Iron Cement Research Articles

FeOOH@MoS2 as a highly effective and stable activator of peroxymonosulfate-based advanced oxidation processes for pollutant degradation

Fe-based materials are widely used as activators in advanced oxidation processes (AOPs) for the degradation of persistent organic pollutants because of their high activity and environmental friendliness. The continuous consumption of Fe2+ and the generation of excessive Fe3+, however, lead to the formation of sludge (iron cement) and the degradation of material performances. In this work, we report MoS2 with a self-assembled ultrathin Fe (oxy)hydroxide layer on the surface (FeOOH@MoS2) as a highly effective and stable activator for peroxymonosulfate (PMS)-based AOPs system. The FeOOH@MoS2/PMS system performed exceptionally for removing antibiotics from aquatic environment under both acidic and basic conditions, with function pH condition from 4 to 10. The stability of FeOOH@MoS2 was also outstanding, with only 10.1% decrease after 5 cycles under pH 8, which is much better than conventional heterogeneous Fe-based activator for PMS based AOPs. The combination of quenching experiments, electron paramagnetic resonance (EPR) tests and surface analysis suggest that such high performance is attributed to high catalytic activity of MoS2 as the co-catalyst and the strong interface interaction between MoS2 and FeOOH. While the Fe2+FeOOH in FeOOH effectively activate PMS to produce SO4•− and •OH radical to remove antibiotics, the produced Fe3+FeOOH is reduced back to Fe2+FeOOH by MoS2 co-catalyst, enabling the recycle of Fe2+. Our results provide a facile strategy for improving the activity and stability of heterogeneous Fe-based catalysts for AOP systems, particularly under basic environment, which contribute towards the large-scale implementation.

Treatment of copper converter slag with deep eutectic solvent as green chemical.

Industrial copper slag is among the most important wastes to be evaluated in terms of containing valuable metals and the amount of waste approaching 30 million tons per year. Therefore, in this study, it was aimed to propose a feasible route for copper and zinc recovery from copper converter slag (CCS) by using choline chloride (ChCl) based deep eutectic solvent which is applied on this type of slag for the first time. During the leaching experiments with the pure ChCl-2urea mixture, temperature (25-95°C), leaching duration (2-72h), and pulp density (1/10-1/40g/mL) were selected as the parameters to be investigated for Cu and Zn extraction. After the experimental results, the optimized conditions for the ChCl-2urea leaching process, which gave 89.9% Cu and 65.3% Zn extraction was found at 48h, 95°C, 1/20g/mL pulp density with 600rpm stirring speed. It is noted that the iron dissolution ratio is very low (max. 4.7%) under the selected conditions. At the end of the iron cementation stage, the total recovery efficiency as a pure metallic copper was 63%. The calculated activation energy for the dissolution of the copper and zinc from CCS is 8.86kJmol-1 and 14.48kJmol-1, respectively.

Rare Crucible from Medieval Karelian Hillfort: Mineralogical Fingerprints of Functional Use

A rare crucible with an unusually large volume and a pot-shaped bottom was excavated at the Tiversk hillfort (late 13–14th century—1411 AD) in the North-Western Ladoga region (Russia). ICP-MS data showed that the crucible might be attributed to local technical ceramics. Because of its specific volume and shape, which are not typical for crucibles used in non-ferrous metallurgy in medieval Karelia, earlier it had been attributed to the technical ceramics used for the cementation of iron. The present research has revealed tin bronze metal alloy along with copper sulfide minerals recorded on the crucible walls, suggesting it might have been used in non-ferrous metal working. Thermal treatment of the crucible at temperatures above 1050 °C is evidenced by the heterogeneous composition of quartz, the thermal breakdown of biotite, recorded in the temper of the ceramic fabric, and Raman spectra characteristics of hematite.

