WO2015152457A1

WO2015152457A1 - Method for separating and recovering silver and tin from anode slime

Info

Publication number: WO2015152457A1
Application number: PCT/KR2014/003892
Authority: WO
Inventors: 이강명; 이기웅; 김홍인; 김광중; 손현태
Original assignee: 성일하이텍(주)
Priority date: 2014-03-31
Filing date: 2014-04-30
Publication date: 2015-10-08
Also published as: KR101481366B1

Abstract

The present invention relates to a method for separating and recovering silver and tin from anode slime and, more particularly, to a method for separating and recovering silver and tin from anode slime, comprising the steps of: putting anode slime, which had no electrochemical involvement in electrolysis, in a strong acid solution to stir the same, and then filtering the same; recovering silver by washing the residue obtained through the filtration step; and recovering tin from the residue by adding a hydroxide to a filtered solution obtained through the filtration step and filtering the same.

Description

Method for separation and recovery of silver and tin from anode slime

The present invention relates to a method for separating and recovering silver and tin from a cathode slime which is not electrochemically participated in electrolysis.

The soluble residue of the metal is called the anode slime when it is electrolyzed when it is electrolyzed.

Generally, electronic scrap wastes such as printed circuit boards and electronic parts are made of copper such as copper (Cu), iron (Fe), nickel (Ni), tin (Sn), lead (Pb), aluminum (Al), zinc About 30% of noble metal components such as gold (Au), silver (Ag), and palladium (Pd) are mixed. Among the electronic scraps, the printed circuit board has the above-mentioned valuable noble metal in the printed circuit board, the edge connectors printed on the surface thereof, and the semiconductor elements such as ICs and transistors which are integrated circuits disposed thereon. As such, electronic scrap (hereinafter referred to as electronic scrap) comprising an electronic component such as a printed circuit network of a valuable metal printed on a printed circuit board itself, an edge connector and an integrated circuit (IC) mounted on a printed circuit board, ) Is separated from a printed circuit board to recover valuable metals. The method involves a complicated sorting process in various stages, separating plastics and valuable metals from each other, sorting the selected valuable metals back into a wet or dry smelting process A refining process such as an electrochemical process is optionally used to finally sort and collect valuable metals such as Au, Ag, Pd, Cu and the like, such as precious metals, and recycle them. Low-purity Cu anodes containing noble metals obtained by the refining process are usually dissolved in the anode and electrodeposited in high-purity Cu from the cathode, and the noble metals are concentrated in the anode slime. As described above, although there is a wet method as a method for recovering the noble metal from the anode slime, silver and tin can not be separated and recovered, and the purity of silver and tin is low.

As a prior art related to this, there is a method for producing high purity reduced silver disclosed in Korean Patent Laid-Open No. 10-1997-0074957 (published on Dec. 10, 1997).

Accordingly, the present invention provides a method for selectively separating and recovering silver and tin from a cathode slime.

The problems to be solved by the present invention are not limited to the above-mentioned problem (s), and another problem (s) not mentioned can be understood by those skilled in the art from the following description.

In order to solve the above-described problems, the present invention provides a method for manufacturing a lithium secondary battery, comprising: electrochemically injecting a cathode slime not participating in electrolysis into a strong acid solution; Washing the residue obtained in the filtration step to recover silver; And recovering tin from the residue by adding hydroxide to the filtration solution obtained in the filtration step and filtering the recovered tin and the tin from the anode slime.

At this time, the strong acid solution is a mixed solution of a hydrochloric acid solution and a nitric acid solution, and the hydrochloric acid solution and the nitric acid solution are mixed at a volume ratio of 1: 0.05-0.1.

The positive slurry and the strong acid solution are mixed at a liquid ratio of 45 to 55% (volume of positive slurry (g) / volume (ml) of strong acid solution).

The mixing of the positive slurry and the strong acid solution is performed at a temperature of 70 to 80 ° C.

The hydroxide may be selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonia, magnesium hydroxide, and iron hydroxide.

