Process method for treating building gravel processing wastewater

Abstract

The invention discloses a construction gravel processing wastewater treatment process method. The process method comprises the following steps: 1, fine sand recovery and sewage conveying; 2, sewage treatment; 3, performing drying treatment on the slurry conveyor; and 4, recycling the wastewater. The process of the fine sand recovery device, the concentration device and the plate-and-frame filter press is adopted, stone powder, waste water and sludge generated in the production of the gravel processing system can be automatically recycled through the centralized control system, the stone powder is recycled through the fine sand recovery device, and the stone powder can be added into finished sand. The adjusting device is used for adjusting fineness modulus and stone powder content of finished sand; the sludge dried and recycled by the plate-and-frame filter press can be used for manufacturing hollow bricks after a certain amount of cement is added, and meanwhile, the sludge can also be used for projects such as ecological restoration and land reclamation, so that resource reutilization is realized; after wastewater treated by the wastewater treatment system becomes clear water, the clear water is pressurized by a clear water pump on the clear water tank and then is used for a water using unit, so that wastewater recycling of the building gravel processing system is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of sand and gravel processing wastewater treatment, and specifically relates to a process for treating construction sand and gravel processing wastewater. Background Art

[0002] With the continuous expansion of construction projects, the natural aggregate resources for construction are gradually decreasing. At present, most domestic projects or construction companies use artificial construction sand and gravel aggregates instead of natural sand and gravel aggregates. Construction sand and gravel aggregates are affected by the raw material source. Most of them will be mixed with some useless materials during the mining and blasting process. Most of the useless materials are soil, strongly weathered materials, and some recyclable stone powder, etc., which will affect the quality of the finished aggregate. The domestic construction sand and gravel system usually adopts the raw material crushing and pre-screening process to remove some useless materials smaller than 10-20mm, but some raw materials larger than 10-20mm still have other harmful substances such as powder coating and mud cuttings. After crushing and screening, they will also be mixed in the finished aggregate. This part of the harmful substances will directly affect the construction quality of the project, and seriously affect the design service life of the entire project. Therefore, the "high-pressure water washing + sedimentation tank dosing" process is often used to remove harmful substances to ensure that the finished aggregate meets national standards. In this production process, the wastewater addition flocculation and sedimentation requires a certain amount of time. The precipitated mud has a high water concentration and requires sufficient drying space. The sludge is collected and utilized after it is dried, and the site occupies a large area. The recyclable stone powder in the wastewater of most engineering projects is directly transported to the designated yard after the sludge is dried. It is not recycled, resulting in a waste of resources. At the same time, the wastewater is directly discharged into rivers, lakes and reservoirs after treatment, and the treatment method is also inappropriate.

[0003] How to recycle and reuse stone powder, wastewater and sludge in the construction sand and gravel processing system to maximize resource utilization is an urgent problem to be solved in the sand and gravel technology industry. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a construction sand and gravel processing wastewater treatment process method in view of the deficiencies in the above-mentioned prior art.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a construction sand and stone processing wastewater treatment process, characterized in that the method comprises the following steps:

[0006] Step 1: Fine sand recovery and sewage transportation: The raw materials of the construction sand and gravel processing system are crushed by the crusher and screened by the screening machine. The finished coarse aggregate is transported to the finished coarse aggregate bin by a belt conveyor. The sand is washed by a wheeled sand washer, a linear dewatering screen and a fine sand recovery device in turn, and then transported to the finished sand bin by a belt conveyor. The sewage is transported to the sewage collection pool through the sewage pipeline;

[0007] Step 2, sewage treatment: The sewage in the sewage collection tank is stirred by the first automatic agitator so that the fine particles in the sewage are evenly distributed in the water, and then transported to the concentrator through the first slurry pump for sewage purification. Before the sewage enters the concentrator, the dosing device automatically adds a reagent to the sewage, so that the suspended matter and fine particles in the sewage are quickly settled to the bottom of the concentrator. The clean water on the top flows out through the overflow pipe at the top of the concentrator and is transported to the clean water tank through the clean water pipeline;

[0008] Step 3, mud conveyor drying treatment: The mud at the bottom of the concentrator is conveyed to the mud collection pool through the mud pipeline. The mud in the mud collection pool is stirred by the second automatic agitator, and then conveyed to the plate and frame filter press through the sludge water pipe and the second slurry pump for mud drying treatment. A sludge bin is provided under the plate and frame filter press. The dried sludge automatically falls into the sludge bin. The sludge is conveyed to the storage yard for recycling by the loader and dump truck of the external transport unit. The clean water generated by the plate and frame filter press flows into the clean water tank through the clean water pipe;

[0009] Step 4: Wastewater recycling: The clean water in the clean water tank is pressurized by the clean water pump and supplied to the water unit and the bottom of the concentrator for flushing, thereby realizing the recycling of wastewater from the construction sand and gravel processing system and achieving the maximum utilization rate of wastewater;

[0010] When there is too much sludge at the bottom of the concentrator, use water to backwash the blockage;

[0011] When the sludge concentration at the bottom of the concentrating device is too high, use clean water to reduce the sludge concentration at the bottom of the pool.

