Method and apparatus for co-processing municipal solid waste and zinc-containing solid waste in dry-process cement clinker production lines

Abstract

This invention belongs to the field of solid waste recycling technology and discloses a method for co-processing municipal solid waste and zinc-containing solid waste in a cement clinker production line. The method includes the following steps: cement raw meal enters a cyclone preheater I-1 and undergoes multi-stage preheating before entering a decomposition furnace, then a rotary kiln for clinker calcination, yielding high-temperature flue gas and cement clinker; municipal solid waste, zinc-containing solids, and auxiliary materials enter a pelletizer to form pellets, which then enter the rotary kiln to generate zinc-containing flue gas; the zinc-containing flue gas and high-temperature flue gas merge and enter the decomposition furnace, then enter a cyclone preheater I-2, where heat is recovered and then the secondary zinc oxide is recovered in the large chamber of a bag filter dust collector; tertiary air enters a cyclone preheater V to preheat the raw meal before entering the small chamber of a bag filter dust collector, and the exhaust gas is introduced into a chimney by a fan for emission. This invention solves the problem of ineffective utilization of zinc-containing solid waste and municipal solid waste, and can simultaneously produce secondary zinc oxide and zinc calcined sand without changing the existing cement clinker production line's cement clinker production.

Description

Technical Field

[0001] This invention belongs to the field of solid waste recycling technology, and relates to a method and apparatus for co-processing municipal solid waste and zinc-containing solid waste in a cement clinker production line. Background Technology

[0002] Traditional dry-process cement clinker production includes preheating and decomposition, clinker calcination, and clinker grinding. In this process, the material is separated into dust and flue gas by cyclone separators one through four before entering the decomposition furnace for high-temperature decomposition. Inside the furnace, the material is broken down into dust and flue gas, which then enters cyclone separator five for further separation. The flue gas separated by separator five passes through cyclone separators four through one for heat recovery before entering a dust collector, fan, and chimney for compliant emissions. The dust separated by separator five enters the kiln tail for high-temperature calcination to become cement clinker. With the impact of cement capacity reduction, many regions have mandated the elimination of clinker production capacity of 2500 t / d and below. Many cement clinker production lines will face the dilemma of capacity replacement, closure, or demolition, making transformation imperative.

[0003] Traditional methods of disposing of municipal solid waste, such as sanitary landfill and composting, have drawbacks including difficulties in site selection, low resource recovery rates, and secondary pollution. Waste-to-energy incineration faces challenges such as high investment costs and limited coverage. While co-processing municipal solid waste in cement kilns is widely used, this method typically involves incinerating the waste in a waste incinerator and then decomposing the high-temperature gases in a decomposition furnace to meet emission standards, releasing them along with the cement kiln exhaust. However, this approach neglects the recovery and utilization of valuable components from waste incineration, failing to truly achieve resource recovery from municipal solid waste.

[0004] The current method for treating zinc-containing solid waste is to mix it with fuels such as coal and produce zinc oxide in a rotary kiln. This method is costly and inefficient. In particular, low-content solid waste is not used and still causes environmental pollution problems.

[0005] Therefore, utilizing cement clinker production lines to co-process municipal solid waste and zinc-containing solid waste, thereby enabling the full recycling and utilization of these materials, is also an effective way to replace the capacity of small-capacity cement clinker production lines. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a method for co-processing municipal solid waste and zinc-containing solid waste in a dry-process cement clinker production line. This method solves the problem of the ineffective utilization of zinc-containing solid waste and municipal solid waste, and can simultaneously produce secondary zinc oxide and zinc calcined sand without altering the existing cement clinker production line's cement clinker production.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a method for co-processing municipal solid waste and zinc-containing solid waste in a dry-process cement clinker production line, comprising the following steps:

[0009] 1) Cement raw meal enters cyclone preheater I-1 from the upper solid phase inlet, and is preheated in sequence by cyclone preheater II, cyclone preheater III and cyclone preheater IV. After that, it enters the decomposition furnace for pre-decomposition from the bottom discharge pipeline of cyclone preheater IV. Then, it enters the rotary kiln for clinker calcination from the kiln tail flue gas collection chamber connected to the decomposition furnace, and high temperature flue gas and cement clinker are obtained. The cement clinker enters the grate cooler for cooling.

[0010] 2) Domestic waste, zinc-containing solid materials and auxiliary materials enter the pelletizing machine to form pellets. The pellets enter the rotary kiln through the kiln tail smoke collection chamber to generate zinc-containing flue gas through high-temperature combustion.

