scholarly journals Mineralogical and Geotechnical Properties of Clay Minerals in Northern Borno, Nigeria

2020 ◽  
Vol 5 (9) ◽  
pp. 1062-1068
Author(s):  
Fatimoh Dupe Adams ◽  
Shettima Bukar ◽  
Mohammed Bukar ◽  
B. A. Umdagas
Keyword(s):  
Particle Size ◽  
Aluminum Silicate ◽  
Engineering Structures ◽  
Fine Grained ◽  
Clay Deposits ◽  
Composite Layers ◽  
Silicate Structure ◽  
Free Swell ◽  
Sheet Silicate ◽  
Engineering Soil

Clay generally refers to either fine grained earth material with particle size of less than two micron (< 2 m) or group of hydrous aluminum silicate minerals that are characterized by sheet silicate structure of composite layers stacked along the C-axis. They are common deposits found in most geological setting like in fine grained sedimentary rocks such as shale, mudstone, and siltstone, in fine grained metamorphic slate and phyllite. The interest in clay deposits arises from its numerous uses of the mineral group and the behaviour of soils constituents when used as engineering soil and its resultant effects on engineering structures like roads, dams, bridges and houses. Evaluation of the soil properties of the Chad Formation indicated that the plasticity characteristics of the samples are of low to medium plasticity as indicated by matching the result with the DIN. chart. The results of free swell showed that the samples are susceptible to swelling when they absorbed water. The particle size distribution tests indicate that the percentage of fine (i.e. samples passing the 75µm sieve) is about 1.7 % implying that the grain sizes are within the texture of medium grain fraction

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.

scholarly journals Flotation and Tailing Discarding of Copper Cobalt Sulfide Ores Based on the Process Mineralogy Characteristics

Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1078
Author(s):  
Wentao Hu ◽  
Kai Tian ◽  
Zhengyang Zhang ◽  
Jiuchuan Guo ◽  
Xinwei Liu ◽  
...  
Keyword(s):  
Particle Size ◽  
Sulfide Mineral ◽  
Cobalt Sulfide ◽  
Sulfide Concentration ◽  
Total Recovery ◽  
Copper Sulfides ◽  
Fine Grained ◽  
Mineralogical Characteristics ◽  
Process Mineralogy ◽  
Mineralogical Characteristic

The mineral composition of copper–cobalt ores is more complex than that of copper sulfides, and it is also difficult to discard tailing efficiently in primary flotation for the fine-grained disseminated of ore. In this work, a mineral liberation analyzer (MLA) was employed to study the characteristics of minerals. As a significant mineralogical characteristic, the liberation degree of useful mineral aggregates was determined after grinding, and a correlation was established between the ore grinding size and mineralogical characteristics. The results showed that the adopted ore occurred in sulfide form. However, the particle size of the mineral’s monomer was fine grained, whereas its aggregate was coarse. The sulfide mineral aggregate obtained after primary grinding was selected as the recovery object, and its mineralogical characteristics, such as liberation degree and particle size, were investigated to promote total recovery in primary flotation. The copper–cobalt sulfide concentration was obtained at the following optimal conditions: the grinding size of −0.074 mm (65%), the aggregate’s liberation degree of 67%, a collector dosage of 50 g·t−1, a collector combination of 35% aerofloat + 65% butyl xanthate, a pH of 8.5, and 2# oil (a terpineol type foaming agent) dosage of 60 g·t−1. The recovered rough Cu and Co concentrates were 89.45% and 88.03%, respectively. Moreover, the grades of Cu and Co were 13.4% and 4.81%, respectively, with 85.07% of the ore weight discarded as tailing. The consideration of sulfide aggregates instead of singeral minerals mineralogy characters in primary grinding and primary flotation provides an effective theoretical guide for the sorting of sulfide minerals and reduction in the power consumption of grinding.

