CN103515668A - Complete-set device for recycling metal in waste lithium battery - Google Patents

Abstract

A complete device for recycling metals from waste lithium batteries belongs to the technical field of environmental protection. Lithium, cobalt, copper, nickel, light rare earth and other materials can be extracted from waste lithium-ion batteries. The recycling of lithium batteries has huge potential commercial value, and its recycling prospects are broad. In this design, the waste lithium battery is first crushed and pretreated, fed, and then enters the baking room for a baking, and then enters the rotary incinerator for secondary combustion, and then continuously cools down three times, and performs exhaust gas purification, and finally the flue gas reaches the standard and is discharged into the atmosphere. In the process of exhausting the flue gas, a quenching device is used to quickly cool down the exhaust gas to prevent the generation of dioxins. The heat of the plate heat exchanger is recovered to achieve the purpose of resource utilization.

Description

A complete device for recycling metals from waste lithium batteries

Technical field

The invention relates to a complete set of equipment for recycling metals in waste lithium batteries. It belongs to the field of environmental protection technology.

Background technique

In 2011, my country's lithium-ion battery output was about 1.25 billion, becoming the world's largest producer and consumer of lithium-ion batteries. Lithium-ion batteries can generally be used for about 3 years. In 2012, the number of lithium-ion batteries discarded worldwide reached 1 billion.

Lithium, cobalt, copper, nickel, light rare earth and other materials can be extracted from waste lithium-ion batteries. The recycling of lithium batteries has huge potential commercial value, and its recycling prospects are broad. In addition, the polluting components of waste lithium batteries, such as chlorofluorocarbons, halogen flame retardants, mercury, selenium, nickel, lead, chromium, etc., if not properly disposed of and directly landfilled or incinerated, will cause pollution to the air, soil and water. severe pollution.

In China, the recycling method of scrap lithium batteries is the same as that of most other electronic wastes, which are landfilled, incinerated, and composted together with urban domestic waste. This simple lithium battery treatment method has had a serious impact on the natural environment. Since lithium batteries contain a large amount of lithium hexafluorophosphate (LiPF ₆ ) organic carbonate electrolyte, LiPF ₆ is highly corrosive and easily reacts with water to generate HF poisonous gas, while other refractory lithium batteries such as DME (methoxy Ethane), methanol, formic acid and other toxic and harmful substances will pollute the atmosphere, soil and water in direct contact with them, thereby endangering the human ecosystem and environment.

The main component of the positive electrode material of lithium-ion batteries is LiCoO ₂ . China is a cobalt-poor country, and the natural storage capacity is low. Metal cobalt mainly depends on imports to meet the demand, and cobalt is a heavy metal element. Heavy metal elements such as cobalt accumulate in the natural environment and will eventually harm humans. In addition, various metal materials of waste lithium-ion batteries have high recycling value. Therefore, if metals such as lithium, cobalt, copper, nickel, iron, and aluminum can be recovered from waste lithium-ion batteries, it will not only have significant economic benefits, but also It can avoid its pollution to the environment and has good social benefits.

Contents of the invention

The invention relates to a complete set of devices for recycling precious metals in waste lithium batteries. The whole set of waste lithium battery resource recycling system should be able to eliminate the environmental pollution caused by exhaust gas and residue discharge through a series of technological processes on the basis of realizing the recovery of precious metal resources. In order to meet the above requirements, the complete set of lithium battery resource recovery and treatment incinerator device includes the following equipment: baking chamber, waste lithium battery incinerator body, finned tube heat exchanger, quenching tower, exhaust waste heat recovery plate heat exchanger, feed and Pipeline system, electric control system, flue gas purification device, induced draft fan, independent chimney.

The present invention is realized by adopting the following technical methods.