[0011] 3) Zinc-containing flue gas and high-temperature flue gas converge in the kiln tail flue gas collection chamber and enter the decomposition furnace. After the flue gas exits from the top flue gas outlet of the decomposition furnace, it enters the cyclone preheater I-2. After gas-solid separation, the flue gas at the top of the cyclone preheater I-2 enters the waste heat boiler to recover heat and then passes through the large chamber of the bag dust collector to recover secondary zinc oxide. The dust at the bottom of the small chamber of the bag dust collector enters the cyclone preheater I-1.

[0012] 4) The tertiary air from the grate cooler enters the cyclone preheater V through the upper gas phase inlet of the cyclone preheater V, and then passes through the cyclone preheater IV, cyclone preheater III, cyclone preheater II and cyclone preheater I-1 in sequence to preheat the raw material. After exiting the top exhaust outlet of the cyclone preheater I-1, part of the exhaust gas enters the bag filter chamber, and the other part enters the bottom gas inlet of the decomposition furnace. The exhaust gas in the bag filter chamber is treated by the flue gas treatment system and then introduced into the chimney by the fan for discharge.

[0013] The technical solution of this invention also includes step 5): stop the cement raw material feeding in step 1), close the bottom discharge pipeline of cyclone preheater IV to the feed valve of the decomposition furnace, and put the secondary zinc oxide obtained in step 3) into cyclone preheater I-1 through the sealing pump. After being heated in sequence through cyclone preheater II, cyclone preheater III, cyclone preheater IV and cyclone preheater V to volatilize the chlorine in the secondary zinc oxide, zinc calcined sand is obtained. The zinc calcined sand is collected from the bottom discharge pipeline of cyclone preheater V and enters the zinc calcined sand storage silo.

[0014] The particle size of the municipal solid waste described in this invention is ≤1mm; the particle size of the zinc-containing solid material is ≤1mm, and the zinc content of the zinc-containing solid material is preferably above 8%. The municipal solid waste in this invention includes paper, plastics, fruit shells, and kitchen waste, all of which are hydrocarbons; the municipal solid waste also includes batteries, where the lead and zinc can be converted into zinc oxide. The zinc-containing solid material can be: flue gas ash from steel plant treatment (domestic annual production exceeds 10 million tons); leaching slag, zinc-cobalt slag, and zinc-copper slag from zinc smelting; water-quenched slag from lead smelting; zinc-containing dust from copper smelting; zinc oxide ore; slag from zinc chemical processing and gold smelting dust; and slag from recycled copper waste, etc.; but it is not limited to these.

[0015] The auxiliary materials mentioned in the technical solution of this invention include tire residue and furfural residue, and the particle size of tire residue and furfural residue is ≤1mm.

[0016] In step 2) of the technical solution of the present invention, the particle size of the pellets is 2.5~4cm.

[0017] Secondly, the present invention provides an apparatus for co-processing municipal solid waste and zinc-containing solid waste in a dry-process cement clinker production line, comprising:

[0018] Cyclone preheaters I-1, I-2, II, III, IV, and V are connected in sequence. The cement raw material feeding pipeline is connected to the upper solid phase inlet of cyclone preheater I-1, the bottom discharge pipeline of cyclone preheater IV is connected to the solid phase inlet of the decomposition furnace, the bottom discharge pipeline of cyclone preheater V is connected to the decomposition furnace, and the pellet conveying pipeline is connected to the kiln tail smoke collection chamber.

[0019] The decomposition furnace is used to pre-decompose the preheated cement raw materials. Its bottom is connected to the kiln tail smoke collection chamber, its top flue gas outlet is connected to the upper flue gas inlet of the cyclone preheater I-2, and its lower gas inlet is connected to the top exhaust gas outlet of the cyclone preheater I-1.

[0020] The rotary kiln is used for burning pellets and calcining cement clinker, and is connected to the smoke collection chamber at the kiln tail.

[0021] The grate cooler is connected to the kiln head of the rotary kiln. The tertiary air outlet pipeline of the grate cooler is connected to the upper gas phase inlet of the cyclone preheater V, which provides heat to the cyclone preheater V, cyclone preheater IV, cyclone preheater III, cyclone preheater II and cyclone preheater I-1 in sequence.

[0022] The waste heat boiler is connected to the flue gas outlet at the top of the cyclone preheater I-2 to recover heat from the flue gas.

[0023] The bag filter has a large chamber connected to the gas outlet of the waste heat boiler to collect secondary zinc oxide in the flue gas after heat recovery, and a small chamber connected to the dust inlet of the cyclone preheater I-1 to recover lost raw materials.

[0024] Pelletizing machines are used to pelletize household waste, zinc-containing solids, and auxiliary materials.

