KR20070071174A - Electrogenerated chlorine leaching apparatus - Google Patents

Abstract

A very simple leaching process which has a very high leaching efficiency during leaching and promptly recovers leached valuable metal components at the same time by using an electroleaching apparatus, and the electroleaching apparatus used in the leaching process are provided. An apparatus for electroleaching valuable metals using chlorine or chlorine compounds comprises: a leaching reaction chamber(1) and a leached metal recovery reaction chamber(2) divided by a membrane(3); an oxidation electrode(5) installed in the leaching reaction chamber, and a reduction electrode(6) installed in the leached metal recovery reaction chamber so as to produce electrogenerated chlorine or chlorine compounds; and a separation refiner(9). The leaching reaction chamber further includes a stirring rod(7), a stirring motor(8) for driving the stirring rod, and a sealing cover(4).

Description

Electrolytic leaching apparatus using electrolytically generated chlorine or chlorine compounds

1 is a cross-sectional view of the electroleaching apparatus of the present invention.

Explanation of symbols on main parts of drawing

1 Leaching Reaction Chamber 2 Recovery Reaction Chamber

3 separator 4 cover

5 anode 6 cathode

7 Stirring Rod 8 Stirring Motor

9 Separator / purifier

The present invention relates to leaching of valuable metals by electrochemically generated chlorine or chlorine compounds and an electrolytic leaching apparatus therefor.

In general, noble metals or poorly soluble metals having high redox potential are leached by reacting high concentrations of oxidizing acid at high temperatures. In this case, due to the constant consumption of acid, a large amount of acid is required, and the treatment of waste liquid generated therein can cause environmental problems. In addition, a separate recovery device is required to recover the leached valuable metals, and separate energy is consumed for this purpose.

In addition, the conventional chlorine or chlorine leaching method is to inject chlorine gas stored in the high-pressure gas container into the reaction vessel (Hydrometallurgy, 29 (1992) 205-215), or chemically generate chlorine by adding chemicals to the gaseous state. Chlorine must be handled outside the leaching vessel, which can complicate the device and cause safety problems. In addition, after the leaching is completed, it is necessary to go through a recovery step of a separate leaching metal is the same as the general acid leaching. In order to solve this problem, the present inventors electrochemically oxidize chlorine ions in a solution containing chlorine ions to produce chlorine, leach valuable metals by chlorine, and reduce them in a reduction reaction chamber through a separator to recover metals. Filed an invention (Korean Application No. 10-2005-25950) for. However, the present inventors needed to develop a new device for further increasing the recovery efficiency of leached valuable metals and effectively reducing the recovery time. The apparatus of the present invention is mainly for recycling the waste containing various valuable metals to effectively recover the desired valuable metals. When there is only one kind of valuable metal contained, a simple separator that separates and passes the dissolved valuable metal from the solid may be sufficient. However, in the case of various types of metals contained therein, it is necessary to separate and purify only valuable metals for recovery from the leaching-containing metal components and supply them to the reduction reaction chamber. Therefore, in order to effectively recycle precious metals or soluble metals having a high redox potential, it is necessary to develop a new method of safe and low energy, environmentally friendly leaching and recovery method.

The present invention is simple to install, while using a minimum amount of acid with a very low concentration compared to the conventional leaching method, leaching by chlorine or chlorine compounds with high energy efficiency as it is possible to recover valuable metals at the same time leaching It is an object of the present invention to provide a method and an electroleaching apparatus for the same, and to improve recovery efficiency by separating and purifying necessary recovered metal components.

The present invention provides a leaching using an electrolytically produced chlorine or chlorine compound which can be very efficiently applied to leaching the metal from solid materials containing precious metals or other valuable metals, which are difficult to leach by the conventional chemical leaching method, and an electrolytic leaching device therefor. The present invention relates to an electrolytic generation step of chlorine or a chlorine compound which oxidizes chlorine ions contained in a solution at an anode, a leaching reaction step of reacting an electrolytically produced chlorine or chlorine compound with a leaching target material, and simultaneously leaching at a reduction electrode. The present invention relates to a leaching method divided into recovery steps of valuable valuable metals and an electrolytic leaching apparatus for realizing the same.

The present invention also relates to an electrolytic leaching apparatus capable of recovering valuable metals leached by chlorine or chlorine compounds produced by the anode more quickly and efficiently.

In particular, the electrolytic generation of chlorine or chlorine compounds and the leaching reaction using the same is characterized in that the same progress in the same reactor.

That is, the present invention relates to a method of leaching using chlorine or a chlorine compound electrolytically generated from an anode in a leachate containing chlorine ions and to a configuration of an electrolytic leaching apparatus for recovering valuable metals leached from a cathode while leaching. The valuable metals leached from the anode are separated, purified and transported to the reduction chamber efficiently to recover valuable metals.

