Device for preparing lime milk from solid waste

Abstract

The utility model provides a device for preparing lime milk by using solid waste, which comprises a ball mill, an ash melting machine, a lime milk sieve, a waste sand hopper, a waste sand conveyor, a carbide slag conveyor, a waste sand liquid barrel and a lime milk barrel, and can be used for preparing lime milk by using solid waste, namely waste sand, generated by alkali preparation by an ammonia-alkali method and solid waste, namely carbide slag, in the chlor-alkali industry. According to the device, recycling of waste sand and utilization of carbide slag are organically combined, particularly, the carbide slag is utilized on a large scale, a new process conversion from'production by ash 'to'production by gas' in sodium carbonate production in the ammonia alkali industry is completed, a new balanced process mode of preparing sodium carbonate from ash for ammonia analysis and carbon dioxide is balanced, comprehensive utilization of the two solid wastes is realized, and the production cost is reduced. The method not only reduces the use amount of limestone and coke, achieves the effects of energy conservation and coal reduction, but also greatly reduces the emission of carbon dioxide, and has a remarkable carbon reduction effect.

Description

Technical Field

[0001] The utility model belongs to the technical field of comprehensive utilization of solid wastes, and specifically relates to a device for preparing evaporated ammonia ash emulsion by utilizing carbide slag and waste sand. Technical Background

[0002] In the process of making alkali by ammonia-soda process, lime milk (mainly calcium hydroxide) is generally used to extract NH3 from NH4Cl solution. A large amount of digested lime milk is digested by burning and calcining limestone and white coal. Therefore, the production of ammonia-soda process generally adopts the "production based on ash" mode, that is, the production is organized according to the amount of ash milk that meets the demand for ammonia extraction, which causes a large amount of kiln gas to be discharged, wasting resources.

[0003] At the same time, a large amount of waste sand is generated during the digestion of quicklime. About 80 kg of waste sand is required to be discharged for each ton of soda ash produced. This part of solid waste is generally transported to outside the factory by car for storage. The solid waste contains about 10% Ca(OH)2, which has not been fully utilized, resulting in a waste of resources. It not only occupies a large tract of land for storage, but also easily generates a large amount of dust during storage, affecting the surrounding environment and causing certain pollution to the air, groundwater and surface water.

[0004] Limestone and coke are one of the main raw materials for the production of soda ash. In recent years, the supply of raw material limestone has become more difficult. On the other hand, there are more than 120 large-scale enterprises in the chlor-alkali resin industry nationwide, and the annual solid waste calcium carbide slag generates more than 26 million tons. The main component of this solid waste is Ca(OH)2, which happens to be the main component of ammonia analyzed by ammonia-alkali enterprises.

[0005] In the early stage, the use of waste sand was studied - the method of recycling ash and waste residue (publication number CN1194236A). This method can make good use of the waste sand produced by the ammonia-soda process, but the amount of Ca(OH)2 recovered is small, and it cannot solve the essential defect of more gas and less ash in the lime production process of ammonia-soda. At the same time, the discharge of kiln gas causes waste of resources, and it is also necessary to deal with particulate matter, SO2, and NOx in the discharged kiln gas, which requires large investment and high operating costs. Utility Model Content

[0006] The utility model aims to provide a device for preparing ash milk by using solid waste, which can prepare ash milk for ammonia distillation by using solid waste in ammonia-alkali and chlor-alkali industries.

[0007] In order to achieve the above object, the technical solution of the utility model is:

[0008] A device for preparing ash milk using solid waste mainly comprises a ball mill, a ash dissolving machine and an ash milk screen, and its structural feature is that it also comprises a waste sand hopper, a vibrating feeder is arranged below the discharge port of the waste sand hopper, a waste sand conveyor is arranged below the vibrating feeder, a ball mill inlet is arranged below the end of the waste sand conveyor, a rear lower side of the ball mill outlet is connected to a waste sand liquid barrel through a first chute, a waste sand liquid barrel is connected to a waste sand liquid pump, a waste sand liquid pump is connected to the ash dissolving machine inlet through a pipeline, a carbide slag conveyor is arranged in front of the ash dissolving machine inlet, the ball mill inlet, the waste sand liquid barrel and the ash dissolving machine inlet are all connected to a seawater pipeline, the ash dissolving machine outlet is connected to the ash milk screen inlet through a second chute, the ash milk outlet of the ash milk screen is connected to the ash milk barrel through an ash milk pipeline, and a third chute is arranged at the lower part of the ash milk screen slag discharge port.

