KR20190118347A - Separation of valuable metals from waste secondary batteries by alkaline fritting method - Google Patents

Abstract

The present invention provides a method of separating valuable metals from waste secondary batteries by an alkali fritting process. The method comprises: a first step of mixing metal oxides of the waste secondary batteries with solid KOH and NaOH to obtain a mixture; a second step of pulverizing the mixture by using mechanochemical equipment to obtain a pulverized mixture; a third step of roasting the pulverized mixture in a firing furnace by the alkali fritting process to obtain a roasted mixture; a fourth step of dissolving the roasted mixture in water and performing a floatation process to obtain floated CoO and NiO; and a fifth step of drying and recovering the floated CoO and NiO. According to the present invention, the method has an effect of enabling Co, Ni, Li and Mn in the oxides of the waste secondary batteries to be separated and then, recycled by the alkali fritting process. Particularly, according to the present invention, the method has an effect of improving energy activation of the mixture by mechanochemically treating the mixture to increase surface area of the mixture. Further, according to the present invention, the method has effects of not only enabling the valuable metals to be recycled as resources, but also minimizing environmental pollution by separating and recovering the valuable metals remained in the waste secondary batteries.

Description

Separation of valuable metals from waste secondary batteries by alkaline fritting method}

The present invention relates to a valuable metal separation method of a waste secondary battery using an alkali fritting method, and more particularly, an alkali fritting method for separating and recovering CO, Ni, Mn, and Li contained in the waste secondary battery. It relates to a valuable metal separation method of the used secondary battery.

In general, secondary batteries are mainly used in IT small home appliances for mobile phones and mobile devices. However, as the technology for increasing the capacity has been developed, the secondary batteries market is rapidly growing, especially in the medium and large sizes, as the use of batteries for electric vehicles and large-capacity energy storage devices is expanded. have.

As a result, the development of high-yielding recycling technology is expected to be accelerated. Therefore, the development of technology to minimize the processing chemicals and to set high recovery rate of resources to lower the manufacturing cost will eventually bring high profits in the recycling market and lead the competition in technology competition. It can be secured.

Among them, the positive electrode active material constituting the positive electrode of the secondary battery is the main target of recycling, and since a large amount and expensive valuable metals such as cobalt, Ni, Li and Mn are the core materials for secondary battery recycling, the positive electrode active material containing these metals Is a key to recycling technology, with high recovery rate without any loss during the recycling process.

Most secondary battery processes in Korea consist of shredding-classification-incineration-shredding-classification-extraction process, and the loss of cathode active materials containing valuable metals such as cobalt in the shredding and classification process is close to 10-20%. Got to.

In addition, copper, which is a negative electrode plate, aluminum of a positive electrode plate, a separator, an electrolyte, etc., is difficult to recycle due to crushing and incineration, and there is a problem in that loss occurs.

The biggest problem of the existing method is that the process is complicated and the main purpose is to recover cobalt and lithium, which is important in the waste secondary battery, and thus, other electrode components such as copper, aluminum, electrolyte, and separator are mostly crushed or incinerated. Even if it is not or is recovered, it is mostly difficult to recycle because it contains impurities.

In addition, as the crushing process and the classification process goes through several times, the loss rate of valuable metals such as cobalt and lithium increases, and there is a problem of waste acid treatment and crushed new wastes.

In addition, conventionally, after crushing a secondary battery, iron components are removed by magnetic lines, and non-metallic components, copper, and aluminum are separated by various methods such as specific gravity difference and air classification, and the cobalt component is first concentrated, followed by acid leaching. Wet recovery techniques that recover cobalt by precipitation, electrolytic extraction, and solvent extraction are the mainstream.

In particular, the wet recovery technique has a high loss rate of cobalt in powder in the crushing and separation process, which is a pretreatment process, and recovers high-purity cobalt in the wet concentration process, but it is difficult to process large quantities and has a problem of secondary environmental pollution by waste acid.