A device for separating and purifying valuable metals leached from the oxidation reaction chamber as described above and transferring them to a reduction reaction chamber, wherein a separate separation / purifier is installed on a path of the leaching reaction chamber and the recovery reaction chamber of the anode to generate the leaching reaction chamber. The valuable metal ions are selectively transported to a recovery reaction chamber, which is a reduction reaction chamber, and reduced at an electrode of the recovery reaction chamber to recover the metal ions.

The separation / purifier employed in the present invention is used to isolate and / or separate valuable metals leached by chlorine or chlorine compounds produced in the leaching reaction chamber by using solvent extraction or ion exchange which is applied to selectively separate valuable metals in the art. Purification and transfer to the reduction reaction chamber. In the present invention, the technology related to the separation and purification of the separation and purification device uses a solvent extraction method or an ion exchange method commonly known in the art, and the related technology is known. For example, the principle of the apparatus related to the solvent extraction method is described in J. of the Korea Inst. of Met. & Mater. pp 486-490, Vol. 34, No 40 (1996) or pp. 399-403, Vol 43, No. 5 (2005) of the same document can also be applied to the apparatus using a solvent extraction method, J. of the Korea Inst. of Met. & Mater. pp 600-607, Vol. 30, No. 5 (1992) can be used in combination with the electrolytic leaching apparatus of the present invention by producing a separation purifier from the technique such as ion exchange method.

In the leaching method using chlorine or chlorine compounds produced by electrolysis according to the present invention, since chlorine or chlorine compounds having a very strong oxidizing power are used directly in a reaction solution at a relatively low temperature, a leaching reaction is required if there is a low concentration of chlorine ion source. This is possible, and theoretically, there is no consumption of chlorine or chlorine compounds in the solution, which has the advantage that no supply of excess chlorine or chlorine compounds for leaching is required. In addition, the electrolytic recovery of valuable metals leached out as a large reaction of electrolytic generation of chlorine or chlorine compounds is possible at the same time, which is very efficient in terms of energy. In particular, since chlorine or chlorine compounds are generated and consumed only in the reactor, which can cause problems when leaking, it is a leaching method that requires only very safe and simple equipment compared to the existing chlorine leaching method.

Salts or acids may be further used for the leaching solution of the present invention. Salts are added for the purpose of imparting ionic conductivity of the electrolyte, and available salts include sulfates and nitrates, as well as those containing chlorine ions such as ammonium chloride (NH ₄ Cl), potassium chloride (KCl) and sodium chloride (NaCl). Various kinds are available. In addition, the acid component is not particularly limited as long as it can increase the ionic conductivity as a common compound such as an organic acid or an inorganic acid.

When an oxidation current is applied to the anode in the leachate containing chlorine ions of the present invention, the chlorine generation reaction occurs by the following equation (1).

_{^{2Cl - → Cl 2 + 2e -}} (1)

Chlorine produced in the anode is spread through the leaching solution through efficient stirring, and valuable metals of solid components present in the leaching solution are leached by the reactions as shown in the following formulas (2) and (3). At this time, the chlorine leaching the metal (M) back to the chlorine ion can be prevented to minimize the consumption of chlorine in the leachate and no additional chlorine supply.

_{(n / 2) Cl 2 +} ne - → nCl - (2)

^{M → Mn + + ne - (} 3)

At this time, the overall reaction formula is as (4).

M + (n / 2) Cl 2 → Mn + + nCl - (4)

Metals that can be leached through this reaction are possible when the redox potential is lower than the redox potential of chlorine. When the voltage is increased when the oxidation current is applied, chlorine compound, oxychloride, may be formed. It also has an oxidizing power and can be used for leaching reactions.

Chlorine compounds according to the invention ^{_{HClO, HClO 2, ClO 3 -}} , ClO 4 -, ClO 2, ClO -, ClO 2 - , etc., and leaching the precious metals by the following leaching reaction, such as in the acid by these do.

M + n / 2HClO + n / 2H + → Mn + + n / 2Cl - + nH 2 O

^{_{M + n / 2ClO 4 - +}} nH + → Mn + + n / 2HClO 3 - + n / 2H 2 O

^{_{M + n / 2ClO 3 - +}} 3n / 2H + → Mn + + n / 2HClO 2 + n / 2H 2 O

_{M + n / 4HClO 2 + 3n} / 4H + → Mn + + n / 4Cl - + n / 2H 2 O

Unlike chlorine dissolved in water, hydrogen is consumed, so a system having a large amount of chlorine is preferable to obtain a more efficient system.

Hereinafter, the electrolytic leaching apparatus will be described in more detail with reference to the accompanying drawings.

