scholarly journals CHARACTERIZATION AND STUDY OF THE KINETICS OF SEDIMENTATION OF REJECT OF THE IRON ORE INDUSTRY

2018 ◽  
Vol 15 (30) ◽  
pp. 647-653
Author(s):  
J. H. M. SANTOS ◽  
P. C. M. SANTOS ◽  
F. T. VIEIRA ◽  
J. D. FABRIS ◽  
A. B. REIS ◽  
...  
Keyword(s):  
Iron Ore ◽  
Negative Impact ◽  
Mining Industry ◽  
Water Recovery ◽  
Recycle Water ◽  
Industrial Activity ◽  
The Earth ◽  
Energy Spectrometer ◽  
Kinetics Of ◽  
Scanning Electron

Currently the mining industry plays an important role in the generation of wealth of a country through the exploitation of natural resources of the earth, and in some cases, responsible for a significant fraction of the economic matrix. Like any other industrial activity, mining has a negative impact on the environment, which leads the industry to constantly face the challenge of achieving the sustainability of its activities. The study aimed to characterize the iron ore reject seeking the feasibility of reprocessing and water recovery. The reject sample was characterized using Scanning Electron Microscopy with Dispersive Energy Spectrometer. Studies of the sedimentation kinetics of the tailings were carried out to implement techniques to recover the iron present in the tailings and recycle water in the mineral processing. In the sedimentation tests it was possible to recover approximately 50% of water without compromising the transport operations of the material. It can be concluded that the ore reject analyzed is composed mainly of Fe and Si respectively, showing that the reject has reprocessing potential, and recovery of water present in the clarified.

scholarly journals Use of Multi-Anionic Sodium Tripolyphosphate to Enhance Dispersion of Concentrated Kaolin Slurries in Seawater

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1085
Author(s):  
Williams Leiva ◽  
Norman Toro ◽  
Pedro Robles ◽  
Edelmira Gálvez ◽  
Ricardo Ivan Jeldres
Keyword(s):  
Rheological Properties ◽  
Fine Particles ◽  
Sodium Tripolyphosphate ◽  
Mining Industry ◽  
Chord Length ◽  
Water Recovery ◽  
Reflectance Measurement ◽  
Anionic Charge ◽  
Free Environment ◽  
The Impact

This research aims to analyze the impact of sodium tripolyphosphate (STPP) as a rheological modifier of concentrated kaolin slurries in seawater at pH 8, which is characteristic of copper sulfide processing operations. The dispersion phenomenon was analyzed through chord length measurements using the focused beam reflectance measurement (FBRM) technique, complementing size distributions in unweighted and square-weighted modes. The reduction of the rheological properties was significant, decreasing from 231 Pa in a reagent-free environment to 80 Pa after the application of STPP. A frequency sweep in a linear viscoelastic regime indicated that by applying a characteristic dosage of 0.53 kg/t of STPP, the pulp before yielding increases its phase angle, which increases its liquid-like character. Measurements of the chord length verified the dispersion of particles, which showed an apparent increase in the proportion of fine particles and a reduction of the coarser aggregates when STPP was applied. Measurements of the zeta potential suggested that the high anionic charge of the reagent (pentavalent) increases the electrostatic repulsions between particles, overcoming the effect of cations in seawater. The results are relevant for the mining industry, especially when the deposits have high contents of complex gangues, such as clays, that increase the rheological properties. This increases the energy costs and water consumption needed for pumping the tailings from thickeners to the tailing storages facilities. The strategies that allow for the improvement of the fluidity and deformation of the tailings generate slack in order to maximize water recovery in the thickening stages.

scholarly journals Influencing Factors of the Mineral Carbonation Process of Iron Ore Mining Waste in Sequestering Atmospheric Carbon Dioxide

2021 ◽  
Vol 13 (4) ◽  
pp. 1866
Author(s):  
Noor Allesya Alis Ramli ◽  
Faradiella Mohd Kusin ◽  
Verma Loretta M. Molahid
Keyword(s):  
Carbon Dioxide ◽  
Particle Size ◽  
Chemical Composition ◽  
Iron Ore ◽  
Divalent Cations ◽  
Mining Industry ◽  
Mining Waste ◽  
Aluminum Silicate ◽  
Mineral Carbonation ◽  
Carbonation Process