Recently, a dry treatment method by high temperature melting has been studied due to this problem, but there is an advantage that a large amount of treatment is possible and treatment problems such as waste acid do not occur, but unlike a wet process in which cobalt is selectively leached using acid, in a molten state Since there is a limit in separating metals other than cobalt, the purity of the cobalt is low, and a second refining process by wet treatment is required.

In addition, the above methods use hydrochloric acid or pickling waste liquid, or aqua regia solution, which is a mixed solution of hydrochloric acid and nitric acid, which causes problems of increased wastewater treatment costs and environmental problems due to the generation of strong acid wastewater. It became.

In addition, in order to separate valuable metals, some technologies for selectively separating specific materials from various metals and inorganic components contained in ores are applied. However, according to the methods disclosed in these prior arts, metals are not present with high separation efficiency. A large amount of basic wastewater is generated in a separation process of separating a calcium-based alkaline compound and the like, which causes a problem of a large increase in wastewater treatment cost.

Therefore, there is an urgent need for a method for recovering high-purity valuable metals more economically and easily.

Korean Unexamined Patent Publication No. 10-1997-0074957 (1997.12.10) Korea Patent Publication No. 10-0207041 (1999.07.01) Korea Patent Publication No. 10-0415448 (2004.01.24) Korean Patent Publication No. 10-1233779 (2013.02.15) Korea Patent Publication No. 10-1481366 (2015.01.14) Korea Patent Publication No. 10-1805704 (2017.12.08)

Therefore, the present invention has been made to solve the above conventional problems,

An object of the present invention is to provide a method for separating valuable metals of a waste secondary battery using an alkali fritting method to efficiently purify and recover valuable metals contained in the waste secondary battery and minimize recycling of by-products.

Valuable metal separation method of the waste secondary battery using the alkali fritting method of the present invention for achieving the above object,

A first step of mixing the metal oxide of the spent secondary battery with solid KOH and NaOH;

A second step of grinding the mixture using a mechanochemical facility (100);

A third step of roasting the pulverized mixture in a baking furnace using an alkali fritting method;

A fourth step of dissolving and floating the roasted mixture in water;

And a fifth step of drying and recovering the enriched CoO and NiO.

Wherein the third step is characterized in that the roasting operation to charge the pulverized mixture in a kiln and keep for 2 to 4 hours at 500 to 600 ℃.

On the other hand, the mechanochemical equipment 100 includes a first body 110 having an inlet 111 in the upper portion and the outlet 112 in the lower portion; A pair of primary crushing rollers 113 for crushing the mixture by rotating against the inner upper portion of the first body 110; A pair of secondary grinding rollers 114 which rotate in contact with each other at an inner middle of the first body 110 and provide a grinding protrusion radially in an outer diameter to secondary grind the mixture; A mesh network 115 formed on the inner lower portion of the first body 110 to sort the pulverized material by particle size; A storage tank 118 connected to the outlet 112 to store the pulverized product passing through the mesh network 115; A second body 120 connected to one side of the first body 110 to receive a pulverized product that does not pass through the mesh network 115; A plurality of grinding balls 121 inserted into the second body 120 to collide with the grinding material to be crushed; Discharge holes 122 for discharging the pulverized product passing through the grinding ball 121; A third body 130 connected to one side of the second body 120 to receive a pulverized product passing through the discharge hole 122; A grinding roller 131 which crushes the pulverized product while rotating in contact with the inner surface of the third body 130; A driving unit 132 for rotating the grinding roller 131; An outlet 133 formed at a lower portion of the third body 130 to discharge the pulverized product passing through the grinding roller 131; An elastic body 141 formed on the outer side of the first body 110 and the third body 130, respectively; A supporter 140 coupled to the outside of the elastic body 141; It characterized in that it comprises a; vibration unit 150 for supporting the lower portion of the support 140 to move up and down.

Here, one side of the mesh network 115 is rotated in the vertical direction about the rotating shaft 116 formed on the inner side of the first body 110, the other side of the inner side of the first body (110) It is characterized in that the connection with the spring 117 to be formed.

