 1, is characterized in that, in raw materials, the floor sludge and/or the pyrolysis slag account for 5-50% by weight, the fly ash accounts for 40-70% by weight and the bentonite accounts for 5-15% by weight, and the sum of the floor sludge and/or the pyrolysis slag, the fly ash and the bentonite accounts for 100% by weight.
3. The production process for preparing high-performance lightweight aggregate by using the floor sludge and the pyrolysis slag, which is disclosed in claim 1, is characterized in that the floor sludge is screened by a forklift with a screening function, stones and other sundries with the size larger than 20mm are screened out, the floor sludge which is screened out by the forklift is sent into a crusher to be crushed and scattered, the floor sludge after the crushing treatment is sent into a drum screening machine to be screened out, the floor sludge with the size smaller than or equal to 5mm is sent into a proportioning bin of a proportioning system for standby, and materials with the size larger than 5mm are sent into the crusher again to be processed; the pyrolysis slag is pyrolysis slag generated from pyrolysis of the oil sludge.
4. The process for preparing high-performance lightweight aggregate by using the floor sludge and the pyrolysis slag as claimed in claim 1, wherein the water content of the raw material of the ceramsite fed to the first double-shaft mixer is controlled to be 8-15% in a segmented manner, and the water content of the raw material of the ceramsite fed to the second double-shaft mixer is controlled to be 18-25% in a segmented manner.
5. The production process for preparing high-performance lightweight aggregate by using the floor sludge and the pyrolysis slag, which is disclosed in claim 1, is characterized in that the granularity is controlled to be 5-15mm when the ceramsite raw material is granulated, and the sphericity is controlled to be less than or equal to 2.0 when the ceramsite raw material is shaped.
6. The production process for preparing high-performance lightweight aggregate by using floor sludge and pyrolysis residues, which is disclosed in claim 1, is characterized in that after the kiln tail flue gas subjected to SNCR denitration in a kiln is subjected to dust removal and then is subjected to indirect heat exchange by a heat conduction oil heat exchanger, the temperature is reduced to 300-350 ℃ and enters a flue gas treatment system for treatment, and then the flue gas is discharged after reaching standards, the temperature of the heat conduction oil is increased to 200-350 ℃, the heat conduction oil brings the kiln tail waste heat into a rotary indirect dryer for drying ceramsite raw pellets, and the heat conduction oil discharged from the rotary indirect dryer is recycled to a heat conduction oil heat exchanger for supplementing heat sources.
7. The production process for preparing high-performance lightweight aggregate by using floor sludge and pyrolysis residues, which is characterized by comprising the steps of quenching 300-350 ℃ flue gas subjected to heat exchange in a flue gas treatment system, rapidly cooling the flue gas to 190-200 ℃ while controlling the residence time of the flue gas in a temperature zone of 200-350 ℃ to be less than 1S, removing dioxin and acid gas from the quenched flue gas at 190-200 ℃, removing dust from the reacted flue gas to remove particles in the flue gas, enabling the concentration of the particles in the flue gas to be not more than 20mg/m 3 , enabling the dust-removed flue gas to enter a two-stage wet deacidification system, realizing gas-liquid contact enhanced mass transfer effect through liquid atomization, enabling acid substances in the flue gas to be removed through acid-base neutralization reaction, and introducing the deacidified flue gas into a chimney through an induced draft fan to reach the standard for emission.
8. The production process for preparing high-performance lightweight aggregate by using the floor sludge and the pyrolysis slag as claimed in claim 1, wherein a part of water in the water treatment system is used for the sludge ceramsite granulating system.
9. The production process for preparing high-performance lightweight aggregate by using the floor sludge and the pyrolysis slag, as claimed in claim 1, wherein the drying heat source of the belt dryer is 250-300 ℃ hot air after dust removal from a grate cooler and/or circulating air heated by a natural gas hot air furnace.
10. The production process for preparing high-performance lightweight aggregate by using floor sludge and pyrolysis residues, which is disclosed in claim 1, is characterized in that a part of drying waste gas containing low-concentration petroleum hydrocarbon and water vapor, which is generated by drying ceramsite raw material balls in a belt dryer, enters a hot blast stove to serve as combustion air and burn off the petroleum hydrocarbon, the rest part of the waste gas is sequentially dedusted and condensed and then is sent into a grate cooler, a part of the waste gas is blown into a grate cooler high-temperature section to serve as combustion air to enter a ceramsite rotary kiln to burn off the petroleum hydrocarbon, the other part of the waste gas is blown into a grate cooler medium-low-temperature section to serve as a cooling air source to cool high-temperature ceramsite in the grate cooler to obtain heat, and then the heat is sent into the belt dryer again to dry the ceramsite raw material balls, so that waste gas recycling is realized, and the condensed waste water enters a water treatment system to treat and then is discharged after reaching standards.
