• Advances in concrete construction
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• v.6 no.3
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• pp.221-243
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• 2018

Utilization of mine waste rocks and tailings in concrete as aggregates will help in sustainable and greener development. The literature shows the potential use of iron ore tailings as a replacement of natural fine aggregates. As natural sand reserves are depleting day by day, there is a need for substitution for sand in concrete. A comprehensive overview of the published literature on the use of iron ore waste and tailings and other industrial waste in concrete is being presented. The effect of various properties such as workability, compressive strength, split tensile strength, flexural strength, durability and microstructure of concrete have been presented in this paper.

• Resources Recycling
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• v.25 no.4
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• pp.23-31
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• 2016

It was found that there was no problem in recycling by-products (waste rock and tailings) from Yangyang iron mine themselves through matter conversion because they are not hazardous according to results of KSLT method. In case of using tailings as sub-materials of cement, it recommended the use of less than 3% tailings dosage not to exceed 0.6% of total alkali ($R_2O$) content based on standard quality of portland cement (KS L 5201). Non sintered eco-brick corresponding to class 1 quality of recycled clay brick (KS I 3013) can replace 15% of cement with tailings and 100% of general fine aggregate with waste rock from iron mine. As mentioned above, recycling the by-products (waste rock and tailings) as sub-materials of cement and non sintered eco-brick could gain both environmental and economic benefits, that is, reduction of scale and maintenance cost of tailing ponds, decrease of energy use and $CO_2$ emission.

• Advances in concrete construction
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• v.3 no.1
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• pp.55-69
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• 2015

Tailing Material (TM) and Fly Ash (FA) are obtained as waste products from the mining and thermal industries. Studies were carried out to explore the possibility of utilizing TM as a part replacement to fine aggregate and FA as a part replacement to cement, in concrete mixes. The effect of replacing fine aggregate by TM and cement by FA on the standard sized specimen for compressive strength, split tensile strength, and flexural strengths are evaluated in this study. The concrete mix of M40 grade was adopted with water cement ratio equal to 0.40. Concrete mix with 35% TM and 65% natural sand (TM35/S65) has shown superior performance in strength as against (TM0/S100, TM30/S70, TM40/S60, TM50/S50, and TM60/S40). For this composition, studies were performed to propose the optimal replacement of Ordinary Portland Cement (OPC) by FA (Replacement levels studied were 20%, 30%, 40% and 50%). Replacement level of 20% OPC by FA, has shown about 0-5% more compressive strength as against the control mix, for both 28 day and 56 days of water curing. Interestingly results of split tensile and flexural strengths for 20% OPC replaced by FA, have shown strengths equal to that of no replacement (control mix).

• Geomechanics and Engineering
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• v.29 no.4
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• pp.421-434
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• 2022

In the present study, reference samples were prepared using ore preparation facility tailings taken from the copper mine (Kure, Kastamonu), Portland cement (PC) in certain proportions (3 wt%, 5 wt%, 7 wt%, 9wt% and 11 wt%), and water. Then natural zeolite taken from the Bigadic Region was mixed in certain proportions (10 wt%, 20 wt%, 30 wt% and 40 wt%) for each cement ratio, instead of the PC, to prepare zeolite-substituted CPB samples. Thus, the effect of using Zeolite instead of PC on CPB's strength was investigated. The obtained CPB samples were kept in the curing cabinet at a temperature of 25℃ and at least 80% humidity, and they were subjected to the Uniaxial Compressive Strength (UCS) test at the end of the curing periods of 3, 7, 14, 28, 56, and 90 days. Except for the 3 wt% cement ratio, zeolite substitution was observed to increase the compressive strength in all mixtures. Also, the liquefaction risk limit for paste backfill was achieved for all mixtures, and the desired strength limit value (0.7 MPa) was achieved for all mixtures with 28 days of curing time and 7 wt%, 9 wt%, 11 wt% cement ratios and 5% cement - 10% zeolite substituted mixture. Moreover, the limit value (4 MPa) required for use as roof support was obtained only for mixtures with 11% cement - 10% and 20% zeolite content. Generally, zeolite substitution seems to be more effective in early strength (up to 28th day). It has been determined that the long-term strength losses of zeolite-substituted paste backfill mixtures were caused by the reaction of sulfate and hydration products to form secondary gypsum, ettringite, and iron sulfate.

• Advances in concrete construction
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• v.5 no.3
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• pp.201-219
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• 2017

With the rapid growth in construction sector, it becomes all the more important to assess the amount of Construction and Demolition (C&D) waste being generated and analyze the practices needed to handle and use this waste before final disposal. This serves waste management and disposal issues, paving way to waste utilization in construction industry from the sustainability point of view. C&D waste constitutes a major bulk of total solid waste produced in the world. In this work, an attempt is made to study the performance of concrete using water soaked Recycled Coarse Aggregates (RCA) in replacement levels of 0%, 25%, 50%, 75% and 100% to Natural Coarse Aggregates (NCA). Experiments were designed and conducted to study the performance of RCA based concrete. Further suitable performance enhancement techniques to RCA based concrete were attempted, to achieve compressive strength at least equal to or more than that for no RCA based concrete (control concrete). Performance enhancement study is reported here for 50% and 100% RCA based concretes. All four techniques attempted have given favorable results encouraging use of RCA based concretes with full replacement levels, to adopt RCA based concrete in structural applications, without any kind of concern to the stake holder. Further attempts have also been made to use Recycled Fine Aggregates (RFA) with appropriate modifications to serve as fine aggregates in mortar and concrete. Using RFA blended with river sand fractions as well as RFA with Iron Ore Tailings (IOT) fractions, have given good results to serve as fine aggregates to the extent of 100% replacement levels in mortars and concretes.