In particular, the inner surface of the third body 130 is characterized in that the grinding plate 134 is formed to be in contact with the grinding roller 131.

On the other hand, the vibration unit 150 is characterized in that the cam 150 to form a support rollers (151, 152) for supporting the lower portion of the support (140) on the top and bottom.

The present invention has the effect of separating and recycling Co, Ni and Li, Mn in the oxide of the waste secondary battery using an alkali fritting method.

In particular, the present invention has the effect of increasing the surface area through the mechanochemical treatment to improve energy activation.

In addition, the present invention has the effect of separating and recovering valuable metals remaining in the waste secondary battery to be recycled as a resource, as well as minimizing environmental pollution.

1 is a flow chart of the valuable metal separation method of the waste secondary battery using the alkali fritting method of the present invention.
Figure 2 is a cross-sectional view showing the structure of the mechanochemical plant in the present invention.

Hereinafter, the preferred manufacturing method of the present invention will be described in detail.

The present invention comprises a first step of mixing the metal oxide of the spent secondary battery with solid KOH and NaOH;

A second step of grinding the mixture using a mechanochemical facility (100);

A third step of roasting the pulverized mixture in a baking furnace using an alkali fritting method;

A fourth step of dissolving and floating the roasted mixture in water;

And a fifth step of drying and recovering the enriched CoO and NiO.

In the present invention, the metal oxide of the waste secondary battery means various forms such as scrap, jelly roll, slurry, waste battery, etc. generated from the waste secondary battery.

The metal oxide of the waste secondary battery is a pretreatment method performed to make it into a powder form, and the waste secondary battery is cut into a predetermined size, first classified and fired to separate the electrode active material and the current collector, and other organic materials and the separator are volatilized.

Next, the metal oxide of the fired waste secondary battery is classified secondly and sorted through specific gravity screening, magnetic screening, and the like to obtain the metal oxide of the waste secondary battery.

The waste secondary battery oxide thus obtained is mixed by reacting solid KOH and NaOH.

At this time, CO, Ni and Li, Mn is separated from the waste secondary battery oxide.

Here, LiO and MnO components, which are oxide components, are easily reacted with solid NaOH and KOH by alkali fritting when heated, melted into water-soluble substances, and CoO and NiO, which are unreacted substances, are precipitated.

The reason why the metal oxide of the spent secondary battery is mixed with KOH and NaOH, which are solid alkali components, is to reduce the oxide component in the byproduct to water solubility.

Next, a process of pulverizing the mixture of the metal oxide, solid KOH and NaOH of the waste secondary battery using the mechanochemical facility 100 will be described.

The mechanochemical facility 100 is provided with an inlet 111 for injecting a mixture of metal oxide and KOH and NaOH of the waste secondary battery in the upper portion and the outlet 112 in the lower portion as shown in FIG. First body 110; A pair of primary crushing rollers 113 for crushing the mixture by rotating against the inner upper portion of the first body 110; A pair of secondary grinding rollers 114 which rotate in contact with each other at an inner middle of the first body 110 and provide a grinding protrusion radially in an outer diameter to secondary grind the mixture; A mesh network 115 formed on the inner lower portion of the first body 110 to sort the pulverized material by particle size; A storage tank 118 connected to the outlet 112 to store the pulverized product passing through the mesh network 115; A second body 120 connected to one side of the first body 110 to receive a pulverized product that does not pass through the mesh network 115; A plurality of grinding balls 121 inserted into the second body 120 to collide with the grinding material to be crushed; Discharge holes 122 for discharging the pulverized product passing through the grinding ball 121; A third body 130 connected to one side of the second body 120 to receive a pulverized product passing through the discharge hole 122; A grinding roller 131 which crushes the pulverized product while rotating in contact with the inner surface of the third body 130; A driving unit 132 for rotating the grinding roller 131; An outlet 133 formed at a lower portion of the third body 130 to discharge the pulverized product passing through the grinding roller 131; An elastic body 141 formed on the outer side of the first body 110 and the third body 130, respectively; A supporter 140 coupled to the outside of the elastic body 141; It includes; a vibration unit 150 for supporting the lower portion of the support 140 to move up and down.