11. The production process for preparing high-performance lightweight aggregate by using the floor sludge and the pyrolysis slag, as claimed in claim 1, is characterized in that the height of the material blocking boss is not more than 1/2 of the height of the arch height, and the feeding end of the arch height is provided with a flow guiding table.
12. A production system for preparing high-performance lightweight aggregate by using floor sludge and pyrolysis slag for realizing the production process as claimed in any one of claims 1-11 is characterized by comprising a sludge pretreatment system, a sludge ceramsite granulating system, a rotary indirect dryer, a belt dryer, a kiln tail heat recovery system, a kiln head heat recovery system, a firing system and a flue gas treatment system, wherein the firing system comprises a ceramsite rotary kiln and a grate cooler; the system comprises an oil sludge pretreatment system, an oil sludge ceramsite granulation system, a rotary indirect dryer, a belt dryer, a kiln tail and a kiln, wherein the oil sludge pretreatment system is used for pretreating the floor sludge entering a factory into fine particles less than or equal to 5mm, the oil sludge ceramsite granulation system is used for mixing and granulating all the pretreated floor sludge, pyrolysis slag, fly ash and bentonite powder, a material outlet of the oil sludge ceramsite granulation system is connected with a material inlet of the rotary indirect dryer, a material outlet of the rotary indirect dryer is connected with a material inlet of the belt dryer, and a material outlet of the belt dryer is connected with the kiln tail of a ceramsite rotary kiln; the inside of the kiln tail of the haydite rotary kiln is provided with a high-temperature SNCR denitration device, a flue gas outlet of the kiln tail of the haydite rotary kiln is connected with a gas inlet of a first dust remover, a gas outlet of the first dust remover is connected with a gas inlet of a heat conducting oil heat exchanger, a gas outlet of the heat conducting oil heat exchanger is connected with a flue gas treatment system, a heat conducting oil outlet of the heat conducting oil heat exchanger is connected with a drying medium inlet of the rotary indirect dryer, and a drying medium outlet of the rotary indirect dryer is connected with a heat conducting oil inlet of the heat conducting oil heat exchanger; The tertiary air outlet of the grate cooler is connected with the gas inlet of the second dust remover, and the gas outlet of the second dust remover is connected with the drying medium inlet of the belt dryer; The drying waste gas outlet of the rotary indirect dryer is connected with the gas inlet of the third dust remover, the gas outlet of the third dust remover is connected with the gas inlet of the condensing system, the gas outlet of the condensing system is connected with the gas inlet of the high-temperature section of the grate cooler, the condensed water outlet of the condensing system is connected with the water treatment system, and the outlet of the water treatment system is connected with the inlet of the sludge ceramsite granulating system; The first drying waste gas outlet of the belt dryer is connected with the gas inlet of the fourth dust remover, the gas outlet of the fourth dust remover is connected with the gas inlet of the second condensing system, the gas outlet of the second condensing system is respectively connected with the gas inlet of the high-temperature section and the medium-low temperature Duan Qiti inlet of the grate cooler, the condensed water outlet of the second condensing system is connected with the water treatment system, the second drying waste gas outlet of the belt dryer is connected with the gas inlet of the hot blast stove, and the gas outlet of the hot blast stove is connected with the gas inlet of the belt dryer.
13. The production system for preparing high-performance lightweight aggregate by using floor sludge and pyrolysis slag according to claim 12, wherein the flue gas treatment system comprises a quenching tower, a dry deacidification tower, a bag-type dust remover and a two-stage wet deacidification tower, wherein a gas outlet of the heat transfer oil heat exchanger is connected with an inlet of the quenching tower, a gas outlet of the quenching tower is connected with a gas inlet of the dry deacidification tower, a gas outlet of the dry deacidification tower is connected with a gas inlet of the bag-type dust remover, a gas outlet of the bag-type dust remover is connected with a gas inlet of the two-stage wet deacidification tower, and a gas outlet of the two-stage wet deacidification tower is connected with a gas inlet of a chimney.
