JP4296289B2 - Method for removing mercury in sulfuric acid - Google Patents
Method for removing mercury in sulfuric acid Download PDFInfo
- Publication number
- JP4296289B2 JP4296289B2 JP2003316768A JP2003316768A JP4296289B2 JP 4296289 B2 JP4296289 B2 JP 4296289B2 JP 2003316768 A JP2003316768 A JP 2003316768A JP 2003316768 A JP2003316768 A JP 2003316768A JP 4296289 B2 JP4296289 B2 JP 4296289B2
- Authority
- JP
- Japan
- Prior art keywords
- sulfuric acid
- mercury
- ppm
- concentration
- added
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Removal Of Specific Substances (AREA)
Description
本発明は、非鉄金属製錬工程などで製造される濃硫酸（単に、硫酸という。）中に含有される水銀を除去する方法に関するものである。 The present invention relates to a method for removing mercury contained in concentrated sulfuric acid (simply referred to as sulfuric acid) produced in a nonferrous metal smelting process or the like.
製錬工程で製造される硫酸は、大部分が銅、鉛、亜鉛などの非鉄金属を製錬する際に発生する亜硫酸ガスから製造されるが、製錬原料の非鉄金属硫化物中には硫黄と上記の目的とする非鉄金属のほかにも、水銀などの易揮金属が混在している場合がある。この場合には亜硫酸ガス中に水銀などの金属が揮発して混在し、製造される硫酸中に水銀が混入してしまうことがある。
硫酸は多岐に渡る化学工業の基礎原料薬品であって、水銀が一般的には微量と考えられる量でも硫酸中に混在すると硫酸の用途が制限されるばかりではなく、製造業等に重大な影響を与えることになる。また、水銀を含めて環境規制が強化される中で、環境負荷を低減した製品を提供することは企業としての責務となる。
Sulfuric acid produced in the smelting process is mostly produced from sulfurous acid gas generated when smelting nonferrous metals such as copper, lead, and zinc. In addition to the above non-ferrous metals, there are cases where volatile metals such as mercury are mixed. In this case, a metal such as mercury is volatilized and mixed in the sulfurous acid gas, and mercury may be mixed in the produced sulfuric acid.
Sulfuric acid is a basic chemical in a wide variety of chemical industries, and even if the amount of mercury that is generally considered to be a trace amount is mixed in sulfuric acid, not only the use of sulfuric acid is limited, but it also has a serious impact on the manufacturing industry. Will give. In addition, as environmental regulations including mercury are strengthened, it is a company's responsibility to provide products with reduced environmental impact.
これまで硫酸中に水銀が混入するのを低減すべく原料の硫化物鉱石中から水銀を除去する方法や亜硫酸ガス中から水銀を除去する方法があり、さらには硫酸中から水銀を除去する方法が報告されているが、コスト、操業性、水銀除去率等から総合的に判断して硫酸中から水銀を除去する方法が採用される場合が少なくない。 To date, there have been methods of removing mercury from the raw sulfide ore, mercury from sulfurous acid gas, and methods of removing mercury from sulfuric acid in order to reduce mercury contamination in sulfuric acid. Although it has been reported, there are many cases where a method of removing mercury from sulfuric acid is adopted based on comprehensive judgment from cost, operability, mercury removal rate and the like.