[0012] The above-mentioned construction sand and gravel processing wastewater treatment process is characterized in that: in step 2, the dosing device automatically adds the agent in the process: the liquid detector monitors the agent concentration and liquid level in the agent pool in real time. If the liquid level and concentration are insufficient, the dry powder agent is automatically weighed by the internal weighing and dosing system through the agent delivery device, and the dry powder agent is quickly blended with clean water. The dosing pump is fully automatically delivered to the agent pool below; the agent flow rate and flow are adjusted according to the results monitored by the third density detector to ensure the sedimentation rate of suspended matter and fine particles in the sewage, and to ensure the concentration of the mud at the bottom of the concentrator, wherein the agent flow rate and flow are measured by a flowmeter.

[0013] The above-mentioned construction sand and gravel processing wastewater treatment process method is characterized in that a first density detector is installed on the sewage collection tank, and a second density detector is installed on the mud collection tank.

[0014] The above-mentioned construction sand and gravel processing wastewater treatment process is characterized in that the fine sand recovery device is a fine sand recovery cyclone with a multi-conical structure, which recovers fine particles larger than 0.035 mm in the sewage, and the recovery efficiency is 95%.

[0015] The above-mentioned construction sand and gravel processing wastewater treatment process method is characterized in that: the concentrating device adopts a concrete foundation, an upper cylindrical steel structure, and a lower conical steel structure. A sewage collecting cylinder is arranged in the middle of the concentrating device, and the sewage and the reagent pass through the sewage collecting cylinder to purify the sewage; the concentrating device is divided into a clear water area, a turbid area, and a sludge area from top to bottom. A maintenance manhole is arranged at the bottom of the sludge area to facilitate maintenance. The inner wall of the lower cone of the concentrating device is at an angle of 55° to the ground, and the bottom of the cone is at an angle of not less than 5° to the horizontal ground, so as to ensure that the mud in the sludge area flows into the mud pipe under the influence of gravity.

[0016] The above-mentioned construction sand and gravel processing wastewater treatment process is characterized in that: the moisture content of the sludge after drying by the plate and frame filter press is 3%, and the sludge is used for ecological restoration and land reclamation; after adding a set amount of cement, the sludge is used to make hollow bricks to achieve resource recycling.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] 1. The sewage collection tank and the slurry collection tank of the present invention are designed with density detectors, which can detect the sewage concentration in the tank at any time. The automatic stirring device can be started at any time through the intelligent centralized control system to keep the density of the sewage in the tank always within a suitable density range, which can effectively prevent the fine particles in the sewage from settling to the bottom of the sewage collection tank, increase the workload, reduce the service life of the slurry pump, and facilitate promotion and use.

[0019] 2. The concentrator of the present invention adopts a concrete foundation, an upper cylindrical steel structure, and a lower conical steel structure. A sewage collecting cylinder is arranged in the middle of the concentrator. Sewage and reagents pass through the sewage collecting cylinder to purify the sewage. The concentrator is divided into a clear water area, a turbid area, and a sludge area from top to bottom. An inspection manhole is arranged at the bottom of the sludge area to facilitate inspection and maintenance. If the sludge blocks the mud pipeline, the clean water in the clean water tank can be used to backwash the mud pipeline to ensure that the pipeline is unobstructed. The lower cone of the concentrator also adopts a steel structure. The angle between the inner wall of the cone and the ground is 55°, and the angle between the bottom of the cone and the horizontal ground is not less than 5°, so that the mud in the sludge area can be ensured to flow into the mud pipe under the influence of gravity.