[0025] The device in the technical solution of the present invention further includes:

[0026] A sealing pump is used to pump the collected zinc oxide into the cyclone preheater I-1;

[0027] The bottom discharge pipeline of the cyclone preheater V is connected to the zinc roasted sand extraction pipeline.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] In this invention, the cement raw meal is preheated and then enters the decomposition furnace through the bottom discharge pipeline of cyclone preheater IV, while the pellets enter the rotary kiln through the kiln tail smoke collection chamber through the bottom discharge pipeline of cyclone preheater V. The feeding of raw meal and pellets do not affect each other. The CO flue gas generated when municipal solid waste is incompletely burned can be used as a reducing agent to reduce zinc in municipal solid waste and zinc-containing solid waste, iron in cement, etc., into elemental substances, so that they can reach the boiling point and volatilize at high temperature. The higher the temperature of the rotary kiln, the higher the vapor pressure, the more zinc-containing solid waste, and the more zinc-containing flue gas is obtained. The unvolatilized solid material is calcined in the high-temperature environment of the rotary kiln to obtain cement clinker. This realizes the large-scale recycling of municipal solid waste and zinc-containing solid waste, solves the problem of ineffective utilization of zinc-containing solid waste and municipal solid waste, and can simultaneously produce secondary zinc oxide without changing the original cement clinker production line.

[0030] This invention makes reasonable use of both the original one-in-one and one-out-of-line cyclone preheaters I. Cement raw materials are fed into cyclone preheater I-1, and tertiary air enters cyclone preheater V to provide heat for the preheating of raw materials in cyclone preheaters IV, III, II, and I-1. Zinc-containing flue gas and high-temperature flue gas enter cyclone preheater I-2 after exiting the top flue gas outlet of the decomposition furnace. After heat recovery by the waste heat boiler, the gas is then recovered in the large chamber of the bag filter to obtain secondary zinc oxide. Dust from the bottom of the small chamber of the bag filter enters cyclone preheater I-1 to recover lost raw materials. In addition, part of the exhaust gas from the top outlet of cyclone preheater I-1 enters the small chamber of the bag filter, and the other part enters the bottom gas inlet of the decomposition furnace to provide combustion gas for pulverized coal combustion in the decomposition furnace.

[0031] After stopping the feeding of cement raw materials, the collected zinc oxide is fed into cyclone preheater I-1 via sealing pump 14. The heat of the tertiary air is still used to heat the zinc oxide through cyclone preheater I-1, cyclone preheater II, cyclone preheater III, cyclone preheater IV and cyclone preheater V to fully volatilize the chlorine in the zinc oxide and obtain the product zinc calcined sand. Attached Figure Description

[0032] Figure 1 This is one of the schematic diagrams of the device for co-processing municipal solid waste and zinc-containing solid waste in a dry-process cement clinker production line according to the present invention.

[0033] Figure 2 This is the second schematic diagram of the device for co-processing municipal solid waste and zinc-containing solid waste in the dry process cement clinker production line of the present invention.

[0034] The following labels are used in the attached diagram: 1-1 Cyclone preheater I-1, 1-2 Cyclone preheater I-2, 2 Cyclone preheater II, 3 Cyclone preheater III, 4 Cyclone preheater IV, 5 Cyclone preheater V, 6 Decomposition furnace, 7 Rotary kiln, 8 Grate cooler, 9 Cement raw material feeding pipeline, 10 Zinc calcined sand extraction pipeline, 11 Zinc calcined sand storage silo, 12 Waste heat boiler, 13 Bag filter, 14 Sealing pump, 15 Pellet conveying pipeline, 16 Pelletizer, 17 Makeup air pipeline. Detailed Implementation

[0035] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the test methods in the following embodiments are conventional methods.

[0036] Example 1

[0037] This embodiment describes a device for co-processing municipal solid waste and zinc-containing solid waste in a dry-process cement clinker production line, such as... Figure 1 As shown, it includes: cyclone preheater I-1 1-1, cyclone preheater I-2 1-2, cyclone preheater II 2, cyclone preheater III 3, cyclone preheater IV 4 and cyclone preheater V 5, decomposition furnace 6, rotary kiln 7, grate cooler 8, waste heat boiler 12, bag filter dust collector 13, and pelletizer 16.

[0038] The gas phase outlet and inlet, solid phase inlet and outlet of cyclone preheaters I-1 1-1, I-2 1-2, II 2, III 3, IV 4 and V 5 are connected in sequence. The cement raw material feeding pipeline 9 is connected to the upper solid phase inlet of cyclone preheater I-1 1-1. The bottom discharge pipeline of cyclone preheater IV 4 is connected to the solid phase inlet of decomposition furnace 6. The bottom discharge pipeline of cyclone preheater V is connected to the decomposition furnace. The pellet conveying pipeline 15 is connected to the kiln tail smoke collection chamber.