[0009] Furthermore, the waste sand conveyor is provided with a waste sand belt scale, and the seawater pipeline section connected to the ball mill inlet is provided with a first seawater self-regulating valve; the carbide slag conveyor is provided with a carbide slag belt scale, and the seawater pipeline section connected to the ash machine inlet is provided with a second seawater self-regulating valve; the waste sand liquid pump is provided with a waste sand liquid self-regulating valve on the pipeline connecting the ash machine.

[0010] Furthermore, a set of water pressure washing screen device is provided inside the ash machine, the main drive motor is started by a frequency converter, and an internal lifting plate is provided along the axial direction at the discharge end.

[0011] Furthermore, the waste sand liquid barrel and the ash milk barrel are both provided with electric stirring devices.

[0012] Furthermore, the waste fine sand outlet of the ash milk screen is provided with a waste fine sand conveyor, and the waste sand conveyor, carbide slag conveyor and waste fine sand conveyor are all provided with belt cleaners and passive hydraulic deviation adjusters.

[0013] Furthermore, a vibrator is provided on the side wall of the waste sand hopper, and a rod valve is provided at the hopper outlet.

[0014] After adopting such a device, the ball mill can recycle Ca(OH)2 in waste sand, and the ash mill can recycle Ca(OH)2 in carbide slag, which makes up for the defect of more gas and less ash in the lime production process of ammonia-soda, and can achieve "zero" emission of kiln gas in the production process of soda ash, thereby improving the utilization rate of limestone and coke, and the economic benefits of soda ash. At the same time, it turns the waste carbide slag in the chlor-alkali resin industry into a commodity, realizing the "turning waste into treasure", improving its economic benefits, and achieving significant energy-saving and carbon-reduction effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of a device for preparing ash milk using solid waste according to the utility model;

[0016] In the figure: 1. Waste sand conveyor; 2. Calcium carbide slag conveyor; 3. Waste sand belt scale; 4. Calcium carbide slag belt scale; 5. Seawater pipeline; 6. Ball mill; 7. First seawater self-regulating valve; 8. Waste sand liquid self-regulating valve; 9. First chute; 10. Waste sand liquid barrel; 11. Ash machine; 12. Second chute; 13. Ash milk screen; 14. Ash milk pipeline; 15. Waste fine sand conveyor; 16. Ash milk barrel; 17. Second seawater self-regulating valve; 18. Waste sand liquid pump; 19. Waste sand hopper; 20. Vibrating feeder. DETAILED DESCRIPTION

[0017] The utility model is further described in detail below in conjunction with the accompanying drawings.

[0018] Reference Figure 1 A device for preparing ash milk using solid waste mainly includes a ball mill 6, a ash dissolving machine 11, an ash milk screen 13, and a waste sand hopper 19. A vibrating feeder 20 is provided below the discharge port of the waste sand hopper 19, a waste sand conveyor 1 is provided below the vibrating feeder 20, a waste sand conveyor 1 is provided on the waste sand conveyor 1, a waste sand belt scale 3 is provided on the waste sand conveyor 1, and the inlet of the ball mill 6 is provided below the end of the waste sand conveyor 1. The lower rear side of the outlet of the ball mill 6 is connected to the waste sand liquid barrel 10 through a first chute 9.