(1) Pretreatment

Before the waste lithium battery enters the rotary incinerator, it is crushed and pretreated by a crusher. After crushing, the material with uniform size can significantly improve the combustion efficiency; and it can also reduce the content of CO in the exhaust gas. The crushed waste enters the pretreatment area for temporary storage, and mixes ingredients in the pretreatment area. The entire pretreatment area is also set in a closed micro-negative pressure state, and the air is introduced into the furnace through the furnace induced draft fan, so as to ensure that harmful gases are not released. Spill.

(2) Feed

The incineration system consists of a baking chamber, a rotary incinerator and a control system. After pretreatment and crushing, the waste lithium battery waste to be treated is proportioned in an appropriate proportion and then enters the heated feeder. The waste is sent to the incinerator feed port by the conveying device of the feeder to complete the feeding. The waste can be preheated in the feeder, from 20°C to 200°C, the heat of the whole preheating process is provided by the heat transfer oil at the outlet of the finned tube heat exchanger that has been cooled down once, and the heat transfer oil is passed into the jacket. After preheating the waste, the outlet temperature of the heat transfer oil drops to 230°C, and then continues to pass into the finned tube heat exchanger.

(3) Baking once

Under the action of the continuous rotation of the rotary incinerator, the waste material is constantly turned in the kiln, and first enters the baking chamber to separate the waste material electrolyte, and complete drying, gasification and preliminary combustion. After one baking, the waste material is further preheated, which is also conducive to improving the combustion efficiency and making the combustion more thorough.

(4) Secondary combustion

With the rotation of the kiln body, the waste will be moved to the middle part with higher temperature, pyrolysis will start, and the substances with low ignition point will start to burn; then move to the end of the kiln, the temperature will rise further, and the hazardous waste will be cracked into combustible gases such as carbon monoxide and waste residue . In the rotary incinerator, the hazardous waste is basically completely decomposed into combustible gas and residue through repeated turning and continuous propulsion of the waste and combustion of low ignition point gas.

(5) Cool down once

The flue gas at the outlet of the rotary incinerator first enters the finned tube heat exchanger (the flue gas is cooled to 800°C) to heat the heat transfer oil from the production workshop at 230°C to 260°C for waste preheating, and the temperature of the heat transfer oil at the outlet of the waste preheating system will be reduced It is lowered to 230°C, and then continues to pass through the finned tube heat exchanger to cool down the flue gas once, and recover part of the heat energy in the high-temperature flue gas again. The whole process realizes the effective recycling of heat in the same process flow .

(6) Second cooling

When the temperature is in the temperature range of 250-500°C, the regeneration reaction of dioxins will easily occur in the exhaust gas. Therefore, in order to avoid the regeneration of dioxins during the cooling process of the exhaust gas to the greatest extent, the heat exchange of finned tubes should be carried out. The flue gas at the outlet of the device quickly drops below 200°C in order to quickly "jump over" the formation temperature zone of dioxins. Technically, a flue gas quenching tower is used to reduce the flue gas to 200°C in a very short time of about 1 second. The quenching tower is quenched by spraying water, and the water spraying method in the quenching tower is mixed with the flue gas upstream, so that the temperature of the flue gas is rapidly reduced to avoid the strong area where dioxins are produced; in addition, the cooling water heated by the flue gas can For factory recycling.

(7) The third cooling

Since the flue gas temperature at the exit of the quenching tower is 200°C, if it is discharged into the air at this time, it will not only waste energy, but also cause thermal pollution of the atmosphere. Therefore, a third cooling is required. This step is completed by the tail gas waste heat recovery plate heat exchanger. After the third cooling, the outlet temperature of the plate heat exchanger drops to 150°C, which meets the flue gas temperature emission standard.

(8) Flue gas purification and emission

The flue gas at the outlet of the plate heat exchanger will enter the semi-dry reaction device for flue gas purification. Activated carbon and Ca(OH)2 are sprayed into the dry reaction device to further deacidify the flue gas, and to remove heavy metals and possibly reproduced Dioxin and other substances are adsorbed; the flue gas with a large amount of particulate matter comes out of the reaction tower and enters the subsequent bag filter, and part of the unreacted lime is attached to the filter bag and reacts again with the acid gas passing through the filter bag to remove The efficiency is further improved; finally, the last process of flue gas purification is wet deacidification, spraying lye into the wet deacidification tower to remove acid gases such as SO ₂ , HCl, HF, etc., to meet strict flue gas emission standards. Finally, the purified flue gas is heated to eliminate white smoke, and then sent into the chimney through the action of the induced draft fan to be discharged into the atmosphere.

