• Title/Summary/Keyword: 금 회수

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The Effective Recovery of Gold from the Invisible Gold Concentrate Using Microwave-nitric Acid Leaching Method (마이크로웨이브-질산침출방법에 의한 비가시성 금의 회수율 향상)

  • Lee, Jong-Ju;Myung, Eun-Ji;Park, Cheon-Young
    • Journal of the Mineralogical Society of Korea
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    • v.32 no.3
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    • pp.185-200
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    • 2019
  • This study aimed to liberate gold from invisible gold concentrate (Au = 1,840.00 g/t) through microwave nitric acid leaching experiments. For the purpose, this study conducted microwave-nitric acid leaching experiments and examined nitric acid concentration effect, microwave leaching time effect and sample addition effect. The results of the experiments were as follows: Au (gold) contents were not detected in all of the microwave leaching conditions. In the insoluble-residue, weight loss rate tended to decrease as the nitric acid concentration, microwave leaching time and sample addition increased. In an XRD analysis with solid-residue, it was suggested that gypsum and anglesite were formed due to dissolution of calcite and galena by nitric acid solution. When a fire assay was carried out with insoluble-residue, it was discovered that gold contents of the solid-residue were 1.3 (Au = 2,464.70 g/t) and 28.8 (52,952.80 g/t) times more than those of concentrate. But in the gold contents recovered, a severe gold nugget effect appeared. It is expected that the gold nugget effect will decrease if a sampling method of concentrate is improved in the microwave-nitric acid leaching experiments and filtering paper with smaller pore size is used for leaching solution and burned filter paper is used for sampling in lead-fire assay.

A Study on Inter-agency Fare Allocation Methods under the Integrated Distance-based Fare System in Seoul (서울시의 대중교통 통합거리비례요금제 하에서 운영기관 간 요금정산방안에 관한 연구)

  • Yun, Ji-Hyeon;Kim, Seong-Su
    • Journal of Korean Society of Transportation
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    • v.25 no.1 s.94
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    • pp.37-47
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    • 2007
  • The Integrated Public Transport Reforms of the Seoul Metropolitan Government, which were implemented on the $1^{st}$ of July. 2004, launched a new fare allocation method. However, when a Private transit operator or a new transport system is introduced into the existing system, it will cause an allocation problem. Therefore, this study aims to Propose a rational fare allocation method which can be applicable regardless of the number of Public transportation modes or operators. To create alternatives, this study has adopted a fundamental principle of revenue allocation methods for the transit or communications sectors, and has applied it to the current transit system of Seoul. This study kas analyzed results of the cost recovery ratios and characteristics of each alternative through case studies. This study kas Presented an assessment criterion Z in order to select an optimal alternative. The criterion consists of the sum of the cost recovery ratio of each operator and the difference of the cost recovery ratio for each agency in inter-agency transit. Using the assessment criterion. the results showed that Alternative 1 is superior to the others : Alternative 1 is considering passenger-km of each operator and unit cost of passenger-km for each operator.

Improvement Plan for Calculation of Financial Contributions to Treatment of Waste Electrical and Electronic Equipments (폐전기·전자제품 처리에 대한 분담금 산정의 개선방안)

  • Kim, Han-Soo;Kim, Dae-Bong
    • Resources Recycling
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    • v.29 no.4
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    • pp.45-50
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    • 2020
  • Producer and distributor of electrical and electronic equipment may directly collect waste electrical and electronic equipment that falls under the class to which the equipment they distributed belongs, or may join KERC(Korea Electronic Recycling Cooperative) and have KERC fulfill the duty to collect on behalf. In this study, the system of calculating the financial contributions is reviewed, and then the defined problems and improvement plan are proposed. First, the standard operation and time should be set for collection and transportation costs, taking into account the operation by collection type. Second, since there is a difference in the screening method of the recycling center, the standard cost for the allocation factor should be set by reflecting the difference in these methods and the characteristics of the product line being processed. Third, it is necessary to secure a budget of sufficient size by determining the median or average value rather than the minimum value in the forecast model for visit collection. This study is suggesting in that it examines the problems of the allotted contributions paid by the mutual aid members to KERC and suggests ways to improve them.