この場合において、例えば特開昭５２−１１１４９５号公報（特許文献１）は硫酸にヨウ化カリウム等のヨウ化物を添加し次いで硫化水素やチオ硫酸ナトリウム等を添加して硫酸中の微量水銀を除去する方法に関するものであり、特開昭５０−１１５６９４号公報（特許文献２）は硫酸にアルミニウム粉および銅粉を添加して硫酸中の水銀を析出沈殿させ分離除去する方法に関するものであり、特開昭４８−０３６０９２号公報（特許文献３）は硫酸に硫化物、水硫化物、多硫化物、硫化水素、セレン化合物、硫黄等を添加して硫酸中の水銀を硫化水銀またはセレン化水銀として沈殿分離せしめて除去する方法に関するものであり、特開昭４９−１２１７９５号公報（特許文献４）は硫酸に多硫化物を添加して反応させ硫酸中の微量水銀を除去する方法に関するものであり、さらにこれらの他にも活性炭吸着法、有機溶媒抽出法、電解による方法など硫酸からの種々の水銀除去に関する発表が見られる。 In this case, for example, Japanese Patent Application Laid-Open No. 52-111495 (Patent Document 1) removes a trace amount of mercury in sulfuric acid by adding iodide such as potassium iodide to sulfuric acid and then adding hydrogen sulfide, sodium thiosulfate or the like. JP-A-50-115694 (Patent Document 2) relates to a method of adding aluminum powder and copper powder to sulfuric acid and precipitating and separating mercury in sulfuric acid to separate and remove it. Japanese Laid-Open Patent Publication No. 48-036092 (Patent Document 3) adds sulfide, hydrosulfide, polysulfide, hydrogen sulfide, selenium compound, sulfur, etc. to sulfuric acid to convert mercury in sulfuric acid to mercury sulfide or mercury selenide. JP-A-49-12195 (Patent Document 4) relates to a method of separating and removing precipitates. JP-A-49-12195 (Patent Document 4) removes a trace amount of mercury in sulfuric acid by adding polysulfide to sulfuric acid and reacting it. To relates to a method, further activated carbon adsorption method In addition to these, the organic solvent extraction method, announcement is observed for various mercury removal from sulfuric acid, etc. The method according to electrolysis.
これらの方法は、硫酸中の水銀を簡便に除去することができ工業的に優位な技術であると考えられるが、硫酸中の水銀を０．１ｐｐｍ以下にまで除去することを目的とする場合には不十分であったり、多くの時間またはコストを要する場合があったり、また水銀除去後の硫酸における硫黄析出による白濁などが発生するといった問題点を有するものであった。
解決しようとする問題点は、硫酸中の水銀を高度に、特に０．１ｐｐｍ以下にまで除去できないことであり、また水銀分離後の硫黄析出による硫酸の白濁等が防止できず、特に透過率９９．９％以上に維持できないことである。 The problem to be solved is that mercury in sulfuric acid cannot be removed to a high level, particularly 0.1 ppm or less, and white turbidity of sulfuric acid due to sulfur precipitation after mercury separation cannot be prevented. It cannot be maintained above 9%.
本発明は第１に、水銀を含有する硫酸に金属銅粉（単に、銅粉という。）と、アンモニアまたはアンモニア化合物と、硫化物とを添加し、次いで固液分離を行うことを特徴とする硫酸中の水銀除去方法であり、第２に、水銀を含有する硫酸に銅粉と、アンモニアまたはアンモニア化合物とを添加し次いで硫化物を添加し、撹拌した後に濾過して該硫酸中の水銀濃度を０．１ｐｐｍ以下にすることを特徴とする硫酸中の水銀除去方法であり、第３に、前記固液分離後または前記濾過後の硫酸を酸化し該硫酸の白濁を防止する、第１または２に記載の硫酸中の水銀除去方法であり、第４に、前記固液分離後または前記濾過後の硫酸に過酸化水素水を添加し該硫酸の透過率を９９．９％以上に維持する、第１または２に記載の硫酸中の水銀除去方法である。 The present invention is characterized in that, first, metallic copper powder (simply referred to as copper powder), ammonia or an ammonia compound, and sulfide are added to sulfuric acid containing mercury, followed by solid-liquid separation. A method for removing mercury in sulfuric acid. Secondly, copper powder and ammonia or an ammonia compound are added to sulfuric acid containing mercury, then sulfide is added, and after stirring, the concentration of mercury in the sulfuric acid is filtered. A method for removing mercury in sulfuric acid, characterized in that the sulfuric acid after the solid-liquid separation or the filtration is oxidized to prevent the sulfuric acid from becoming cloudy. 4. The method for removing mercury in sulfuric acid according to 2, wherein fourth, hydrogen peroxide is added to the sulfuric acid after the solid-liquid separation or after the filtration to maintain the transmittance of the sulfuric acid at 99.9% or more. The method for removing mercury in sulfuric acid according to claim 1 or 2 A.