At this time, the first body 110 is a mixture of the metal oxide and KOH and NaOH of the waste secondary battery to be introduced into the powder form while sequentially passing through the primary grinding roller 113 and secondary grinding roller 114 Proceed with grinding.

Particularly, the primary grinding roller 113 grinds a mixture of metal oxide, KOH and NaOH of the waste secondary battery in a smooth outer diameter, and the secondary grinding roller 114 provides a radial grinding mill at an outer diameter to close the waste. It is possible to improve the grinding efficiency of the mixture of the metal oxide and KOH and NaOH of the secondary battery.

In addition, the mesh network 115 is a means for sorting the pulverized material of the metal oxide and KOH and NaOH by the particle size of the waste secondary battery, the pulverized material passing through the mesh network 115 to the storage tank 118 The pulverized product that is not supplied and is not passed due to a large particle size may be supplied into the second body 120.

Here, one side of the mesh network 115 is rotated in the vertical direction about the rotating shaft 116 formed on the inner side of the first body 110, the other side of the inner side of the first body (110) In conjunction with the spring 117 to be formed, the mesh net 115 can be shaken up and down to smoothly sort the pulverized by particle size.

On the other hand, the metal oxide of the secondary battery and the KOH and NaOH crushed to be supplied to the inside of the second body 120 is crushed while colliding with a plurality of the grinding balls 121.

In this case, the diameter of the grinding ball 121 may be formed to have various diameters according to the grinding efficiency.

In this way, the metal oxide of the waste secondary battery and the pulverized product of KOH and NaOH pass through the discharge hole 122 and are supplied into the third body 130.

In particular, the metal oxide of the secondary battery supplied to the inside of the third body 130 and the pulverized product of KOH and NaOH may be formed between the outer diameter of the rotating roller 131 and the inner surface of the third body 130. As it passes through, it is finely pulverized and at the same time the surface area is increased to activate energy.

At this time, the inner surface of the third body 130 may be provided to be in contact with the grinding roller 131 by forming a grinding plate 134.

In addition, the vibration unit 150 causes the vibration by moving up and down the elastic body 141 and the support 140, respectively formed on the outside of the first body 110 and the third body 130 to increase the grinding efficiency Can be improved.

At this time, the elastic body 141 is guided to be moved up and down and left and right by the operation of the vibration unit 150 using a spring or the like.

Here, the vibration unit 150 is composed of a cam 150 to form a support roller (151, 152) for supporting the lower portion of the support 140 in the upper and lower portions to rotate the cam 150 to the support The support 140 may be moved up and down according to the positions of the rollers 151 and 152.

In this case, the support rollers 151 and 152 may have different diameters to set different positions for moving the supporter 140 up and down according to the rotation operation of the cam 150.

As such, the metal oxide of the waste secondary battery and the pulverized product of KOH and NaOH may increase the surface area to improve the chemical reaction efficiency.

Next, the ground mixture is roasted in a kiln using an alkali fritting method.

Here, the alkali fritting method is produced in a powder form in which the reaction occurs at a low temperature of about 550 ° C. and the material coming out after the reaction is easily dissolved in water instead of a solid melt.

Therefore, by charging the pulverized mixture into a kiln and maintaining the baking operation at 500 to 600 ° C for 2 to 4 hours, it is possible to react with impurities in the mixture to separate CO and Ni using oxide and specific gravity difference.

At this time, Li and Mn components in the oxide react in the kiln, CoO, NiO unreacted.

Particularly, the firing temperature is preferably 500 to 600 ° C., which means that when the firing temperature is less than 500 ° C., CoO and NiO do not precipitate to the oxide surface. On the contrary, when the firing temperature is above 600 ° C., CaO, SiO, Reaction of MgO, MnO, AlO, and S component is inadequate.

