Method for treating peculiar smell of mineral processing xanthate

Abstract

The invention belongs to the field of smelting, and particularly relates to a method for reducing xanthate peculiar smell in a mineral separation workshop of a smeltery, which comprises the following steps: collecting gas above a site or equipment with xanthate peculiar smell in the mineral separation workshop, introducing the gas into a rotary supergravity machine, introducing a sodium hydroxide solution at the same time, and emptying the discharged gas of the rotary supergravity machine. According to the scheme, the collected beneficiation xanthate peculiar smell gas containing CS2 enters the rotating supergravity machine, CS2 tiny liquid drops and the sodium hydroxide washing liquid subjected to high-speed rotating atomization are intensively stirred, mixed and collided in the supergravity machine, the CS2 tiny liquid drops are promoted to be condensed and react (2NaOH (liquid phase) + CS2 (oil phase)-> Na2COS2 + H2O), and the CS2 tiny liquid drops are separated from a gas phase under the intense action of rotating centrifugal force, so that the CS2 peculiar smell gas containing CS2 is obtained. The separated CS2 tiny liquid drops flow out of the supergravity machine along with the washing liquid, so that the aim of purifying the waste gas is fulfilled. By adopting the scheme, the content of carbon disulfide in discharged gas of the rotary supergravity machine is reduced to 5.5 ppm or below, and the carbon disulfide can be directly discharged.

Description

Technical Field

[0001] This invention belongs to the field of metallurgy, specifically relating to a method for reducing the off-odor of xanthate in a ore dressing workshop of a smelter. Background Technology

[0002] Xanthate is a commonly used flotation reagent. During the preparation and addition of powdered xanthate with water, it easily releases a strong, pungent odor, the main component of which is carbon disulfide (CS2). The uncontrolled emission of this odorous gas can easily cause environmental pollution and occupational health problems, a common issue in most flotation plants.

[0003] Existing methods for eliminating the odor of xanthate include incineration and washing:

[0004] Incineration utilizes the combustibility of carbon disulfide. For example, a Chinese patent application titled "Method for Treating Volatile Gases from Mineral Processing" (Patent Publication No. CN 119468224 A) proposes a method to directly transport collected volatile gases from mineral processing to a pyrometallurgical furnace where the gases are being processed. The high temperature of the furnace causes the gases to burn naturally, and the incineration products are then processed along with the smelting flue gas into an acid production system. While this method claims to solve the problem of volatile gases from mineral processing at "zero cost," it requires the installation of pipelines to transport the gases from the mineral processing workshop to the smelting workshop. In reality, the two workshops involve different smelting processes and are generally far apart (at least one kilometer), making the installation and maintenance of pipelines extremely difficult.

[0005] Washing involves spraying odorous gases with alkaline detergents (such as sodium hydroxide solution) or other washing liquids, causing carbon disulfide in the gas to react with the alkaline reagent (2NaOH + CS2 → Na2COS2 + H2O) to remove the odor. For example, a Chinese utility model patent entitled "An Odor Collection and Purification System for a Mineral Processing Xanthate Workshop" (authorization publication number CN 221207472 U) describes a scheme that uses sodium hydroxide alkaline washing combined with high-pressure atomization of plant-based liquid to deodorize the collected odor from mineral processing xanthate. This can capture, separate, and purify carbon disulfide, alcohols, ammonia, hydrogen sulfide, etc., in the odorous gases from the xanthate workshop, ensuring that the purified odorous gases meet emission standards. It also increases the gas-liquid phase contact area, prolongs the total reaction time, and improves the efficiency of fume purification and deodorization. However, in actual operation, due to the extremely high volatility of carbon disulfide, the odor removal effect is poor; the carbon disulfide in the odorous gas can only be reduced by a maximum of 10%, thus making this scheme impractical.

[0006] Therefore, how to effectively solve the problem of xanthate odor in the mineral processing workshop and thus improve the working environment of the mineral processing workshop still needs to be explored continuously. Summary of the Invention

[0007] The purpose of this invention is to provide a method for treating the off-odor of xanthate in mineral processing, which utilizes centrifugation and a hypergravity environment to increase the probability of inelastic collisions between detergent and CS2, thereby improving the CS2 removal rate.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a method for treating the off-odor of xanthate in mineral processing, which involves collecting the gas above the site or equipment with the off-odor of xanthate in the mineral processing workshop, passing it into a rotating centrifuge, and simultaneously passing a sodium hydroxide solution into the centrifuge, and then venting the gas out of the rotating centrifuge.

[0009] In the above scheme, the collected CS2-containing xanthate odorous gas enters a rotating centrifuge. Tiny CS2 droplets are intensely mixed and collided with a high-speed rotating atomized sodium hydroxide washing liquid within the centrifuge, causing the CS2 droplets to coalesce and react (2NaOH (liquid phase) + CS2 (oil phase) → Na2COS2 + H2O). Under the strong centrifugal force, the CS2 droplets separate from the gas phase and flow out of the centrifuge along with the washing liquid, thus achieving the purpose of waste gas purification. Using this scheme, the carbon disulfide content in the exhaust gas from the rotating centrifuge is reduced to below 5.5 ppm (carbon disulfide emission standard ≤1.5 kg / h), allowing for direct emission. Detailed Implementation

[0010] The technical solution of the present invention will be further described in detail below with reference to the embodiments.

[0011] A method for treating the off-odor of xanthate in mineral processing involves collecting the gas above the area or equipment in the mineral processing workshop where the off-odor of xanthate is present, and passing it into a rotating centrifuge. At the same time, a sodium hydroxide solution is passed through the centrifuge, and the gas is discharged from the rotating centrifuge.