[0039] The decomposition furnace 6 is used to pre-decompose the preheated cement raw materials. Its bottom is connected to the kiln tail smoke collection chamber, its top flue gas outlet is connected to the upper flue gas inlet of the cyclone preheater I-2 1-2, and its lower gas inlet is connected to the top exhaust gas outlet of the cyclone preheater I-1 1-1.

[0040] Rotary kiln 7 is used for pellet combustion and cement clinker firing, and is connected to the kiln tail smoke collection chamber.

[0041] The grate cooler 8 is connected to the kiln head of the rotary kiln 7. The tertiary air outlet pipeline of the grate cooler 8 is connected to the upper gas phase inlet of the cyclone preheater V5, and provides heat to the cyclone preheaters V5, IV4, III3, II2 and I-11-1 in sequence.

[0042] Waste heat boiler 12 is connected to the top flue gas outlet of cyclone preheater I-2 1-2 and is used to recover heat from the flue gas.

[0043] The bag filter 13 has a large chamber connected to the gas outlet of the waste heat boiler 12 for collecting secondary zinc oxide in the flue gas after heat recovery. The small chamber of the bag filter 13 is connected to the dust inlet of the cyclone preheater I-1 1-1 for recovering lost raw materials.

[0044] Pelletizer 16 is used to pelletize household waste, zinc-containing solids, and auxiliary materials.

[0045] It should be noted that the cyclone preheaters I-V, decomposition furnace 6, rotary kiln 7, baghouse dust collector 13, grate cooler 8, and other equipment involved in the above-mentioned device are all conventional devices in existing cement clinker production lines, and their structures will not be described in detail in this embodiment. The baghouse dust collector 13 is divided into a large chamber and a small chamber by a steel plate. The zinc-containing flue gas that has recovered its heat enters the large chamber, while the zinc-free flue gas exiting from the top of the cyclone preheater I-1 enters the small chamber. The area of ​​the large chamber and the small chamber can be calculated by those skilled in the art based on the amount of zinc-containing and zinc-free flue gas.

[0046] Taking a cement clinker production line with a rotary kiln capacity of 2500 t / d as an example, this embodiment describes a method for co-processing municipal solid waste and zinc-containing solid waste in a dry-process cement clinker production line based on the above-mentioned device, specifically including the following steps:

[0047] 1) Cement raw meal enters cyclone preheater I-1 1- from the upper solid phase inlet of cyclone preheater I-1 1-1, and is preheated in sequence by cyclone preheater II 2, cyclone preheater III 3 and cyclone preheater IV 4. After being preheated, it enters decomposition furnace 6 from the bottom discharge pipeline of cyclone preheater IV 4 for pre-decomposition. Then, it enters rotary kiln 7 (1150~1500 ℃) from the kiln tail flue gas collection chamber connected to decomposition furnace 6 for clinker calcination, resulting in high temperature flue gas and cement clinker. The cement clinker enters grate cooler 8 for cooling.

[0048] 2) Domestic waste, zinc-containing solid materials and auxiliary materials enter the pelletizer 16 to form pellets with a particle size of 2.5~4 cm. The pellets enter the rotary kiln 7 through the pellet conveying pipeline 15 and the kiln tail smoke collection chamber for high-temperature combustion to generate zinc-containing flue gas.

[0049] 3) Zinc-containing flue gas and high-temperature flue gas converge in the kiln tail flue gas collection chamber and enter the decomposition furnace 6. After the flue gas exits from the top flue gas outlet of the decomposition furnace 6, it enters the cyclone preheater I-2 1-2. After gas-solid separation, the flue gas at the top of the cyclone preheater I-2 1-2 enters the waste heat boiler 12 to recover heat and then passes through the large chamber of the bag dust collector 13 to recover secondary zinc oxide. The dust at the bottom of the small chamber of the bag dust collector enters the cyclone preheater I-1 1-1.

[0050] 4) The tertiary air (800~1000 ℃) from the grate cooler 8 enters the cyclone preheater V5 through the upper gas phase inlet. After preheating the raw material by passing through cyclone preheaters IV 4, III 3, II 2 and I-1 in sequence, the exhaust gas exits from the top exhaust outlet of cyclone preheater I-1. Part of the exhaust gas passes through the classifier (not shown in the figure) after the raw material grinding and then enters the bag filter 13 chamber. The other part enters the bottom gas inlet of the decomposition furnace 6. The exhaust gas in the bag filter 13 chamber is treated by the flue gas treatment system and then introduced into the chimney by the fan for discharge.