14. The production system for preparing high-performance lightweight aggregate by using the floor sludge and the pyrolysis slag as claimed in claim 12, further comprising a natural gas hot blast stove, wherein the natural gas hot blast stove is connected with a drying medium inlet of the belt dryer.

Description

Production process and system for preparing high-performance lightweight aggregate by using floor sludge and pyrolysis slag Technical Field The invention relates to the technical field of oil sludge ceramsite production, in particular to a production process and a system for preparing high-performance lightweight aggregate by using floor oil sludge and pyrolysis residues. Background The oil sludge is produced by the fact that fine particles in a petroleum reservoir and produced liquid of different petroleum are infiltrated into a ground system together in the processes of crude oil exploitation, transportation, refining and storage or petroleum accidents, so that a large amount of dangerous solid wastes such as oil sludge, oil sand and the like are produced. The organic pollutants such as microorganisms, heavy metals, inorganic salts, benzene series, phenols, petroleum hydrocarbon and the like in the oil-containing sludge not only pollute the surrounding soil and water, but also emit a certain amount of malodorous gas. According to different oil sludge generation ways, the method can be roughly divided into three types of (1) floor oil sludge generated in the crude oil extraction process, (2) tank bottom oil sludge generated in the crude oil gathering and transportation process and (3) oil sludge generated in the oil-containing sewage treatment process of an oil refinery. The total amount of newly increased sludge is about 600 ten thousand tons each year in the country, wherein the oil field sludge and the oil refinery sludge are 300 ten thousand tons each, and in addition, a large amount of stored sludge formed by historical account-lack is also present. At present, domestic sludge treatment technology is various, but the problems of small technical application range, high treatment cost and the like generally exist, so that a considerable proportion of newly increased sludge per year is not effectively treated, and the phenomena of illegal landfill, non-standard discharge and the like are relatively common. The untreated direct discharge of the oil sludge not only causes resource waste, but also can have serious influence on land, human health, surface vegetation, surface and underground water and the like. Therefore, how to dispose of the sludge becomes a technical bottleneck that is urgently needed to break through. The pyrolysis slag is a dangerous waste which is produced by the oil sludge pyrolysis process and takes inorganic matters as main components. The pyrolysis technology of oil sludge is characterized by that under the condition of oxygen-free and high-temp., the organic matter and oil in the oil-containing sludge can be undergone the processes of pyrolysis and thermal shrinkage, under the action of catalyst the distillation and thermal decomposition can be integrated into one body, and the sludge can be converted into solid, liquid and gas-containing three-phase material. The oil and the petroleum hydrocarbon can be sold as products and obtain economic benefits, but the pyrolysis slag is also dangerous waste, and the landfill of the pyrolysis slag is forbidden by related departments of the country, so that the pyrolysis slag has no effective utilization way at present and needs to be solved. Fly ash is a byproduct of finely ground coal powder in a coal-fired power plant after being combusted in a boiler, the fly ash is generally gray brown, is generally acidic, has a specific surface area of 250-500 m 2/kg, has a size of hundreds of micrometers to several micrometers, is generally spherical particles, has main chemical components of SiO 2、Al2O3 and Fe 2O3, and sometimes also contains higher CaO. Fly ash is a typical heterogeneous material containing unburned carbon, unchanged mineral quartz, and the like. The annual output of the fly ash in China is increased year by year, the accumulated stock quantity is also continuously increased year by year, the differences of the output, stock quantity and comprehensive utilization condition of the fly ash are obvious due to the differences of the resource lean and rich, economical strength, basic construction scale and the like in different regions of the whole country, and particularly the output and stock quantity of the fly ash in regions such as Shanxi, inner Mongolia and Shaanxi are large, but the comprehensive utilization rate is low, and the problem of urgent need of seeking a proper utilization mode for recycling and high-value utilization is solved. In general, when solid waste and dangerous waste are utilized to prepare ceramic granules, in order to improve the yield of a rotary kiln, the granulated ceramic raw material balls need to be dried at 100-300 ℃ before being calcined, and then the ceramic raw material balls can enter the kiln for being calcined, and only one conventional rotary drying device is selected for drying. Aiming at the fact that a certain amount of inflammable and explosive volatile substances such as volatile VOC componen