• Resources Recycling
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• v.17 no.1
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• pp.59-65
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• 2008

The adsorption features of nickel ion in wastewater on manganese dioxide from spent batteries were investigated for its usage as an adsorbent. The aquatic behavior of nickel ion was characterized by MINTEQ program and the considered influential variables on the adsorption of nickel ion were its initial concentration, reaction temperature, the amount of adsorbent, and pH. The adsorption ratio of nickel ion decreased with increasing its initial concentration and thermodynamic estimation has been carried out based on the adsorption characteristics of nickel ion depending on temperature. In addition, the adsorption of nickel ion was shown to be promoted according to the amount of manganese dioxide and a lot of nickel ions were adsorbed as the solution pH was raised.

• Journal of Space Technology and Applications
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• v.3 no.2
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• pp.154-164
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• 2023

In space exploration, spectroscopic observation is useful for understanding objects' composition and physical properties. There are various methods for analyzing spectral data, and there are differences depending on the object and the wavelength. This paper introduces a method for analyzing visible & nearinfrared (VNIR) spectral data, which is mainly applied in lunar exploration. The main analysis methods include false color ratio image processing, reflectance pattern analysis, integrated band depth (IBD) processing, and continuum removal as preprocessing before analysis. These spectroscopic analysis methods help to understand the mineral properties of the lunar surface in the VNIR region and can be applied to other celestial bodies such as Mars.

• Resources Recycling
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• v.16 no.3 s.77
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• pp.3-11
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• 2007

Presently, most of gold is smelted from gold concentrates and anode slimes. Anode slimes are by-products of nonferrous smelters such as lead and copper. In addition, gold is recovered from waste dental and medical materials, waste gold coating solution, and waste printed circuit boards (waste PCBs). The smelting method of gold from gold concentrates and various wastes containing high concentration of gold is largely divided into chlorination, cyanidation, and amalgamation methods. For the anode slimes, electrolysis method is usually used, which largely consists of roasting, high temperature melting and electrolysis processes. Also, various wastes containing low concentration of gold are mainly treated by pyrometallursical processes. In the paper, current status on gold smelting technology is reviewed, and a novel process for gold smelting which is researched in the recent is briefly introduced.

• Resources Recycling
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• v.17 no.2
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• pp.30-35
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• 2008

Mixed acidophilic bacteria were approached for leaching of cobalt and lithium from wastes of lithium ion battery industries. The growth substrates for the mixed mesophilic bacteria are elemental sulfur and ferrous ion. Bioleaching of the metal was due to the protonic action of sulfate ion on the metals present in the waste. It was investigated that bioleaching of cobalt was faster than lithium. Bacterial action could leach out about 80 % of cobalt and 20 % of lithium from the solid wastes within 12 days of the experimental period. Higher solid/liquid ratio was found to be detrimental for bacterial growth due to the toxic nature of the metals. At high elemental sulfur concentration, the sulfur powder was observed to be in undissolved form and hence the leaching rate also decreased with increase of sulfur amount.

• Journal of Powder Materials
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• v.15 no.1
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• pp.13-17
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• 2008

Visible-light responsive $TiO_2$:Zr, N powders were prepared by polymer complex solution method and the particle properties were characterized by using transmission electron microscope, BET method, X-ray diffractometer and UV-Vis spectrophotometer. The photocatalytic reactivity of the catalysts was also estimated by analyzing NO degradation. Polyhedral $TiO_2$ powder having about 20 um in the average particle diameter was successfully prepared, The XRD analysis revealed that the as-prepared powder consisted of anatase and rutile phases. The light absorption of the as-prepared $TiO_2$:Zr, N powder was shifted to the visible light. In addition, the as-prepared $TiO_2$:Zr, N nanoparticles showed the higher photocatalytic activity than the commercial $TiO_2$ under both UV and visible lights.

• Economic and Environmental Geology
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• v.39 no.2 s.177
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• pp.173-180
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• 2006

The synthesis of polyphase waste form, which is an immobilization matrix fur the high level radioactive wastes, was performed with the mixed composition of garnet and spinel $(Gd_3Fe_5O_{12}+(Ni_xMn_{1-x})(Fe_yCr_{1-y})_2O_4)$ in the range of 1200 to $1400^{\circ}C$. The phases synthesized from all stoichiometric compositions were garnet, perovskite, and spinel. Especially, garnet was synthesized only in the composition of the highest content of Fe(y=0.9), whereas it was not synthesized in other compositions. This result indicated that the content of Fe was closely related to the formation of garnet. The composition of garnet revealed that the content of Gd was exceeded and that of Fe was depleted. Preferential distribution of elements in the phases can be attributed to the nonstoichiometric composition of garnet.