Mining waste may contain potential minerals that can act as essential feedstock for long-term carbon sequestration through a mineral carbonation process. This study attempts to identify the mineralogical and chemical composition of iron ore mining waste alongside the effects of particle size, temperature, and pH on carbonation efficiency. The samples were found to be alkaline in nature (pH of 6.9–7.5) and contained small-sized particles of clay and silt, thus indicating their suitability for mineral carbonation reactions. Samples were composed of important silicate minerals needed for the formation of carbonates such as wollastonite, anorthite, diopside, perovskite, johannsenite, and magnesium aluminum silicate, and the Fe-bearing mineral magnetite. The presence of Fe2O3 (39.6–62.9%) and CaO (7.2–15.2%) indicated the potential of the waste to sequester carbon dioxide because these oxides are important divalent cations for mineral carbonation. The use of small-sized mine-waste particles enables the enhancement of carbonation efficiency, i.e., particles of <38 µm showed a greater extent of Fe and Ca carbonation efficiency (between 1.6–6.7%) compared to particles of <63 µm (0.9–5.7%) and 75 µm (0.7–6.0%). Increasing the reaction temperature from 80 °C to 150–200 °C resulted in a higher Fe and Ca carbonation efficiency of some samples between 0.9–5.8% and 0.8–4.0%, respectively. The effect of increasing the pH from 8–12 was notably observed in Fe carbonation efficiency of between 0.7–5.9% (pH 12) compared to 0.6–3.3% (pH 8). Ca carbonation efficiency was moderately observed (0.7–5.5%) as with the increasing pH between 8–10. Therefore, it has been evidenced that mineralogical and chemical composition were of great importance for the mineral carbonation process, and that the effects of particle size, pH, and temperature of iron mining waste were influential in determining carbonation efficiency. Findings would be beneficial for sustaining the mining industry while taking into account the issue of waste production in tackling the global carbon emission concerns.

Ethylene Glycol and Glycerin as the Solvent for Alkaline Treatment of Poly(ethylene Terephthalate) Fabrics

1997 ◽  
Vol 67 (10) ◽  
pp. 760-766 ◽  
Author(s):  
M.-C. Yang ◽  
H.-Y. Tsai
Keyword(s):  
Ethylene Glycol ◽  
Degradation Rate ◽  
Ethylene Terephthalate ◽  
Treatment Time ◽  
Alkaline Treatment ◽  
Aqueous System ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Kinetics Of ◽  
Scanning Electron

Poly(ethylene terephthalate) fabrics are treated with sodium hydroxide using ethylene glycol or glycerin as the solvent. Compared with conventional aqueous alkaline hydrolysis, the degradation rate in ethylene glycol increases tenfold. The kinetics of the alkaline-ethylene glycol treatment show that the weight loss is linear with respect to time. The moisture regain rate and tensile properties of the treated fabrics are measured; other tests include scanning electron microscopy and dyeing properties. The results show that the properties of the treated fabrics do not depend significantly on the solvent; therefore, using ethylene glycol can greatly shorten the treatment time to achieve results similar to those with the conventional aqueous system.

scholarly journals Metal Removal from Acid Waters by an Endemic Microalga from the Atacama Desert for Water Recovery

Minerals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 378 ◽  
Author(s):  
Marcela Martínez ◽  
Yanett Leyton ◽  
Luis Cisternas ◽  
Carlos Riquelme
Keyword(s):  
Mine Drainage ◽  
Metal Removal ◽  
Atacama Desert ◽  
Mining Industry ◽  
Mining Activity ◽  
Water Recovery ◽  
Metallic Ions ◽  
Mineral Extraction ◽  
High Concentrations ◽  
Acid Waters

The environmental problems generated by waste from the mining industry in the mineral extraction for business purposes are known worldwide. The aim of this work is to evaluate the microalga Muriellopsis sp. as a potential remover of metallic ions such as copper (Cu2+), zinc (Zn2+) and iron (Fe2+), pollutants of acid mine drainage (AMD) type waters. For this, the removal of these ions was verified in artificial acid waters with high concentrations of the ions under examination. Furthermore, the removal was evaluated in waters obtained from areas contaminated by mining waste. The results showed that Muriellopsis sp. removed metals in waters with high concentrations after 4–12 h and showed tolerance to pH between 3 and 5. These results allow proposing this species as a potential bioremediator for areas contaminated by mining activity. In this work, some potential alternatives for application in damaged areas are proposed as a decontamination plan and future prevention.

scholarly journals Kinetics of Gaseous Reduction of Iron Ore Fines.

1993 ◽  
Vol 33 (11) ◽  
pp. 1168-1173 ◽  
Author(s):  
Sujoy K. Dutta ◽  
Ahindra Ghosh
Keyword(s):  
Iron Ore ◽  
Gaseous Reduction ◽  
Reduction Of Iron ◽  
Iron Ore Fines ◽  
Kinetics Of

scholarly journals Preparation and Assessment of Some Characteristics of Nanoparticles Based on Sodium Alginate, Chitosan, and Camellia chrysantha Polyphenols

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Phu Hoang Luong ◽  
Thuy Chinh Nguyen ◽  
The Dan Pham ◽  
Do Mai Trang Tran ◽  
Thi Ngoc Lien Ly ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Release Kinetics ◽  
Release Kinetic ◽  
Ionic Gelation ◽  
Visible Spectroscopy ◽  
Polyphenol Content ◽  
Release Process ◽  
Kinetics Of ◽  
Scanning Electron

