JP2011140675A - Method for collecting silver and palladium from waste scrap of conductive paste - Google Patents

Method for collecting silver and palladium from waste scrap of conductive paste Download PDF

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JP2011140675A
JP2011140675A JP2010000420A JP2010000420A JP2011140675A JP 2011140675 A JP2011140675 A JP 2011140675A JP 2010000420 A JP2010000420 A JP 2010000420A JP 2010000420 A JP2010000420 A JP 2010000420A JP 2011140675 A JP2011140675 A JP 2011140675A
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palladium
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Koji Nagao
幸治 長尾
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Ohkuchi Electronics Co Ltd
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for easily and selectively collecting silver and palladium contained in the nitric acid solution in which burned ash of the waste is dissolved when collecting precious metals out of the waste of containers, instruments or the like on which used conductive paste scrap and conductive paste scrap are deposited. <P>SOLUTION: Burned ash obtained by burning wastes such as conductive paste scrap is dissolved in nitric acid, and hydrochloric acid is added to the obtained nitric acid solution to separate and collect silver chloride. Then, ammonium chloride is added to the solution after collecting silver by ≥2 mole equivalent to the palladium, and the oxidizing agent is added to the solution to adjust the oxidation-reduction potential to be ≥900 mV, thus selectively precipitating a palladium salt. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、銀やパラジウムなどの貴金属を含有する導電性ペースト屑などから貴金属を回収する方法、更に詳しくは、導電性ペースト屑などの廃棄物を硝酸で溶解した後、その硝酸酸性溶液から銀とパラジウムを選択的に分離回収する方法に関する。   The present invention relates to a method for recovering noble metal from conductive paste waste containing noble metal such as silver and palladium, and more specifically, waste such as conductive paste waste is dissolved in nitric acid, and then silver nitrate is removed from the nitric acid acidic solution. And a method for selectively separating and recovering palladium.

導電性ペーストには銀やパラジウムなどの貴金属が含まれているため、使用済みの導電性ペーストの屑及び導電性ペースト屑が付着した容器や器具などの廃棄物は貴金属のリサイクルを目的として集められ、種々の精製回収工程を経て貴金属が回収されている。   Since conductive paste contains noble metals such as silver and palladium, waste of used conductive paste and waste such as containers and equipment with conductive paste scraps collected are collected for the purpose of recycling precious metals. The noble metal is recovered through various purification and recovery steps.

一般的に、導電性ペースト屑及び導電性ペースト屑が付着した容器や器具などの廃棄物にはプラスチック製のものが含まれている。そのため、使用済みの導電性ペースト屑及び導電性ペースト屑が付着した容器や器具などの廃棄物は、図２に示すように、まず焼却処理を行い、その焼却灰を集めて硝酸で溶解した後、銀やパラジウムの回収処理を行っていた。   Generally, wastes such as conductive paste waste and containers and appliances to which conductive paste waste is attached include plastic ones. Therefore, wastes such as used conductive paste waste and containers and appliances to which conductive paste waste adheres are first incinerated as shown in FIG. 2, after the incineration ash is collected and dissolved in nitric acid The silver and palladium were collected.

具体的には、上記した導電性ペースト屑等の焼却灰を硝酸で溶解した硝酸酸性溶解液は、導電性ペースト屑中の銀やパラジウムなどの貴金属と鉛などが含まれているので、まず塩酸や食塩などを添加して、銀を塩化銀（ＡｇＣｌ）として分離回収する。次に、銀を回収した後の溶液に苛性ソーダなどを添加して中和し、パラジウムや鉛などを水酸化物として沈殿させて回収する。   Specifically, the acid solution of nitric acid obtained by dissolving incineration ash such as the conductive paste waste with nitric acid contains noble metals such as silver and palladium and lead in the conductive paste waste. Silver is separated and collected as silver chloride (AgCl). Next, sodium hydroxide or the like is added to the solution after the silver is recovered to neutralize it, and palladium or lead is precipitated as a hydroxide and recovered.