[0020] 3. The method of the present invention has simple steps. The dosing device can realize automatic dosing and liquid preparation. The density detector arranged on the concentrating device can adjust the flow rate and flow of the added liquid at any time to ensure the sedimentation rate of suspended matter and fine particles in the sewage, realize automatic monitoring of the concentration of the mud at the bottom of the concentrating device, and extend the service life of the slurry pump. The clean water treated by the wastewater treatment system flows into the clean water tank through the clean water pipe and is used for the water unit and other water of the system after being pressurized by the clean water pump, thereby realizing the recycling of the wastewater of the construction sand and gravel processing system in the system, achieving the maximum utilization rate of the wastewater, and saving water resources.

[0021] 4. The fine sand recovery device of the present invention is a fine sand recovery cyclone, which adopts a multi-cone design structure and can fully recover fine particles larger than 0.035 mm in sewage. The recovery efficiency is as high as 95% after testing. The sludge dried by the plate and frame filter press has a moisture content of 3%. After adding a certain amount of cement, it can be used to make hollow bricks for the construction industry; at the same time, the sludge can also be used in projects such as ecological restoration and land reclamation, realizing resource recycling.

[0022] 5. The automatic agitator, density detector, slurry pump, dosing device, clean water pump and plate and frame filter press in the wastewater system of the present invention are centrally controlled by an intelligent system. The concentration and liquid level of sewage, sludge and reagents are detected to adjust the corresponding operating parameters and time, thereby reducing the work of patrol and inspection personnel, effectively increasing the working efficiency of the wastewater system, reducing the equipment operating load, realizing automatic and intelligent operation, and reducing operating costs.

[0023] In summary, the present invention is easy to promote and use.

[0024] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The figure is a flowchart of the method of the present invention.

[0026] Figure 2 This is a process flow chart for treating sand and gravel processing wastewater according to the present invention.

[0027] Description of reference numerals:

[0028] 1—wheel sand washing machine; 2—linear dewatering screen; 3—fine sand recovery device;

[0029] 4—Belt conveyor; 5—Finished sand bin; 6—Sewage collection tank;

[0030] 7-1—first automatic stirrer; 7-2—second automatic stirrer; 8-1—first density detector;

[0031] 8-2—second density detector; 8-3—third density detector; 9-1—first slurry pump;

[0032] 9-2—Second slurry pump; 10—Concentration device; 11—Dosing device;

[0033] 12—medicine delivery device; 13—liquid detector; 14—drug delivery pump;

[0034] 15—flow meter; 16—clean water tank; 17—water use unit;

[0035] 18—clean water pump; 19—mud collection tank; 20—plate and frame filter press;

[0036] 21—Sludge silo; 22—External transport unit. DETAILED DESCRIPTION

[0037] like Figure 1 and Figure 2 As shown, a construction sand and gravel processing wastewater treatment process of the present invention comprises the following steps:

[0038] Step 1: Fine sand recovery and sewage transportation: The raw materials of the construction sand and gravel processing system are crushed by the crusher and screened by the screening machine. The finished coarse aggregate is transported to the finished coarse aggregate bin by a belt conveyor. The sand is washed by the wheeled sand washing machine 1, the linear dewatering screen 2 and the fine sand recovery device 3 in turn, and then transported to the finished sand bin 5 by a belt conveyor 4. The sewage is transported to the sewage collection tank 6 through the sewage pipeline;

[0039] It should be noted that the fine sand recovery device 3 is an efficient fine sand recovery cyclone with a multi-cone design structure, which can fully recover fine particles larger than 0.035 mm in the sewage and transport them to the finished sand bin 5 through the belt conveyor 4 to adjust the fineness modulus and stone powder content of the finished sand, thereby improving the product quality of the finished sand; the recovery of some fine particles larger than 0.035 mm can reduce the concentration of suspended matter in the sewage, improve the working conditions of subsequent equipment in the wastewater treatment system, and increase the working efficiency of the equipment; for the sewage pipeline, the slope ratio of the pipeline should not be less than 5%, otherwise it will affect the sewage discharge rate, causing the sewage pipeline to be blocked and the pipeline to fail to work normally.

[0040] Step 2, sewage treatment: The sewage in the sewage collection tank 6 is stirred by the first automatic agitator 7-1 so that the fine particles in the sewage are evenly distributed in the water, and then transported to the concentrator 10 through the first slurry pump 9-1 for sewage purification treatment. Before the sewage enters the concentrator 10, the dosing device 11 automatically adds a reagent to the sewage, so that the suspended matter and fine particles in the sewage are quickly settled to the bottom of the concentrator 10, and the clean water on the upper part flows out through the overflow pipe at the top of the concentrator 10 and is transported to the clean water tank 16 through the clean water pipeline;