This paper presents the characteristics, morphology, and properties of alginate/chitosan/polyphenol nanoparticles, in which polyphenols were extracted from Camellia chrysantha leaves collected in Tam Dao district, Vinh Phuc province (Vietnam). The alginate/chitosan/polyphenol nanoparticles were prepared by ionic gelation method at different polyphenol content. The characteristics and morphology of these nanoparticles were investigated using infrared spectroscopy (IR), ultraviolet-visible spectroscopy (UV-Vis), and scanning electron microscopy (SEM). Release kinetic of polyphenols from the alginate/chitosan/polyphenol nanoparticles was conducted in simulated human body fluids. The release kinetics of polyphenols from the above nanoparticles were also evaluated and discussed. The experimental results showed that the release process of polyphenols from the nanoparticles was dependent on three factors: time, pH of solution, and amount of polyphenols.

scholarly journals SUSTAINABLE DEVELOPMENT OF THE MINING COMPLEX OF THE MURMANSK REGION: MINIMIZATION OF MAN-MADE IMPACTS ON THE ENVIRONMENT

2021 ◽  
Vol 13 (2) ◽  
pp. 188-200
Author(s):  
Vladimir MASLOBOEV ◽  
◽  
Dmitry MAKAROV ◽  
Elena KLYUCHNIKOVA ◽  
◽  
...  
Keyword(s):  
Sustainable Development ◽  
Russian Federation ◽  
Negative Impact ◽  
Raw Materials ◽  
Mining Industry ◽  
The Arctic ◽  
Green Growth ◽  
Murmansk Region ◽  
The Russian Federation ◽  
Mining Complex

The Murmansk region is a region with the largest enterprises of the mining complex of the Russian Federation: KF JSC “Apatit”, JSC “Kola MMC”, JSC “Olkon”, JSC” Kovdorsky GOK”, JSC” North-West Phosphorus Company”, LLC”Lovozersky GOK”. They provide the majority of the country’s demand for phosphate ores, zirconium raw materials (baddeleyite), niobium, tantalum, and rare earth metals. In addition, the mining and processing of copper-nickel, iron and chrome ores, nepheline and ceramic raw materials, facing stone and building materials is carried out. At the same time, the activities of enterprises have a very negative impact on the environment. The issues of environmental safety in the extraction and processing of minerals, storage of mining waste in the Arctic zone of the Russian Federation are of particular relevance. The definition of sustainable development in relation to the mining industry is given. The concepts of available best technologies, circular economy, and “green growth” are considered from the point of view of their contribution to sustainable development. It is shown that the sustainable development of enterprises at the present stage is impossible without improving the environmental friendliness of production. The article analyzes the legislation of the Russian Federation and the practice of its application to identify mechanisms that promote sustainable development and eliminate barriers to the implementation of this concept in the mining industry. New technological solutions have been developed for mining enterprises of the Murmansk region, aimed at reducing aero-technogenic emissions, cleaning waste (mine) water, processing tailings of enrichment as man-made deposits, which allows both to minimize man-made environmental impacts and to increase the full use of mineral raw materials. Thus, the expediency of using the principles of “green growth” for the development of economic development policies in the Arctic is justified.

The Pen and the Spade: Gerrard Winstanley and the Digger Movement

2018 ◽  
Author(s):  
Renata Colwell
Keyword(s):  
Civil Wars ◽  
Negative Impact ◽  
The Bible ◽  
The Earth ◽  
Great Insight ◽  
English Society ◽  
Communal Living ◽  
Religious Sects ◽  
Gerrard Winstanley ◽  
Insight Into

In the wake of the English Civil Wars of the 1640s, increased religious tolerance gave rise to unprecedented religious radicalism. While most emerging religious sects adopted unorthodoxinterpretations of the Bible, some sects were more radical than others. The Diggers, led by Gerrard Winstanley, were unique in that their biblically inspired focus on private property’s inherent corruption drove them to establish an agricultural commune in Surrey in 1649. By setting an example for the rest of the world and encouraging others to adopt their methods, they hoped to ultimately restore the Earth to a state of ‘Common Treasury.’ Drawing on scriptural precedent and personal interpretation of the Bible, Winstanley offered an eloquent, politically charged justification for the Diggers’ program of communal living in The True Levellers Standard (1649), which became the Digger manifesto. It pointedly critiquedseventeenth-century English society, had both a positive and negative impact on the Diggers’ reception at the time, and survived the movement’s violent suppression and subsequent collapse. Today, it continues to offer great insight into the origins, development and fate of the Digger movement, while at the same time inspiring modern scholars to delve deeper into the movement’s significance, and raising questions about property and equality that remain highly relevant in this day and age. 

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