研究等業績 - その他 - 柴山　敦

Beneficiation of Low-Grade Lithium Ores from Eastern Kazakhstan by Dense Media Separation (DMS) and Froth Flotation

Sagzhanov D.

Minerals, Metals and Materials Series ( Minerals, Metals and Materials Series )    201 - 213   2024年

LithiumLithium is one of the critical elements required for clean energy technology to achieve a carbon-neutral target. In this study, the beneficiation ofLow-grade spodumene ore a low-grade spodumene ore (0.3–0.6% Li2O) from Eastern Kazakhstan is investigated by dense medium separation (DMS)Dense Medium Separation (DMS) and froth flotationFlotation to obtain lithiumLithium concentrate. The main gangue minerals in the spodumene ore are feldspar, quartz and mica. The highest lithiumLithiumgrade in concentrate from DMSDense Medium Separation (DMS) of 1000/+ 850 µm size fractions of the low-grade spodumene oreLow-grade spodumene ore is achieved at approximately 5.7% from 0.6% (Li2O), with a recoveryRecovery of about 90%. Furthermore, the spodumene ore is beneficiated by reverse flotationFlotation using NaOL and DAA as mixed collectorsMixed collector. The maximum lithiumLithiumrecoveryRecovery of approximately 30% with the highest lithiumLithium grade of 1.0% was obtained from a low-grade spodumene oreLow-grade spodumene ore under flotationFlotation condition of 1000 g/t NaOL/DAA, ratio of 1:5, pH 10. Conditioning the pulp with starch has little effect on the flotationFlotationrecoveryRecovery of lithiumLithiumfrom low-grade spodumene oreLow-grade spodumene ore improving lithiumLithium grade from 1.0 to 1.45%.

DOI

Establishment of a Hydrometallurgical Scheme for the Recovery of Copper, Nickel, and Cobalt from Smelter Slag and Its Economic Evaluation

Godirilwe L.L.

Sustainability (Switzerland) ( Sustainability (Switzerland) )  15 ( 13 )   2023年07月

DOI

Tin Recovery from WPCBs by Immersion Using Lead-Tin Molten Metal

Ueda S.

World of Metallurgy - ERZMETALL ( World of Metallurgy - ERZMETALL )  76 ( 4 ) 261 - 266   2023年07月

Waste printed circuit boards (WPCBs) contain a variety of metals, including copper, tin, and precious metals, some of which are valuable. These raw materials are called "urban mines (E-scrap)" and have attracted much attention. Among these, this study focused on solder used on circuit boards. The main component of solder is tin, with trace amounts of silver and copper. Tin has a relatively low melting point among metals and is easy to process. Currently in Japan, WPCBs are mainly recycled via copper smelting with concentrate. However, tin is preferentially oxidized in copper smelting and is mostly dispersed in slag. Currently, the recycling rate of tin in Japan is extremely low at about 8 % [1]. Furthermore, the establishment of a high recovery rate technology for tin is still inadequate. The objective of this study is to improve the tin recycling rate by recovering tin at an earlier stage before feeding the WPCBs into a copper smelting furnace. Therefore, this study focused on the immersion method in lead-tin molten solution as a method to selectively recover solder from WPCBs using the dry smelting method. In the experimental method, WPCBs were immersed in a molten lead-tin alloy solution for a certain amount of time. Subsequently, evaluations were conducted on the substrate side and the alloy side. Optimal conditions for the immersion method were studied and basic tests were conducted to achieve a solder recovery rate of more than 70 % from the WPCBs. The results confirmed that the solder recovery rate by the immersion method was more than 80 % within one minute. This suggests that the immersion method can achieve a high recovery rate in a short time by using a highly conductive alloy. In the future, the continuous immersion testing of substrates and efficient testing conditions will continue to be studied to work toward actual operation.

Recovery of Pd(II) by solvent extraction with a dithiophenol-based extractant from the undiluted leachate of spent automotive catalysts followed by water scrubbing and thiourea stripping

Yamada M.

Hydrometallurgy ( Hydrometallurgy )  215   105986 - 105986   2023年01月

DOI

Copper Recovery from Chalcopyrite Concentrate by Oxidative Roasting and Acid Leaching

Tumen-Ulzii N.

International Journal of the Society of Material Engineering for Resources ( International Journal of the Society of Material Engineering for Resources )  25 ( 1 ) 56 - 62   2022年