The hydroxide is characterized in that it is mixed with the filtrate solution in a liquid ratio of 15 to 25% (weight of hydroxide (g) / volume (ml) of filtration solution).

The antifoaming agent may further include a defoaming agent, and dimethylpolysiloxane or silica oil may be used as the defoaming agent.

The flocculant may further include one selected from the group consisting of polychlorinated aluminum, aluminum sulfate and ferric chloride, and the activated carbon may contain 10 to 30 wt% of tin %. &Lt; / RTI >

According to the present invention, silver and tin contained in the residue can be recovered in high purity from the residue (slime) which is not electrochemically dissolved when electrolysis is carried out using a metal as an anode, and selectively separated by silver and tin, .

1 is a flowchart showing a method of separating and recovering silver and tin from a cathode slime according to the present invention.

FIG. 2 is a graph showing the concentration of elements contained in residues according to the amount of nitric acid added in the separation and recovery method of silver and tin from a cathode slime according to the present invention. FIG.

FIG. 3 is a graph showing the concentrations of metals contained in tin residues after silver recovery in the separation and recovery method of silver and tin from a cathode slime according to the present invention.

4 is a graph showing the concentration of metal contained in the filtered solution after recovery of tin in the method of separating and recovering silver and tin from the anode slime according to the present invention.

FIG. 5 is a graph showing the filtration rate according to the addition of coagulant and activated carbon in the separation and recovery method of silver and tin from the anode slime according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving it will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings.

The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

The present invention relates to a method for producing a slurry, which comprises: mixing a slurry of a positive electrode into a strong acid solution and stirring the slurry;

Washing the residue obtained in the filtration step to recover silver; And

And recovering tin from the residue by adding a hydroxide to the filtrate obtained in the filtration step and filtering the recovered tin.

The method of separating and recovering silver and tin from the cathode slime according to the present invention is capable of recovering silver and tin contained in the residue from the remaining slurry (slime) with high purity without electrochemically dissolving when electrolysis is carried out using a metal as an anode, And tin, and can be recovered at a high recovery rate.

1 is a flowchart showing a method of separating and recovering silver and tin from a cathode slime according to the present invention. Hereinafter, the present invention will be described in detail with reference to Fig.

The method for separating and recovering silver and tin from the cathode slime according to the present invention includes a step (S10) of mixing a cathode slime which is not electrochemically dissolved in a strong acid solution, stirring the solution and filtering the slurry.

In the method of separating and recovering silver and tin from a cathode slime according to the present invention, the cathode slime does not participate in electrochemical electrolysis, and the strong acid solution is a mixed solution of a hydrochloric acid solution and a nitric acid solution, 1: 0.05 to 0.1 by volume. When the volume ratio is less than 0.05, there is a problem in that silver and tin are contained in the residue as well as silver and the silver and tin can not be recovered. When the volume ratio is more than 0.1, lead content in the residue is increased to increase the impurity content There is a problem of increasing. The concentration of the hydrochloric acid solution is 92 to 97%, and the concentration of the nitric acid solution is 3 to 8%.

It is preferable that the anode slime and the strong acid solution are mixed at a liquid ratio (anode slime weight (g) / volume (ml) of strong acid solution) of 45 to 55%. When the solid-liquid ratio is less than 45%, there is a problem that a sufficient amount of metal is not dissolved because the anode slime is less than that of the strong acid solution, and when the solid ratio exceeds 55%, unreacted materials that have not reacted with strong acid are increased have.

The mixing of the positive slurry and the strong acid solution is preferably performed at a temperature of 70 to 80 ° C. When the temperature is lower than 70 ° C., there is a problem that copper or tin is contained in the residue after the filtration step to separate them from silver. When the temperature exceeds 80 ° C., the addition amount of defoamer and water for removing bubbles due to a violent reaction There is an increasing problem.

