CN1727066A

CN1727066A - Method for processing worn-out fluorescent tube

Info

Publication number: CN1727066A
Application number: CNA200410021571XA
Authority: CN
Inventors: 张敬; 孙举柱; 孙德文; 金成日
Original assignee: LIDA ENVIRONMENT ENGINEERING Co Ltd DALIAN
Current assignee: LIDA ENVIRONMENT ENGINEERING Co Ltd DALIAN
Priority date: 2004-07-26
Filing date: 2004-07-26
Publication date: 2006-02-01
Anticipated expiration: 2024-07-26
Also published as: CN100400168C

Abstract

A method for treating the used fluorescent tube includes such steps as breaking in horizontal rotation breaker, absorbing the Hg gas by a absorbing system consisting of Venturi tubes and sprinkling tower suing the aqueous solution of potassium permanganate, separating metal from glass, washing glass with sulfuric acid solution to recover fluorescent powder, reducing the used solution of potassium permanganate by Fe powder, depositing, filter, treating the dregs, adding calcium chloride to the used sulfuric acid solution, reaction, and adding lime to neutralize the drained water.

Description

Method for treating waste fluorescent lamp tube

The technical field is as follows: the invention relates to centralized treatment and disposal of waste fluorescent tubes, and the method comprises the steps of collecting crushed mercury-containing gas, fluorescent powder and metal accessories, recycling the absorbed and washed liquid medicine and carrying out aftertreatment and discharge.

Background art: chinese patent publication No. 1182380 application No. 96193517.0, published in 1998, "method and system for mechanically separating various materials/substances from waste fluorescent tubes and similar broken lamps" includes a fan-driven exhaust air system designed for material debris and air transport and separation and supplying air from three separations. The fluorescent tubes are crushed by a crusher and conveyed to a first separation tower where larger material fragments are separated, while smaller material fragments and particles leave the tower together with the outflowing air, and the metal fragments from the sieve are passed through a metal crusher connected to a second separation tower. The magnetic separator separates magnetic material from a conveyor for glass and metal fragments. The glass fragments pass from the conveyor through a glass crusher connected to a third separation column. From the crude component outlet of the third column, the glass chips are conveyed through a rotary drum to a waste container. A cyclone with a downstream filter separates the phosphor from the exhaust air.

The invention content is as follows:

the invention provides a treatment method for integrally treating and recovering all components of a fluorescent tube, which aims to solve the problems of timely absorbing and separating mercury component gas after crushing the fluorescent tube and timely treating waste liquid of absorption and washing.

The waste fluorescent lamp tube treatment method is characterized in that waste fluorescent lamp tubes enter a crushing system and are crushed by a horizontal rotary crusher; the crushed glass fragments and waste metal enter a container storage box for containing water, and simultaneously, the generated mercury vapor enters an absorption system under the guidance of negative pressure airflow generated by a fan, the absorption system is subjected to two-stage absorption, the first stage is a Venturi tube absorption method, the second stage is a spray tower with a filler for absorption, and the absorption liquid is an aqueous solution of potassium permanganate; manually sorting the broken fluorescent tubes, sorting out metal and glass, and reusing aluminum; washing the sorted glass fragments to remove fluorescent powder, and then recycling the glass fragments, wherein the washing is reciprocating type vibrating screen spraying washing, the washing liquid is recycled, and a sulfuric acid solution is adopted for washing in the washing process; the mercury-containing potassium permanganate alkalescent wastewater is precipitated and filtered after the reaction is finished by adopting a sodium sulfide iron salt complexation and precipitation mode, the detected Hg of the effluent is less than 0.01mg/L, and the precipitated waste residue enters a residue treatment system; washing the weakly acidic waste water of the glass, removing mercury by adopting a sodium sulfide iron salt complexing andprecipitation mode, adjusting the pH value to 7 +/-0.3 by using acid and alkali, then adding calcium chloride for reaction, and finally adding lime into the effluent to adjust and neutralize, so as to remove fluoride ions. The detected fluorine and mercury in the water reach the discharge standard.

Compared with the prior art, the method has the advantages that the environment can be effectively protected by processing the waste fluorescent lamp tubes, resources are recycled, the mercury pollution problem of the waste fluorescent lamp tubes is effectively solved by utilizing the traditional mercury absorption method and combining the current requirement of environmental protection. The crushing is operated under negative pressure, so that the mercury-containing gas is prevented from leaking; indirect low-temperature heating ensures the recovery of glass and metal and realizes the purpose of resource utilization; part of mercury-containing waste gas is internally circulated to reduce the discharge amount of waste gas and reduce the treatment cost of waste gas.