<p>In this study, a combined process consisting of salt roasting and acid leaching was conducted to recover copper per sulphide concentrate with 43.5% of chalcopyrite. The chalcopyrite concentrate was roasted in the absence and the presence of potassium chloride (mass ratio of concentrate:KCl from 1:0.5 to 1:0.9) at various temperatures (400-600°C) and different roasting times (1-4 hours) under air atmosphere. The roasted concentrate was dissolved in sulphuric acid solution (60 g/L) with a solid-liquid ratio of 1:8 at an ambient temperature for 2 hours. The chalcopyrite concentrate, roasted samples, and leached residues were analyzed using atomic absorption spectrometry, UV-VIS spectrophotometer, and X-ray diffractometer. Thermogravimetry and differential thermal analyses were applied on the chalcopyrite concentrate and the concentrate with KCl up to 1000°C. Results showed that about 80% and 90% of chalcopyrite decomposed under the conditions with the copper concentrate:KCl ratio of 1:0.6, roasting time of 2 hours at 500°C and 550°C, respectively. The DTA-TG analyses revealed variant phase regions associated with chalcopyrite decomposition through the roasting. Copper dissolution with the sulphuric acid solution from the roasted concentrates was over 99.7% and 99.0% under the determined conditions. The thermodynamic stability of chalcopyrite with KCl was discussed by calculating Gibb's free energy.</p>

DOI CiNii Research

Process Development for Gold Concentrate Recovery by Multi-stage Flotation using Optimized Conditions

Tun N.W.

International Journal of the Society of Material Engineering for Resources ( International Journal of the Society of Material Engineering for Resources )  25 ( 2 ) 235 - 242   2022年

<p>A pre-treatment method for upgrading gold from a polymetallic gold-zinc-lead ore by flotation was studied. X-ray diffraction analysis of the gold sulfide ore showed that quartz, calcite, pyrite, sphalerite, and galena are the main constituents of the ore. The composition of the polymetallic ore contained 6.49 ppm Au, 3.48% Zn, 1.25% Pb, 17.98% Fe, and 20.36% S. Due to the complexity of the polymetallic ore, the gold recovery is generally low. The objective of this study is to develop a primary flotation process to recover gold in a bulk sulfide concentrate. The effects of particle size, collector type, flotation time, and the slurry pH on the recoveries and grades of gold, zinc, and lead were investigated. The developed flotation process consisted of rougher, scavenger, and cleaner stages. High recovery of gold was found to be linked with a high recovery of Pb which was achieved by the utilization of a mixture of collector AERO 7249 and PAX. The gold flotation kinetics were fast with more than 50% of gold recovered within 5 minutes of flotation. Under optimized flotation conditions with rougher, scavenger, and cleaner stages, a total gold recovery of 88.36 % and a final gold grade of 60.97 ppm were obtained. A total gold enrichment ratio of 9.4 was achieved, confirming the viability of the flotation method in upgrading the gold from the polymetallic sulfide ore prior to further processing.</p>

DOI CiNii Research

Removal of Silicon, Aluminum and Phosphorus Impurities from Low-grade Iron Ore by Reverse Froth Flotation and Alkaline Roasting

Batnasan A.

International Journal of the Society of Material Engineering for Resources ( International Journal of the Society of Material Engineering for Resources )  25 ( 1 ) 122 - 128   2022年

<p>In this paper, the removal processes for silicon (Si), aluminum (Al) and phosphorus (P) impurities from low-grade iron ore, in which hematite (Fe₂O₃), goethite (FeO(OH)), and quartz (SiO₂) are the main mineral constituents, have been presented. The reverse froth flotation process was applied to remove silicon and aluminum impurities from the iron ore using dodecyltrimethylammonium bromide (DTAB) and dodecylamine acetate (DAA) cationic collectors at a broad slurry pH ranging from 2 to 12. Whereas alkaline roasting followed by a water washing process was employed to remove phosphorus impurity from the iron ore under the various sodium hydroxide concentrations, different roasting temperatures, and prolonged varying times. Results showed that the maximum removal rate of SiO₂ and Al₂O₃ achieved were 58.3% and 31.0% via reverse froth flotation using DTAB collector at pH 12, whereas 38.7% SiO₂ and 10.0% Al₂O₃ with DAA collector. The level of total (SiO₂+Al₂O₃) impurities in the tailing as iron ore product from the reverse flotation was reduced from 7.4 mass% to 4.4 mass% as the initial level. On the other hand, about 61% of phosphorus in the iron ore was removed by the combined alkaline roasting and water washing at the conditions optimized as 50 g/kg-ore NaOH at 300°C for 0.5 h. The grade of phosphorus impurity reached 0.04 mass% from 0.09 mass% (initial grade). Simultaneously, the iron grade and level of SiO₂+Al₂O₃ impurity in the iron ore product from reverse flotation of the low-grade iron ore with DTAB collector reached 60.0 mass% and 4.4 mass%, which are acceptable levels for ironmaking.</p>

DOI CiNii Research

The Role of Lead in Suppressing Passivation of High Silver-Containing Copper Anodes During Electrorefi ning

Godirilwe L.L.

