• Progress in Superconductivity and Cryogenics
• /
• v.22 no.2
• /
• pp.17-20
• /
• 2020

Comprehensive utilization of tungsten tailings resources not only solves environmental problems but also creates huge economic benefits. The high content of iron impurity in tungsten tailings will have adverse effect on the downstream comprehensive utilization, whether flotation or pickling. In this paper, the Superconducting High Gradient Magnetic Separation(S-HGMS) is used to remove of Fe impurities from tungsten tailings. The optimal experimental parameters are as follows: background magnetic induction intensity is 3.0T, slurry flow velocity is 500ml/min. The Fe removal rate of Fe was 68.8% and the recovery rate was 59.53%.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.05a
• /
• pp.781-786
• /
• 2003

This study has focused on the possibility for recycling tailings from the Sangdong tungsten mine as admixture for concrete. The XRD(X-ray diffraction analysis) and PSA(Particle size analysis) were performed to find mineralogical characteristics. As a result of XRD analysis, the tailings were composed of quartz, feldspars and muscovites, and C-S-H and quartz were found in cement mortar. As a result of KSLT for cement mortar mixed with tailings, most of heavy metals were determined as below the guide line for waste material. In addition, the setting time and compressive strength of cement mortar mixed with tailings were investigated. It was indicated that the initial and final set were retarded according to increasing replacement. The compressive strength of mortar was decreased with increasing replacement.

• Economic and Environmental Geology
• /
• v.37 no.1
• /
• pp.87-98
• /
• 2004

Tailings and contaminated soils from Cheongyang mine and Seobo mine have been analysed by ICP-AES from 5-step sequential extraction method of multielement determination on extraction solutions at each step. As and Co within tailings and contaminated soils from Cheongyang mine and Seobo mine are mainly in the residual phase. In case of Cd, Cu and Zn, the most dominant fraction for tailings of Cheongyang mine is the oxidizable phase, while tailings of Seobo mine is dominated by the residual phase. In contaminated soils from Seobo mine, the predominant fraction for Cd, Cu and Zn is the Fe-Mn oxide phase. The exchangeable fraction of Pb in tailings from Cheongyang mine and Seobo mine is relatively high compared with those of other metals; whereas Pb fraction in contaminated soils from Seobo mine is largely associated with the residual fraction.

• Journal of Korea Soil Environment Society
• /
• v.4 no.1
• /
• pp.35-47
• /
• 1999

Mine tailings, soils. stream sediments around Gubong disused mine were analyzed in order to investigate their distribution and pollution levels of heavy metals and cyanide. The average contents of As, Cd, Cu. Hg, Pb, Zn, and CN￣ in mine tailings were 6.93$\times$$10^{3}$, 56.9, 209, 5.03, 3.25$\times$$10^{3}$, 1.89$\times$$10^{3}$, 21mg/kg respectively. The pollution indices that calculated by the tolerance level of Kloke were 42~95 and the pH values were slightly alkaline in mine tailings. The contents of heavy metals and cyanide in field soils near the mine were higher than the paddy soils. The contents of heavy metals in the stream sediment were up to that of the tailings, so contamination from the mine tailings were serious.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.11a
• /
• pp.743-747
• /
• 2005

In South Korea, about 900 metal mines have been abandoned, and about 88 million-t metal mine wastes have been discarded in recent years. The treatment of the tailings which are the main wastes in the abandoned metal mines becomes a social problem because they cause environmental pollution such as acidic waste water generation, groundwater contamination, and dust generation. Since almost whole quantities of the tailings have disposed by landfill now, the development of effective recycling methods for the tailings are strongly requested. It is expected that the fine tailings obtained by centrifugal separation process among the tailings can be utilized as admixture for cement. The purpose of this study is to evaluate the micro-structure of cement mortar admixed with fine tailing. Various admixtures were made of Fine tailings and 2 Types of OPC, fly-ash and blast furnace slag. The hydration reactivity of cement mortar with FT was examined by Porosity, XRD and SEM morphology analysis. The anolytical result about hardened hydrates shows that waste fine tailing help hydrates none densified due to it,s filling-space, These densified effect is concluded with improving the resistance to attack of cement mortar including waste fine tailing.

• Korean Journal of Environment and Ecology
• /
• v.29 no.1
• /
• pp.88-94
• /
• 2015

An investigation was conducted on the effects of arbuscular mycorrhizal fungus, Glomus etunicatum on the formation of soil aggregate and mycorhizal development in the roots of Robinia pseudoacacia seedlings in coal mine tailings and forest soil. G. etunicatum formed mycorrhizas by 35.1 % in coal mine tailings and by 48.9 % in forest soil. Its infection was the typical Arum-type forming inter-cellular hyphae and intra-cellular arbuscules. Ergosterol contents were 3.20 ppm in forest soil and 1.92 ppm in coal mine tailings. The formation of soil aggregate per 50 g pot soil was 19.6 g and 9.5 g in inoculated and noninoculated forest soil and 16.5 g and 11.0 g in inoculated and non-inoculated coal min tailings, respectively. In conclusion, G. etunicatum inoculation increased the formation of soil aggregate both in forest soil and coal mine tailings, but was less effective in the latter.