The method of separating and recovering silver and tin from the anode slime according to the present invention may further include an antifoaming agent during the stirring. The antifoaming agent may be a silicone-based antifoaming agent and may remove bubbles or bubbles. Specifically, dimethylpolysiloxane, silica oil, etc. may be used.

Next, a method for separating and recovering silver and tin from the cathode slime according to the present invention includes a step (S20) of washing the residue obtained in the filtration step to recover silver.

When the filtration process is performed with a general filter paper or vacuum filtration, it can be separated into a residue and a filtrate solution. The filtered residue contains a large amount of silver, and the silver can be recovered after washing it.

The method of separating and recovering silver and tin from the anode slime according to the present invention includes a step (S30) of adding hydroxide to the filtration solution obtained in the filtration step, and recovering tin from the filtrate by filtration.

The remaining filtrate after recovering the silver from the residue separated by the filtration process contains a large amount of tin. In order to recover the tin, hydroxide is added to adjust the pH of the filtrate to 1.1-1.5 to recover tin have.

The hydroxide may be one selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonia, magnesium hydroxide and iron hydroxide, and the hydroxide may be used in an amount of 15-25% by weight of the filtrate solution (hydroxide weight (g) Volume (ml) of the solution). When the solid-liquid ratio is less than 15%, there is a problem that the amount of tin recovered is small. When the solid-liquid ratio exceeds 25%, there is a problem that tin contains impurities such as lead and copper after silver recovery.

The method of separating and recovering silver and tin from the anode slime according to the present invention may further comprise a flocculant or activated carbon after the hydroxide addition.

The coagulant or activated carbon serves as a carrier capable of coagulating tin or supporting tin, and the coagulant may be one selected from the group consisting of polychlorinated aluminum, aluminum sulfate and ferric chloride, Is preferably contained in an amount of 10 to 30% by weight of the tin. When the activated carbon is contained in an amount of less than 10% by weight of tin, the filtration time is long. In the case of exceeding 30% by weight, the filtration time is not shortened further. proper.

Example 1: Separation of Silver and Tin from a Positive Slime 1

10 kg of Sn-Ag slime was added little by little to a solution of 20 L of hydrochloric acid and 1 L of nitric acid. When the Sn-Ag slime was added to the mixed solution, the temperature was raised to 80 ° C and stirred for 5 minutes at 1 hour. The bubbles were removed by using about 15 ml of defoamer in order to remove bubbles at 50 ℃ when the temperature was raised.

The filtrate was subjected to primary filtration using a filter paper to recover silver from the filtrate residue.

5 M NaOH was added to the filtrate so as to adjust the pH to 1.1 to 1.5 by adding a liquid ratio (NaOH content / filtrate volume) of 20% to the filtrate, and then activated carbon was added in an amount of 10% by weight of the tin contained in the filtrate After secondary filtration, tin was recovered from the residue.

Table 1 below shows the ICP analysis results of the anode slime.

Table 1

element	Content before moisture removal (%)	Content after moisture removal (%)
Ag	15.25	27.38
Sn	17.53	31.48
Pb	4.14	7.42
Cu	7.34	13.17

Example 2: Number of separations of silver and tin from the anode slime 2

4 kg of Sn-Ag slime was added, and silver and tin were removed in the same manner as in Example 1, except that bubbles were removed by using about 1 L of water to remove bubbles during sample loading Respectively.

Experimental Example 1: Separation of yield of silver

In the separation and recovery method of silver and tin from the anode slime according to the present invention, the amounts of the elements in the residue and the filtrate solution after the filtration process were analyzed, and the results are shown in Tables 2 to 5.

Tables 2 and 3 below show that 10 kg of the anode slime is used (Example 1).

Table 2

element	Primary filtration solution (ppm)	Primary filtered residue (ppm)
Ag	28	4894
Sn	142200	117

As shown in Table 2, only 28 ppm of Ag remained in the primary filtrate solution and 4894 ppm of Ag remained in the filtered residue by the separation and recovery method of the present invention. On the other hand, Sn can be recovered by separating Ag since 142200 ppm remains in the filtrate solution.