その後、回収した水酸化物を塩酸に溶解し、アンモニア水をｐＨ８以上になるまで添加してパラジウムを溶解性のアンモニア錯体に変換する。このとき、鉛はアンモニア錯体を形成しないため、アンモニア錯体を沈殿物として濾別することができる。次に、濾液のアンモニア水溶液に塩酸を添加し、溶解度の小さいパラジウムのジクロロジアンミン錯体の塩を生成させ、濾過によりパラジウム塩を回収する。   Thereafter, the recovered hydroxide is dissolved in hydrochloric acid, and ammonia water is added until the pH is 8 or more to convert palladium into a soluble ammonia complex. At this time, since lead does not form an ammonia complex, the ammonia complex can be filtered off as a precipitate. Next, hydrochloric acid is added to the aqueous ammonia solution of the filtrate to produce a low-solubility palladium dichlorodiammine complex salt, and the palladium salt is recovered by filtration.

しかし、上記した従来の方法では、銀を回収した後の溶液に苛性ソーダなどを添加して中和すると、パラジウムや鉛などの微細な水酸化物が生成されるが、この微細な水酸化物は濾過性が非常に悪かった。そのため、この微細な水酸化物を工業的に処理するには、フィルタープレスなどの高価な設備が必要であった。また、パラジウム回収までの工程が長く、回収時間や薬品コストが高くなるという問題もあった。   However, in the conventional method described above, when hydroxide is added to neutralize the solution after recovering silver, fine hydroxides such as palladium and lead are produced. The filterability was very poor. Therefore, expensive equipment such as a filter press is required to industrially process this fine hydroxide. In addition, there is a problem that the process until the recovery of palladium is long, and the recovery time and chemical cost are increased.

一方、特開２００１−２００３２０号公報（特許文献１）には、銀電解スライムから塩化ジアンミンパラジウムを経由してパラジウムを回収する際に、銀電解スライムを溶解して得た粗塩化ジアンミンパラジウムを精製する方法が記載されている。この精製方法によれば、粗塩化ジアンミンパラジウムをアンモニア水に溶解し、過酸化水素などの酸化剤を添加した後、塩酸を添加して精製された塩化ジアンミンパラジウムを沈殿させている。   On the other hand, Japanese Patent Laid-Open No. 2001-200320 (Patent Document 1) purifies crude diamine palladium obtained by dissolving silver electrolytic slime when collecting palladium from silver electrolytic slime via diammine palladium chloride. How to do is described. According to this purification method, crude diammine palladium chloride is dissolved in aqueous ammonia, an oxidizing agent such as hydrogen peroxide is added, and hydrochloric acid is added to precipitate purified diammine palladium chloride.

しかし、上記の方法は粗塩化アンミンパラジウムのアンモニア水溶液から精製された塩化ジアンミンパラジウムを回収する方法であり、また、酸性溶液からの回収方法でもない。尚、硝酸酸性溶液中でのパラジウムの挙動は詳しく知られておらず、特に鉛が共存する場合にパラジウムを選択的に且つ簡単に分離回収する方法は知られていなかった。   However, the above-described method is a method for recovering purified diamine palladium chloride from an ammonia aqueous solution of crude ammine palladium chloride, and is not a method for recovering from an acidic solution. Incidentally, the behavior of palladium in a nitric acid acidic solution is not known in detail, and a method for selectively separating and recovering palladium selectively and easily particularly when lead coexists has not been known.

特開２００１−２００３２０号公報JP 2001-200320 A

本発明は、上記した従来の問題点に鑑みてなされたものであり、使用済みの導電性ペースト屑及び導電性ペースト屑が付着した容器や器具などの廃棄物から貴金属を回収する際に、その導電性ペースト屑などの廃棄物の焼却灰を溶解した硝酸酸性溶液から、含有される銀とパラジウムを簡単な方法で選択的に回収する方法を提供することを目的とするものである。   The present invention has been made in view of the above-described conventional problems, and when collecting noble metals from wastes such as used conductive paste waste and containers and appliances to which conductive paste waste has adhered, It is an object of the present invention to provide a method for selectively recovering silver and palladium contained in a simple method from a nitric acid acidic solution in which waste incineration ash such as conductive paste waste is dissolved.