Diagenesis and Porosity Evolution of the Pachmarhi Sandstones (Early Triassic), Satpura Gondwana Basin, Central India

This study deals with the diagenetic history of the Pachmarhi Sandstones of Satpura Gondwana Basin, Central India. The sandstones are classified as quartz-arenite and sub-arkose type. Monocrystalline quartz grains dominate the detrital mineralogy followed by polycrystalline quartz grains, feldspars (more alkali-feldspar than plagioclase), rock fragments, detrital mica and heavy minerals. The diagenetic signatures observed in the Pachmarhi Sandstones include mechanical compaction, cementation (Fe-oxide, quartz overgrowths, calcite, matrix and clay minerals), replacement and dissolution of feldspar and calcite cement. The most commonly observed type of secondary porosity is dissolution of feldspars. The porosity loss is mainly due to cementation by pore occlusion and by early stage of mechanical compaction. In addition, several clay minerals occurred as pore-filling and pore-lining cements. The nature of various types of grain- to grain contacts suggests early cementation and consequent minor compaction. Among the various cements, calcite is the earliest followed by iron oxide while silica cementation occurred probably at a late stage. The carbonate cement formed during burial by dissolution and re-precipitation represents redistributed calcite which was buried with the sandstone. The iron cement was perhaps derived from weathering and leaching of ferromagnesian minerals of overlying Deccan traps. Silica cement was derived from the corrosion of quartz and feldspar grains. Types of grain contacts, minus-cement porosity and porosity reduction indicate a shallow depth of burial conditions for these sandstones.

Subgrade fill strength and bearing characteristics of weathered phyllite blended with red clay

ABSTRACT This study presents the results of a systematic investigation on enhancing the shear strength and bearing capacity of subgrade fill by blending the completely weathered phyllite (CWP) with locally won red clay at varying blending ratios. Many CWP soil samples were prepared at varying bended ratios for carrying out a compaction test, micro-penetration test and direct shear test. The effects of the red clay blending ratio, moisture content (w) and compaction coefficient (K) on the shear strength of CWP clay were also been investigated. Micro-penetration test results show that there are three types of micro-penetration strength growth patterns. It is found that, at a given set level of moisture content and compact coefficient, an increase of red clay in the blending ratio result in a higher shear strength and the ultimate bearing capacity. Cubic polynomial function models were developed to predict the ultimate bearing capacity and cohesion of the CWP blended soils with the red clay at varying blending ratios. The observed three stages of strength growth can be predicted, and the mechanism of this phenomenon has been analyzed using the results from soil micro-structure analysis. It has been found that the addition of red clay increases clay content within the soil mass and enhances iron cementation among the soil particles. At a given blending ratio, the ultimate bearing capacity increases linearly with the compaction coefficient and decreases linearly with moisture content. The ultimate bearing capacity calculation model of blended subgrade fill was developed based on the Bzz-100 load standard, and the optimum schemes of blending soils were proposed to meet the requirement of urban road bearing capacity. Field trials and applications show that the optimum scheme proposed in this paper can not only improve the bearing capacity of CWP, but also reduce the cracking potential of red clay.

The Ordovician iron ore of the Anti-Atlas, Morocco: Environment and dynamics of depositional process

In Morocco, iron deposits of sedimentary origin are mainly developed in the Ordovician where they are interbedded at different levels of the stratigraphic column. A detailed analysis of the sedimentary facies shows that the iron ores are not randomly distributed but are concentrated at omission surfaces of the sequences thus raising the question of their sedimentological significance within the sequences that shelter them. This study determines three morphological types of ore, which provide a possible avenue for economic exploitation. These morphological types are: firstly, from metric to decametric bodies of regional extension (examples are “Caid Rami” and “Tachilla”), consisting of a set of detrital facies organized in two stratigraphic stages that cyclically recur to form genetic sequences. Within each sequence, the maximum mineralization is at the top of the prograding basal stage and is expressed by diagenetic iron cement and at the base of the regressive stage in the form of strata of iron oolites, or in massive beds. Secondly, lenses with a thickness up to 30 m over a kilometer width (example of “Imi n’Tourza” field), corresponding to incisions cut along the ravinement surfaces. The maximum mineralization of this second type is within the median sandstone stage in connection with a large transgressive event. Thirdly, there is a type of reworked material consisting of discontinuous layers of ferruginous conglomerates and bioclastics lining the ravinement surface that separates the higher order sequences. It is this third type that has generated the most economic interest. The iron-bearing mineral phases identified are: magnetite, hematite, iron chlorite, maghemite, iron hydroxides (goethite, lepidocrocite) and siderite. The ultimate source of iron would probably be the large reserves of banded iron formation of the West Africa Craton (Mauritania in particular). Intense tropical weathering would have leached the silica and left a highly enriched iron residuum that was carried as particulate iron to shallow marine shelf environments where Fe3+ was converted to Fe2+ during early diagenesis. This reduced iron was recycled into the water column by tidal currents or storm waves where it precipitated as ferric oxide or ferrous silicate ooliths. This depositional mechanism accounts for the positioning of ironstone beds at times of stasis and reworking.

