A device for treating cyanide-containing wastewater by chemical precipitation

Abstract

This utility model discloses a chemical precipitation method for treating cyanide-containing wastewater. Sealing end plates are installed at both the upper and lower ends of the outer cylinder. The lower end of the inner cylinder is fixed to the lower sealing end plate of the outer cylinder, and the upper end is also equipped with a sealing end plate. Gaps exist between the upper end of the inner cylinder and the upper sealing end plate of the outer cylinder, as well as between the outer wall of the inner cylinder and the inner wall of the outer cylinder, serving as a space for circulating water flow. An inlet pipe and an outlet pipe are connected to this circulating water flow space. Several turbulence plates are evenly distributed around the inner wall of the inner cylinder. The device also includes a feed pipe and a discharge pipe that pass through the side walls of the outer and inner cylinders. The feed direction of the feed pipe is tangential to the inner wall of the inner cylinder. When using chemical precipitation to treat cyanide-containing wastewater, this device achieves a non-powered stirring function for the reaction apparatus; it has good sealing properties to prevent the leakage of cyanide-containing wastewater or hydrogen cyanide; and temperature control is achieved through circulating water.

Description

Technical Field

[0001] This utility model relates to a reaction device for treating cyanide-containing wastewater, specifically a reaction device for treating cyanide-containing wastewater using a chemical precipitation method. Background Technology

[0002] Gold smelting companies that use cyanide leaching technology to process ores generate large amounts of cyanide-containing wastewater. Since this wastewater is classified as hazardous waste, it must undergo harmless treatment. Chemical precipitation is a commonly used method for treating cyanide-containing wastewater, offering advantages such as fast treatment speed, good efficiency, and the ability to comprehensively recover valuable metals.

[0003] Under acidic conditions, cyanide in cyanide-containing wastewater combines with hydrogen ions to form highly toxic hydrogen cyanide gas. Especially at reaction temperatures above 26°C, hydrogen cyanide gas can escape from the liquid phase, potentially causing poisoning if it enters the working environment. Therefore, a treatment device is needed that can achieve a closed reaction system and temperature control when using chemical precipitation to treat cyanide-containing wastewater, thus meeting both the process requirements and safety requirements for chemical precipitation-based cyanide wastewater treatment.

[0004] Currently, there is no simple and reliable reaction device that can effectively solve the above problems. Chinese invention patent application CN101016584A discloses a "Multi-flow-tube air-circulation bioreactor for bacterial leaching and cultivation of leaching bacteria," which uses a multi-flow-tube air-circulation bioreactor for leaching minerals and cultivating leaching bacteria. This reactor uses compressed air as the liquid lifting power to reduce the wear of the ore and agitator blades on the microbial cells, while providing oxygen for microbial growth and the bio-oxidation of minerals. The reactor has multiple flow-tubes inside to reduce the height-to-diameter ratio (H / D), which is beneficial for the large-scale development of the bioreactor. It is evident that this method uses electric agitation and relies on compressed air for agitation power, resulting in numerous mechanical parts, a complex structure, high cost, and significant difficulties in widespread application. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a chemical precipitation method for treating cyanide-containing wastewater. When using chemical precipitation to treat cyanide-containing wastewater, firstly, the reaction device achieves a non-powered stirring function; secondly, it has good airtightness to prevent the overflow of cyanide-containing wastewater or hydrogen cyanide; and thirdly, temperature control is achieved through circulating water.

[0006] The technical solution of this utility model is as follows:

[0007] A chemical precipitation method for treating cyanide-containing wastewater includes a cylindrical outer cylinder and a cylindrical inner cylinder installed inside the outer cylinder. Sealing end plates are installed at both the upper and lower ends of the outer cylinder. The lower end of the inner cylinder is fixed to the lower sealing end plate of the outer cylinder, and its upper end is also equipped with a sealing end plate. Gaps exist between the upper end of the inner cylinder and the upper sealing end plate of the outer cylinder, and between the outer wall of the inner cylinder and the inner wall of the outer cylinder, serving as a space for circulating water flow. An inlet pipe and an outlet pipe are connected to this circulating water flow space. Several turbulence plates are evenly distributed around the inner wall of the inner cylinder. The device also includes a feed pipe and a discharge pipe passing through the side walls of the outer and inner cylinders. The feed end of the feed pipe is located at the bottom of the inner cylinder, and the discharge end of the discharge pipe is located at the upper end of the inner cylinder. The feed direction of the feed pipe is tangent to the inner wall of the inner cylinder.