上記目的を達成するため、本発明者は、パラジウムと共に鉛を含有する硝酸酸性溶液からパラジウムを選択的に回収する方法について検討した。まず、パラジウムは通常は２価の形態で溶液中に存在するため塩化アンモニウム塩の錯体を形成しないが、パラジウムの４価の塩化物は下記化学式１によりアンモニウム塩の錯体を形成することが知られている。   In order to achieve the above object, the present inventor has studied a method for selectively recovering palladium from a nitric acid acidic solution containing lead together with palladium. First, palladium is usually present in solution in a divalent form and does not form an ammonium chloride complex, but it is known that palladium tetravalent chloride forms an ammonium salt complex according to the following chemical formula 1. ing.

［化学式１］
Ｈ２ＰｄＣｌ６＋２ＮＨ４Ｃｌ→（ＮＨ４）２ＰｄＣｌ６＋２ＨＣｌ [Chemical Formula 1]
H 2 PdCl 6 + 2NH 4 Cl → (NH 4 ) 2 PdCl 6 + 2HCl

上記化学式１により生成するパラジウムと塩化アンモニウムの錯体は溶解度が小さく、一方で鉛などの卑金属はアンモニウム塩の錯体を形成しないので、パラジウムを鉛などの卑金属と分離することが可能である。しかし、硝酸酸性溶液中においてパラジウムは硝酸塩として存在するため、上記化学式１をそのまま適用して、塩化アンモニウムの添加により鉛と分離することはできない。   The palladium-ammonium chloride complex produced by the above chemical formula 1 has low solubility, while a base metal such as lead does not form an ammonium salt complex, so that palladium can be separated from a base metal such as lead. However, since palladium exists as a nitrate in an acidic nitric acid solution, it cannot be separated from lead by addition of ammonium chloride by applying the above chemical formula 1 as it is.

そこで、更に検討を重ねた結果、導電性ペースト屑などの廃棄物から貴金属を回収する際に、導電性ペースト屑などの廃棄物を焼却し、その焼却灰を溶解した硝酸酸性溶液から銀を塩化銀として沈殿分離した後、得られた溶液（濾液）に塩化アンモニウムを添加し、更に次亜塩素酸ナトリウムなどの酸化剤を添加して溶液の酸化還元電位を９００ｍＶ以上に調整することによって、パラジウムが定量的にアンモニウム塩として沈殿する一方、鉛などの卑金属は沈殿しないことを見出し、本発明を完成するに至った。   Therefore, as a result of further studies, when recovering precious metals from waste such as conductive paste waste, the waste such as conductive paste waste is incinerated and silver chloride is chlorinated from the nitric acid acidic solution in which the incineration ash is dissolved. After precipitation and separation as silver, ammonium chloride was added to the resulting solution (filtrate), and an oxidizing agent such as sodium hypochlorite was added to adjust the redox potential of the solution to 900 mV or more, thereby adding palladium. Was quantitatively precipitated as an ammonium salt, but no base metal such as lead was precipitated, and the present invention was completed.

即ち、本発明は、導電性ペースト屑を含む廃棄物から銀とパラジウムを回収する方法であって、該導電性ペースト廃棄物を焼却した焼却灰を硝酸に溶解し、得られた硝酸酸性溶液に塩酸を添加して塩化銀を分離回収した後、銀回収後の溶液に塩化アンモニウムをパラジウム量に対し２モル当量以上添加すると共に、酸化剤を添加して該溶液の酸化還元電位を９００ｍＶ以上に調整することにより、パラジウム塩を選択的に析出させることを特徴とする。   That is, the present invention is a method for recovering silver and palladium from waste containing conductive paste waste, wherein the incinerated ash obtained by incineration of the conductive paste waste is dissolved in nitric acid, and the resulting nitric acid acidic solution is obtained. After hydrochloric acid is added and silver chloride is separated and recovered, ammonium chloride is added to the solution after silver recovery in an amount of at least 2 molar equivalents relative to the amount of palladium, and an oxidizing agent is added to bring the redox potential of the solution to 900 mV or higher. By adjusting, the palladium salt is selectively deposited.