Biological re-colonization of sub-aerial boundaries of an ‘artificial construction-niche’ contaminated by iron mine tailings: laboratory bioassays

The ability of colonizer organisms to tolerate high metal concentrations is important to the restoration and rehabilitation of mining sites. We investigated colonization on modular cellular surfaces—artificial construction-niche—prepared by combining different proportions of iron mine tailings (8% tailing dam material), soil (90%), and cement (2%) through bioassays conducted under stable laboratory conditions of humidity, temperature, and light intensity. The establishment of microorganisms was measured using CO2-respirometry and microbiological assays. Sub-aerial communities grown on the experimental materials were composed of heterotrophic and phototrophic macro- and microorganisms. Four groups of phototrophic species were observed: cyanobacteria, algae, mosses, and ferns. The cyanobacteria comprised three genera: Phormidium sp., with branched filaments, Nostoc sp. and Pseudanabaena sp.; algae included Trentepohlia sp. (Chlorophyceae), a sub-aerial or terrestrial green algae. Macroscopic fungal hyphae were also observed. CO2 production occurred in all cellular modules due to the growth of bacteria, actinobacteria, and fungi. The presence of living organisms on these artificial construction-niche containing iron ore tailings was a promising finding as those colonizers could initiate the processes of primary succession and occupy significant portions of the sub-aerial surfaces, thus actively participating in weathering and soil formation to create new ecological niches for recuperating ironstone outcrop ecosystems.

Iron concretions within a highly altered unit of the Berlins Porphyry, New Zealand: an abiotic or biotic story?

The Berlins Porphyry located on the South Island of New Zealand provides an opportunity to examine iron concretions formed in a subterranean system. Specifically, an alteration zone within the Berlins Porphyry contains iron concretions similar to sedimentary biologically-mediated iron concretions. Here, we provide evidence for two sources of dissolved Fe (II) that potentially aided in the formation of the iron concretions. Furthermore, we discuss the potential for microbial involvement in the anaerobic oxidation of Fe (II) to Fe (III) to form magnetite. Evidence in support of this hypothesis includes the low concentrations of iron and sulfur in the white hydrothermally altered porphyry outcrop and concretion cores; concentrated pyrite and magnetite mineralisation surrounding the cores; and δ13C values indicative of organic carbon (averaging −26 ‰ ± 4 ‰) within the iron cement, porphyry-core-boundary and outer weathered rinds of the concretions. Overall, these unusually preserved iron concretions could represent a new environmental niche for microorganisms and a potential analogue for microbially induced iron-oxidation. More importantly, this study illustrates the many obstacles involved in analysing and interpreting potential subterranean biosignatures.