[0008] Preferably, the device further includes a dosing pipe that passes sequentially from above into the upper sealing end plate of the outer cylinder and the upper sealing end plate of the inner cylinder.

[0009] Preferably, the device further includes a pH meter probe and a thermometer probe disposed inside the inner cylinder; the signal lines of the pH meter probe and the thermometer probe respectively extend upward from the upper sealing end plate of the inner cylinder and the upper sealing end plate of the outer cylinder and are respectively connected to the pH meter and the thermometer.

[0010] The positive effects of this utility model are as follows:

[0011] First, when using chemical precipitation methods such as copper salt precipitation, iron salt precipitation, or zinc salt precipitation to treat cyanide-containing wastewater, the wastewater is disturbed by a jet that enters tangentially along the inner cylinder and several turbulence plates arranged longitudinally along the inner wall of the inner cylinder, achieving the purpose of thorough mixing without power, and promoting the full mixing and reaction of the copper salt, iron salt, or zinc salt reagents with the cyanide-containing wastewater.

[0012] Secondly, by injecting alkaline water at a certain temperature into the interlayer between the inner and outer cylinders, this alkaline water circulates and exchanges heat with the reaction system inside the inner cylinder, thereby achieving the purpose of controlling the reaction temperature of cyanide-containing wastewater.

[0013] Third, both ends of the inner and outer cylinders are sealed, which can effectively prevent the overflow of cyanide-containing wastewater or hydrogen cyanide in the reaction system and avoid safety accidents.

[0014] Fourth, the reaction apparatus is equipped with a pH detection device and a temperature detection device, which can more conveniently realize the detection and control of pH and temperature during the reaction process. Attached Figure Description

[0015] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model.

[0016] In the diagram, 1: outer cylinder, 2: inner cylinder, 3: feed pipe, 4: discharge pipe, 5: water inlet pipe, 6: water outlet pipe, 7: dosing pipe, 8: turbulence plate, 9: pH meter probe, 10: thermometer probe. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] like Figure 1 The main body of this utility model embodiment includes a cylindrical outer cylinder 1 and a cylindrical inner cylinder 2 installed inside the outer cylinder 1. Sealing end plates are installed at both the upper and lower ends of the outer cylinder 1. The lower end of the inner cylinder 2 is fixed to the lower sealing end plate of the outer cylinder 1, and the upper end is also sealed, meaning both the upper and lower ends of the outer cylinder 1 and the inner cylinder 2 are sealed. A gap exists between the upper end of the inner cylinder 2 and the upper sealing end plate of the outer cylinder 1, and between the outer side wall of the inner cylinder 2 and the inner side wall of the outer cylinder 1, serving as a space for circulating water flow. Specifically, the height of the inner cylinder 2 is less than that of the outer cylinder 1, and the outer diameter of the inner cylinder 2 is less than the inner diameter of the outer cylinder 1. An inlet pipe 5 and an outlet pipe 6 are connected to the circulating water flow space.

[0019] An embodiment of this invention further includes a dosing tube 7 that passes sequentially through the upper sealing end plate of the outer cylinder 1 and the upper sealing end plate of the inner cylinder 2. An embodiment of this invention also includes a pH meter probe 9 and a thermometer probe 10 disposed inside the inner cylinder 2. The signal lines of the pH meter probe 9 and the thermometer probe 10 pass upwards from the upper sealing end plate of the inner cylinder 2 and the upper sealing end plate of the outer cylinder 1, respectively, and are connected to the pH meter and the thermometer. Both the pH meter probe 9 and the thermometer probe 10 can be moved vertically to ensure they are submerged below the liquid level inside the inner cylinder 2.