本発明によれば、銀及びパラジウムと共に鉛を含有する使用済みの導電性ペースト屑及び導電性ペースト屑が付着した容器や器具などの廃棄物から、簡単な方法によって、銀を分離回収し、更にパラジウムを鉛と分離して選択的に析出させて効率よく回収することができる。   According to the present invention, silver is separated and recovered by a simple method from used conductive paste waste containing lead together with silver and palladium, and wastes such as containers and appliances to which the conductive paste waste has adhered, Palladium can be separated from lead and selectively deposited for efficient recovery.

従来方法による導電性ペースト屑などの廃棄物から銀とパラジウムを回収する工程を示すフロー図である。It is a flowchart which shows the process of collect | recovering silver and palladium from waste materials, such as electrically conductive paste waste by a conventional method. 本発明による導電性ペースト屑などの廃棄物から銀とパラジウムを回収する工程を示すフロー図である。It is a flowchart which shows the process of collect | recovering silver and palladium from wastes, such as the electrically conductive paste waste by this invention.

本発明による導電性ペースト屑などの廃棄物からの銀とパラジウムを回収する方法について、図１を参照して説明する。まず、導電性ペースト屑などの廃棄物を焼却し、その焼却灰を硝酸で溶解する。得られた硝酸酸性溶液には、導電性ペーストの主成分である銀と共に、パラジウムや鉛が含まれている。そこで、まず銀の回収工程として、上記硝酸酸性溶液に塩酸を添加することにより、硝酸酸性溶液中の銀を塩化銀として沈殿させ、濾過することにより分離回収する。   A method for recovering silver and palladium from waste such as conductive paste waste according to the present invention will be described with reference to FIG. First, waste such as conductive paste waste is incinerated, and the incinerated ash is dissolved with nitric acid. The obtained nitric acid acidic solution contains palladium and lead together with silver which is the main component of the conductive paste. Therefore, first, as a silver recovery step, hydrochloric acid is added to the acid solution of nitric acid so that silver in the acid solution of nitric acid is precipitated as silver chloride and is separated and recovered by filtration.

次のパラジウムの回収工程では、上記銀回収後の溶液（濾液）に溶液中のパラジウム量に対し２モル当量以上の塩化アンモニウムを添加し、同時に又は前後して酸化剤を添加して、溶液の酸化還元電位を９００ｍＶ以上に調整することにより、パラジウム塩が選択的に析出される。析出したパラジウム塩は通常の設備により容易に濾過して分離回収することができる。一方、濾液中には鉛が残るので、必要に応じて更に排水処理工程に送って処理する。   In the next palladium recovery step, 2 mol equivalents or more of ammonium chloride to the amount of palladium in the solution is added to the solution after the silver recovery (filtrate), and an oxidizing agent is added simultaneously or before and after the solution. By adjusting the oxidation-reduction potential to 900 mV or more, the palladium salt is selectively deposited. The precipitated palladium salt can be easily filtered and separated and recovered by ordinary equipment. On the other hand, since lead remains in the filtrate, it is further sent to a wastewater treatment process for treatment as necessary.

上記パラジウムの回収工程においてパラジウムが選択的に析出する理由は明らかではないが、銀回収の際に塩酸を硝酸酸性溶液に過剰に添加する結果、銀回収後の溶液は塩酸酸性となり、パラジウムも塩化物の形態となっていると考えられる。そのため、上記した化学式１と同様の反応により、パラジウムは塩化アンモニウムと溶解度の小さいのアンモニウム塩、例えば（ＮＨ４）２ＰｄＣｌ６のような錯体を形成して析出するものと考えられる。 The reason for the selective precipitation of palladium in the above palladium recovery process is not clear, but as a result of adding hydrochloric acid to the nitric acid acidic solution excessively at the time of silver recovery, the solution after silver recovery becomes acidic with hydrochloric acid, and the palladium is also chlorinated. It is thought to be in the form of a thing. Therefore, it is considered that palladium is precipitated by forming a complex such as ammonium chloride and ammonium salt having a low solubility, for example, (NH 4 ) 2 PdCl 6 , by the reaction similar to the above-described chemical formula 1.