ANALISA SIFAT KETEGUHAN PATAH DAN TEKAN BETON SEMEN DARI TULANG ROTAN

Indonesia has the potential of rattan is enough large, but the value of the sale and utilization is still limited as materials for baskets, furniture, handicrafts and so on. This research purpose to obtain bending and compressure strength properties when the rattan used for substitution of iron materaial making to cement concrete building simple houses. The raw material of used for research this is rattan has done processing (preservation and drying). Cement concrete frame made of rattan and molds for casting. Concrete frame rattan incorporated in the mold and filled dough (cement: gravel: sand = 1: 2: 3 plus water as needed). Treatment was observed that the diameter rattan (A) which includes: 8 mm (a1), 10 mm (a2) and 12 mm (a3); and the distance between the iron ring (B) which includes 11 cm (b1); 15 cm (b2); and 19 cm (b3). The number of repeat 3 times. Parameters observed bending and compressure strength.The results of the research rattan diameter 8-12 mm and the distance ring iron 11-19 cm produces bending strength from 18.24 to 40.13 kg /cm2 lower than cement concrete from iron materials (95.76 to 120.36 kg / cm2); and compressure strength from 28.33 to 42.85 kg/cm2 larger than from iron cement concrete materials (20 to 34.67kg/cm2). The results of the research show bending strength from rattan lower and compressure sterngth than big concrete from iron.Keywords: rattan, cement concrete, bending strength, compressure strength

The Research on Performance of Mixed Soft Ferrite

This paper is concerned with the study of the performance of soft magnetic ferrite mixed with aluminum cement and silicon steel sheet. By measuring the amount of different substitution, the mix proportion of the soft magnetic ferrite, the temperature of different experimental point on the transformer, and the output voltage, we can analysis the performance of soft ferrite on permeability, loss rate and so on. After the data was analyzed, we can get the best mix proportion of iron aluminum and cement,and the best amount of substitution replacing silicon steel sheet.Then a new type of mix soft magnetic ferrite is developed. This experimental study can be applied to large-scale power and electrical equipment which can reduce production costs and improve production efficiency.

Dividend Interdependency: A Study on Select Iron and Steel and Cement Industries in India

The purpose of this paper is to measure interdependency of declaring dividend by the companies that belong to the same industry. The researchers collect, compile and analyse publically available data like EPS, DPS and payout ratio of selected companies from the annual reports over the period 2004–2012. Descriptive as well as inferential statistical tools are used to arrive at any conclusion. The hypotheses are tested with 95% of significance level. The results suggest that the dividend decision is greatly influenced by the profitability of the firm as well as dividend of competitors. The study depends more on empirical procedures rather than a theoretical justification in the anomalies on the dividend policy. The research is totally based on publically available information and limited with regard to the time span and sample size. No holdout sample has been used and the entire data set is subjected to simple statistical analysis. This to some extent limits the findings and implications. Dividend decision is directly associated with the financing and investment decision and it becomes imperative of a firm to decide optimum dividend decision to the shareholders. This also makes a judicious balance between the retention and shareholders’ satisfaction. The present study concentrates on matters like: do the companies belonging to the same industry declare similar percentage of dividend and interdependent in declaring dividend? Does the growth rate fluctuate, when dividend is declared? Do the dividends declared by the companies differ significantly from one company to other?

Analysis of Domestic Media Reported Burst Events on Water Distribution System in 2012

By means of the Internet platform for rapid and timely, the relevant data of domestic media in 2012 reported burst events were collected and collated. The statistics showed that burst mainly occurred in the southern coastal cities; winter was the main season for burst, especially in January, February and December; in July burst also was frequent; 5:00-17:00 was a dangerous phase during a whole day; the trunk road intersection or crossings and the construction site were more likely to become the incident locations. Generally recognizing that improper construction and aging were the main reasons for burst. The diameter of burst was concentrated in DN300-DN600, DN800 and DN1000-DN1200, especially in DN600. Pipes of cast iron pipes and cement pipes, and pipes pipeline in 20-30 years old was more likely to burst.