[0051] It is worth noting that those skilled in the art can adjust the addition ratio of cement raw meal and pellets according to the processing capacity of rotary kiln 7. To ensure sufficient heat in the system, if the processing capacity of rotary kiln 7 is 2500 t / d, the general ratio of cement raw meal to pellets is 3000 t: 450~500 t. Furthermore, the flue gas treatment system of this invention is an SCR system used for denitrification treatment of flue gas. SCR systems are conventional equipment in flue gas treatment, and their structure will not be described in detail in this embodiment.

[0052] In this invention, the cement raw meal is preheated and then enters the decomposition furnace 6 through the bottom discharge pipeline of the cyclone preheater IV 4, while the pellets enter the rotary kiln 7 through the kiln tail smoke collection chamber via the pellet conveying pipeline 15. The feeding of raw meal and pellets do not affect each other. The CO flue gas generated when municipal solid waste is incompletely burned can be used as a reducing agent to reduce zinc in municipal solid waste and zinc-containing solid waste, iron in cement, etc., into elemental substances, so that zinc can reach its boiling point and volatilize at high temperature. The higher the temperature of the rotary kiln 7, the higher the steam pressure, the more zinc-containing solid waste, and the more zinc-containing flue gas is obtained. The unvolatile solid materials (iron, silicon, calcium, aluminum) and calcium and some silicon and aluminum in the raw meal are calcined in the high temperature environment of the rotary kiln 7 to obtain cement clinker. This realizes the large-scale recycling of municipal solid waste and zinc-containing solid waste, solves the problem of ineffective utilization of zinc-containing solid waste and municipal solid waste, and can simultaneously produce secondary zinc oxide without changing the original cement clinker production line.

[0053] In existing cement clinker production lines, raw cement meal is fed from cyclone preheater I-1 1-1. Tertiary air from grate cooler 8 enters decomposition furnace 6. High-temperature flue gas generated by rotary kiln 7 exits from the top of decomposition furnace 6 and enters cyclone preheater V5. The temperature of the high-temperature flue gas is used to provide heat for the preheating of raw meal in cyclone preheater V5, cyclone preheater IV 4, cyclone preheater III 3, cyclone preheater II 2, and cyclone preheater I-1 1-1. This invention makes reasonable use of both the original one-in-one and one-out-of-line cyclone preheaters I. Cement raw materials are fed into cyclone preheater I-1 1-1, and tertiary air enters cyclone preheater V5 to provide heat for the preheating of raw materials in cyclone preheaters IV 4, III 3, II 2, and I-1 1-1. Zinc-containing flue gas and high-temperature flue gas exit from the top flue gas outlet of the decomposition furnace 6 and enter cyclone preheater I-2 1-2. After heat recovery by the waste heat boiler 12, the gas is then recovered in the large chamber of the bag filter 13 to obtain the product secondary zinc oxide. Dust from the bottom of the small chamber of the bag filter enters cyclone preheater I-1. 1-1, recover the lost raw materials; in addition, after exiting the top exhaust outlet of the cyclone preheater I-11-1, part of it enters the small chamber of the bag filter 13, and the other part enters the bottom gas inlet of the decomposition furnace 6, providing combustion gas for the pulverized coal combustion in the decomposition furnace.

[0054] Example 2

[0055] This embodiment describes a device for co-processing municipal solid waste and zinc-containing solid waste in a dry-process cement clinker production line, such as... Figure 2 As shown, it includes: cyclone preheater I-1 1-1, cyclone preheater I-2 1-2, cyclone preheater III3, cyclone preheater IV4 and cyclone preheater V5, decomposition furnace 6, rotary kiln 7, grate cooler 8, waste heat boiler 12, bag filter dust collector 13, pelletizer 16, and sealing pump 14.

[0056] The gas phase outlet and inlet, solid phase inlet and outlet of cyclone preheaters I-1 1-1, I-2 1-2, II 2, III 3, IV 4 and V 5 are connected in sequence. The cement raw material feeding pipeline 9 is connected to the upper solid phase inlet of cyclone preheater I-1 1-1. The bottom discharge pipeline of cyclone preheater IV 4 is connected to the solid phase inlet of decomposition furnace 6. The bottom discharge pipeline of cyclone preheater V 5 is connected to zinc calcined sand extraction pipeline 10 and decomposition furnace. Zinc calcined sand extraction pipeline 10 is connected to zinc calcined sand storage silo 11. The pellet conveying pipeline 15 is connected to the kiln tail smoke collection chamber.