本発明の硫酸中の水銀除去方法は、硫酸中の水銀を高度に、好ましくは０．１ｐｐｍ以下にまで簡便な操作によって比較的少ない反応時間で、低コストで効率的に除去することができ、また水銀分離後の硫黄析出を抑制して硫酸の白濁等を防止した透過率の高い硫酸が得られるものであり、好ましくは透過率９９．９％以上に維持することができるという利点がある。 The method for removing mercury in sulfuric acid of the present invention can efficiently remove mercury in sulfuric acid at a low cost with a relatively short reaction time by a simple operation to a high degree, preferably to 0.1 ppm or less, Further, it is possible to obtain sulfuric acid having a high transmittance in which sulfur precipitation after mercury separation is suppressed to prevent white turbidity of sulfuric acid and the like, and preferably has an advantage that the transmittance can be maintained at 99.9% or more.
本発明においては、水銀を含有する硫酸に、銅粉と、粒状ＮＨ４Ｃｌを別個にまたは同時に添加し、次いで硫化物を添加し撹拌して硫酸中の水銀を硫化し、また銅粉の硫化反応に伴って共沈若しくは吸着させた後に濾過することによって硫酸中の水銀濃度を０．１ｐｐｍ以下にする。
なお、本発明を実施するにあたって、処理対象となる硫酸中に懸濁物、析出物、沈殿等がある場合には必要に応じて予め濾過などの固液分離処理を行って固体分を除去しておくと以降の水銀除去工程を効果的に進行させることができる。
In the present invention, copper powder and granular NH 4 Cl are added separately or simultaneously to sulfuric acid containing mercury, and then sulfide is added and stirred to sulfidize mercury in sulfuric acid. The mercury concentration in sulfuric acid is reduced to 0.1 ppm or less by filtering after coprecipitation or adsorption with the reaction.
In carrying out the present invention, if there are suspensions, precipitates, precipitates, etc. in the sulfuric acid to be treated, a solid-liquid separation process such as filtration is performed in advance to remove solids as necessary. If this is done, the subsequent mercury removal step can be effectively advanced.
本発明の処理対象となる硫酸の濃度に関しては特に限定されないが、濃硫酸と呼ばれる通常約９０重量％（重量％を単に、％と表す。）以上の濃度のものが本発明によって好適に処理される。
本発明に係る処理前の水銀の濃度に関しても特に限定されるものではないが、通常は上記硫酸中に数１０−１ｐｐｍ〜数１０ｐｐｍの水銀が含有されているものであって、本発明によって水銀濃度を０．１ｐｐｍ以下にまで除去することができる。
The concentration of the sulfuric acid to be treated in the present invention is not particularly limited, but concentrated sulfuric acid having a concentration of about 90% by weight (concentrated sulfuric acid is simply expressed as%) or higher is suitably treated by the present invention. The
Is not particularly limited with respect to the concentration of mercury pretreatment according to the present invention, normally it is those mercury number 10 -1 ppm to number 10ppm in the sulfuric acid is contained, the present invention Mercury concentration can be removed to 0.1 ppm or less.
さらに、上記の銅粉の粒径は特に限定されないが、反応性の点からは粒径が小さいものが好ましいものの、ハンドリング、コスト等の点から粒径が小さすぎる場合も不適当であり、粒径が３０〜１００μｍφの銅粉が好ましい。
なお、銅粉に代えて又は銅粉とともに銀粉を使用した場合にも銅粉を使用した本発明の場合と同様の効果を奏することができる。
Further, the particle size of the copper powder is not particularly limited, but a small particle size is preferable from the viewpoint of reactivity, but it is also inappropriate when the particle size is too small from the viewpoint of handling, cost, etc. Copper powder having a diameter of 30 to 100 μm is preferable.