[0019] Reference Figure 1 The waste sand liquid barrel 10 is connected to a waste sand liquid pump 18, which is connected to the inlet of the ash dissolving machine 11 through a pipeline. A carbide slag conveyor 2 is arranged in front of the inlet of the ash dissolving machine 11, and a carbide slag belt scale 4 is arranged on the carbide slag conveyor 2. The inlet of the ball mill 6, the waste sand liquid barrel 10, and the inlet of the ash dissolving machine 11 are all connected to the seawater pipeline 5. The outlet of the ash dissolving machine 11 is connected to the inlet of the ash milk screen 13 through the second chute 12, and the ash milk outlet of the ash milk screen 13 is connected to the ash milk barrel 16 through the ash milk pipeline 14. A third chute (not shown in the figure) is arranged at the lower part of the slag discharge port of the ash milk screen 13; the waste sand liquid barrel 10 and the ash milk barrel 16 are both provided with electric stirring devices.

[0020] Reference Figure 1 , a first seawater self-regulating valve 7 is provided on the seawater pipeline 5 section connected to the inlet of the ball mill 6, and the waste sand belt scale 3 and the first seawater self-regulating valve 7 form a regulating loop, which automatically adjusts the incoming seawater according to the amount of waste sand entering the ball mill 6; a second seawater self-regulating valve 17 is provided on the seawater pipeline 5 section connected to the inlet of the ash machine 11, and the carbide slag belt scale 4 and the second seawater self-regulating valve 17 form a regulating loop, which automatically adjusts the incoming seawater according to the amount of carbide slag entering the ash machine 11; a waste sand liquid self-regulating valve 8 is provided on the pipeline connected to the waste sand liquid pump 18 and the ash machine 11, which automatically adjusts the incoming waste sand liquid according to the amount of carbide slag entering the ash machine 11. A set of water pressure washing screen mesh device is provided inside the ash machine 11, and the main drive motor is started by a frequency converter. An internal copying plate along the axial direction is provided at the discharge end, which is a conventional setting and will not be described in detail here.

[0021] Reference Figure 1 A waste fine sand conveyor 15 is provided at the waste fine sand outlet of the ash milk screen 13. The waste sand conveyor 1, the carbide slag conveyor 2 and the waste fine sand conveyor 15 are all provided with belt cleaners and passive hydraulic deviation adjusters. A vibrator is provided on the side wall of the waste sand hopper 19, and a rod valve is provided at the hopper outlet. These are conventional settings and are not described in detail here.

[0022] The working process of the utility model:

[0023] The scale of this embodiment is to process 320,000 tons of waste sand and 832,000 tons of carbide slag per year, and produce 3.6 million tons of ash milk per year.

[0024] The waste sand is pushed into two underground waste sand hoppers 19 (size 4000×2500×1800mm, silo wall vibrator power 0.55KW, 500×500 rod valve at the bottom) by the loader, and sent to the waste sand conveyor 1 (B=800mm, v=0.8m / s, β=11.48°, 60t / h, 11KW) through the vibrating feeder 20 (50t / h, power 2×4=8KW), and then measured by the waste sand belt scale 3 and enters the ball mill 6 (40t / h, discharge 0.075mm, φ2400×9000, motor 560KW, n=17.3r / min), where it is mixed with seawater for wet ball milling. The waste sand liquid (mass fraction 50%, ρ=1220kg / m 3) flows into the waste sand liquid barrel 10 (φ4800×3500mm, stirring motor 18.5KW, n=5.2r / min) through the first chute 9 by the position difference. After the slurry treatment, the waste sand liquid is sent to the ash machine 11 (φ3000×22791mm, processing capacity 2500t / d, inner drum lining and channel steel dustpan Q345C, inner and outer screens and screen cover 316L, main drive motor N=55kw, n=740r / min, slow drive motor N=4kw, n=1500r / min) through the pipeline through the waste sand liquid pump 18 (Q=150m³ / h, H=20m), and the calcium carbide slag is discharged from the bucket The wheel reclaimer feeds the ash into the carbide slag conveyor 2 (B=1000mm, v=1.0m / s, β=14.18°, 150t / h, 18.5KW), and then enters the ash dissolving machine 11 after being weighed by the carbide slag belt scale 4, and is mixed with seawater and waste sand liquid to prepare 120tt of ash emulsion solution. The ash emulsion enters the ash emulsion screen 13 (360m³ / h, sieve hole 3mm, 16.4r / min, motor 15KW) through the second chute 12, and the sieved ash emulsion enters the ash emulsion barrel 16 (φ4800×4000mm, stirring motor 18.5KW, n=5.2r / min), and is used for ammonia distillation after slurry adjustment. The waste fine sand separated from the tail of the ash emulsion screen returns to the ball mill for further grinding. This device organically combines the reuse of waste sand with the utilization of carbide slag, especially the large-scale utilization of carbide slag, completing the new process transformation from "production based on ash" to "production based on gas" in the soda ash production of the ammonia-soda industry, and balancing the new balanced process mode of producing soda ash from the ash used in the analysis of ammonia and the carbon dioxide, realizing the comprehensive utilization of the two major solid wastes, not only reducing the use of limestone and coke, achieving the effect of energy conservation and coal reduction, but also greatly reducing carbon dioxide emissions, with a significant carbon reduction effect.