[0057] The decomposition furnace 6 is used to pre-decompose the preheated cement raw materials. Its bottom is connected to the kiln tail smoke collection chamber, its top flue gas outlet is connected to the upper flue gas inlet of the cyclone preheater I-2 1-2, and its lower gas inlet is connected to the top exhaust gas outlet of the cyclone preheater I-1 1-1.

[0058] Rotary kiln 7 is used for pellet combustion and cement clinker firing, and is connected to the kiln tail smoke collection chamber.

[0059] The grate cooler 8 is connected to the kiln head of the rotary kiln 7. The tertiary air outlet pipeline of the grate cooler 8 is connected to the upper gas phase inlet of the cyclone preheater V5, and provides heat to the cyclone preheaters V5, IV4, III3, II2 and I-11-1 in sequence.

[0060] Waste heat boiler 12 is connected to the top flue gas outlet of cyclone preheater I-2 1-2 and is used to recover heat from the flue gas.

[0061] The bag filter 13 has a large chamber connected to the gas outlet of the waste heat boiler 12 for collecting secondary zinc oxide in the flue gas after heat recovery. The small chamber of the bag filter 13 is connected to the dust inlet of the cyclone preheater I-1 1-1 for recovering lost raw materials.

[0062] Pelletizer 16 is used to pelletize household waste, zinc-containing solids, and auxiliary materials.

[0063] The sealing pump 14 is used to pump the collected zinc oxide into the cyclone preheater I-1 1-1.

[0064] It should be noted that the cyclone preheaters I-V, decomposition furnace 6, rotary kiln 7, bag filter 13, grate cooler 8, and other equipment involved in the above-mentioned device are all conventional devices in existing cement clinker production lines, and their structures will not be described in detail in this embodiment. In order not to affect the normal production of the original cement clinker production line, the cement clinker production line is used to co-process domestic waste and zinc-containing solid waste. After stopping the cement raw meal feeding, the valve on the make-up air pipeline 17 is closed to stop the air supply to the decomposition furnace 6. The heat of the tertiary air is used to calcine the secondary zinc oxide in the cyclone preheaters I-1-V to obtain zinc calcined sand. A two-way valve can be installed on the bottom discharge pipeline of the cyclone preheater V5. One channel is used for feeding a small portion of the cement raw meal into the decomposition furnace 6, and the other channel is used to extract zinc calcined sand from the discharge pipeline. The two channels do not affect each other. Stopping the cement raw meal feeding operation allows for the temporary storage of collected zinc oxide in a silo. Once a certain quantity is reached, the sealing pump 14 is activated to process the zinc oxide and extract zinc calcined ore. Afterward, the cement raw meal feeding operation resumes to continue producing cement clinker and zinc oxide. To increase the yield of zinc oxide, the cement raw meal feed can be gradually reduced in the early stages of stopping the cement raw meal feeding, while the pellet feed can be gradually increased. This increases the production of zinc-containing flue gas, allowing for the collection of more zinc oxide and the further extraction of more zinc calcined ore. Alternatively, after stopping the cement raw meal feeding operation, the pellet feed rate can be increased to further increase the production of zinc-containing flue gas. Compared to the normal daily zinc oxide production of 80 t / day with cement raw meal feeding, increasing the pellet feed rate by 5-6 times can yield 200 t / day of zinc oxide. The tertiary air volume is generally around 40,000 m³. 3 An air volume of over / h can meet the heat requirements for heating zinc oxide, enabling normal production of zinc calcined sand.

[0065] Taking a cement clinker production line with a rotary kiln capacity of 2500 t / d as an example, this embodiment describes a method for co-processing municipal solid waste and zinc-containing solid waste in a dry-process cement clinker production line based on the above-mentioned device, specifically including the following steps:

[0066] 1) Cement raw meal enters cyclone preheater I-1 1- from the upper solid phase inlet of cyclone preheater I-1 1-1, and is preheated in sequence by cyclone preheater II 2, cyclone preheater III 3 and cyclone preheater IV 4. After being preheated, it enters decomposition furnace 6 from the bottom discharge pipeline of cyclone preheater IV 4 for pre-decomposition. Then, it enters rotary kiln 7 (1150~1500 ℃) from the kiln tail flue gas collection chamber connected to decomposition furnace 6 for clinker calcination, resulting in high temperature flue gas and cement clinker. The cement clinker enters grate cooler 8 for cooling.

[0067] 2) Domestic waste, zinc-containing solid materials and auxiliary materials enter the pelletizer 16 to form pellets with a particle size of 2.5~4 cm. The pellets enter the rotary kiln 7 through the pellet conveying pipeline 15 and the kiln tail smoke collection chamber for high-temperature combustion to generate zinc-containing flue gas.