In addition, even when it replaces with copper powder or uses silver powder with copper powder, there can exist an effect similar to the case of this invention which uses copper powder.
本発明で添加されるアンモニアまたはアンモニア化合物は、前記の銅粉の硫化反応に伴っていったん共沈または吸着されたＨｇＳが過剰のＳイオンと反応して再溶解することを防止すべくこの過剰のＳイオンと反応して取り除くものであって、アンモニア、アンモニア水、ＮＨ４Ｃｌなどを使用することができ、また本発明で添加される硫化物としてはＮａＳＨ等の水硫化物、アルカリ金属もしくはアルカリ土類金属の硫化物もしくは多硫化物、さらには硫化水素ガスなどを使用することができるが、いずれもこれらの化合物に限定されないものである。 Ammonia or an ammonia compound added in the present invention is used in order to prevent HgS once coprecipitated or adsorbed in the copper powder sulfidation reaction from reacting with excess S ions and redissolving. It is removed by reacting with S ions, and ammonia, aqueous ammonia, NH 4 Cl and the like can be used. The sulfide added in the present invention is a hydrosulfide such as NaSH, an alkali metal or an alkali. Earth metal sulfides or polysulfides, and also hydrogen sulfide gas can be used, but any of them is not limited to these compounds.
固液分離は濾過、沈降、遠心分離などから適宜選択することができるが、コスト、処理速度、液の清澄性の点から濾過が好ましい。
上記水銀分離後において硫黄析出を抑制し白濁等を防止するための硫酸の酸化は空気吹き込み、酸素ガス吹き込みまたは電解酸化によって行ってもよいが、発生期の酸素を生ずる過酸化水素水の添加が酸化力、操作上からも好ましく、一週間以上硫酸の透過率を９９．９％以上に維持することができる。
Solid-liquid separation can be appropriately selected from filtration, sedimentation, centrifugation, and the like, but filtration is preferred from the viewpoint of cost, processing speed, and liquid clarity.
Oxidation of sulfuric acid to suppress sulfur precipitation and prevent white turbidity after mercury separation may be carried out by air blowing, oxygen gas blowing or electrolytic oxidation. Oxidizing power is preferable from the viewpoint of operation, and the sulfuric acid permeability can be maintained at 99.9% or more for one week or more.
なお、本発明において透過率は波長６６０ｎｍのタングステンランプを光源とし、測定対象硫酸をセルに入れ、比較用の純水の透過率を１００％として光電管を用いた検出器により強度を測定して求めた。 In the present invention, the transmittance is obtained by measuring the intensity with a detector using a photoelectric tube, using a tungsten lamp having a wavelength of 660 nm as a light source, putting sulfuric acid to be measured into a cell, and setting the transmittance of comparative pure water as 100%. It was.
以下に本発明の実施例を示すが、本発明の技術的範囲は実施例の記載に限定されるものではない。 Examples of the present invention are shown below, but the technical scope of the present invention is not limited to the description of the examples.
