Contaminated acid pressurizing and vulcanizing treatment system

Abstract

A waste acid inlet pipe is arranged at the top of a homogenizing tank, a liquid outlet at the bottom of the homogenizing tank is connected with a pipeline, one branch of the pipeline extends into the bottom of a vulcanizing tank, the other branch of the pipeline is connected into a spray tower, the bottom of the spray tower is communicated with the top of the homogenizing tank, and an exhaust port at the top of a settling tank is communicated with the spray tower through an exhaust pipeline. The bottom of the vulcanizing tank is communicated with a liquid inlet of the vulcanizer, an outlet of the vulcanizer is communicated with the vulcanizing tank, an overflow port of the vulcanizing tank is connected with the settling tank, the elevated tank is higher than the vulcanizer, and a bottom outlet of the elevated tank is communicated with a medicament inlet of the vulcanizer through a pipeline; a slag slurry port at the bottom of the settling tank is communicated with an inlet of the filter press; and a supernatant overflow port of the settling tank and a filtrate outlet of the filter press are connected with pipelines to a defluorination process. The device has the beneficial effects that the vulcanization reaction is completed in the closed container, hydrogen sulfide can be prevented from overflowing regardless of the acidity of waste acid, hydrogen sulfide is forced to participate in the reaction, and the vulcanization efficiency is improved.

Description

Technical Field

[0001] This utility model belongs to the field of waste acid treatment and relates to equipment for treating waste acid by pressure sulfidation. Background Technology

[0002] Flue gas is used to produce acid, which is absorbed by dilute sulfuric acid to remove particulate impurities, producing waste acid. This waste acid contains harmful elements such as copper, arsenic, and chromium from the flue gas. Arsenic is highly toxic, and the presence of fluorine accelerates equipment corrosion, so these elements must also be removed. Sulfidation is a common method for removing arsenic and other elements. However, in conventional sulfidation processes, if the waste acid is highly acidic, the addition of sulfidation agents quickly generates hydrogen sulfide gas, which escapes in large quantities, leading to low sulfidation efficiency, high agent consumption, and even the risk of hydrogen sulfide poisoning. Therefore, improvements to existing technologies are necessary. Utility Model Content

[0003] The purpose of this invention is to propose a pressurized sulfurization treatment system for waste acid.

[0004] The technical solution of this utility model is as follows: a pressurized sulfurization treatment system for waste acid, comprising a sulfurization tank, a dosing tank, and a sulfurizer; equipped with a homogenization tank, a spray tower, a settling tank, a high-level tank, and a filter press; the top of the homogenization tank is provided with a waste acid inlet pipe, and the bottom outlet of the homogenization tank is connected to a pipeline; a pump is installed on the pipeline, and the pump outlet pipe branches, one branch extending into the bottom of the sulfurization tank and the other branch connecting to the spray tower; the bottom of the spray tower is connected to the top of the homogenization tank; the exhaust port at the top of the settling tank is connected to the spray tower through an exhaust pipe, in which hydrogen sulfide flows. The gas is connected to the bottom of the vulcanizing tank and the liquid inlet of the vulcanizer via pipes and pumps. The outlet of the vulcanizer is connected to the vulcanizing tank. The overflow port of the vulcanizing tank is connected to the settling tank via pipes. The height of the high-level tank is above the height of the vulcanizer. The bottom outlet of the high-level tank is connected to the reagent inlet of the vulcanizer via pipes. The dosing tank and the high-level tank are connected to the liquid circulation path via pipes and pumps. The slurry port at the bottom of the settling tank is connected to the inlet of the filter press via a slurry pump and pipes. The overflow port of the supernatant of the settling tank and the filtrate outlet of the filter press are connected to the defluorination process via pipes.

[0005] Preferably, the homogenization tank has a volume of 28m³.

[0006] Preferably, the spray tower has a nozzle spraying structure.

[0007] Furthermore, the overflow outlet of the supernatant in the settling tank and the connecting pipe of the filter press filtrate outlet are combined into one pipe and flow into the defluorination process.

[0008] A hydrogen sulfide concentration detector is installed on the upper part of the sulfidation tank, and an automatic valve is installed at the bottom outlet of the high-level tank. The hydrogen sulfide concentration detector is interlocked with the automatic valve.

[0009] The beneficial effects of this utility model are as follows: The pressure vulcanization process is an innovative technology based on the conventional vulcanization process. The vulcanization reaction is completed in a closed container. Regardless of the acidity of the waste acid, hydrogen sulfide leakage can be avoided, and hydrogen sulfide is forced to participate in the reaction, thereby improving the vulcanization efficiency. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the components of this utility model. Detailed Implementation