1 is a schematic view showing an electrolytic leaching apparatus according to the present invention, which describes a leaching reaction chamber 1 and a leaching metal recovery reaction chamber 2 separated by a separator 3 formed at the center thereof; A cover 4 of the leaching reaction chamber; A stirring rod (7) and a stirring motor (8), which are electrolyte stirring apparatuses in a leaching reaction chamber; An anode (5) for producing electrolytic chlorine or chlorine compounds in the leaching reaction chamber and a reducing electrode (6) for the leaching metal recovery reaction chamber; Electrolytic leaching device consisting of a separator / purifier (9).

The separator 3 can pass only leached metal ions but only porous simple membranes or specific ions that do not pass through a device that induces consumption of excess chlorine or chlorine compounds between leach residues or separators. Ion exchange membrane, or a combination thereof. The leaching reaction chamber (1) and the recovery reaction chamber (2) are both made of a material that is corrosion resistant to the oxidation of chlorine or chlorine compounds, and the shape of the container can be variously modified. The lid 4 of the leaching reaction chamber prevents external leakage of electrolytically generated chlorine or chlorine compounds to seal the leaching reaction chamber and also supports the stirring rod 7 and the anode 5. Stirring rod (7) is an electrolytically generated chlorine or chlorine compound effectively into the electrolyte solution to play an important role to increase the efficiency of the leaching reaction, the shape of the stirring blade can be variously designed so that this effect is the maximum. The anode 5 plays a role in electrolytic generation of chlorine or chlorine compounds when an oxidizing current is applied, and can be produced in various forms with graphite or other conductive materials that are physicochemically stable even during electrolysis of chlorine or chlorine compounds. . The stirring rod 7 and the anode 5 can be designed in various shapes and positions. The stirring motor 8 may be fixed or separated on the cover 4 of the leaching reaction chamber.

The reduction electrode 6 of the leaching metal recovery reaction chamber can be made of most conductive materials that are stable to the electrolyte used as the electrode to which the leached metal ions are electrolytically reduced and recovered. It is convenient.

Referring to the operation principle of the electrolytic leaching method and the electrolytic leaching device according to the present invention, the electrolytic leaching device of the present invention is stable to the leachate containing the chlorine or chlorine compounds generated electrolytically and various materials having a mechanical strength sufficient to maintain the function of the device The chlorine ions contained in the leachate are oxidized into chlorine or chlorine compounds by the oxidation current applied to the anode 5 during electrolytic leaching, and the chlorine or electrolytically produced by stirring the solution of the stirring rod 7. The chlorine compound effectively reacts with the metal components of the leachate contained in the leachate to dissolve into metal ions. In the dissolution reaction, chlorine or chlorine compounds are reduced back to chlorine ions so that the consumption of chlorine ions in the leachate does not occur. The amount of chlorine or chlorine compounds produced per unit time is determined by the amount of oxidation current and the electrode area of the anode, which is directly related to the amount of leaching. On the other hand, the leached metal is present in the leaching liquid as metal ions, and when using a simple separator, it passes through the separator (3) to the reduction reaction chamber and then electrolytically precipitates as metal at the reducing electrode to which a reduction current is applied.

In the present invention, the separation / purifier 9 serves to selectively separate the dissolved metal ions using a solvent extraction method or an ion exchange resin for selectively concentrating the dissolved metal components and transfer them to a reduction reaction chamber which is a recovery reaction chamber. Before and after the separation / purifier, it is possible to install a solid / liquid separation filter or an adsorption filter for a specific organic phase, depending on the purpose.

In addition, a separate solution storage container may be installed between the separation / purifier and the recovery reaction chamber to store the excess solution.

In addition, the temperature control of the electrolyte during the leaching of electrolyte can be controlled using a separate solution heating device.

In addition, it is possible to install a separate leach sample charging and residue recovery device for charging the leach sample and recovery of the residue after leach without impairing the sealability of the leach device.

An embodiment using the electrolytic leaching apparatus according to the present invention is as follows.

Example 1

Electrolytic chlorine leaching was carried out using 400 mL of a 1M HCl solution using waste electronic equipment scrap containing about 45.7% of the metal leachate and the main metal component Cu as the leach sample. At this time, the average particle size of the crushed scrap used was used in the leaching experiment between 0.6mm ~ 1.2mm 10g. The anode was made of graphite having a surface area of 50 cm ² , and the cathode was made of titanium. The applied current was 20 mA / cm ² , agitation speed 400 rpm, and a solution temperature of 50 ° C. After 180 minutes, the metal leaching rate was 97.4%.

Example 2

Electrolytically produced chlorine leaching was carried out using 400 mL of 1M HCl solution using waste electronic equipment scrap containing about 45.7% of the metal leachate and Cu as the main metal constituent. At this time, the average particle size of the crushed scrap used was between 0.6mm ~ 1.2mm 10g was used in the leaching experiment. 50 cm ² of graphite was used for the anode and titanium was used for the reduction electrode. It was conditions of applied voltage 4V, stirring speed 400rpm, and solution temperature of 50 degreeC. After 180 minutes, the metal leaching rate was 95.2%.