[0012] The phrase "collecting the gas above areas or equipment in the mineral processing workshop that have a xanthate odor" specifically refers to installing sealed gas collection hoods in the reagent storage area, reagent mixing tank, reagent dosing platform, and flotation cell, with exhaust vents on the sealed gas collection hoods connected to a vacuum pump. The downstream of the vacuum pump is connected to the air inlet pipe of the rotating centrifuge. The sodium hydroxide solution has a mass concentration of 5-20%.

[0013] To improve exhaust quality, the exhaust of the rotating supergravity machine can be treated to remove water mist, that is, the exhaust air of the rotating supergravity machine is first treated by a demister before being discharged.

[0014] This invention employs a rotating hypergravity machine, a breakthrough technology for enhancing transport and multiphase reaction processes. "Hypergravity" places matter in an environment exceeding Earth's gravitational acceleration, thus accelerating chemical reactions. This hypergravity environment is achieved through a rotating centrifugal force field. In this field, the injected alkaline washing water is torn into liquid films, filaments, and droplets on the rotor surface. The liquid films are further torn into filaments, which, after being stretched and broken, contract into a liquid mist. The alkaline mist then undergoes inelastic collisions with insoluble CS2 microdroplets, coalescing back into liquid films or larger-diameter droplets. With a fixed liquid flow rate, smaller droplet diameters or a higher volume fraction of atomized liquid result in a larger liquid surface area, which increases the probability of inelastic collisions with the CS2 microdroplets.

[0015] The principle of the rotating centrifuge for purifying CS2 micro-droplets is to spray alkaline washing water onto a high-speed rotating rotor. The washing water is atomized by high-speed rotation, and the water mist is intensely stirred, mixed, and collided with the CS2 micro-droplets inside the centrifuge casing, causing the CS2 micro-droplets to condense. Under the strong action of centrifugal force, the CS2 micro-droplets are separated from the gas phase, and the separated CS2 micro-droplets flow out of the centrifuge along with the washing liquid, thereby achieving the purpose of purifying the CS2 micro-droplet exhaust gas.

[0016] Compared to conventional methods, centrifugal separation of CS2 liquid particles offers advantages such as high separation efficiency and small equipment size, while avoiding problems like equipment blockage and fire hazards. The liquid sprayed onto the rotor surface is forcibly atomized by centrifugal force, matching the droplet size with that of the CS2 liquid particles. This increases the probability of inelastic collisions between the droplets and CS2 liquid particles, thereby improving the CS2 removal rate.

[0017] According to the structure and operation of the rotating supergravity machine, the removal mechanism of CS2 liquid particles includes three aspects: (1) Rotational centrifugal separation: After entering the supergravity machine, the particles are separated by high-speed rotational centrifugal force; (2) High-frequency collision: The outer and inner cavities of the rotor are filled with tiny particles such as droplets and liquid films. High-speed rotation enhances the stirring and mixing with CS2 liquid particles, and the phase interface is rapidly renewed, which increases the inelastic collision frequency; (3) Filtration separation: When CS2 liquid particles pass through the packing layer of the supergravity machine rotor, the packing layer plays a filtering and separation role on the particles in the airflow.

[0018] Example

[0019] According to the above plan, sealed gas collection hoods are installed in the reagent storage area, reagent mixing tank, reagent dosing platform and flotation cell of the mineral processing workshop. The gas outlet of the sealed gas collection hood is connected to the air inlet of the rotating centrifuge through a vacuum pump. A sodium hydroxide solution with a mass concentration of 15% is introduced into the liquid inlet of the rotating centrifuge (a certain pressure can be applied to the sodium hydroxide solution entering the rotating centrifuge using a hydraulic pump). The exhaust gas of the rotating centrifuge enters the demister for demisting treatment and is then discharged into the air.

[0020] The CS2 odor gas concentration detector was used to detect the CS2 concentration of each device or site before and after the treatment of yellow medicine odor using the solution of this application. The test results are shown in Table 1.

[0021] Table 1 Comparison of CS2 concentrations before and after treatment at various sites or equipment

[0022] venue or equipment <![CDATA[CS2 concentration value (ppm) before adopting this solution]]> <![CDATA[CS2 concentration value (ppm) after adopting this solution]]> Pharmaceutical storage room 79.0 14.2 Pharmacy preparation platform 8.4 5.0 Pharmaceutical mixing tank 9.2 4.5 Mofu plant reagent platform 9.7 5.3 Operating fan outlet -- 5.5

[0023] The test data above shows that the rotational supergravity technology has a significant effect on removing the odor of yellow medicine.

Claims

1. A method for treating the off-odor of xanthate in mineral processing, characterized in that: The gas above the site or equipment in the ore dressing workshop that has a xanthate odor is collected and introduced into a rotating centrifuge, along with a sodium hydroxide solution. The gas from the rotating centrifuge is then discharged into the air.

2. The method for treating off-odors in xanthate processing according to claim 1, characterized in that: A sealed gas collection hood is installed in the drug storage area, drug mixing tank, drug dosing platform and flotation tank, and an exhaust hole is opened on the sealed gas collection hood to connect with the air pump. The downstream of the air pump is connected to the air inlet pipe of the rotating supergravity machine.

3. The method for treating off-odors in xanthate processing according to claim 1, characterized in that: The sodium hydroxide solution has a mass concentration of 5-20%.

4. The method for treating off-odors in xanthate processing according to claim 1, characterized in that: The air from the rotating supergravity machine is first defoamed by a demister before being discharged.