SHEAR STRENGTH AND STIFFNESS BEHAVIOR OF FINE-GRAINED SOILS AT DIFFERENT SURFACE HYDRATION CONDITIONS

2021 ◽  
Author(s):  
Jeongki Lee ◽  
Dante Fratta ◽  
Idil Deniz Akin
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Charge Density ◽  
Wave Velocity ◽  
Complex Function ◽  
Shear Stiffness ◽  
Experimental Program ◽  
S Wave ◽  
Interparticle Forces ◽  
Fine Grained

We developed an experimental program to monitor how interparticle forces control fine-grained soils' mechanical behavior when saturation changes from the tightly adsorbed regime to saturation. The testing program uses stiffness (i.e., S-wave velocity) and strength (i.e., Brazilian tensile strength) tests on kaolinite, silica flour, and diatomaceous earth soil samples at very low confining stresses (< 5 kPa). Three fine-grained soils yield a range of different properties, including particle size, specific surface area, negative charge density, and internal/external particle porosity. Results show that shear stiffness and tensile strength follow similar trends, emphasizing that the same interparticle forces control the mechanical responses. In particular, the interpretation of S-wave velocity measurements shows three different behavior ranges: a van der Waals attraction range, a capillary-dominated interparticle forces range, and the continuous decrease in the capillary forces from the saturation at the air-entry pressure until full saturation. We show that the interparticle forces respond to a complex function of water content, particle size, particle separations, surface charge density, and the presence of internal particle porosity.

Fine-Grained Concrete with Nanodispersed Silica Additive

2020 ◽  
Vol 992 ◽  
pp. 156-161
Author(s):  
N.P. Lukuttsova ◽  
E.G. Borovik ◽  
D.A. Pehenko
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Pore Diameter ◽  
Fine Grained ◽  
Silica Concentration ◽  
Calcium Hydrosilicates ◽  
Additive Particle ◽  
Nanodispersed Silica ◽  
Silica Additive ◽  
Number Of Particles

The effect of the modifying nanodispersed silica (NS) additive, obtained by the polycondensation method, on the properties of fine-grained concrete (FGC) is studied. It is revealed that the dependence of the NS-additive particle size on its age is extreme. The maximum number of particles of up to 100 nm in the additive is observed at the age of 10 days, and then their number decreases. However, it affects the FGC strength little even after 30 days of the additive storage. It is established that the NS-additive could be most effectively used with 0.23% of an active silica concentration and pH 4.1 in combination with S-3. At that, the porosity declines from 17.5 to 12.9% and the pore diameter diminishes from 3.171 to 0.689 μm. It leads to an increase in the compressive strength by 2 times and a decrease in water absorption by 1.6 times as compared to the control composition without additives. An increase in the frost resistance of the modified fine-grained concrete to F250 is recorded; it occurs due to a decrease in porosity at portlandite binding with amorphous silica additives into low-basic calcium hydrosilicates.

scholarly journals Effects of Tailings Gradation on Rheological Properties of Filling Slurry

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Bingwen Wang ◽  
Tingyong Xiong ◽  
Lijing Gao ◽  
Yuepeng Chai ◽  
Xiangyu Cui ◽  
...  
Keyword(s):  
Particle Size ◽  
System Design ◽  
Rheological Properties ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Analysis Software ◽  
Key Technology ◽  
Fine Grained ◽  
Viscosity Coefficients ◽  
Filling System

The key technology in filling mining is the gravity transportation of high-density slurries, and the filling system design is a significant part of this technology. The filling effect depends on the fluidity of the filling slurry. To investigate the influence of the gradation of tailings on the rheological properties of the filling slurry, this study uses particle size analysis to prepare three types of tailings: powder-, relatively fine-, and fine-grained tailings, which are then mixed in different proportions. The rheological properties of the resulting filling slurries are tested; the viscosity coefficients and yield stresses of the slurries are obtained using the analysis software provided with the MCR102 advanced rheometer that is used to measure the rheological properties of the slurries. The experimental results demonstrate that there is no absolute relationship between the rheological properties of the slurry and the size of the tailings particles, but the rheological properties are related to the gradation of tailings. Lubricating effect is weakened with an insufficient content of powder-grained particles in the tailings. On the contrary, when the content of powder-grained particles in the tailings is too high, the viscous substances in the slurry increase. Both of these conditions can increase the friction loss of the slurry.

Thermomechanical Treatments of Ultrahigh Carbon Steels and Optimal Microstructures to Improve Toughness

2007 ◽  
Vol 539-543 ◽  
pp. 4826-4831 ◽  
Author(s):  
Manuel Carsí ◽  
A. Fernández-Vicente ◽  
Oleg D. Sherby ◽  
Félix Peñalba ◽  
Oscar A. Ruano
Keyword(s):  
Particle Size ◽  
Carbide Particle ◽  
Thermomechanical Processing ◽  
Ferrite Matrix ◽  
Carbon Steels ◽  
Processing Route ◽  
Austenitizing Temperature ◽  
Fine Grained ◽  
Carbide Size ◽  
Carbide Particles