Claims

1. A device for preparing ash milk using solid waste, mainly comprising a ball mill (6), an ash dissolving machine (11), and an ash milk screen (13), characterized in that: It also comprises a waste sand hopper (19), a vibrating feeder (20) being provided below the discharge port of the waste sand hopper (19), a waste sand conveyor (1) being provided below the vibrating feeder (20), an inlet of a ball mill (6) being provided below the end of the waste sand conveyor (1), a rear lower side of the outlet of the ball mill (6) being connected to a waste sand liquid barrel (10) through a first chute (9), the waste sand liquid barrel (10) being connected to a waste sand liquid pump (18), and the waste sand liquid pump (18) being connected to a chemical pump via a pipeline. An inlet of an ash machine (11); a carbide slag conveyor (2) is provided in front of the inlet of the ash machine (11); the inlet of the ball mill (6), the waste sand liquid barrel (10), and the inlet of the ash machine (11) are all connected to a seawater pipeline (5); the outlet of the ash machine (11) is connected to the inlet of an ash milk screen (13) via a second chute (12); the ash milk outlet of the ash milk screen (13) is connected to an ash milk barrel (16) via an ash milk pipeline (14); and a third chute is provided at the lower part of the slag discharge port of the ash milk screen (13).

2. The device for preparing ash milk using solid waste according to claim 1, characterized in that: The waste sand conveyor (1) is provided with a waste sand belt scale (3), and a first seawater self-regulating valve (7) is provided on a section of a seawater pipeline (5) connected to the inlet of the ball mill (6); the carbide slag conveyor (2) is provided with a carbide slag belt scale (4), and a second seawater self-regulating valve (17) is provided on a section of a seawater pipeline (5) connected to the inlet of the ash dissolving machine (11); and a waste sand liquid self-regulating valve (8) is provided on a pipeline connecting the waste sand liquid pump (18) and the ash dissolving machine (11).

3. The device for preparing ash milk using solid waste according to claim 1, characterized in that: The ash dissolving machine (11) is provided with a set of water pressure washing screen mesh device inside, the main transmission motor is started by a frequency converter, and the discharge end is provided with an internal lifting plate along the axial direction.

4. The device for preparing ash milk using solid waste according to claim 1, characterized in that: The waste sand liquid barrel (10) and the ash milk barrel (16) are both provided with electric stirring devices.

5. The device for preparing ash milk using solid waste according to claim 1, characterized in that: The waste fine sand outlet of the ash milk screen (13) is provided with a waste fine sand conveyor (15), and the waste sand conveyor (1), the calcium carbide slag conveyor (2), and the waste fine sand conveyor (15) are all provided with a belt cleaner and a passive hydraulic deviation adjuster.

6. The device for preparing ash milk using solid waste according to claim 1, characterized in that: The side wall of the waste sand hopper (19) is provided with a vibrator, and the hopper outlet is provided with a rod valve.

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