• Journal of the Mineralogical Society of Korea
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• v.22 no.4
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• pp.359-370
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• 2009

Arsenic and heavy metals leached out as a result of oxidation of tailings exposed to the surface pose a serious environmental contamination of mine areas. This study investigated how arsenic behavior is controlled by a variety of processes, such as oxidation of sulfides and formation or alteration of secondary minerals, based on mineralogical methods. The study was carried out using the tailing samples obtained from Nakdong mine located in Jeongseongun, Gangwondo. After separating magnetic and non-magnetic minerals using pretreated tailing samples, each mineral sample was classified according to their colors and metallic lusters observed by the stereoscopic microscope. Subsequently, the mineralogical properties were determined using various instrumental analyses, such as x-ray diffractometer (XRD), energy dispersive spectroscopy (EDS), and electron probe micro analyzer (EPMA). The literature review confirmed that various ore minerals were identified in the Nakdong ore deposits. In this study, however, there were observed a few original ore minerals as well as secondary and/or tertiary minerals newly formed as a result of weathering including oxidation. In particular, we did not recognize pyrrhotite which has been known to originally exist in a large abundance, but peculiarly colloform-type iron (oxy)hydroxides were identified, which indicates most of pyrrhotite has been altered by rapid weathering due to its large reactivity. In addition, a secondary scorodites filling the fissure of weathered primary arsenopyrites were identified, and it is speculated that arsenic is immobilized through such a alteration reaction. Also, we observed tertiary iron (oxy)hydroxides were formed as a result of re-alteration of secondary jarosites, and it suggests that the environment of tailing has been changed to high pH from low pH condition which was initiated and developed by oxidation reactions of diverse primary ore minerals. The environmental change is mainly attributed to interactions between secondary minerals and parental rocks around the mine. As a result, not only was the stability of secondary minerals declined, but tertiary minerals were newly formed. As such a process goes through, arsenic which was immobilized is likely to re-dissolve and disperse into surrounding environments.

• Resources Recycling
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• v.1 no.1
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• pp.69-77
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• 1992

In this study, a talc flotation was fundamentally carried out with dolomite origin talc ore produced in Dong Yang Talc Mine at Chung-Ju. This ores are mainly composed with talc as a valuable mineral, dolomite as a gangue mineral and other minor minerals of hornblende, tremolite, actinolite, chlorite, calcite, epidote and iron oxide. In order to obtain some of fundamental data for the talc flotation from low grade dolomitic talc tailings which were abandoned -25mm +17 mm size, after the treatment of crude talc ores by screening and hand -picking at the mine, flotation characteristics of the pure talc and dolomite in this ores were first investigated by measuring floatability of the minerals at some experiment conditions. Furthermore, Several times of batch flotations for talc were performed experimentally to recover talc from the low grade dolomitic talc tailings. From the results obtained in this experiment, the conclusions can be summarized as follows ; 1) In the flotation of pure talc, the use of Dowfroth 250 as frother was the most effective in various kinds of frother and the proper addition amount was about 50 mg/${\ulcorner}$(200g/t) at the condition of this experiment. 2) In the flotation of pure talc, the use of kerosene as collector was not adequate, at the addition over 50mg/l of Dowfroth 250. 3) The adequate pH of pulp ranged from pH6 to pH9 in the talc flotation using Dowfroth 250 as frother. 4) The use of Quebracho as depressant for dolomite was not adequate for the recovery of talc, and more selective depressant was required. 5) In the talc flotation on D sample(dolomitic talc tailing), the suitable number of cleaning time was about 3. 6) At this experimental conditions for the talc flotation on D sample, the talc flotation concentrates of 1. 40% CaO and 84.5 whiteness could be recovered with the talc recovery of about 53%.

• Journal of the Korean Geotechnical Society
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• v.27 no.6
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• pp.49-61
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• 2011

This paper presents the applicability of rheological models for describing fine-laden debris flows and analyzes the flow characteristics as a function of grain size. Two types of soil samples were used: (1) clayey soils - Mediterranean Sea clays and (2) silty soils - iron ore tailings from Newfoundland, Canada. Clayey soil samples show a typical shear thinning behavior but silty soil samples exhibit the transition from shear thinning to the Bingham fluid as shear rate is increased. It may be due to the fact that the determination of yield stress and plastic viscosity is strongly dependent upon interstructrual interaction and strength evolution between soil particles. So grain size effect produces different flow curves. For modeling debris flows that are mainly composed of fine-grained sediments (<0.075 mm), we need the yield stress and plastic viscosity to mimic the flow patterns like shape of deposition, thickness, length of debris flow, and so on. These values correlate with the liquidity index. Thus one can estimate the debris flow mobility if one can measure the physical properties.