[0041] The clean water of the dosing device 11 is connected to the water injection port of the dosing device 11 through an external pipeline. A flow meter 15, a check valve, a valve, etc. are arranged in front of the water injection port. The flow rate and flow rate of the water injection are automatically adjusted by the system, thereby realizing automatic water injection;

[0042] In this embodiment, in step 2, the dosing device 11 automatically adds the agent in the process: the liquid detector 13 monitors the agent concentration and liquid level in the agent pool in real time. If the liquid level and concentration are insufficient, the dry powder agent is automatically weighed by the internal weighing and dosing system through the agent delivery device 12, and the dry powder agent is quickly blended with clean water. The dosing pump 14 automatically delivers it to the agent pool below; the agent flow rate and flow are adjusted according to the results monitored by the third density detector 8-3 to ensure the sedimentation rate of suspended matter and fine particles in the sewage, and to ensure the concentration of the mud at the bottom of the concentrator 10, wherein the agent flow rate and flow are measured by the flow meter 15.

[0043] In this embodiment, a first density detector 8-1 is installed on the sewage collection tank 6, and a second density detector 8-2 is installed on the slurry collection tank 19, which can detect the density of the sewage in the sewage collection tank 6 at any time. The automatic agitator can be started at any time through the centralized control system to keep the density of the sewage in the tank within a suitable density range, which can effectively prevent fine particles in the sewage from settling to the bottom of the sewage collection tank 6, increase the workload, and reduce the service life of the slurry pump 9.

[0044] In this embodiment, the concentrator 10 adopts a concrete foundation, an upper cylindrical steel structure, and a lower conical steel structure. A sewage collecting cylinder is arranged in the middle of the concentrator 10, and the sewage and the reagent pass through the sewage collecting cylinder to purify the sewage; the concentrator 10 is divided into a clear water area, a turbid area, and a sludge area from top to bottom. A maintenance manhole is arranged at the bottom of the sludge area for easy maintenance. The inner wall of the lower cone of the concentrator 10 is at an angle of 55° to the ground, and the bottom of the cone is at an angle of not less than 5° to the horizontal ground, so as to ensure that the sludge in the sludge area flows into the sludge pipe under the influence of gravity.

[0045] Step 3, mud conveyor drying treatment: The mud at the bottom of the concentrator 10 is conveyed to the mud collection tank 19 through the mud pipeline. The mud in the mud collection tank 9 is stirred by the second automatic agitator 7-2, and then conveyed to the plate and frame filter press 20 through the sludge water pipe and the second slurry pump 9-2 for mud drying treatment. A sludge bin 21 is provided under the plate and frame filter press 20. The dried sludge automatically falls into the sludge bin 21. The sludge is conveyed to the storage yard for recycling by the loader and dump truck of the external transport unit 22; the clean water generated by the plate and frame filter press 20 flows into the clean water tank 16 through the clean water pipe;

[0046] Step 4: Wastewater recycling: The clean water in the clean water tank 16 is pressurized by the clean water pump 18 and supplied to the water unit 17 and the bottom of the concentrator 10 for flushing, thereby realizing the recycling of wastewater from the construction sand and gravel processing system and achieving the maximum utilization rate of wastewater;

[0047] When there is too much sludge at the bottom of the concentrator 10, water is used to backwash the sludge;

[0048] When the sludge concentration at the bottom of the pool of the concentrator 10 is too high, clean water is used to reduce the sludge concentration at the bottom of the pool.

[0049] In this embodiment, the moisture content of the sludge after drying by the plate and frame filter press 20 is 3%, and the sludge is used for ecological restoration and land reclamation; the sludge is added with a set amount of cement to make hollow bricks, thereby realizing resource recycling.

[0050] When the present invention is used, the slurry pump 9, the clean water pump 18, and the dosing pump 14 are all used in a one-for-one standby manner. If one is damaged, the other can be immediately activated to continue operating without affecting the system production. The automatic agitator, density detector, slurry pump, dosing device, clean water pump, and plate and frame filter press in the wastewater system are centrally controlled by the intelligent system. The corresponding operating parameters and time are adjusted by detecting the concentration and liquid level of sewage, sludge, and chemicals, reducing the work of patrol and inspection personnel, effectively increasing the working efficiency of the wastewater system, and reducing the equipment operation load, realizing automatic operation and intelligent operation, and reducing operating costs.