Example 3

Electrolytically produced chlorine leaching was carried out using 400 mL of 0.5M HCl solution using waste electronic equipment scrap containing about 45.7% of the metal leachate and Cu as the main metal constituent. At this time, the average particle size of the crushed scrap used was used in the leaching experiment between 0.6mm ~ 1.2mm 10g. The anode was made of graphite of 50 cm ² and the cathode was made of titanium. The applied current was 10 mA / cm ² , agitation speed 800 rpm, and a solution temperature of 50 ° C. After 180 minutes, the metal leaching rate was 93.5%.

Example 4

Electrolytically produced chlorine leaching was carried out using 400 mL of 1M HCl solution using waste electronic equipment scrap containing about 45.7% of the metal leachate and Cu as the main metal constituent. At this time, the average particle size of the crushed scrap used was used in the leaching experiment between 0.6mm ~ 1.2mm 10g. The anode was made of graphite of 50 cm ² and the cathode was made of titanium. The applied current was 10 mA / cm ² , agitation speed 800 rpm, and a solution temperature of 30 ° C. After 180 minutes, the metal leaching rate was 91.5%.

Example 5

Electrolytically produced chlorine leaching was carried out using 400 mL of 1M HCl solution using waste electronic equipment scrap containing about 45.7% of the metal leachate and Cu as the main metal constituent. At this time, the average particle size of the crushed scrap used was used in the leaching experiment between 0.6mm ~ 1.2mm 10g. The anode was made of graphite of 50 cm ² , the cathode was made of titanium, and the separator was made of Neosepta CMX cation exchange membrane from Tokuyama, Japan. The applied current was 10 mA / cm ² , agitation speed 800 rpm, and a solution temperature of 30 ° C. After 180 minutes, the metal leaching rate was 91.5%. The leaching solution is circulated with the separating purifier, and the separating purifier is composed of three stages of a mixer-settler made of acrylic material having a width of 10 cm, a length of 15 cm, and a length of 30 cm. For solvent extraction of copper, the organic phase was kerosene and LIX84 (2-hydroxy-5-nonylacetophenon oxime) was used as extractant, and the aqueous phase was removed with sulfuric acid solution when stripped. The sulfuric acid solution used was kept at least 30g / L concentration of copper in consideration of the efficiency of the recovery process, and stored in a separate storage tank and the circulation tank and the reduction reaction chamber at a rate of 200mL per minute. Under the above conditions, the copper obtained in the reduction reaction chamber was 1.68 g and the current efficiency was 99.5%. The purity of the obtained copper was 3N or more.

The purity of copper was significantly higher and the current efficiency was also higher compared to the case of electrolytic precipitation without separate purification device.

The chlorine or chlorine compound leaching method produced according to the present invention uses a low concentration of acid as an electrolyte and does not require additional chlorine or chlorine compounds during the leaching reaction, so the efficiency of the process is very high, and the effluent of chlorine or chlorine compounds is externally discharged. The risk is extremely low and has a very high stability compared to the conventional chlorine leaching method. In addition, by using the separation purifier in the present invention, it was found that the purity of the metal to be separated and the current efficiency were also excellent, resulting in high energy efficiency.

Claims (5)

Oil price by chlorine or chlorine compound comprising a leaching reaction chamber and a leaching metal recovery reaction chamber, an electrode for producing electrolytic chlorine or chlorine compounds in the leaching reaction chamber, a reducing electrode in the leaching metal recovery reaction chamber, and a separation purifier separated by a separator Metal Electrolytic Leaching Device. The method of claim 1, The leaching reaction chamber is a valuable metal electrolytic leaching device by the chlorine or chlorine compound, characterized in that it further comprises a stirring motor and a sealing cover for driving the stirring rod and the stirring rod. The method of claim 1 Valuable metal electroleaching by chlorine or chlorine compound consisting of a porous separator or a ion exchange membrane that selectively passes only specific ions, or a combination thereof, allowing the separator to pass only leached metal ions or dissolved materials and not passing solid matter. Device. The method of claim 1 The anode is a valuable metal electrolytic leaching apparatus, characterized in that the electrochemical generation of chlorine or chlorine compound electrochemically stable when an oxidation current or voltage is applied and chemically stable to the oxidation of chlorine or chlorine compound produced electrolytically. The method according to any one of claims 1 to 4 The separation and purifier is a valuable metal electrolytic leaching apparatus, characterized in that the function of separating only the target components of the leaching metal ions by a solvent extraction method or ion exchange resin and transported to the recovery reaction chamber.

Images