[0068] 3) Zinc-containing flue gas and high-temperature flue gas converge in the kiln tail flue gas collection chamber and enter the decomposition furnace 6. After the flue gas exits from the top flue gas outlet of the decomposition furnace 6, it enters the cyclone preheater I-2 1-2. After gas-solid separation, the flue gas at the top of the cyclone preheater I-2 1-2 enters the waste heat boiler 12 to recover heat and then passes through the large chamber of the bag dust collector 13 to recover secondary zinc oxide. The dust at the bottom of the small chamber of the bag dust collector enters the cyclone preheater I-1 1-1.

[0069] 4) The tertiary air (800~1000℃) from the grate cooler 8 enters the cyclone preheater V5 through the upper gas phase inlet. After preheating the raw material through the cyclone preheater IV 4, cyclone preheater III 3, cyclone preheater II 2 and cyclone preheater I-1, part of the exhaust gas from the top exhaust outlet of cyclone preheater I-1 1-1 passes through the classifier after the raw material grinding and then enters the bag filter 13 chamber. The other part enters the bottom gas inlet of the decomposition furnace 6. The exhaust gas in the bag filter 13 chamber is treated by the flue gas treatment system and then introduced into the chimney by the fan for discharge.

[0070] 5) Stop feeding cement raw materials in step 1), close the bottom discharge pipeline of cyclone preheater IV 4 to the feed valve of decomposition furnace 6, and feed the secondary zinc oxide obtained in step 3) into cyclone preheater I-1 1-1 via sealing pump 14. After being heated by cyclone preheater II 2, cyclone preheater III 3, cyclone preheater IV 4 and cyclone preheater V 5 in sequence, the chlorine in the secondary zinc oxide will volatilize to obtain zinc calcined sand. The zinc calcined sand is collected from the bottom discharge pipeline of cyclone preheater V 5 and enters zinc calcined sand storage silo 11.

[0071] After stopping the feeding of cement raw materials, the collected zinc oxide is fed into cyclone preheater I-1 1-1 via sealing pump 14. The heat of the tertiary air is still used to heat the zinc oxide through cyclone preheater I-1 1-1, cyclone preheater II 2, cyclone preheater III 3, cyclone preheater IV 4 and cyclone preheater V 5 to fully volatilize the chlorine in the zinc oxide and obtain the product zinc calcined sand.

[0072] This invention utilizes a cement clinker production line to co-process municipal solid waste, zinc-containing solid waste, and auxiliary materials (tire residue and furfural residue). Raw material costs are low and sources are wide-ranging. The processing fee for municipal solid waste is only 65-180 yuan / ton, and for zinc-containing solid waste, it is 500 yuan / ton. Municipal solid waste can be processed without sorting, and the product profit is high, with zinc calcined ore valued at 7500 yuan / ton. This invention solves the problem of ineffective utilization of zinc-containing solid waste and municipal solid waste. Furthermore, it allows the use of existing equipment to simultaneously produce secondary zinc oxide and zinc calcined ore without altering the existing cement clinker production line, thereby replacing cement clinker production capacity and helping small-capacity cement production enterprises transform and upgrade.

[0073] The embodiments described above are merely preferred embodiments of the present invention and are only used to explain the present invention. They are not intended to limit the scope of the present invention. For those skilled in the art, other implementation methods can be easily made by substitution or modification based on the technical content disclosed in this specification. Therefore, all changes and improvements made on the principle of the present invention should be included within the scope of the patent application of the present invention.