Simulation-based life cycle cost modeling and maintenance plan for water mains

Life cycle cost (LCC) is an essential approach to decide on alternative rehabilitation strategies for infrastructure systems, such as water mains. The research presented in this article identifies several rehabilitation methods for water mains, which are classified into three main categories: repair, renovation and replacement. A simulation-based LCC (SLCC) model is developed to compare different rehabilitation scenarios/alternatives for various types of water mains (i.e. cast iron, ductile iron, concrete, polyvinyl chloride and asbestos cement). Results show that ‘open trench’ and ‘slip lining’ are the most appropriate methods for the ‘repair’ and ‘renovation’ categories, respectively. However, the most suitable method for the ‘replacement’ category is ‘pipe bursting’ for pipe diameters less than 750 mm (<30″) and ‘open cut’ for pipe diameters greater than 750 mm (>30″). A rehabilitation plan is developed based on the SLCC results. This plan recommends repairing pipes using ‘open trench’ until the breakage rate reaches 0.5 breaks/km/year, then, replace the pipe beyond this threshold. Based on the designed SLCC model, web-based software is developed to determine the optimal rehabilitation scenarios. The developed model and software help academics and practitioners (e.g. municipal engineers) to predict the suitable new installation and/or rehabilitation programs as well as their corresponding costs.

Correlating river terrace remnants using an Equotip hardness tester: An example from the Miño River, northwestern Iberian Peninsula

This paper describes a new method to distinguish river terrace levels based on clast hardness and degree of weathering measured with an Equotip hardness tester. The technique was applied to a series of terraces on the Miño River in the northwestern Iberian Peninsula, where the lack of suitable material, high degree of weathering, and intense iron cementation precluded routine dating. Detailed mapping demonstrated that terrace sediments occupy a range of altitudes that make assignment to a specific terrace, and/or correlation between levels, difficult. Statistical analysis of the Equotip hardness data from quartzite clasts using k-means clustering allowed four probable terrace levels to be identified; a series of t-tests generally supported these groupings. A fifth, lowermost terrace level, was not included in the analysis because of limited exposure above a reservoir. Clast hardness and degree of terrace weathering were generally consistent with progressive river downcutting. The occurrence of faulted sediments, however, suggested that terrace elevations were modified locally by post-depositional tectonic movements, which may explain why probable younger terraces in some sectors of the Miño River are at higher elevations than older terraces in adjacent sectors. The Equotip tester helped to resolve stratigraphic uncertainties and to assign deposits to specific terrace levels and was found to be a useful tool to distinguish and correlate river terraces.

Theoretical and Experimental Treatment of Gaseous Cementation of Iron

Mathematical model is developed for cementation of iron taking into account the diffusion of atomic carbon C through the γ phase. Analytical solutions are obtained assuming constant diffusion coefficients, firstly the analytical method proposed that test to control the process of gaseous cementation, controlled the technological parameters of the cementation such: time (t), temperature (T), initial concentration (Co), potential carbon or atmospheric concentration (Catm), and speed of the gas flow (xw), secondly to accelerate the process of the gaseous cementation. Finally the results are quantitatively compared with those obtained experimentally taking into account the micro hardness profile. In addition, it is shown that the layer cemented produced during cementation of iron can be predicted by the numerical simulation.

Facies controlled porosity evolution of the Neoproterozoic Upper Bhander Sandstone of Western India

Abstract The Upper Bhander Sandstone is dominantly composed of quartzarenites. The basal and top portions are sandstones, with the middle section comprising thinly bedded shales with interlayer silt and sandstone units. The sandstone units are composed of several varieties of quartz, feldspar, micas, rock fragments and heavy minerals. The Upper Bhander Sandstone was deposited in a transgressive phase and later modified by tidal processes and wave- and storm-dominated processes in a tide-influenced Barrier Beach Complex of the shallow marine environment. This study reveals that, during mechanical compaction, a rearrangement of grains took place and point and long contacts were formed. The early silica cementation and shallow burial resulted in high primary porosity. This phase was followed by chemical compaction and the replacement of silica cement by iron cement (Fe-cement) under the deep burial phase of these sandstones. Dissolution of Fe-cement and feldspars resulted in secondary porosity development. Quartz overgrowths are better developed on coarse- to medium-sized grains than on fine-sized grains. These observations suggest a progressive compaction, which initiated at the sediment–water interface and continued till deep burial diagenesis in a rapidly subsiding basin. The existing optical porosity of the Upper Bhander Sandstone is 4% and the minus cement porosity is 18%.

