Strength characteristics of iron ore tailing concrete

Materials used in proportioning of concrete have significant impact on the properties of concrete produced. Iron ore tailings (IOTs) is a waste product generated from the production process of iron ore. In this study, IOTs is used as partial replacement for natural sand in the production of normal strength concrete. Samples of Iron ore tailings from two different mines in Kota Tinggi were collected. The Physical properties of natural sand and these Iron ore tailings were determined. The Energy Dispersive X-ray Spectroscopy (EDS) and the microscopic image of these materials were also studied. Normal strength concrete was designed based on water/cement ratio of 0.54 and cement content of 463Kg/m3 was used in preparing the fresh concrete. For each kind of Iron ore tailings concrete, four different types of concrete samples were produced. The percentage of Iron ore tailings as partial replacement for sand in the sample was varied from 10% to 40% at 10% interval. For each concrete sample, the average of three cubes, three cylinders and three prism specimen results was used for the determination of the compressive strength, splitting tensile strength and the flexural strength respectively. Also studied are the water absorption, the ultrasonic pulse velocity and the mode of failure of the IOTs concrete compared with the normal strength concrete. The concrete sample CZT30 containing 30% IOTs recorded the highest 28days compressive strength of 43.7 N/mm2

Survey of the Endogonaceae in Minnesota With Synoptic Keys to Genera and Species

Sixteen species in the Endogonaceae (Zygomycotina) were identified from 22 different plant species from a native prairie, an intensively cultivated vegetable field, a reclaimed iron ore tailings basin, an undisturbed site adjacent to the iron ore tailings basin, and from a Pinus resinosa plantation. Seven species of Endogonaceae identified in this study are new records for Minnesota. Synoptic keys to genera and species are presented

Utilisation of iron ore tailings as aggregates in concrete

Sustainable handling of iron ore tailings is of prime concern to all stakeholders who are into iron ore mining. This study seeks to add value to the tailings by utilising them as a replacement for aggregates in concrete. A concrete mix of grade 40 MPa was prepared in the laboratory with water–cement ratio of 0.5. The concrete were cured for 1, 2, 3, 7, 14 and 28 days. The properties of the concrete such as workability, durability, density, compressive strength and indirect tensile strength were tested. A controlled mix of concrete was also prepared in similar way using conventional materials and the results were compared with the tailings concrete. It was found that the iron ore tailings may be utilised for complete replacement for conventional aggregates in concrete. The iron ore tailings aggregates concrete exhibited a good mechanical strength and even in the case of compressive strength, there was an improvement of 11.56% over conventional aggregates concrete. The indirect tensile strength did not improve against the control mix due high content of fines in the tailings aggregates but showed 4.8% improvement compared with the previous study where the conventional fine aggregates was partially replaced by 20% with iron ore tailings

Thermal conductivity and impact properties of iron ore tailings filled epoxy composites

Iron ore tailings which is the waste material derived from the beneficiation of iron ore was dispersed in epoxy as micro scale particle fillers. The effect of particle size and particle loading on the thermal conductivity and impact properties of the composites were then investigated experimentally. A comparison of the experimental results for the former to results obtained from existing theoretical models was also done. It was discovered that the impact resistance increased with increasing volume content of iron ore tailings from 20 vol. % with a maximum toughness of 0.098 kJm-2 recorded for composite with 300 µm at 30 vol. %. Thermal conductivity of epoxy improved with decreasing particle size while the Maxwell, Lewis and Nelson and parallel models gave reasonable predictions for epoxy filled with 212 µm at 10 vol. % and 20 vol. % contents; with least variations of 0.18 % and 1.26 %, respectively. Keywords: Composite, Epoxy, Impact, Iron ore tailings, Particle size, Particle loading, Thermal conductivit

Synthesis of Fe-MCM-41 Using Iron Ore Tailings as the Silicon and Iron Source

Highly ordered Fe-MCM-41 molecular sieve was successfully synthesized by using n-hexadecyl-trimethyl ammonium bromide (CTAB) as the template and the iron ore tailings (IOTs) as the silicon and iron source. X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), diffuse reflectance UV-visible spectroscopy, 29Si magic-angle spinning (MAS) nuclear magnetic resonance (NMR), and nitrogen adsorption/desorption were used to characterize the samples. The results showed that the mesoporous materials had highly ordered 2-dimensional hexagonal structure. The synthesized sample had high surface area, and part of iron atoms is retained in the framework with formation of tetrahedron after removal of the template by calcinations. The results obtained in the present work demonstrate the feasibility of employing iron ore tailings as a potential source of silicon and iron to produce Fe-MCM-41 mesoporous materials

Effect of sulphuric acid on concrete with iron ore tailings

Researches into the uses of waste materials are increasingly being explored to meet up society’s needs and global protection for sustainable, safe and economic development. This paper assessed concrete with iron ore tailings (IOT) exposed to dilute sulphuric acid. Iron ore tailings are the materials left-over after separating the valuable fraction from the uneconomic fraction of an ore. To study the effect of sulphuric acid, concrete of 100 mm cube with a different mix ratios containing IOT were prepared and cured for 28 days in water. The cubes were later immersed into dilute sulphuric acid at a concentration of 5%. The compressive strength of concrete at 7, 28 and 90 days of water curing were determined. Mass loss and strength reduction due to sulphuric effect were evaluated at 7, 28 and 90 days respectively. XRD microstructure of concrete specimens was analysed. Test results indicated that the IOT could be used in concrete as sand replacement since the concrete with IOT has similar trend in compressive strength loss and mass loss to sulphuric acid attack compared to control specimen. The mineralogical crystal failure patterns due to the sulphuric acid in terms X-ray diffraction analysis are the same for control and IOT concrete