［実施例１］硫酸濃度９８．０〜９９．２％（以下の各実施例および各比較例における硫酸も同じ。）および水銀濃度０．２５〜０．３７ｐｐｍの硫酸２５０ｍｌに対して、銅粉（０〜１００ｐｐｍ）、ＮＨ４Ｃｌ（１０〜１００ｐｐｍ）、ＮａＳＨ（濃度１．２５〜２５％、０．５ｍｌ）を添加し、６時間撹拌して濾過したところ、硫酸中の水銀濃度が０．０３〜０．１ｐｐｍになり、０．１ｐｐｍ以下を達成することができた。
図１に、ＮａＳＨの濃度が２．５％と５％の場合についての銅粉添加量と水銀濃度の関係を示す。
上記濾過後の硫酸に３０％濃度の過酸化水素水０．３〜１．０ｍｌ（以下の各実施例および各比較例においても同じ。）を添加したところ、透過率９９．９％が一週間以上持続し、白濁等の着色がなかった。
[Example 1] Copper powder with respect to 250 ml of sulfuric acid having a sulfuric acid concentration of 98.0 to 99.2% (the sulfuric acid in each of the following examples and comparative examples is the same) and a mercury concentration of 0.25 to 0.37 ppm. (0-100 ppm), NH 4 Cl (10-100 ppm), NaSH (concentration 1.25-25%, 0.5 ml) were added, and the mixture was stirred for 6 hours and filtered. It became 03-0.1 ppm and was able to achieve 0.1 ppm or less.
FIG. 1 shows the relationship between the added amount of copper powder and the mercury concentration when the concentration of NaSH is 2.5% and 5%.
When 0.3-1.0 ml of 30% hydrogen peroxide solution (the same applies to each of the following examples and comparative examples) was added to the sulfuric acid after filtration, the transmittance was 99.9% for one week. This persisted and there was no coloring such as cloudiness.
［実施例２］水銀濃度０．２５〜０．３７ｐｐｍの硫酸２５０ｍｌに対して、銅粉（２０〜１００ｐｐｍ）、ＮＨ４Ｃｌ（１０〜１００ｐｐｍ）、硫化水素ガス（濃度１００％、０〜２０ｍｌ）を添加し、６時間撹拌して濾過したところ、硫酸中の水銀濃度が０．０２〜０．０９ｐｐｍになり、０．１ｐｐｍ以下を達成することができた。
図２に、硫化水素ガス添加量と水銀濃度の関係を示す。
上記濾過後の硫酸に過酸化水素水を添加したところ、透過率９９．９％が一週間以上持続し、白濁等の着色がなかった。
[Example 2] Copper powder (20 to 100 ppm), NH 4 Cl (10 to 100 ppm), hydrogen sulfide gas (concentration 100%, 0 to 20 ml) with respect to 250 ml of sulfuric acid having a mercury concentration of 0.25 to 0.37 ppm Was added, and the mixture was stirred for 6 hours and filtered. As a result, the mercury concentration in sulfuric acid was 0.02 to 0.09 ppm, and 0.1 ppm or less could be achieved.
FIG. 2 shows the relationship between the amount of hydrogen sulfide gas added and the mercury concentration.
When hydrogen peroxide solution was added to the sulfuric acid after filtration, the transmittance of 99.9% was maintained for one week or more, and there was no coloring such as cloudiness.
［比較例１］水銀濃度０．２５〜０．３７ｐｐｍの硫酸２５０ｍｌに対して、ＮａＳＨ（濃度１．２５〜２５％、０．５ｍｌ）を添加し、６時間撹拌して濾過したところ、硫酸中の水銀濃度は０．２１〜０．３２ｐｐｍであって、０．１ｐｐｍ以下を達成することができなかった。
上記濾過後の硫酸に過酸化水素水を添加したところ、透過率は７４〜９４％であって白濁があった。
[Comparative Example 1] To 250 ml of sulfuric acid having a mercury concentration of 0.25 to 0.37 ppm, NaSH (concentration 1.25 to 25%, 0.5 ml) was added, and the mixture was stirred for 6 hours and filtered. The mercury concentration was 0.21 to 0.32 ppm, and could not be achieved below 0.1 ppm.
When hydrogen peroxide was added to the sulfuric acid after filtration, the transmittance was 74 to 94% and white turbidity was observed.