Determination of gold concentration in ore by ICP-AES with MIBK (ICP-AES와 MIBK 용매를 이용한 광물중의 금 분석)

  • Lim, Heon-Sung;Lee, Sueg-Geun
    • Analytical Science and Technology
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    • v.20 no.6
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    • pp.496-501
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    • 2007
  • The 242.795 nm on ICP-AES for the gold analysis was the most sensitive wavelength which was also interfered severely by the spectra of other metal ions such as manganese, chromium, cobalt, and iron. In order to analyze the gold in ore, the gold must be separated from the interfering ions. The best solvent for separation of gold in ore solution was 10 % n-hexane contained MIBK mixed solvent. The gold recovery was 97.5 % from mixed metal solution contained about 2 M $HNO_3$ and 0.5 M HCl.

프린팅월드 - 미국 제책업계 동향

  • Jo, Gap-Jun
    • 프린팅코리아
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    • s.29
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    • pp.162-165
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    • 2004
  • 미국에서는 새로운 중철기 업그레이드 제품들이 업계에 경종을 울릴 만큼 발전을 거듭하며 소규모 인쇄업체에 적합하게 자동화를 이루고 있다. 물론 각 제조업체들은 수동 중철기도 최상의 출력을 목표로 발전시켜 왔다. 후가공 업계에서 자동화 장비의 변화 단계는 투자회수금(ROI)최대화에 요구되는 적당한 가격과 기술을 선택할 수 있도록 진행돼 왔다. 이 글에서는 미국 사용자들이 현재의 옵션과 시장에 공급되고 있는 최신 중형 중철기들을 활용하고 있는 사례에 대해 다룬다.

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The Efficiency of Fe Removal Rate from Gold Ore in the Oxidation Zone by Ammonia Leaching (암모니아 용출에 의한 산화대 금 광석으로부터 Fe 제거 효율에 관한 연구)

  • Kim, Bong-Ju;Cho, Kang-Hee;Choi, Nag-Choul;Park, Cheon-Young
    • Journal of the Mineralogical Society of Korea
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    • v.29 no.3
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    • pp.113-122
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    • 2016
  • This study aims to improve the recovery of gold and silver by removing hematite from gold ore of an oxidation zone with ammonia solution. Quartz, hematite and muscovite were present in the oxidation zone, while hematite was hydrogenous. As a result of performing an ammonia leaching test on variables, it is found that the maximum Fe leaching parameter was $-45{\mu}m$ particle size, 1.0 M sulfuric acid concentration, 5.0 g/l ammonium sulfate concentration and 2.0 M hydrogen peroxide concentration. It is also confirmed that goethite was precipitated and formed from that ammonia elution. As the amount of Fe-removal was increased in a solid-residue, the recovery of Au and Ag were increased, too.

Current Status on the Pyrometallurgical Process for Recovering Precious and Valuable Metals from Waste Electrical and Electronic Equipment(WEEE) Scrap (폐전기전자기기(廢電氣電子機器) 스크랩으로부터 귀금속(貴金屬) 및 유가금속(有價金屬) 회수(回收)를 위한 건식공정(乾式工程) 기술(技術) 현황(現況))

  • Kim, Byung-Su;Lee, Jae-Chun;Jeong, Jin-Ki
    • Resources Recycling
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    • v.18 no.4
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    • pp.14-23
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    • 2009
  • In terms of resources recycling and resolving waste disposal problems, it is very important to recover precious metals like Au, Ag and Pd and valuable metals like Cu, Sn and Ni from the scraps of waste electrical and electronic equipment(WEEE) that consists of detective electrical and electronic parts discarded during manufacturing electrical and electronic equipments and waste electrical and electronic parts generated during disassembling them. In general, the scraps of WEEE are composed of various metals and alloys as well as refractory oxides and plastic components. Precious and valuable metals from the scraps of WEEE can be recovered by gas-phase-volatilization, hydrometallurgical, or pyrometallurgical processes. However, the gas-phase-volatilization and hydrometallurgical processes have been suggested but not yet commercialized. At the present time, most of the commercial plants for recovering precious and valuable metals from the scraps of WEEE adopt pyrometallurgical processes. Therefore, in this paper, the technical and environmental aspects on the important pyrometallurgical processes through literature survey are reviewed, and the scale-up result of a new pyrometallurgical process for recovering the precious and valuable metals contained in the scraps of WEEE using waste copper slag is presented.