In addition, when the firing time is less than 2 hours, firing is not sufficient, and when the firing time is more than 4 hours, it is not preferable in terms of energy loss.

Next, the roasted mixture is introduced into the buoy, and then the stirring blades installed inside the buoy are rotated to generate bubbles to separate CoO and NiO from the waste secondary battery oxide due to the difference in specific gravity.

CoO and NiO thus removed are recovered by filtration and drying after washing.

Specifically, Li and Mn components of the secondary battery oxides are dissolved in a solution when water is added by reacting with an alkali, and the oxides are suspended in an aqueous solution in powder form.

Thereafter, the aqueous solution is passed through a funnel-shaped filter equipped with a filter.

Then, the aqueous solution in which the Li and Mn components are dissolved is collected through the filter and collected in the lower collector, and the CoO and NiO components suspended in the aqueous solution do not pass through the filter and remain on the filter.

Since the remaining components on the top of the filter is CoO and NiO, it may be used after reducing and drying the metal of Co and Ni.

Therefore, in the present invention, the waste secondary battery oxide is calcined with KOH, NaOH, etc., dissolved, and then flotation is carried out to separate CoO and NiO by using a specific gravity difference. It can be recovered.

As described above, the embodiments of the present invention have been described in detail, but the scope of the present invention is not limited thereto, and it is natural that the present invention is included in the scope of the present invention to a configuration that is substantially equivalent to the embodiments of the present invention. Do.

Claims (6)

A first step of mixing the metal oxide of the spent secondary battery with solid KOH and NaOH;
A second step of grinding the mixture using a mechanochemical facility;
A third step of roasting the pulverized mixture in a baking furnace using an alkali fritting method;
A fourth step of dissolving and floating the roasted mixture in water;
And a fifth step of drying and recovering the bared CoO and NiO. 5. The valuable metal separation of the waste secondary battery using the alkaline fritting method according to claim 1, wherein the third step is to charge the pulverized mixture into a calcination furnace and carry out roasting while maintaining the mixture at 500 to 600 ° C. for 2 to 4 hours. Way. The apparatus of claim 1, wherein the mechanochemical plant comprises: a first body having an inlet at an upper portion thereof and an outlet at a lower portion thereof; A pair of primary grinding rollers which crush the mixture by rotating against the inner upper portion of the first body; A pair of secondary grinding rollers which rotate in contact with each other at an inner middle of the first body, and provide a grinding protrusion radially to an outer diameter to secondary grind the mixture; A mesh net formed on the inner lower portion of the first body to sort the pulverized product by particle size; A storage tank connected to the outlet to store the pulverized product passing through the mesh network; A second main body connected to one side of the first main body to receive a pulverized product not passing through the mesh network; A plurality of grinding balls inserted into the second body to collide with the grinding material to be ground; A discharge hole for discharging the pulverized product passing through the grinding ball; A third main body connected to one side of the second main body to receive a pulverized product passing through the discharge hole; A grinding roller for pulverizing a pulverized product while rotating in contact with the inner surface of the third body; A drive unit for rotating the grinding roller; A discharge port formed at a lower portion of the third body to discharge the pulverized product passing through the grinding roller; Elastic bodies respectively formed on the outer sides of the first body and the third body; A supporter coupled to an outer side of the elastic body; Vibration unit for supporting the lower portion of the support to move up and down; The valuable metal separation method of the waste secondary battery using an alkaline fritting method comprising a. The method of claim 3, wherein one side of the mesh network is rotated in the vertical direction around the rotational shaft formed on the inner side of the first body, the other side is connected to the spring formed on the other side of the inside of the first body. Valuable metal separation method of a spent secondary battery using an alkali fritting method. The method of claim 3, wherein the inner surface of the third body to form a grinding plate to contact with the grinding roller, characterized in that the valuable metal separation method of the spent secondary battery using the alkaline fritting method. The method of claim 3, wherein the vibration unit is a valuable metal separation method of the waste secondary battery using an alkaline fritting method, characterized in that the cam forming the support roller for supporting the lower portion of the support on the top and bottom.

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