また、銀回収後の溶液に添加する塩化アンモニウムの量に関しては、溶液中に含まれているパラジウムに対して２モル当量添加すれば、パラジウムが上記化学式１と同様の反応に従って、定量的にアンモニウム塩の錯体として沈殿することが実験的に確認された。従って、塩化アンモニウムの添加量は、パラジウム量に対して少なくとも２モル当量あればよく、反応を促進するための過剰な添加はほとんど必要ないか、若しくは若干過剰に添加すれば十分である。   In addition, regarding the amount of ammonium chloride to be added to the solution after silver recovery, if 2 molar equivalents are added to palladium contained in the solution, palladium is quantitatively converted to ammonium according to the same reaction as in the above chemical formula 1. It was experimentally confirmed to precipitate as a salt complex. Therefore, it is sufficient that the amount of ammonium chloride added is at least 2 molar equivalents with respect to the amount of palladium. It is not necessary to add excessively to accelerate the reaction, or it is sufficient to add it slightly in excess.

銀回収後の溶液に添加する酸化剤としては、溶液の酸化還元電位を９００ｍＶ以上に維持することができるものであれば特に制限はなく、例えば、次亜塩素酸ソーダ、亜塩素酸ソーダ、塩素ガスなどの使用が好ましい。   The oxidizing agent added to the solution after silver recovery is not particularly limited as long as the oxidation-reduction potential of the solution can be maintained at 900 mV or more. For example, sodium hypochlorite, sodium chlorite, chlorine Use of gas or the like is preferable.

また、上記パラジウムを析出回収する際には、溶液の温度を３０℃以下に保持することが望ましい。生成するパラジウムのアンモニウム塩との錯体の溶解度は温度によって差があり、温度が低いほど溶解度が小さくなるからである。ただし、常温でもパラジウムの回収率は９９％程度以上となるため、コストをかけて極端な低温にまで冷却する必要はなく、０℃以上３０℃以下の温度に保持することが好ましい。   Further, when the palladium is deposited and recovered, it is desirable to keep the temperature of the solution at 30 ° C. or lower. This is because the solubility of the complex with the ammonium salt of palladium produced varies depending on the temperature, and the solubility decreases as the temperature decreases. However, since the recovery rate of palladium is about 99% or more even at room temperature, it is not necessary to cool to an extremely low temperature at cost, and it is preferable to maintain the temperature at 0 ° C. or higher and 30 ° C. or lower.

［実施例１］
導電性ペースト屑などの廃棄物の焼却灰を硝酸に溶解し、得られた硝酸酸性溶液に塩酸を添加して、溶液中の銀を塩化銀として分離回収した。銀回収後の溶液（濾液）をビーカーに入れ、撹拌しながら塩化アンモニウム（ＮＨ４Ｃｌ）を下記表１に示す添加量で添加すると共に、次亜塩素酸ソーダ２０ｍｌを添加した。溶液の酸化還元電位（Ａｇ−ＡｇＣｌ電極値）は７９０ｍＶから９０８ｍＶまで上昇し、溶液からパラジウム塩が析出した。 [Example 1]
Waste incineration ash such as conductive paste waste was dissolved in nitric acid, and hydrochloric acid was added to the resulting nitric acid acidic solution to separate and collect silver in the solution as silver chloride. The solution (filtrate) after silver recovery was placed in a beaker, and ammonium chloride (NH 4 Cl) was added in the addition amount shown in Table 1 below with stirring, and 20 ml of sodium hypochlorite was added. The oxidation-reduction potential (Ag-AgCl electrode value) of the solution increased from 790 mV to 908 mV, and a palladium salt was precipitated from the solution.