Claims

1. A method for co-processing domestic waste and zinc-containing solid waste in a dry cement clinker production line, characterized in that, The method comprises the following steps: 1) cement raw material enters the cyclone preheater I-1 from the upper solid phase inlet of the cyclone preheater I-1, is preheated in the cyclone preheater II, the cyclone preheater III and the cyclone preheater IV in sequence, and then enters the pre-decomposition furnace from the bottom discharge pipeline of the cyclone preheater IV to be pre-decomposed, and then enters the rotary kiln from the kiln tail smoke collecting chamber connected with the pre-decomposition furnace; 2) domestic waste, zinc-containing solid material and auxiliary material enter the balling machine to form pellets, the pellets enter the rotary kiln through the kiln tail smoke collecting chamber, and are fired together with the cement raw material to obtain high-temperature flue gas, zinc-containing flue gas and cement clinker, wherein the domestic waste comprises paper, plastic, kitchen waste or batteries, the zinc-containing solid waste comprises flue dust generated in the treatment of flue gas of a steel plant, leaching residue of zinc smelting, zinc-cobalt residue, zinc-copper residue, water-quenched residue of lead smelting, zinc-containing dust of copper smelting, zinc oxide ore or dross generated in the recovery of metal waste copper, the particle size of the domestic waste is ≤1 mm, the particle size of the zinc-containing solid material is ≤1 mm, the particle size of the pellets in step 2) is 2.5-4 cm, the auxiliary material comprises tire residue and furfural residue, and the particle size of the tire residue and the furfural residue is ≤1 mm; 3) the zinc-containing flue gas and the high-temperature flue gas enter the pre-decomposition furnace through the kiln tail smoke collecting chamber, the flue gas enters the cyclone preheater I-2 from the top flue gas outlet of the pre-decomposition furnace, the top flue gas of the cyclone preheater I-2 enters the waste heat boiler to recover heat, and then the flue gas enters the bag-type dust collector to obtain secondary zinc oxide, and the dust at the bottom of the bag-type dust collector enters the cyclone preheater I-1; 4) the tertiary air from the grate cooler enters the cyclone preheater V from the upper gas phase inlet of the cyclone preheater V, is preheated by the cyclone preheater IV, the cyclone preheater III, the cyclone preheater II and the cyclone preheater I-1 in sequence, and then part of the flue gas from the top waste gas outlet of the cyclone preheater I-1 enters the small chamber of the bag-type dust collector, and the other part of the flue gas enters the bottom gas inlet of the pre-decomposition furnace, the waste gas in the small chamber of the bag-type dust collector is treated by a flue gas treatment system and then introduced into a chimney through a fan for emission.

2. The method of claim 1, wherein, The method further comprises the following step 5): the cement raw material feeding in step 1) is stopped, the feeding valve from the bottom discharge pipeline of the cyclone preheater IV to the pre-decomposition furnace is closed, the secondary zinc oxide obtained in step 3) enters the cyclone preheater I-1 through a sealing pump, and the secondary zinc oxide is heated in the cyclone preheater II, the cyclone preheater III, the cyclone preheater IV and the cyclone preheater V in sequence to volatilize chlorine in the secondary zinc oxide to obtain zinc calcine, and the zinc calcine is collected from the bottom discharge pipeline of the cyclone preheater V and then enters a zinc calcine storage bin.

3. The method of claim 1, wherein, The particle size of the domestic waste is ≤1 mm, and the particle size of the zinc-containing solid material is ≤1 mm.

4. The method of claim 1, wherein, The auxiliary material comprises tire residue and furfural residue, and the particle size of the tire residue and the furfural residue is ≤1 mm.

5. The method of claim 1, wherein, The particle size of the pellets in step 2) is 2.5-4 cm.

6. An apparatus for implementing the method of co-processing domestic waste and zinc-containing solid waste in a dry cement clinker production line according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: the cyclone preheater I-1, the cyclone preheater I-2, the cyclone preheater II, the cyclone preheater III, the cyclone preheater IV and the cyclone preheater V are sequentially connected, the cement raw material feeding pipeline is communicated with the upper solid phase inlet of the cyclone preheater I-1, the bottom discharge pipeline of the cyclone preheater IV is communicated with the solid phase inlet of the pre-decomposition furnace, the bottom discharge pipeline of the cyclone preheater V is communicated with the pre-decomposition furnace, and the pellet conveying pipeline is communicated with the kiln tail smoke collecting chamber; A precalciner for pre-decomposing the preheated cement raw meal, the bottom of which is communicated with the kiln tail collecting chamber, the top flue gas outlet of which is communicated with the upper flue gas inlet of the cyclone preheater I-2, and the lower gas inlet is communicated with the top exhaust gas outlet of the cyclone preheater I-1; A rotary kiln for burning and sintering the pellets and cement clinker, which is communicated with the kiln tail collecting chamber; A grate cooler, which is communicated with the kiln head of the rotary kiln, the tertiary air outlet pipeline of the grate cooler is connected with the upper gas phase inlet of the cyclone preheater V, which in turn provides heat for the cyclone preheater V, the cyclone preheater IV, the cyclone preheater III, the cyclone preheater II and the cyclone preheater I-1; A waste heat boiler, which is communicated with the top flue gas outlet of the cyclone preheater I-2, for recovering heat from the flue gas; A bag-type dust collector, the large chamber of which is communicated with the gas outlet of the waste heat boiler for collecting the secondary zinc oxide in the flue gas after heat recovery, and the small chamber of which is communicated with the dust inlet of the cyclone preheater I-1 for recovering the lost raw meal; A pelletizer for pelletizing the household garbage, the zinc-containing solid material and the auxiliary material.

7. The apparatus of claim 6, wherein, Further comprising: A sealing pump for pumping the collected secondary zinc oxide into the cyclone preheater I-1; The bottom discharge pipeline of the cyclone preheater V is communicated with the zinc calcine extraction pipeline.

Images