• Geomechanics and Engineering
• /
• v.25 no.2
• /
• pp.159-170
• /
• 2021

Particle size of tailings in different areas of dams varies due to sedimentation and separation. Saturated hydraulic conductivity of high-stacked talings materials are seriously affected by void ratio and particle breakage. Conjoined consolidation permeability tests were carried out using a self-developed high-stress permeability and consolidation apparatus. The hydraulic conductivity decreases nonlinearly with the increase of consolidation pressure. The seepage pattern of coarse-particle tailings is channel flow, and the seepage pattern of fine-particle tailings is scattered flow. The change rate of hydraulic conductivity of tailings with different particle sizes under high consolidation pressure tends to be identical. A hydraulic conductivity hysteresis is found in coarse-particle tailings. The hydraulic conductivity hysteresis is more obvious when the water head is lower. A new hydraulic conductivity-void ratio equation was derived by introducing the concept of effective void ratio and breakage index. The equation integrated the hydraulic conductivity equation with different particle sizes over a wide range of consolidation pressures.

• Economic and Environmental Geology
• /
• v.43 no.3
• /
• pp.235-248
• /
• 2010

To construct the standard methods for evaluation of physicochemical characteristics of tailings in Korea, specific gravity, paste pH, grain size, mineral compositions and heavy metal concentrations of total 26 tailings from 21 metallic mines were analyzed. Specific gravity of tailings ranged from 2.61 to 4.31 (avg. 3.04), and sand and silt grain were dominant in the tailings. Ranges of paste pH were 2.1-9.5 in tailings (7.1-9.2 at magmatic, skarn and hydrothermal replacement deposits and 2.1-9.5 at hydrothermal vein deposits). Additionally, hydrothermal vein deposits could be reclassified into three categories: (1) paste pH>7.0, (2) 4.0

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.6
• /
• pp.626-634
• /
• 2005

The objectives of this study was to assess pollution level and contamination status on tailings and soil in the vicinity of four disused metal mines in Kangwon province. As the result of total metal concentrations analysis, the pollution degree of tailings and soil decreased in the order of Wondong > Second Yeonhwa > Sinyemi ${\fallingdotseq}$ Sangdong mines. Total metal concentrations of mine tailings in this study were $1.2{\sim}78.2$ and $1.1{\sim}80.6$ times higher than those in the background soil and the tolerable levels suggested by Kloke, respectively. From these results, we found that tailings served as contamination source of nearby soil. According to sequential extraction of metals, large proportion of heavy metals in all mine tailings existed in the form of a residual fraction, and heavy metals in non-residual form was mainly associated with Fe-Mn oxide fraction and sulfidic-organic fraction. Fe-Mn oxide fraction and sulfidic-organic fraction of heavy metals may be released into and contaminated the nearby environment under the oxidation or reduction condition in long-term. In particular, the proportions of the exchangeable and carbonate fraction of Cd in mine tailings from Second Yeonhwa mine were relatively high. This suggests that Cd may be easily released into and contaminated the nearby environment in the near time. Concentrations of heavy metals in mine tailings and the nearby soil exceeded the standard (agricultural area) of Soil Environment Conservation Law. So it was thought that remediation for mine tailings and the nearby soil is needed. The pollution indices of the samples in this study were for higher than 1.0 and the pollution degree was very serious. Priority remediation site for these mines was Wondong. As Results of danger indices, it was showed that exchangeable form in Wondong and Fe-Mn oxide form in the rest mines should be removed preferentially.

• Economic and Environmental Geology
• /
• v.53 no.6
• /
• pp.781-792
• /
• 2020

Mine tailings, which are inevitably formed by the development of manganese nodules, manganese crusts, and hydrothermal seafloor deposits, have attracted attention because of their quantity and potential toxicity. However, there is a lack of data on the quantity of mine tailings being generated, their physicochemical properties, and their effects as environmental hazards and on marine ecosystems in general. The importance of treating mine tailings in an environmentally friendly manner has been recognized recently and related reduction/treatment methods are being considered. In the case of deep-sea mineral resource development, if mine tailings cannot be treated aboard a ship, the issue becomes one of the cost of transporting them to land and solving the problem of environmental pollution there. Therefore, the Korea Institute of Ocean Science and Technology conducted research on the harmfulness of mine tailings, their effect on marine ecosystem, the diffusion model of contaminated particles, and candidate purification treatment technologies based on five representative controlling factors: 1) effects of pollution /on the environment, 2) effects of environmental/ biological hazards, 3) diffusion of particles, 4) mineral dressings, and 5) reducing/processing mine tailings. The results of this study can provide a basis for minimizing environmental problems by providing scientific evidences of the environmental effects of mine tailings. In addition, it is also expected that these results could be applied to the treatment of pollutants of different origins and at land-based mining waste sites.