Iron Ore Tailings as Partial Replacement for Fine Aggregate in Concrete Production – Review

Normal River sand is one of the major components of concrete, generally termed fine aggregate. A large volume of sand is needed annually for construction work globally. Mining or extraction of sand from the river bed, ocean beds, beaches, and inland dunes is accompanied by several problems such as; lowering of the water table, sinking of bridge piers and erosion of river bed and instability of river bed on the environment, etc. To decrease these environmental impacts and the cost of conventional fine aggregates, alternative materials like mining waste have been studied by several researchers to replace partially fine aggregates in concrete production. Iron ore tailings (IOT) are one of the mining wastes obtained from the beneficiation process of iron ore concentrates. This paper presents an overview of the work carried out on the use of IOT as a partial replacement of fine aggregate in concrete and its effects on the workability, mechanical, and durability properties of concrete

Geopolymer Bricks Using Iron Ore Tailings, Slag Sand, Ground Granular Blast Furnace Slag and Fly Ash

World is pound with million tonnes of industrial wastes such as ground granulated blast furnace slag (GGBS), flyash and mine tailings as a various industrial waste. The best way to make use of these wastes is to incorporate these materials as structural elements, which in turn minimizes the carbon foot print. In this contest, this study focuses on using iron ore tailings and slag sand as a replacement for clay or natural sand for the production of stabilized geopolymer blocks. Also, in this study geopolymer is used as a stabilizer instead of cement. Development of geopolymer binder based bricks using flyash and ground granulated blast furnace slag has been carried out in this research. The study includes mechanical properties of the geopolymer bricks. Sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) solution have been used as alkaline activators. The ratio of alkaline liquid to aluminosilicate solid ratio and percentage of binder had major influence on the strength of brick. The bricks were casted and cured at ambient temperature. The compressive strength was carried out at 7, 14 and 28 days

Characterisation and applications of iron ore tailings in building and construction projects

The mine tailings are generated as the wastes worldwide as a result of exploration, excavation, blasting, beneficiation and extraction of mineral ores. In Western Australia, due to the extensive mining activities and increasing low grade ores, there is generation of mine tailings in large quantities, which could lead to environmental and disposal problems. The common practice of handling the tailings are to store them in tailing dams or as stockpiles near mine sites. Limited quantities are sometimes used as backfills and other applications. The utilisation of tailings in building and construction projects, which may consume a large volume of wastes, have not been explored extensively so far. Additionally, the understanding of chemical composition-based utilisation of tailings has very limited investigation. In the present research, a critical review of the literature was made focusing on the utilisation of mine tailings in large quantities. Experiments have been conducted by developing a methodology to characterise the tailings based on the relationship that exists between electrical resistivity and the relative density of the tailings in dry and wet conditions. The results show that the electrical resistivity of iron ore mine tailings produced in Western Australia in dry condition ranges from 11 kΩm in a more dense state to 19 kΩm in a very loose state, while that in fully saturated condition ranges from 20 Ωm for a very dense state to 31 Ωm in a very loose state. The laboratory investigation has been conducted to utilise iron ore tailings to produce geopolymer bricks. The sized tailings were mixed with sodium silicate solution used as an activator to form a paste. The paste was moulded and cured for different durations. It was found that the geopolymer bricks produced from iron ore tailings could have a compressive strength as high as 50.35 MPa. This is either superior or similar to international standard specifications for conventional bricks. Additionally, the new bricks will be more economical than conventional bricks with potential cost reduction of 36.8%. The research has also investigated the utilisation of iron ore mine tailings to replace conventional aggregates in concrete. 100% of both fine and coarse conventional aggregates were replaced with tailings in the mixed design. The concrete mix was casted into moulds and cured. It was found that the compressive strength of the concrete with tailings aggregates at 28 days was 36.95 MPa which shows an improvement of 11.56% over the concrete with conventional aggregates. Additionally, the new concrete met all other requirements for quality assessment of concrete. Finally, the research has conducted investigation into load-settlement behaviour of iron ore tailings to be considered as a structural fill material. The experiment was conducted in a model test tank in the laboratory varying the relative density of the tailings. It was found that the load-bearing capacity is 22 times higher, and the stiffness is 13.5 times higher than their values for conventional fill materials

An Experimental Study on Utilization of Iron Ore Tailings (IOT) and Waste Glass Powder in Concrete

Cement manufacturing industry is one of the carbon dioxide emitting sources besides deforestation burning of fossil fuels. The global warming is caused by the emission of green house gases, such as CO2, to the atmosphere. Among the greenhouse gases, CO2 contributes about 65% of global warming. The global cement industry contributes about 7% of green house gas emission to the earth’s atmosphere. In order to address environmental effects associated with cement manufacturing, there is a need to develop alternative binders to make concrete. Consequently extensive research is on going into the use of cement replacements, using many waste materials industrial by products. Efforts have been made in the concrete industry to use waste glass as partial replacement of cement and also in recent years almost every mineral producing country is facing the problem of better utilization of mine waste because of its accumulation lack of suitable storage space. In this study, finely powdered waste glass from industries and Iron Ore Tailings (IOT) produced from mining areas are used as a partial replacement  of cement and fine aggregates in concrete respectively.  This work examines the possibility of using Glass powder and iron ore tailing as a partial replacement of cement and fine aggregate in concrete. In the present study  Glass powder and Iron Ore Tailing  ( IOT )  are partially replaced by 10%, 20%, 30% and  40%  tested for its compressive, flexural strength for 7, 28 and 56 days of curing and were compared with those of conventional concrete. Keywords: Glass Powder – GP, Iron Ore Tailings – IOT, Conventional Concrete - C