更に３０分間撹拌を続けた後、析出したパラジウム塩を濾過して回収した。パラジウム塩を濾過した後の溶液（濾液）中のパラジウムと鉛の濃度をＩＣＰ分析器で測定し、パラジウム（Ｐｄ）の沈殿率と鉛（Ｐｂ）の沈殿率を算出した。得られた結果を、原液である硝酸酸性溶液の濃度、塩化アンモニウムの添加量及び溶液中のパラジウム量に対する塩化アンモニウムのモル当量と共に、下記表１に示した。   After further stirring for 30 minutes, the precipitated palladium salt was collected by filtration. The concentration of palladium and lead in the solution (filtrate) after filtering the palladium salt was measured with an ICP analyzer, and the precipitation rate of palladium (Pd) and the precipitation rate of lead (Pb) were calculated. The obtained results are shown in Table 1 below together with the concentration of the nitric acid acidic solution as the stock solution, the addition amount of ammonium chloride, and the molar equivalent of ammonium chloride relative to the amount of palladium in the solution.

Figure 2011140675
Figure 2011140675

この結果から分るように、塩化アンモニウムを溶液中のパラジウム量に対して２モル当量以上添加すれば、パラジウムを９９％以上の沈殿率で析出させることができる。一方、鉛の沈殿率は塩化アンモニウムの添加量が増えるに伴って微増しているが、鉛は殆ど沈殿しないため、パラジウムのみを選択的に沈殿させることができた。   As can be seen from this result, palladium can be precipitated at a precipitation rate of 99% or more by adding ammonium chloride in an amount of 2 molar equivalents or more with respect to the amount of palladium in the solution. On the other hand, the precipitation rate of lead slightly increased as the amount of ammonium chloride added increased, but since lead hardly precipitated, only palladium could be selectively precipitated.

［実施例２］
導電性ペースト屑などの廃棄物の焼却灰を硝酸に溶解し、得られた硝酸酸性溶液に塩酸を添加して、溶液中の銀を塩化銀として分離回収した。銀回収後の溶液（濾液）をビーカーに入れ、撹拌しながら塩化アンモニウム（ＮＨ４Ｃｌ）を下記表２に示す添加量で添加すると共に、次亜塩素酸ソーダの添加量を変えて溶液の酸化還元電位（Ａｇ−ＡｇＣｌ電極値）を下記表２に示す値に調整した。 [Example 2]
Waste incineration ash such as conductive paste waste was dissolved in nitric acid, and hydrochloric acid was added to the resulting nitric acid acidic solution to separate and collect silver in the solution as silver chloride. The solution (filtrate) after silver recovery was put into a beaker, and ammonium chloride (NH 4 Cl) was added in the addition amount shown in Table 2 below while stirring, and the addition amount of sodium hypochlorite was changed to oxidize the solution. The reduction potential (Ag-AgCl electrode value) was adjusted to the values shown in Table 2 below.

更に３０分間撹拌を続けた後、析出したパラジウム塩を濾過して回収した。パラジウム塩を濾過した後の溶液（濾液）中のパラジウムと鉛の濃度をＩＣＰ分析器で測定し、パラジウム（Ｐｄ）の沈殿率と鉛（Ｐｂ）の沈殿率を算出した。得られた結果を、塩化アンモニウムの添加量、溶液中のパラジウム量に対する塩化アンモニウムのモル当量、及び酸化還元電位と共に、下記表２に示した。   After further stirring for 30 minutes, the precipitated palladium salt was collected by filtration. The concentration of palladium and lead in the solution (filtrate) after filtering the palladium salt was measured with an ICP analyzer, and the precipitation rate of palladium (Pd) and the precipitation rate of lead (Pb) were calculated. The obtained results are shown in Table 2 below together with the amount of ammonium chloride added, the molar equivalent of ammonium chloride relative to the amount of palladium in the solution, and the oxidation-reduction potential.