[0051] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for treating construction sand and gravel processing wastewater, characterized in that: The method comprises the following steps: Step 1: fine sand recovery and sewage transportation: the raw materials of the construction sand and gravel processing system are crushed by a crusher, screened by a screener, and the finished coarse aggregate is transported to the finished coarse aggregate bin by a belt conveyor. The sand is washed by a wheeled sand washer (1), a linear dewatering screen (2) and a fine sand recovery device (3) in turn, and then transported to the finished sand bin (5) by a belt conveyor (4). The sewage is transported to the sewage collection tank (6) through a sewage pipeline. Step 2, sewage treatment: The sewage in the sewage collection tank (6) is stirred by a first automatic stirrer (7-1) so that fine particles in the sewage are evenly distributed in the water, and then transported to a concentrator (10) through a first slurry pump (9-1) for sewage purification. Before the sewage enters the concentrator (10), a chemical is automatically added to the sewage through a chemical dosing device (11) to quickly settle suspended matter and fine particles in the sewage to the bottom of the concentrator (10). The clean water on the top flows out through an overflow pipe at the top of the concentrator (10) and is transported to a clean water tank (16) through a clean water pipeline; Step 3, mud conveyor drying treatment: The mud at the bottom of the concentrator (10) is conveyed to the mud collection tank (19) through the mud pipeline. The mud in the mud collection tank (9) is stirred by the second automatic agitator (7-2), and then conveyed to the plate and frame filter press (20) through the sludge water pipe and the second slurry pump (9-2) for mud drying treatment. A sludge bin (21) is provided under the plate and frame filter press (20). The dried sludge automatically falls into the sludge bin (21). The sludge is conveyed to the storage yard for recycling by the loader and dump truck of the external transport unit (22); the clean water generated by the plate and frame filter press (20) flows into the clean water tank (16) through the clean water pipe; Step 4, recycling of waste water: the clean water in the clean water tank (16) is pressurized by the clean water pump (18) and supplied to the water unit (17) and the bottom of the concentrator (10) for flushing, thereby realizing the recycling of waste water from the construction sand and gravel processing system and achieving the maximum utilization rate of waste water; When there is too much sludge at the bottom of the concentrator (10), water is used to flush out the sludge; When the sludge concentration at the bottom of the pool of the concentrating device (10) is too high, clean water is used to reduce the sludge concentration at the bottom of the pool.

2. A construction sand and stone processing wastewater treatment process according to claim 1, characterized in that: In step 2, the dosing device (11) automatically adds the agent during the process: the liquid detector (13) monitors the agent concentration and liquid level in the agent pool in real time. If the liquid level and concentration are insufficient, the dry powder agent is automatically weighed by the internal weighing and dosing system through the agent delivery device (12), and the dry powder agent is quickly blended with clean water. The dosing pump (14) automatically delivers the agent to the agent pool below; the agent flow rate and flow rate are adjusted according to the results monitored by the third density detector (8-3) to ensure the sedimentation speed of suspended matter and fine particles in the sewage and to ensure the concentration of the mud at the bottom of the concentrator (10), wherein the agent flow rate and flow rate are measured by a flow meter (15).

3. A construction sand and gravel processing wastewater treatment process according to claim 1, characterized in that: A first density detector (8-1) is installed on the sewage collection tank (6), and a second density detector (8-2) is installed on the mud collection tank (19).

4. A construction sand and stone processing wastewater treatment process according to claim 1, characterized in that: The fine sand recovery device (3) is a fine sand recovery cyclone with a multi-cone structure, which recovers fine particles larger than 0.035 mm in sewage, with a recovery efficiency of 95%.

5. A construction sand and stone processing wastewater treatment process according to claim 1, characterized in that: The concentrator (10) adopts a concrete foundation, an upper cylindrical steel structure, and a lower conical steel structure. A sewage collecting cylinder is arranged in the middle of the concentrator (10). Sewage and chemicals pass through the sewage collecting cylinder to purify the sewage. The concentrator (10) is divided into a clear water area, a turbid area, and a sludge area from top to bottom. A maintenance manhole is arranged at the bottom of the sludge area to facilitate maintenance. The inner wall of the lower cone of the concentrator (10) is at an angle of 55° to the ground, and the bottom of the cone is at an angle of not less than 5° to the horizontal ground, so as to ensure that the sludge in the sludge area flows into the sludge pipe under the influence of gravity.

6. A construction sand and stone processing wastewater treatment process according to claim 1, characterized in that: The moisture content of the sludge after drying by the plate and frame filter press (20) is 3%, and the sludge is used for ecological restoration and land reclamation; after adding a set amount of cement to the sludge, it is used to make hollow bricks, thereby realizing resource recycling.

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