［比較例２］水銀濃度０．２５〜０．３７ｐｐｍの硫酸２５０ｍｌに対して、硫化水素ガス（濃度１００％、５〜２０ｍｌ）を添加し、６時間撹拌して濾過したところ、硫酸中の水銀濃度は０．２１〜０．３２ｐｐｍであって、０．１ｐｐｍ以下を達成することができなかった。
上記濾過後の硫酸に過酸化水素水を添加したところ、透過率は８８〜９４％であって白濁があった。
[Comparative Example 2] Hydrogen sulfide gas (concentration 100%, 5 to 20 ml) was added to 250 ml of sulfuric acid having a mercury concentration of 0.25 to 0.37 ppm, and the mixture was stirred and filtered for 6 hours. The concentration was 0.21 to 0.32 ppm, and could not be achieved below 0.1 ppm.
When hydrogen peroxide water was added to the sulfuric acid after filtration, the transmittance was 88 to 94% and white turbidity was observed.
［比較例３］水銀濃度０．２５〜０．３７ｐｐｍの硫酸２５０ｍｌに対して、銅粉（２０〜１００ｐｐｍ）、ＮａＳＨ（濃度１．２５〜２５％、０．５ｍｌ）を添加し、６時間撹拌して濾過したところ、硫酸中の水銀濃度は０．２１〜０．３２ｐｐｍであって、０．１ｐｐｍ以下を達成することができなかった。
上記濾過後の硫酸に過酸化水素水を添加したところ、透過率は９２〜９４％であって白濁があった。
[Comparative Example 3] To 250 ml of sulfuric acid having a mercury concentration of 0.25 to 0.37 ppm, copper powder (20 to 100 ppm) and NaSH (concentration 1.25 to 25%, 0.5 ml) were added and stirred for 6 hours. As a result of filtration, the mercury concentration in sulfuric acid was 0.21 to 0.32 ppm, and could not be achieved below 0.1 ppm.
When hydrogen peroxide solution was added to the sulfuric acid after filtration, the transmittance was 92 to 94% and white turbidity was observed.
［比較例４］水銀濃度０．２５〜０．３７ｐｐｍの硫酸２５０ｍｌに対して、銅粉（２０〜１００ｐｐｍ）、硫化水素ガス（濃度１００％、５〜２０ｍｌ）を添加し、６時間撹拌して濾過したところ、硫酸中の水銀濃度は０．２１〜０．３２ｐｐｍであって、０．１ｐｐｍ以下を達成することができなかった。
上記濾過後の硫酸に過酸化水素水を添加したところ、透過率は９２〜９４％であって白濁があった。
[Comparative Example 4] To 250 ml of sulfuric acid having a mercury concentration of 0.25 to 0.37 ppm, copper powder (20 to 100 ppm) and hydrogen sulfide gas (concentration 100%, 5 to 20 ml) were added and stirred for 6 hours. As a result of filtration, the mercury concentration in sulfuric acid was 0.21 to 0.32 ppm, and could not be achieved below 0.1 ppm.
When hydrogen peroxide solution was added to the sulfuric acid after filtration, the transmittance was 92 to 94% and white turbidity was observed.
［比較例５］水銀濃度０．２７〜０．３３ｐｐｍの濃硫酸２５０ｍｌに対して、ＫＩ（２５ｍｇ）を添加し、１時間撹拌して濾過した。その濾液に硫化ソーダ（０．２〜２．０ｇ）または硫化水素ガス（濃度１００％、１２〜２５ｍｌ）を添加し、６時間撹拌後に再び濾過した。このときの硫酸中の水銀濃度は０．１７〜０．２２ｐｐｍであって、０．１ｐｐｍ以下を達成することができなかった。
上記濾過後の硫酸に過酸化水素水を添加したところ、透過率は２２〜９５％であって白濁があった。
[Comparative Example 5] KI (25 mg) was added to 250 ml of concentrated sulfuric acid having a mercury concentration of 0.27 to 0.33 ppm, and the mixture was stirred for 1 hour and filtered. Sodium sulfide (0.2 to 2.0 g) or hydrogen sulfide gas (concentration 100%, 12 to 25 ml) was added to the filtrate, and the mixture was again filtered after stirring for 6 hours. The mercury concentration in the sulfuric acid at this time was 0.17 to 0.22 ppm, and could not be achieved below 0.1 ppm.