International Journal of the Society of Material Engineering for Resources ( International Journal of the Society of Material Engineering for Resources )  25 ( 1 ) 137 - 144   2022年

<p>Passivation behavior of high silver containing copper anodes was investigated using slowly cooled Cu- 1%Ag anodes of different lead (Pb) concentrations. The addition of Pb distributes silver in the Pb phase and reduces the amount of silver that is solidly soluble in copper and, thus, generates a fine silver powder on the anode surface which is a main contributing factor of passivation. Electrorefining experiments were conducted using a synthetic electrolyte containing 40 g/L Cu²⁺ and 180 g/L H₂SO₄, at 60°C. SEM-EDS analysis was used to study the resulting anode slime and showed that increasing Pb content altered the anode slime structure from fine and compact to porous and less adherent to the anode surface. Utilizing a Cu-1%Ag0.2%Pb anode yielded the longest passivation time with a low and stable cell voltage of 0.1V. The slime morphology was characterized by precipitated metallic silver particles either as inclusion or loosely present on the surface of the abundant complex Cu-Ag-Pb sulfate type of compounds. Because of the economic importance of silver recovery from the anode slime, understanding its behavior during electrorefining will enable operating with high impurity anodes especially in secondary copper processing where metallic impurities can result from e-waste and copper alloy scrap.</p>

DOI リポジトリ CiNii Research

Environmentally friendly Pd(II) recovery from spent automotive catalysts using resins impregnated with a pincer-type extractant

Yamada M.

Scientific Reports ( Scientific Reports )  11 ( 1 )   2021年12月

DOI

Extraction of copper from complex carbonaceous sulfide ore by direct high-pressure leaching

Godirilwe L.L.

Minerals Engineering ( Minerals Engineering )  173   2021年11月

DOI

鉱物処理の研究から展開した過熱水蒸気による基板リサイクルと溶媒抽出用「抽出剤」に関する研究

柴山 敦, 山田 学, 川村 茂, 芳賀 一寿

金属   91 ( 10 ) 863 - 866   2021年10月

Copper recovery and reduction of environmental loading from mine tailings by high‐pressure leaching and sx‐ew process

Godirilwe L.L.

Metals ( Metals )  11 ( 9 )   2021年09月

DOI

Investigation of Phosphorus Removal and Dephosphorization Effect from Iron Ore During Alkaline Roasting and Wet Grinding

A. Shibayama, K. Haga, A. Batnasan, M. Mizutani, K. –I. Higuchi

Proceedings of the XXX International Mineral Processing Congress(IMPC2020)     2359 - 2370   2021年04月

Removal of Silica from High Silica Containing Zinc Concentrate by Regrinding and Flotation

K. Haga, T. Ono, A. Batnasan, Y. Takasaki, S. Kawamura, A. Shibayama

Proceedings of the XXX International Mineral Processing Congress(IMPC2020)     2078 - 2087   2021年04月

Selective Extraction of Nickel, Copper and Cobalt from a Smelter Slag in Botswana

L. Godirilwe, K. Haga, G. Danha, Y. Takasaki, A. Shibayama

Proceedings of the XXX International Mineral Processing Congress(IMPC2020)     2451 - 2461   2021年04月

選鉱プロセスにおけるハイパースペクトルイメージングと深層学習を用いたヒ素含有鉱石の分類

岡田 夏男, 前川 陽平, 大和田 済熙, 芳賀 一寿, 柴山 敦, 川村 洋平

資源・素材学会誌 ( 一般社団法人 資源・素材学会 )  137 ( 1 ) 1 - 9   2021年

<p>Currently, there have been issues concerning the depletion and scarcity of mineral resources. This is mostly due to the excavation of high grade minerals having already occurred years and years ago, hence forcing the mining industry to opt for the production and optimization of lower grade minerals. This however brings about a plethora of problems, many of which economic, stemming from the purification of those low grade minerals in various stages required for mineral processing. In order to reduce costs and aid in the optimization of the mining stream, this study, introduces an automatic mineral identification system which combines the predictive abilities of deep learning with the excellent resolution of hyperspectral imaging, for pre-stage of mineral processing. These technologies were used to identify and classify high grade arsenic (As) bearing minerals from their low grade mineral counterparts non-destructively. Most of this ability to perform such tasks comes from the highly versatile machine learning model which employs deep learning as a means to classify minerals for mineral processing. Experimental results supported this statement as the model was able to achieve an over 90% accuracy in the prediction of As-bearing minerals, hence, one could conclude that this system has the potential to be employed in the mining industry as it achieves modern day system requirements such as high accuracy, speed, economic, userfriendly and automatic mineral identification.</p>

DOI

選鉱プロセスにおけるハイパースペクトルイメージングと深層学習を用いたヒ素含有鉱石の分類

岡田夏男, 前川陽平, 大和田済熙, 芳賀一寿, 柴山 敦, 川村洋平

Journal of MMIJ   137 ( 1 ) 1 - 9   2021年

Automated identification of mineral types and grain size using hyperspectral imaging and deep learning for mineral processing

Okada N.

Minerals ( Minerals )  10 ( 9 ) 1 - 22   2020年09月

DOI

Surface properties of copper-sulfide minerals with sodium-hydrosulfide activation

Matsuoka H.

Minerals Engineering ( Minerals Engineering )  156   2020年09月

DOI

Recovery Rates of Used Rechargeable Lithium-Ion Battery Constituent Elements in Heat Treatment

Murakami Y.

Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science ( Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science )  51 ( 4 ) 1355 - 1362   2020年08月

DOI