Experimental Study on Aerated Concrete Produced by Iron Tailings

The non-autoclaved aerated concrete block with greater than 7.5Mpa compressive strength is produced by using iron tailings, lime, aluminum powder, caustic alkali, water, cement and gypsum in the laboratory after the experimental study on the property of iron tailings produced by Anshan Iron and Steel Group. The optimal mix proportion is finally determined by adopting orthogonal experimental method, the evaluating indicator is compressive strength. Aerated concrete block that is made from iron tailing is trial produced according to the national standards, and then its strength is determined by sample examination.

Remote detection and geochemical studies for finding hydrocarbon-induced alterations in Lisbon Valley, Utah

Long-term hydrocarbon microseepages develop diverse arrays of chemical and mineralogical changes in rocks and soils. Alterations that are reported to have affected the Wingate Sandstone, Lisbon Valley, Utah, include bleaching of red beds, precipitation of high limonite and carbonate concentrations, anomalous weathering patterns, and high clay content. To investigate sandstone color alteration patterns, spectroscopy, ASTER multispectral remote sensing and Synthetic Aperture Radar (SAR) data were used as well as geochemical analyses of selected samples. Using ASTER satellite images and SAR data, the altered areas of the Wingate Sandstone were identified and mapped at the northwest and southwest part of the Lisbon Valley anticline. Based on sandstone color alteration patterns three different zones were identified in the Wingate Sandstone; the southwest zone is the most altered, the middle part is unaltered, and the northwest part shows minor alteration. Spectroscopy and thin section studies revealed higher content of clay minerals in altered than in unaltered zones. Major elemental concentrations suggest removal of iron cement and addition of calcite during diagenesis. Trace elemental concentrations in selected altered sandstone samples are characteristic of geochemical halos forming over oil fields. The methodology being developed in this work can provide a completely new technique for petroleum exploration in remote regions of the world where field work is difficult.

Stratigraphy and optically stimulated luminescence dating of subaerially exposed Quaternary deposits from two shallow bays in Hong Kong, China

Episodes of subaerial exposure recorded in Quaternary sedimentary sequences on continental shelves are indicators of sea-level change. In this study, the Quaternary superficial deposits from two shallow bays in Hong Kong are examined in order to identify the timing of such episodes. Two rotary boreholes in Tai O Bay penetrated a succession of marine and terrestrial deposits formed during the last four interglacial-glacial cycles. The interglacial periods and the glacial periods are found to be represented by siliciclastic-dominated shallow marine–estuarine deposits and colluvial–alluvial fan deposits, respectively. An excavation of a coastal land reclamation in Deep Bay revealed Holocene intertidal–subtidal estuarine deposits overlying aeolian deposits of the last glacial age. Optically stimulated luminescence dating carried out has confirmed the last glacial age of the terrestrial unit unconformably overlain by the Holocene marine unit but only minimum ages can be obtained from the pre-last glacial terrestrial units. In one of the Tai O boreholes studied, the density and moisture content distribution is found to reflect the episodes of subaerial exposure of the pre-Holocene interglacial marine units. In the palaeo-desiccated crusts of these units, density increases through iron cementation resulting from acid-sulphate soil development while moisture content decreases as a consequence of desiccation. Quaternary terrestrial deposits occurring on continental shelves are therefore datable to a greater degree of certainty than their subaerial counterparts.

Removal of copper metal by cementation using a rotating iron cylinder

The rate of the copper(II)/iron cementation reaction in the presence of surfactant (SAS) was determined by measuring the rate of cementation of copper on a rotating Fe cylinder from a CuSO 4 solution in the absence and the presence of SAS using an atomic absorption spectrophotometer. The rate of cementation reaction is decreased by an increasing concentration of SAS, temperature and number of rotation. It is found that the order of the rate of decrease of the cementation reaction in the presence of SAS is as follows, Triton X-100 < SDS < SOS. The rate of the cementation reaction was also found to decrease with the addition of small amounts of alcohol. In the presence of alcohol, the amount of decrease ranged from 11.47 to 47.8% depending on the type and as well as the concentration of alcohol used. The effect of mixed surfactant (SAS) on cementation reaction was given. Thermodynamic parameters Δ H * , Δ S * , and Δ G * were calculated.