[0011] like Figure 1 As shown, the waste acid pressurized sulfidation treatment system includes a sulfidation tank 4, a chemical mixing tank 7, and a sulfidator 5. It also includes a homogenization tank 1, a spray tower 2, a settling tank 3, a high-level tank 6, and a filter press 8. The homogenization tank 1 has a waste acid inlet pipe at its top and a pipe connected to its bottom outlet. A pump is mounted on the pipe, with one branch extending into the bottom of the sulfidation tank 4 and the other branch connecting to the spray tower 2. The bottom of the spray tower 2 is connected to the top of the homogenization tank 1. The exhaust port at the top of the settling tank 3 is connected to the spray tower 2 via an exhaust pipe, through which hydrogen sulfide gas flows. The bottom of the vulcanizing tank 4 is connected to the liquid inlet of the vulcanizer 5 by a pipe and a pump. The outlet of the vulcanizer 5 is connected to the vulcanizing tank 4. The overflow port of the vulcanizing tank 4 is connected to the settling tank 3 through a pipe. The height of the high-level tank 6 is above the height of the vulcanizer 5. The bottom outlet of the high-level tank 6 is connected to the reagent inlet of the vulcanizer 5 through a pipe. The dosing tank 7 is connected to the high-level tank 6 through a pipe and a pump to form a liquid circulation path. The slurry port at the bottom of the settling tank 3 is connected to the inlet of the filter press 8 through a slurry pump and a pipe. The overflow port of the supernatant of the settling tank 3 and the filtrate outlet of the filter press 8 are connected to the defluorination process through pipes.

[0012] The discharged waste acid is collected in homogenization tank 1, which has a buffer capacity of 28 m³ and can store waste acid for 5 days. Homogenization tank 1 and spray tower 2 form a liquid circulation pipeline. Spraying from spray tower 2 fully homogenizes the impurity ions in the waste acid (which helps reduce the difficulty of automatic control and precisely control the escape of hydrogen sulfide gas). The homogenized waste acid is pumped to the bottom of sulfidation tank 4, and then pumped into sulfidator 5. Sodium hydrosulfide and water are added to the dosing tank 7 to prepare a 15% aqueous solution, which is pumped into the high-level tank 6. The high-level tank 6 is higher than sulfidator 5 and can flow into sulfidator 5 by gravity. Under positive pressure, the waste acid reacts rapidly with the 15% sodium hydrosulfide solution. The sulfidated waste acid returns to sulfidation tank 4, overflows into settling tank 3, and after settling, the bottom arsenic sulfide slag is pumped into filter press 8 for filtration and separation. The clear liquid overflowing from the top of settling tank 3 merges with the filtrate from filter press 8 and enters the defluorination process. An exhaust pipe is installed at the top of settling tank 3 to send excess hydrogen sulfide gas into spray tower 2, where it comes into countercurrent contact with the sprayed waste acid. The gas is absorbed through the reaction, and simultaneously pre-sulfurizes the waste acid. The absorbed tail gas is then sent to the defluorination alkaline solution tower for further absorption before being discharged into the atmosphere.

[0013] A hydrogen sulfide concentration detector is installed on the upper part of the sulfidation tank 4, and an automatic valve is installed at the bottom outlet of the high-level tank 6. The hydrogen sulfide concentration detector is interlocked with the automatic valve. The opening and closing of the automatic valve at the outlet of the high-level tank is controlled according to the concentration of hydrogen sulfide gas in the sulfidation tank, thereby controlling the amount of sodium hydrosulfide solution added. At the same time, the control signal is adjusted based on the detection of arsenic content in the sulfidation liquid.

Claims

1. A pressurized sulphidation treatment system for spent acid comprising a sulphidation tank (4), a dosing tank (7), a sulphurizer (5), characterized in that: The equalizing tank (1), the spray tower (2), the settling tank (3), the high tank (6) and the filter press (8) are arranged, the equalizing tank (1) is provided with a pipe for entering the waste acid at the top, a pipeline is connected to the liquid outlet at the bottom of the equalizing tank (1), a pump is arranged on the pipeline, the outlet pipe of the pump is branched, one branch extends into the bottom of the sulfurization tank (4), and the other branch is connected to the spray tower (2), the bottom of the spray tower (2) is communicated with the top of the equalizing tank (1), the exhaust pipe is communicated between the exhaust port at the top of the settling tank (3) and the spray tower (2), the exhaust pipe flows with hydrogen sulfide gas, the bottom of the sulfurization tank (4) is communicated with the liquid inlet of the sulfurization device (5) by a pipeline and a pump, the outlet of the sulfurization device (5) is communicated with the sulfurization tank (4), the overflow port of the sulfurization tank (4) is connected to the settling tank (3) through a pipeline, the height of the high tank (6) is higher than the height of the sulfurization device (5), the outlet at the bottom of the high tank (6) is communicated with the reagent inlet of the sulfurization device (5) through a pipeline, the dosing tank (7) and the high tank (6) are connected to form a liquid circulation passage through a pipeline and a pump, the slurry port at the bottom of the settling tank (3) is communicated with the inlet of the filter press (8) through a slurry pump and a pipeline, and the overflow port of the supernatant of the settling tank (3) and the filtrate outlet of the filter press (8) are connected to the pipeline to the defluorination process.

2. The pressurized sulphidation treatment system of the waste acid according to claim 1, characterized in that: The volume of the equalizing tank is 28m³.

3. The pressurized sulphidation treatment system of the waste acid according to claim 1, characterized in that: The spray tower (2) is provided with a water spraying structure.

4. The pressurized sulphidation treatment system of the waste acid according to claim 1, characterized in that: The overflow port of the supernatant of the settling tank (3) and the filtrate outlet of the filter press (8) are connected to form a pipeline, and the pipeline flows into the defluorination process.

5. The pressurized sulphidation treatment system of the waste acid according to claim 1, characterized in that: A hydrogen sulfide concentration detector is arranged at the upper portion of the sulfurization tank (4), an automatic valve is arranged at the outlet at the bottom of the high tank (6), and the hydrogen sulfide concentration detector is connected with the automatic valve in interlocking manner.

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