Description of the drawings: the attached drawings show a flow block schematic diagram of a waste fluorescent tube treatment method and a used equipment schematic diagram of the invention, wherein fig. 1 is the flow block schematic diagram of the waste fluorescent tube treatment method, fig. 2 and 3 are a front view and a side view of crushing and absorbing unit equipment used in the waste fluorescent tube treatment method, fig. 4 is a schematic diagram of an internal structure of a crushing unit used in the waste fluorescent tube treatment method, and fig. 5 is a schematic diagram of a washing equipment structure used in the waste fluorescent tube treatment method. The invention is further illustrated by the following examples in connection with the accompanying drawings.

The specific embodiment is as follows:

the method for treating the waste fluorescent tubes comprises the following steps:

■ crushing and absorbing unit

Waste fluorescent lamp tube inletAnd (4) feeding into a crushing system, and crushing by adopting a horizontal rotary crusher 2. PowderBroken glass fragments and waste metal enter a container 3, mercury vapor generated at the same time enters an absorption system 8 under the guidance of negative pressure airflow generated by a fan 9, the absorption system is divided into two stages for absorption, the first stage is a Venturi tube 6 absorption method, the second stage is a spray tower 7 with a filter filler for absorption, the original absorption liquid is 1% potassium permanganate aqueous solution, and when the absorption concentration is reduced to 0.8%, the potassium permanganate is supplemented to increase the concentration to 1%, or the absorption liquid is replaced again. The consumption of the effective components in the absorption liquid is 0.7-0.8 million per treatment, the effective components are reduced by 0.1 percent (the total amount of the absorption liquid is 0.187 cubic meter), and the main chemical reactions in the absorption process are as follows:

■ separation unit

And manually sorting the broken fragments 4 of the fluorescent lamp tube, sorting out metal and glass, and reusing the metal aluminum.

■ washing unit

The ground glass is attached with a large amount of fluorescent powder, and the fluorescent powder can be recycled after being washed, the washing effect is mainly to see whether the fluorescent powder on the glass is washed clean, the washing method adopted at present is to wash by spraying a reciprocating vibrating screen, the washing liquid is recycled, and sulfuric acid and potassium permanganate solution are adopted for washing in the washing process. The original concentration of the sulfuric acid solution was 0.1% (PH ≈ 1.4) and the lower limit concentration of use was 0.05% (PH ═ 2), and the concentration of the washing solution should be always confirmed during the operation to ensure that the treatment effect can be achieved within the concentration range of 0.05-0.1%.

■ post-processing unit

Generation and treatment of wastewater: the waste water produced in the production process is two kinds, one kind is the alkalescent waste water containing mercury and potassium permanganate in the absorption process, and the main components are potassium permanganate, mercury oxide and Hg₂MnO₂(ii) a The weakly acidic waste water for washing glass contains fluorine, potassium permanganate, mercury oxide and Hg as main components₂MnO₂. The first waste water adopts a mode of complexing and precipitating sodium sulfide and ferric salt, precipitation and filtration are carried out after the reaction is finished, Hg of effluent is detected to be less than 0.01mg/L, and precipitated waste residues enter a residue treatment systemAnd (4) a system. And the second wastewater is firstly subjected to a complexing precipitation mode of sodium sulfide and ferric salt, then is subjected to pH regulation by acid and alkali, then is added with calcium chloride for reaction for 30 minutes, finally is added with lime for regulation and neutralization, and is filtered by a plate frame, and then the fluorine and mercury in the effluent reach the discharge standard.

Generating and treating waste residues: two kinds of waste residues are generated in the production process, one kind of waste residue is mercury-containing waste residue generated in the absorption liquid treatment process, and the residue can be used as a raw material for recovering mercury; or sulfur is added for reaction, and then cement is added for solidification and then the cement is discharged. One is the waste residue of fluorescent powder containing trace mercury generated by acidic waste water generated by washing glass, and is buried after being solidified.

Generation and treatment of exhaust gas: and mercury vapor generated in the crushing process and waste gas after being absorbed by the potassium permanganate solution reach the standard and are discharged. The emission concentration of mercury and compounds thereof in the detected waste gas is 5.0 multiplied by 10³mg/m³The index meets the requirements of the Integrated emission Standard of atmospheric pollutants (GB 16297-1996).