Table 3

element	Primary filtration solution	Primary residue	Recovery of primary filtrate	Primary filtration residue recovery rate
Ag	0.7507g	1675.116 g	0.1%	109.8%
Sn	3812.382g	40.014 g	217.5%	2.3%

As shown in Table 3, the filtrate obtained by the primary filtration process contained a large amount of tin, and the residue obtained by the primary filtration process contained a large amount of Ag, and silver was recovered from the residue. In addition, the primary filtration residue recovery rate was 109.8%, and the recovery of silver was 99% or more, and the recovery rate of the primary filtration solution was 217.5%, and the tin content could be recovered to 99% or more.

Tables 4 and 5 below show that the positive electrode slime is used at 4 kg (Example 2).

Table 4

element	Primary filtration solution (ppm)	Primary filtered residue (ppm)
Ag	31	5209
Sn	45980	123

As shown in Table 4, only 31 ppm of Ag remained in the primary filtrate by the separation and recovery method of the present invention, and 5209 ppm of Ag remained in the filtered residue. On the other hand, 45980 ppm of Sn remains in the filtrate solution, and Ag can be separated and recovered.

Table 5

element	Primary filtration solution	Primary residue	Recovery of primary filtrate	Primary filtration residue recovery rate
Ag	0.7518 g	729.26 g	0.1%	119.5%
Sn	1115.015 g	17.22 g	159.1%	2.4%

As shown in Table 5, the filtrate obtained by the primary filtration process contained a large amount of tin, and the residue obtained by the primary filtration process contained a large amount of Ag, and silver was recovered from the residue. In addition, the primary filtration residue recovery rate was 119.5%, and the recovery rate of silver was 99% or more, and the recovery rate of the primary filtrate was 159.1%, indicating that the tin content could be recovered to 99% or more.

Experimental Example 2: Analysis of concentration in residue according to amount of nitric acid

The concentration of the elements in the residue according to the amount of nitric acid added in the separation and recovery method of silver and tin from the anode slime according to the present invention was analyzed and the results are shown in FIG.

As shown in FIG. 2, when the amount of nitric acid is 0.01 volume ratio (1%), a large amount of tin is contained in the residue. Therefore, the hydrochloric acid solution and the nitric acid solution are preferably mixed in a volume ratio of 1: 0.05-0.1.

Experimental Example 3: Separation of Tin by pH

In the separation and recovery method of silver and tin from the anode slime according to the present invention, the amounts of the elements according to pH in the residue and filtrate obtained by the filtration step after the addition of sodium hydroxide were analyzed, and the results are shown in Tables 6 and 7 And FIG. 4, respectively.

Table 6

pH	Sn (ppm)	Ag (ppm)	Pb (ppm)	Cu (ppm)	Fe (ppm)
1.1	3625	0.8	8.63	88.1	86.9
1.5	3388	1.2	11.83	108.1	121.4
1.8	3066	1.55	20.21	147.6	102.1
2.8	2856	17.49	53.56	232.9	25.61

As shown in Table 6, the residue obtained by filtration after adding sodium hydroxide exhibited a large amount of tin and a small amount of Ag at pH 1.1 to 1.5, but the amount of Ag was increased at a pH of 1.8 or more And the amount of Pb, Cu and Fe increases sharply as the pH is increased, so that it is preferable to add sodium hydroxide so that the pH is in the range of 1.1 to 1.5.

Table 7

pH	Sn (ppm)	Ag (ppm)	Pb (ppm)	Cu (ppm)	Fe (ppm)	Recovery rate
1.1	823	52.66	465	3300	680	99.1
1.5	733.6	44.39	429	2997	520	99.39%
1.8	46.62	45.37	410.7	2659	55.47	99.96%
2.8	0	42.22	233.8	799.1	ND	100

As shown in Table 7, in the filtrate obtained by filtration after adding sodium hydroxide, most tin was recovered from the residue, and a small amount of tin was found. It was found that almost 99% or more of tin was recovered from the residue Able to know.