• Journal of the Korean Ceramic Society
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• v.44 no.9
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• pp.477-482
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• 2007

The effect of the mixing ratio of compounds in a slag-OPC-Gypsum system on the physical properties of Slag cement is investigated in this study. $Na_2SO_4$ was used as an alkali activator. Blast furnace slag cement was prepared from a mixture of blast furnace slag, ordinary Portland cement and anhydride gypsum. The fluidity and the compressive strength according to the ratio of each mixture were analyzed in statistical analyses in order to discover the parameters influencing the fluidity and compressive strength. The results showed that the hydration of blast furnace slag took place with the addition of $Na_2SO_4$ and that column-crystalline ettringite was created as the main hydration product of the blast furnace slag. In addition, it was found that the compressive strength of blast furnace slag cement tends to increase when the ordinary Portland cement content is higher up to three days. However, it is known that the compressive strength tends to increase as the blast furnace slag content becomes higher with increases in the level of OPC after 28 days. As a result of this analysis, it is believed that the ordinary Portland cement content influences the initial compressive strength of blast furnace slag cement, and that in later days this is highly influenced by the slag content.

• Journal of Hydrogen and New Energy
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• v.17 no.2
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• pp.125-132
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• 2006

The alloys which compositions were represented by the formula, $Ti_{(0.22+X)}Cr_{(0.28+1.5X)}V_{(0.5-2.5X)}$ ($0{\leq}X{\leq}0.12$), had the total hydrogen storage capacity higher than 3 wt% and the effective hydrogen storage capacity higher than 1.4 wt%. Particularly, among all the tested alloys, the $Ti_{0.32}Cr_{0.43}V_{0.25}$ alloy exhibited the best effective hydrogen storage capacity of 1.65 wt%. Furthermore, the reversible bcc${\leftrightarrow}$fcc structural transition was observed with hydrogenation and dehydrogenation, which predicted the possibility of pressure cycling. EDS analysis revealed micro-segregation, which suggested the necessity of microstructure homogenization by heat treatment. The $Ti_{0.32}Cr_{0.43}V_{0.25}$ alloy was selected for heat treatment and for other related studies. The results showed that the total and the effective hydrogen storage capacity increased to 3.7 wt% and 2.3 wt%, respectively. The flatness of the plateau region was also greatly improved and heat of hydride formation was determined to be approximately -36 kJ/mol $H_2$.

• Resources Recycling
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• v.14 no.6 s.68
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• pp.37-43
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• 2005

[ $LiCoO_{2}$ ] nanoparticles were synthesized from leach liquor of lithium ion battery waste using flame spray pyrolysis. Electrode Materials containing lithium and cobalt could be concentrated with thermal and mechanical treatment. After dissolution of used cathode materials of the lithium battery with nitric acid, the molar ratio of Li/Co in the leach liquor was adjusted at 1.0 by adding a fresh $LiNO_{3}$ solution. The nanoparticles synthesized by the flame spray pyrolysis showed clear crystallinity and were nearly spherical, and their average primary particle diameters ranged from 11 to 35 nm. The average particle diameter increased with an increase in the molar concentration of the precursor. Raising the maximum flame temperature by controlling the gas flow rates also led to an increase in the average diameter of the particles. The $LiCoO_{2}$ powder was proved to have good characteristics as cathode active materials in charge/discharge capacity and cyclic performance.

• Resources Recycling
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• v.14 no.6 s.68
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• pp.44-59
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• 2005

In this paper the world wide patents on the recycling of used batteries were inspected. The trend and direction of on-going and future technologies on this matter were analyzed. The range of search was limited in the open patents and in DB of U.S.A.(USPTO, DLPHION), Japan(PAJ), Europe(EPO), and Korea(KIPRIS). For the search condition the keyword, battery, batteries, electric cell, patent, and recycling, and IPC classification were used. The total of 2,490 cases was found at the first search stage, then, through the 2 steps of filtering processes the total of 871 cases was selected for the final analysis. These 871 cases were classified by countries, companies, and technologies between the year 1971 and the you 2000.