The beneficial effects of the patent of the present invention are:

The design principle and method of the waste lithium battery metal recycling complete set designed by the present invention are simple and clear. On the basis of retaining the strong adaptability and stable and reliable operation of the rotary incinerator, the flue gas is processed by using a quenching tower and a heat exchanger. , so that the heat of exhaust flue gas, the removal rate of organic matter and the thermal ignition loss rate of incineration residue can meet the requirements of the national standard, and the heat can be recovered by heat exchange to realize the recycling of resources; at the same time, the emission of dioxin and carbon monoxide can be reduced, reaching The purpose of harmless disposal.

Description of drawings

Process flow chart of a complete set of equipment for metal recovery from waste lithium batteries

Detailed ways

The complete set of equipment for metal recovery in waste lithium batteries is described below in conjunction with the process flow chart of the complete set of equipment.

The present invention consists of a baking chamber, a waste lithium battery incinerator body, a finned tube heat exchanger, a quench tower, a plate heat exchanger for exhaust waste heat recovery, a feed and pipeline system, an electric control system, a flue gas purification device, an induced draft fan, independent chimney.

First, the waste lithium battery is crushed and pretreated, and the material is fed; then it enters the baking room for a baking, and then enters the rotary incinerator for secondary combustion to achieve full combustion and decomposition of the lithium battery; then it is discharged by the finned tube heat exchanger The flue gas is cooled once, and the heat-conducting oil used for cooling is used to preheat the lithium battery in the baking chamber; the flue gas discharged from the finned tube heat exchanger is rapidly cooled twice with a rapid cooling tower, skipping the dioxin in the flue gas Generate a temperature range to avoid the generation of dioxins; use a plate heat exchanger to cool the flue gas three times to make it reach the temperature standard for emission into the atmosphere, save energy and avoid thermal pollution; the flue gas at the outlet of the plate heat exchanger passes through The dry-dust removal-wet three-stage flue gas purification device performs sufficient deacidification and dust removal, and finally the harmless flue gas is discharged into the atmosphere through the chimney by the induced draft fan.

Claims (4)

1. this method is a kind of energy-conservation, innoxious, convenient and from waste lithium cell, reclaim efficiently the complete sets of equipment of metal.The present invention preheats and assembled set device that incineration system, tail gas waste heat recovering system and flue gas purification system form by curing, on the basis of adaptable, stable and reliable operation that has retained rotary incinerator, by application quench tower and heat exchanger, flue gas is processed, the hot burn decrement rate that makes to discharge the temperature of flue gas, organic clearance and incineration residue can meet the requirement of GB, heat is carried out to heat exchange recovery, realized resource regeneration; Reduce the discharge of dioxin and carbon monoxide simultaneously, reached the object of harmless treatment.

2. according to right 1, require the described the complete sets of equipment for waste lithium cell metal recovery, it is characterized in that preheating and incineration system, tail gas waste heat recovering system and flue gas purification system three parts form in order by curing.

3. according to right 1, require the described the complete sets of equipment for waste lithium cell metal recovery, it is characterized in that lithium battery was preheated by baking chamber before burning, its origin of heat flue gas heat that finned tube exchanger conduction oil reclaims in flue gas waste heat recovery system.

4. according to right 1, require the described the complete sets of equipment for waste lithium cell metal recovery, it is characterized in that flue gas purification system is by the equipment sequential combination mode of " dry type-dedusting-wet type " syllogic gas cleaning, can fully realize after burning lithium battery and produce deacidifying flue gas dedusting demand.