Selective Recovery of Platinum Group Metals by Solvent Extraction and Electrolysis in Non-aqueous Solution Based on Ionic Liquids (이온성액체 기반 비수계 용액에서 용매추출과 전해에 의한 백금족 금속의 분리회수)

  • Park, Gwang-won;Park, Jesik;Lee, Churl Kyoung
    • Resources Recycling
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    • v.28 no.2
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    • pp.46-53
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    • 2019
  • In this study, the extraction and reduction behavior of platinum group metals in a non-aqueous solvent based on ionic liquids was investigated in order to confirm a new extraction technology of platinum group metals. Platinum was selectively extracted using an ionic liquid $[C_4mim]PF_6$ from a mixed solution of $PdCl_2$, $PtCl_4$ and $RhCl_3$ dissolved with concentration ratio of 10:1:0.5 M. After stripping of the metals by 1 M $HNO_3$ solution, the platinum was preferentially reduced by aqueous electrolysis on gold electrode at -0.8 V (vs. Pt-QRE). The residual palladium and rhodium were transferred to ionic liquid of $[C_4mim]Cl$. The metallic palladium and rhodium could be sequentially reduced on gold and STS304 as working electrodes by non-aqueous electrolysis, respectively.

A Study of the Research Trends and the Material flow on the Unrecycled Materials in Korea - The Current Situation of Recycling Technology for Waste Resources in Korea(2) - (국내(國內) 미이용자원(未利用資源)을 위한 회수(回收) 연구동향(硏究動向) 및 물질(物質)흐름 - 국내자원(國內資源)의 유효이용(有效利用)을 위한 처리(處理) 및 회수기술(回收技術) 동향조사(動向調査)(2) -)

  • Oh, Jae-Hyun;Kim, Mi-Sung;Shin, Hee-Duck;Min, Ji-Won
    • Resources Recycling
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    • v.16 no.2 s.76
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    • pp.63-76
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    • 2007
  • Typical examples as unrecycled materials in Korea were Zinc from the electric arc furnace dust (EAF Dust), and Moiybdenium and Vanadium from the desulfurizing spent catalyst of petrochemical industries. In the otherwise, though recovery of valuable metals from the waste electronic scrap such as printed circuit boards (PCBs) and platinum group metals (PGM) from the waste automobile catalyst have been interesting issues, it is difficult to collect the exact informations or statistics on their material flow system. In this article, The current domestic research trends for unrecycled or less recycled materials have been reviewed, and material flow and recycling technologies on the desulfurizing spent catalyst were surveyed.

Leaching of Gold and Silver from Anode Slime with Inorganic Reagents (양극슬라임으로부터 무기침출제에 의한 금과 은의 침출)

  • Xing, Wei Dong;Lee, Ki Woog;Lee, Man Seung
    • Resources Recycling
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    • v.26 no.1
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    • pp.30-36
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    • 2017
  • Leaching experiments of anode slime were performed with several inorganic acids (HCl, $HNO_3$ and $H_2SO_4$) together with thiourea and thiosulfate solution to recover gold and silver. Gold was not dissolved at all into these inorganic acids in the absence of any oxidizing agents. At the same concentration of inorganic acid, the leaching of percentage of Ag was the highest in the sulfuric acid solution. The leaching percentage of silver increased with the increase of HCl concentration owing to the formation of $AgCl_2{^-}$. Copper, nickel and zinc except tin was almost dissolved in these inorganic acids but no tin was dissolved in nitric acid solution. Most of Au and Ag were dissolved into the mixture of sulfuric acid and thiourea solution. Thiosulfate could dissolve some silver from the anode slime but no gold was dissolved by this agent.