Thermomechanical processing allows the attainment of spheroidized microstructures that show improved mechanical properties. In this work, a thermomechanical processing route consisting of two steps was developed for two ultrahigh carbon steels (UHCS) containing 1.3 and 1.5%C. This route develops structures of fine spheroidized cementite particles in a fine-grained ferrite matrix. Spheroidized microstructures are formed by eutectoid carbide particles in the UHCS- 1.3C and by proeutectoid and eutectoid carbide particles in the UHCS-1.5C. In the latter steel, the proeutectoid carbide particle size is larger than the eutectoid carbide particle size. The carbide size distribution remains basically constant with austenitizing temperature for both steels. Plane-strain fracture toughness of spheroidized UHCS-1.3C is higher than for UHCS-1.5C, about 80 vs 40 MPa m1/2. These values do not vary significantly with austenitizing temperature which is attributed to the constancy of the mean proeutectoid and eutectoid carbide size.

Thermodynamics of the tetragonal-to-monoclinic phase transformation in fine and nanocrystalline yttria-stabilized zirconia powders

2003 ◽  
Vol 18 (12) ◽  
pp. 2912-2921 ◽  
Author(s):  
Arun Suresh ◽  
Merrilea J. Mayo ◽  
Wallace D. Porter
Keyword(s):  
Particle Size ◽  
Phase Transformation ◽  
Transformation Temperature ◽  
Phase Transformation Temperature ◽  
Scanning Calorimetry ◽  
Fine Grained ◽  
Dopant Level ◽  
M Phase ◽  
Additional Strain ◽  
Enthalpy And Entropy Changes

The current study uses high-temperature differential scanning calorimetry to document the shift in phase-transformation temperature with particle size throughout a series of alloys in the zirconia–yttria system (0–1.5 mol% yttria). The tetragonal-to-monoclinic (T→M) phase-transformation temperature is seen to vary inversely with particle size. It is shown that a simple thermodynamic approach first proposed by Garvie predicts this inverse linear relationship. Subsequent determination of the key thermodynamic parameters therein (e.g., the surface and volume free energy, enthalpy, and entropy changes involved in the phase transformation) allows a complete predictive equation for the T→M phase transformation in the yttria–zirconia system to be developed as a function of particle size and yttria dopant level. The yttria–zirconia phase diagram is then redrawn with grain size as a third variable. It should be stressed that the current analysis is valid for particulate systems only; a parallel paper tackles the problem for fine-grained yttria–zirconia solids, where the approach is similar, but additional strain energy terms come into play.

The Effect of the Second Phase Particle Size on Fracture Behavior of Cu – 0.1% Sn Ultra-Fine-Grained Alloy

2016 ◽  
Vol 59 (1) ◽  
pp. 116-120
Author(s):  
S. N. Faizova ◽  
G. I. Raab ◽  
I. A. Faizov ◽  
D. A. Aksenov ◽  
N. G. Zaripov ◽  
...  
Keyword(s):  
Particle Size ◽  
Fracture Behavior ◽  
Phase Particle ◽  
Second Phase ◽  
Fine Grained

scholarly journals Evaluation of Belgian clays for manufacturing compressed earth blocks

2019 ◽  
Vol 22 (3-4) ◽  
pp. 139-148
Author(s):  
Lavie A. MANGO-ITULAMYA ◽  
Frédéric COLLIN ◽  
Pascal PILATE ◽  
Fabienne COURTEJOIE ◽  
Nathalie FAGEL
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Abrasion Resistance ◽  
Clay Deposits ◽  
Compressed Earth Blocks ◽  
Earth Blocks ◽  
Sand And Gravel

This study aims to characterize Belgian clays in order to evaluate their use for manufacture of compressed earth blocks (CEB). Nineteen Belgian clay deposits were sampled in 56 sites and 135 samples were collected and analyzed. The analyses focus on the determination of particle size, plasticity, nature and mineralogy as the main characteristics for assessing the suitability of the raw clays to make CEB. These analyses allow for classifying the sampled clay deposits in three categories: clays that can be used unchanged to make CEB (2 clay deposits), clays that are suitable for the manufacture of CEB but require addition of sand and gravel particles (13 clay deposits) and clays that are suitable for the manufacture of CEB if they are mixed with other raw clays (4 clay deposits). In order to verify the use of these clays, five of them served as a model for making CEB. The strength of these bricks was evaluated by testing for compressive strength and abrasion resistance. The results of these tests confirm the suitability or not of the sampled clays for the manufacture of CEB.

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