When hydrogen peroxide was added to the sulfuric acid after the filtration, the transmittance was 22 to 95% and white turbidity was observed.
本発明は、非鉄金属製錬工程などで製造される水銀を含有する硫酸中から、水銀を従来到達困難だった０．１ｐｐｍ以下にまで除去し、かつ白濁のない硫酸を得るための硫酸の処理の用途に適用することができる。 The present invention removes mercury from sulfuric acid containing mercury produced in a non-ferrous metal smelting process or the like to 0.1 ppm or less, which has been difficult to reach, and treats sulfuric acid to obtain sulfuric acid having no cloudiness. It can be applied to any use.
Claims (4)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003316768A JP4296289B2 (en) | 2003-09-09 | 2003-09-09 | Method for removing mercury in sulfuric acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003316768A JP4296289B2 (en) | 2003-09-09 | 2003-09-09 | Method for removing mercury in sulfuric acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2005082449A JP2005082449A (en) | 2005-03-31 |
| JP4296289B2 true JP4296289B2 (en) | 2009-07-15 |
Family
ID=34416562
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2003316768A Expired - Fee Related JP4296289B2 (en) | 2003-09-09 | 2003-09-09 | Method for removing mercury in sulfuric acid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4296289B2 (en) |
-
2003
- 2003-09-09 JP JP2003316768A patent/JP4296289B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2005082449A (en) | 2005-03-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4559237A (en) | Process for the deposition of metals on semiconductor powders | |
| US3674428A (en) | Mercury removal | |
| US3766036A (en) | Process for the removal of ionic metallic impurities from water | |
| US5730884A (en) | Method of removing selenate ion from selenate ion-containing aqueous waste liquid | |
| CN105668528A (en) | Method for catalytically reducing selenium | |
| EP1347818B1 (en) | Method for removing mercury from gas | |
| CA1214334A (en) | Method for the recovery of silver from waste photographic fixer solutions | |
| Figueroa et al. | Recovery of gold and silver and removal of copper, zinc and lead ions in pregnant and barren cyanide solutions | |
| AU2002217170A1 (en) | Method for removing mercury from gas | |
| JP4296289B2 (en) | Method for removing mercury in sulfuric acid | |
| JP5200588B2 (en) | Method for producing high purity silver | |
| NO332796B1 (en) | Procedure for removing volatile impurities from a weak acid solution | |
| US3764528A (en) | Process for removal of soluble mercury residues from aqueous process streams | |
| JP2021023851A (en) | Method of treating solution containing seleno sulfate | |
| US5939042A (en) | Tellurium extraction from copper electrorefining slimes | |
| EP1468122B1 (en) | Method for the separation of zinc and nickel in the presence of chloride ions | |
| AU695956B1 (en) | Process for extracting and recovering silver | |
| JP5987239B2 (en) | Rhenium recovery method | |
| JP4239801B2 (en) | Method for producing waste acid gypsum | |
| US4428911A (en) | Method of precipitating uranium peroxide | |
| EA007859B1 (en) | Method for removing thallium from a zinc-containing solution | |
| JP5573763B2 (en) | High purity silver production waste liquid treatment method | |
| JPH06145828A (en) | Method for recovering gold and silver | |
| EP3327155B1 (en) | Method for recovering rhenium, method for selectively recovering rhenium from solution including rhenium and other metals, and method for increasing content ratio of rhenium in solution including rhenium and other metals | |
| JP6882110B2 (en) | Method for recovering precipitates containing platinum group elements |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20060724 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20081119 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20081125 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20090126 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20090224 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20090323 |
|
| A711 | Notification of change in applicant |
Free format text: JAPANESE INTERMEDIATE CODE: A712 Effective date: 20090323 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20090323 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20090323 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120424 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120424 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130424 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130424 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140424 Year of fee payment: 5 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |