• Economic and Environmental Geology
• /
• v.32 no.1
• /
• pp.13-18
• /
• 1999

The tailings stocked at two tailing piles in Sangdong aea have raised collapse hazards and various environmental problems. A trial for effective utilization of tailings as fine aggregates for polymer concrete has been performed along with mineralogical and physical characterization of tailings. The tailings from the Sangdong mine, mainly composed of quartz, orthoclase, amphiboles and muscovite, are alkaline and tailings at the new tailing pile are generally finer in grain size than those at the old tailing pile. In case of using New Tailings as fine aggregates, cement mortar with equivalent amounts of tailings and sands shows the highest compressive strength. Cement mortars containing tailings show lower values of compressive strength, splitting tensile strength and flexural strength than those not-containing tailings. Mixture of polymers such as SBR and EVA in cement mortars raises strengths of cement mortars effectively, which shows potential possiblity to utilize the tailings in Sangdong area as fine aggregates for polymer concretes.

• Geomechanics and Engineering
• /
• v.29 no.5
• /
• pp.497-508
• /
• 2022

Tailings fluidization (i.e., tailings behave as being fluidized) under cyclic loading is one concern during the construction of tailings dams, especially in the shallow tailings layers. The primary goal of this study is to evaluate the responses of tailings under cyclic loadings and the tailings potential for fluidization. A series of cyclic triaxial undrained and drained tests were performed on medium and dense tailings samples under various cyclic stress ratios (CSR). The results indicated that axial strain and excess pore water pressure accumulated over time due to cyclic loading. However, the accumulations were dependent on CSR values, densities, and drainage conditions. The fluidization potential analysis in this study was then evaluated based on the obtained cyclic axial strain and excess pore water pressure. As a result, tailings samples were stable (unfluidized) under small CSR values, and the critical CSR values, where the tailings fluidized, varied depending on the density of tailings samples. Tailings fluidization is triggered as cyclic stress ratios reach critical values. In this study, the critical CSR values were found to be 0.15 and 0.40 for medium and dense samples, respectively.

• The Korean Journal of Ecology
• /
• v.23 no.6
• /
• pp.445-452
• /
• 2000

The effects of sludge and fertilizer application on germination and seedling growth of woody plants on heavy metal mine tailings were evaluated by greenhouse experiment. Two different mine tailings (Lead-zinc mine tailings from Kwangmyong, Kyonggi-do and tungsten mine tailings from Sangdong. Kangwon-do). four fertilizer treatments (N +P +K: 20, 40, 60, and 80 kg/m$^3$), and four sewage sludge treatments (5.5, 11, 22.5, and 45 Mg/m$^3$) were used in the experiment. Tested plants were Pinus densiflora, Larix leptolepis, Amorpha fruticosa, and Alnus hirsuta. There were three replicates for each treatment. In addition, vermiculite was used instead of mine tailings to determine the effect of physical amendments. Fifty seeds of a species were sown in a pot (upper diameter 13.5 cm, depth 10 cm) and seedling emergence were recorded daily for 30 days. The highest germination rate was 53% for all treatments. Germination rate of Larix leptolepis was lowest among the four species studied. One month later after seeding, seedlings were thinned and only 5 seedling were left in each pot, and fertilizer and sewage sludge were applied once again. Growth of seedlings were determined for 10 weeks since then. Most plants grew very poorly or died within 5 weeks on lead/zinc mine tailings from Kwangmyong. The analysis of heavy metal contents by the total dissolution method showed that heavy metals generally increased in the order of tungsten mine tailings from Sangdong < sewage sludge from Puchon < lead/zinc mine tailings from Kwangmyong. Growth of woody plants was improved significantly by the fertilizer treatments on tungsten mine tailings. In contrast. survival and growth of woody plants were not affected significantly by the sewage sludge treatment on both tailings. This study shows that fertilizer applied to established seeded stands may provide some benefits in terms of increased ground cover in the field. It is suggested that reclamation should be proceeded by the study of the physico-chemical and biological characteristics of mine tailings.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 1998.11a
• /
• pp.189-194
• /
• 1998

Geochemical study was carried out to find out the distribution of metals and cyanide in soil in the vicinity of the abandoned Keum-Jung mine. Chemical analysis showed that content of As in soil around tailings exceeded 15mg/kg, Korean standard of soil contamination in the farm land. That means the contamination of soil by As is due to input of tailings. According to total decomposition of tailings, As was highly concentrated in tailings. However the water in tailings impoundment was changed to acidic and contaminated by metal and sulfate because the tailings in the top of the tailings impoundment had been oxidized. Acid mine drainage contaminated the water course in the vicinity of the paddy soils. The proper measures are required to prevent contamination of the soil and water in the vicinity of the Keum-Jung mine.

• Journal of Biosystems Engineering
• /
• v.16 no.1
• /
• pp.18-26
• /
• 1991

This study was undertaken to investigate the ratio and compositions of tailings of the tailings return unit in the commercially available head-feed combines. The ratio of the returned tailings to the sum of the threshed grain and the returned tailings was 2.3~7.2% for various varieties of rice and operational conditions of combines tested and increased as the feeding rate and the cleaning air volume increased. The analysis of the returned tailings showed that the composition of rubbish and short straw was decreased as the feeding rate and the cleaning air volume increased.