FIG. 3 is a graph showing the concentrations of metals contained in tin residues after silver recovery in the method of separating and recovering silver and tin from a cathode slime according to the present invention. FIG. 4 is a graph showing the concentrations of metals and tin Which is a graph showing the concentration of the metal contained in the filtered solution after tin recovery in the method. Separation experiments HCl: HNO ₃ = 1: 0.05, and mixed in a solid-liquid ratio (aqueous sodium hydroxide (g) / filtered solution (ml)) was mixed with 20% was carried out at 80 ℃.

As shown in FIG. 3, it can be seen that most of Sn was recovered at pH 1.1 to 1.5, and it was found that a large amount of Cu was contained at pH 1.8 and 2.8, and the amount of Ag in the tin residue was also increased .

Also, as shown in FIG. 4, it can be seen that a trace amount of Sn remained at pH 1.1 and 1.5, but most of the tin was recovered, and the amount of Cu and Pb was increased as the pH was increased.

Experimental Example 4: Filtration Rate Analysis According to Activated Carbon and Coagulant

The filtration rate according to addition of coagulant and activated carbon was analyzed in the separation and recovery method of silver and tin from the anode slime according to the present invention, and the result is shown in FIG.

Separation and recovery of silver and tin were carried out by mixing HCl: HNO ₃ = 1: 0.05 and 20% of liquid ratio (sodium hydroxide (g) / filtrate (ml)).

As shown in FIG. 5, tin can be recovered by adding a flocculant or activated carbon. However, it can be seen that the use of activated carbon is faster than the use of flocculant. In particular, when 10 wt% of activated carbon was used, it was found that filtration time was almost the same as that of using 30 wt% of activated carbon.

Although a specific embodiment of the method of separating and recovering silver and tin from the positive electrode slime according to the present invention has been described, it is apparent that various modifications are possible within the scope of the present invention.

Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

It is to be understood that the foregoing embodiments are illustrative and not restrictive in all respects and that the scope of the present invention is indicated by the appended claims rather than the foregoing description, It is intended that all changes and modifications derived from the equivalent concept be included within the scope of the present invention.

Claims

Mixing the positive slurry into a strong acid solution, stirring the solution, and filtering;

Washing the residue obtained in the filtration step to recover silver; And

And recovering tin from the residue by adding a hydroxide to the filtrate obtained in the filtration step and filtering the recovered tin.
The method according to claim 1,

Wherein the strong acid solution is a mixed solution of a hydrochloric acid solution and a nitric acid solution.
3. The method of claim 2,

Wherein the hydrochloric acid solution and the nitric acid solution are mixed at a volume ratio of 1: 0.05-0.1.
The method according to claim 1,

Wherein the anode slurry and the strong acid solution are mixed at a liquid ratio of 45 to 55% (volume of anode slime (g) / volume (ml) of strong acid solution).
The method according to claim 1,

Wherein the mixing of the positive slurry and the strong acid solution is performed at a temperature of 70 to 80 캜.
The method according to claim 1,

Wherein the hydroxide is one selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonia, magnesium hydroxide and iron hydroxide.
The method according to claim 1,

Wherein the hydroxides are mixed at a liquid ratio of 15 to 25% (hydroxide weight (g) / volume (ml) of filtration solution) to the filtrate solution.
The method according to claim 1,

The method of separating and recovering silver and tin from a cathode slime according to claim 1, further comprising a defoaming agent.
The method according to claim 1,

Wherein the antifoaming agent is dimethylpolysiloxane or silica oil.
The method according to claim 1,

The method of separating and recovering silver and tin from a positive electrode slime according to claim 1, further comprising a flocculant or activated carbon after the addition of the sodium hydroxide.
11. The method of claim 10,

Wherein the flocculant is one selected from the group consisting of polychlorinated aluminum, aluminum sulfate and ferric chloride.
11. The method of claim 10,

Wherein the activated carbon comprises 10 to 30% by weight of tin.