Figure 2011140675
Figure 2011140675

上記した結果から、溶液中のパラジウムの９９％以上を沈殿させて定量的に回収するためには、溶液の酸化還元電位を９００ｍＶ以上に制御することが必要であることが分る。また、塩化アンモニウムの添加量は、溶液中のパラジウム量に対して２モル当量あれば十分であり、反応を促進するための過剰な添加はほとんど必要ないことが分る。   From the above results, it can be seen that it is necessary to control the oxidation-reduction potential of the solution to 900 mV or more in order to precipitate 99% or more of the palladium in the solution and recover it quantitatively. Further, it is understood that it is sufficient that the amount of ammonium chloride added is 2 molar equivalents relative to the amount of palladium in the solution, and an excessive addition for accelerating the reaction is hardly necessary.

Claims (2)

導電性ペースト屑を含む廃棄物から銀とパラジウムを回収する方法であって、該導電性ペースト廃棄物を焼却した焼却灰を硝酸に溶解し、得られた硝酸酸性溶液に塩酸を添加して塩化銀を分離回収した後、銀回収後の溶液に塩化アンモニウムをパラジウム量に対し２モル当量以上添加すると共に、酸化剤を添加して該溶液の酸化還元電位を９００ｍＶ以上に調整することにより、パラジウム塩を選択的に析出させることを特徴とする、導電性ペースト屑廃棄物からの銀とパラジウムの回収方法。   A method for recovering silver and palladium from waste containing conductive paste waste, wherein incinerated ash obtained by incineration of the conductive paste waste is dissolved in nitric acid, and hydrochloric acid is added to the resulting nitric acid acidic solution for chlorination. After separating and recovering silver, ammonium chloride is added to the solution after recovery of silver in an amount of 2 molar equivalents or more with respect to the amount of palladium, and an oxidizing agent is added to adjust the redox potential of the solution to 900 mV or more. A method for recovering silver and palladium from waste conductive paste waste, wherein salts are selectively deposited. 前記パラジウム塩を選択的に析出させる際に、銀回収後の溶液の温度を０℃以上３０℃以下に保持することを特徴とする、請求項１に記載の導電性ペースト屑廃棄物からの銀とパラジウムの回収方法。   The silver from the conductive paste waste waste according to claim 1, wherein the temperature of the solution after silver recovery is maintained at 0 ° C or higher and 30 ° C or lower when the palladium salt is selectively deposited. And palladium recovery method.
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JP2016093804A (en) * 2014-11-10 2016-05-26 国立大学法人信州大学 Method of recovering valuable material from solar cell module and processing equipment for recovering the same
CN106480477A (en) * 2016-11-21 2017-03-08 郴州市金贵银业股份有限公司 The method for reclaiming silver-colored palladium from silver anode slime parting liquid
WO2017143499A1 (en) * 2016-02-22 2017-08-31 Entegris, Inc. Recovery of palladium from palladium-containing components
CN114293023A (en) * 2021-12-28 2022-04-08 昆山鸿福泰环保科技有限公司 Method for recovering silver and palladium from silver and palladium-containing material
CN115449642A (en) * 2022-07-28 2022-12-09 江西铜业技术研究院有限公司 Process for deeply recovering platinum and palladium in silver precipitation tail liquid by improved sodium sulfide precipitation method

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016093804A (en) * 2014-11-10 2016-05-26 国立大学法人信州大学 Method of recovering valuable material from solar cell module and processing equipment for recovering the same
WO2017143499A1 (en) * 2016-02-22 2017-08-31 Entegris, Inc. Recovery of palladium from palladium-containing components
CN106480477A (en) * 2016-11-21 2017-03-08 郴州市金贵银业股份有限公司 The method for reclaiming silver-colored palladium from silver anode slime parting liquid
CN114293023A (en) * 2021-12-28 2022-04-08 昆山鸿福泰环保科技有限公司 Method for recovering silver and palladium from silver and palladium-containing material
CN115449642A (en) * 2022-07-28 2022-12-09 江西铜业技术研究院有限公司 Process for deeply recovering platinum and palladium in silver precipitation tail liquid by improved sodium sulfide precipitation method
CN115449642B (en) * 2022-07-28 2023-12-05 江西铜业技术研究院有限公司 Process for deeply recycling platinum and palladium in silver precipitation tail liquid by improved sodium sulfide precipitation method

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