• Geomechanics and Engineering
• /
• v.19 no.5
• /
• pp.383-392
• /
• 2019

How to safely and economically dispose mining tailings is a challenge to mine operators. This paper presents an alternative upstream method for tailings dam construction, termed as the template construction method (TCM), which has been successfully implemented at Zhelamuqing tailings impoundment since 2004. By the beginning of 2015, the tailings dam wall had reached 95 m in height for the 46 upstream raises, with the total height of the dam including the starter dyke being 128 m. The proposed TCM is relatively simple and cost-effective and provides a good way for constructing rapidly raising tailings dam based on this case.

• Geomechanics and Engineering
• /
• v.35 no.4
• /
• pp.437-447
• /
• 2023

The failures of tailing dams have caused irreparable damage to human lives, assets and environment and this has ultimately resulted in great economic, social and environmental challenges worldwide. Due to this, investigation into mechanical behaviour of tailings has received some attention. However, the knowledge and understanding of mechanics of behaviour in iron tailings is still limited. This study investigates the mechanics of iron tailings from Nigeria considering grading, effects of fabric resulting from different sample preparations and the possibility of non-convergent behaviour. This was achieved by conducting series of one-dimensional compression tests in conjunction with index, microstructural, chemical and mineralogical tests. The materials are predominantly poorly graded, non-clayey and non-plastic. The tailings are characterised by angular particles with no obvious particle aggregations and dominated by silicon, iron, aluminium, haematite and quartz. The compression paths do not converge and unique normal compression lines are not found and this is an important feature of the transitional mode of behaviour. The behaviour of these iron tailings therefore depends on initial specific volume. The preparation methods also have effect on the compression paths of the samples. The gradings of the samples have an influence on the degree of transitional behaviour but the preparation methods do affect the degree of convergence. The transitional mode of behaviour in these iron tailings investigated is very strong.

• Economic and Environmental Geology
• /
• v.45 no.3
• /
• pp.265-276
• /
• 2012

Current study includes the analysis of mine tailings and leachate water and prediction of species originated from the tailings. The variation of contaminants were measured upon the distance from the tailings to the nearby stream. The ions concentration was highest at the tailings and pit mouth and it becomes lower as it goes far away from the origin. This is the reason that the leachate was diluted with the uncontaminated stream water. The tailings were mainly classified into reddish one and yellow one. The main mineral of reddish tailings were quarts, illite, plumbojarosite and a small amount of sphalerite. The main mineral of yellow tailings were muscovite, quarts, plumbojarosite, and a small amount of chalcopyrite and sphalerite. Pb and Zn were found in the leachate in high concentration and become the major contaminants. These come from the dissolution of plumbojarosite and sphalerite contained in the mine tailings.

• Geomechanics and Engineering
• /
• v.31 no.6
• /
• pp.557-571
• /
• 2022

Landslides are often triggered by weak interlayers initiated in tailings dam foundations, and hazards gradually occur. This is serious for landslides in high tailings dams due to their high potential energy. Tailing samples with a fine-grained interlayer at a set dip angle were prepared. Consolidated undrained (CU) triaxial shear tests were carried out by using a high-pressure triaxial apparatus. The results were compared with the results under a low confining pressure. Four reasons were summarized for high tailings dams more prone to instability than low dams. The shear strength of the samples with dipping interlayers decreases with increasing dip angle. An obvious straight drop in the stress path after the peak occurs in samples with dipping interlayers at an angle of 60°. The effect of the interlayer on the mechanical behaviour of tailings is very sensitive, especially for the sample with a dipping interlayer at an angle of 60°. Shear slipping along the interlayer should be given more attention in tailings dams. Compared with the results under low confining pressure, the stress decreases continuously for the samples with dipping interlayers at large angles under high confining pressure. The positive pore pressure, which reduces the effective stress, occurred in tailings samples under high confining pressure. The residual strength of tailings under high confining pressure is smaller than that under low confining pressure. These factors increase the dam break risk and the disaster impact for high tailings dams.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2006.04a
• /
• pp.41-44
• /
• 2006

The objective of this study was to evaluate the stabilization of As and heavy metals in tailings from the Samkwang Au-Ag mine with $Ca(OH)_2$. In order to evaluate the stabilization ability of As and heavy metals in the tailings, column test was implemented with various conditions as 1) particle size of $Ca(OH)_2$, 2) mixing method and 3) flow rate of eluents during 60 days. The results showed that addition with 5% of $Ca(OH)_2$ in 1kg of the tailings had the most effective ability of stabilization up to 95%. In addition, stabilization ability of As and heavy metals in tailings was enhanced using a fine powder of $Ca(OH)_2$. Therefore, stabilization technology can be used as a remediation of As and heavy metals in mine wastes including tailings and a nearby soils from abandoned metal mines.