[0020] Several turbulence plates 8 are evenly distributed around the inner wall of the inner cylinder 2.

[0021] Embodiments of this utility model further include a feeding pipe 3 and a discharging pipe 4 passing through the side walls of the outer cylinder 1 and the inner cylinder 2. The inlet end of the feeding pipe 3 is located at the bottom of the inner cylinder 2, and the discharge end of the discharging pipe 4 is located at the upper end of the inner cylinder 2. The feeding direction of the feeding pipe 3 is tangent to the inner side wall of the inner cylinder 2.

[0022] In use, the inlet pipe 5 and outlet pipe 6 are connected to the outlet and return ends of the water supply tank, respectively, and the feed pipe 3 is connected to the cyanide-containing wastewater supply tank. The water supply tank can be connected to the inlet pipe 5 via a water pump, which provides water pressure; the water supply tank can also be positioned at a high level, utilizing the liquid level difference between it and the inner cylinder 2 to provide water pressure. Generally, the water supplied by the water supply tank is alkaline water. The cyanide-containing wastewater supply tank can be connected to the feed pipe 3 via a water pump, which provides feeding pressure; the cyanide-containing wastewater supply tank can also be positioned at a high level, utilizing the liquid level difference between it and the inner cylinder 2 to provide feeding pressure.

[0023] Cyanide-containing wastewater is fed tangentially through feed pipe 3. The wastewater is agitated by the jet and turbulence plate 8, reacting with chemical precipitants and pH adjusters added through dosing pipe 7. The pH value of the cyanide-containing wastewater is monitored in real time by pH meter probe 9, and the pH is controlled within the required range by adding pH adjusters. After the reaction, the liquid overflows and is discharged through discharge pipe 4. The water temperature in the supply tank is adjusted to a suitable temperature according to the reaction conditions, and the water flows through the circulating water space to heat or cool the reaction system within the inner cylinder 2.

Claims

1. A chemical precipitation method for treating cyanide-containing wastewater, comprising a cylindrical outer cylinder (1) and a cylindrical inner cylinder (2) installed inside the outer cylinder (1), characterized in that: The outer cylinder (1) is equipped with sealing end plates at both the upper and lower ends. The lower end of the inner cylinder (2) is fixed to the lower sealing end plate of the outer cylinder (1), and the upper end is equipped with a sealing end plate. There is a gap between the upper end of the inner cylinder (2) and the upper sealing end plate of the outer cylinder (1), and between the outer side wall of the inner cylinder (2) and the inner side wall of the outer cylinder (1) as a space for circulating water flow. The space for circulating water flow is connected to an inlet pipe (5) and an outlet pipe (6). Several turbulence plates (8) are evenly distributed around the inner wall of the inner cylinder (2). The device also includes a feed pipe (3) and a discharge pipe (4) that pass through the side walls of the outer cylinder (1) and the inner cylinder (2). The feed end of the feed pipe (3) is located at the bottom of the inner cylinder (2), and the discharge end of the discharge pipe (4) is located at the upper end of the inner cylinder (2). The feeding direction of the feed pipe (3) is tangent to the inner side wall of the inner cylinder (2).

2. The chemical precipitation method for treating cyanide-containing wastewater according to claim 1, characterized in that: The device also includes a dosing pipe (7) that passes through the upper sealing end plate of the outer cylinder (1) and the upper sealing end plate of the inner cylinder (2) sequentially from above.

3. The chemical precipitation method for treating cyanide-containing wastewater according to claim 1, characterized in that: The device also includes a pH meter probe (9) and a thermometer probe (10) disposed inside the inner cylinder (2); the signal lines of the pH meter probe (9) and the thermometer probe (10) pass through the upper sealing end plate of the inner cylinder (2) and the upper sealing end plate of the outer cylinder (1) respectively and are connected to the pH meter and the thermometer respectively.

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