As shown in fig. 2, after entering the charging barrel 1 with an inclination angle of 45 °, the waste fluorescent tube slides into a crusher 2 by gravity (see the schematic diagram for the specific structure), the crushing is to crush the fluorescent tube 21 by using a plurality of fast rotating hobs 22 and a reasonable linear velocity and spatial structure of motion parameters (6 m/s-8.5 m/s), and the spatial structure parameters require that the gap between the hob and the stationary knife needs to be larger than the maximum outline size of the glass fragments of the waste fluorescent tube and smaller than the minimum outline size of the aluminum electrode base. The shape and the specification of the fragments are basically consistent, and meanwhile, the aluminum metal electrode seat is deformed and separated from the glass to enter the slag storage tank 3 to finish the crushing process. The crushed material is separately loaded into a crushed material box 4, meanwhile, a suction and dust-absorption (fluorescent powder) pipe is connected to the top of a negative pressure sealed slag storage box 3, the pipe is required to have rigidity and vibration damping property, a filter screen is added in front of the pipe interface, gas is introduced into a sealed high-pressure spray exchange reaction tower through a connecting pipe 5, the action process is as follows, when gas and dust enter an absorption system 6, absorption liquid is sprayed densely at the jet speed of 0.8-2 m/sForming a fog state, and achieving the purposes of dust removal (fluorescent powder) and first mercury vapor absorption. The high pressure nozzle orifice size is about § 1.0, where venturi absorption may also be used. The gas after primary purification is arranged at the bottom side of the spraying atomization chamberThe narrow slit enters a reverse spray packed tower 7 to continuously exchange and absorb mercury vapor, and the packing is made of polypropylene material. Finally, the absorbed gas is exhausted by a high-pressure draught fan 9, and the gas at an outlet 10 is monitored by an environment monitoring center in the large continuous market to obtain the result that the exhaust gas volume is 1.6 multiplied by 10³Ndm³Per h, mercury emission concentration of 4.6X 10^-3mg/Ndm³Mercury emission of 7.4X 10^-6Kg/h according to the new pollutant emission limit in the Integrated emission Standard for atmospheric pollutants (GB16297-1996), wherein the mercury emission concentration limit is 0.012mg/m³The discharge rate is subject to the second-level standard, when the height of the exhaust funnel is lower than 15 m, the exhaust funnel is subject to the strict 50% execution after the calculation by the extrapolation method, and the limit value of the discharge rate standard is 3.0 multiplied by 10^-5Kg/h. Therefore, the treated mercury-containing gas can completely reach the emission standard.

● washing unit

The crushed waste fluorescent tubes are manually sorted to remove waste metals, and then the waste fluorescent tubes enter a washing unit for treatment. As shown in figure 4, the integral treatment device comprises the following parts, the working principle is that after being crushed, the cullet with fluorescent powder is put into a hopper 11, the automatic metering and feeding amount is thrown onto vibrating

screens

13, 14, 15 and 16 and the cullet is conveyed forwards in a vibrating mode, a high-pressure pickling solution spray pipe 17 is arranged above the vibrating screens, the surface 12 of each vibrating screen is in a shallow groove type, and washing solution can stay in the shallow groove type for a period of time to completely clean the fluorescent powder on the surface of the cullet. A section of separating device is arranged on the vibrating screen to separate the washing liquid from the washed glass, and the washed glass enters a feed box 19 to be recycled. The wash liquid enters the waste water treatment device 18.

● Water treatment Unit

The water treatment unit mainly comprises a batch treatment reaction tank, a plate-and-frame filter press, a pump, a stirrer, a pH control system, a dosing system and the like which are matched with the batch treatment reaction tank and the plate-and-frame filter press, and the operation of the whole device is automatically controlled by a PLC.

Claims

1. A method for processing waste fluorescent tubes is characterized by comprising the following steps: crushing the waste fluorescent lamp tubes in a horizontal rotary crusher; the crushed glass fragments and waste metal enter a container storage box, simultaneously, the generated mercury-containing gas enters an absorption system under the guidance of negative pressure airflow generated by a fan, the absorption system is divided into two stages for absorption, the first stage is venturi tube absorption, the second stage is spray tower absorption with filter materials, and the absorption liquid is aqueous solution of potassium permanganate; manually sorting the broken fluorescent tubes to detect metals; washing the sorted glass fragments to remove fluorescent powder, and then recycling the glass fragments, wherein the washing is carried out by spraying and washing on a reciprocating vibrating screen, the washing liquid is recycled, and a mixed solution of sulfuric acid and potassium permanganate is adopted for washing in the washing process; the mercury-containing potassium permanganate alkalescent wastewater is precipitated and filtered after the reaction is finished by adopting a sodium sulfide iron salt complexation and precipitation mode, the detected Hg of the effluent is less than 0.01mg/L, and the precipitated waste residue enters a residue treatment system; washing the weakly acidic waste water of the glass, removing mercury by adopting a sodium sulfide iron salt complexing and precipitation mode, adjusting the pH value to 7 +/-0.3 by using acid and alkali, then adding calcium chloride for reaction, and finally adding lime into the effluent to adjust and neutralize, so as to remove fluoride ions. The detected fluorine and mercury in the water reach the discharge standard.