scholarly journals The enrichment technology of slag from metallurgical processing of copper ore concentrate

2019 ◽  
Vol 28 (3) ◽  
pp. 537-545
Author(s):  
G. A. Shevchenko ◽  
V. G. Shevchenko ◽  
V. A. Baranov ◽  
V. N. Spassky
Keyword(s):  
Particle Size ◽  
Water Supply ◽  
Copper Content ◽  
Raw Materials ◽  
Petrographic Analysis ◽  
Sieve Analysis ◽  
Copper Ore ◽  
Magnetic Separator ◽  
Metallurgical Processing ◽  
Enrichment Technology

The purpose of this research is the development of a technology for the enrichment of slag from metallurgical processing of copper ore concentrate based on     the results of spectral, chemical, sieve and petrographic analysis. The results of spectral analysis indicate the copper content in all three samples of mineral raw materials at more than 1 %. The results of chemical analysis indicated a high copper content in the samples from 13.4 to 17.1%, as well as a high iron content from 9 to 18%. Analysis of the results of the sieve analysis showed that the largest amount of copper is contained in the size classes 0.063–0.05 mm at from 18.6 to 24.1 % and 0.04 mm at from 15.6 to 38 %. In accordance with the petrographic studies, the size of copper grains varies from 0.1–0.3 to 1–5 mm. The most common sizes of copper grains in the studied samples are 0.2-0.3 and 1-2 mm. Based on the results of spectral, chemical, sieve and petrographic analysis, a technology for the enrichment of copper-containing slags has been developed. Gravity wet enrichment technology with a capacity of 5 t/h with Cu recovery in the range of 80–95 % suggests the grinding of raw materials with a constant water supply up to 40 m3/h from the sludge collector. The heavy fractions are fed to a magnetic separator and then to a classifier for the extraction of magnetic concentrate and slag, which after the separation of the fraction of 0.08-0.4 mm with the MVG screen can later be used as a raw material for the building industry. The light fractions after the concentration tables are fed to the classifier, on which the copper concentrate is released. The average density fractions are returned to the closed cycle for further grinding in a ball mill. However, such a wet enrichment scheme requires a continuous water supply and the sludge collector’s presence, which cannot always be ensured. Therefore, the technology of slag dry enrichment with a particle size of 0–100 mm has also been developed. The central apparatus in the proposed enrichment technologies is the MVG vibrating screen, which is designed to separate bulk materials by particle size from 20 microns to several millimeters. Polyfrequency oscillations in the frequency range from several Hz to kHz are implemented on the screen, eliminating blockage of the sieve cells, destruction of the formed aggregates of stuck particles, ensuring their intensive movement in the layer and efficient passage of particles reaching the sieve surface through the cells. This type of vibration makes it possible to achieve much greater efficiency of separation and dehydration of materials than in traditional screens and to ensure continuous self-cleaning of the mesh, which contributes to the process of separation and dehydration. Due to the lack of tension, high durability of the working surface is ensured. Due to the transfer of minimum loads on the base, the screen is installed without arranging special foundations, including on the floors of buildings and structures. A standard- sized row of screens was developed with a screening surface area from 1 to 4 m2 and a different number of tiers.

Preparation and Impaction on the Yield and Abrasion Resistance of Polycrystalline Diamond Powder of Copper/Graphite Raw Materials

2012 ◽  
Vol 550-553 ◽  
pp. 93-98
Author(s):  
Chun Lin Li ◽  
Jian Chen
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Abrasion Resistance ◽  
Heat Treatment Temperature ◽  
Copper Content ◽  
Raw Materials ◽  
Polycrystalline Diamond ◽  
Graphite Powder ◽  
Diamond Powder ◽  
Treatment Temperature

Taking earthy graphite and electrolytic powder as raw materials, copper/graphite raw material is prepared by power metallurgy and then polycrystalline diamond powder is prepared by shock wave synthesis. Impaction on yield and abrasion resistance from copper content, particle size of graphite powder, heat treatment and re-pressing process has been researched. As result, yield of polycrystalline diamond powder is decreasing as decreasing copper content. It is decreased dramatically when the copper content is less than 90%. It is increased and then decreased as increasing the particle size of graphite powder, and the better particle size of graphite powder is 70μm. It is increased slightly and then decreased dramatically as increasing heat treatment temperature before re-pressing. The higher the heat treatment temperature, the more the yield after re-pressing. Impaction on the abrasion resistance of polycrystalline diamond powder from the preparing process of copper/graphite is smaller.

scholarly journals Analysis of a grinding efficiency in the electromagnetic mill for variable process and feed parameters

2017 ◽  
Vol 18 ◽  
pp. 01012
Author(s):  
Marta Wołosiewicz-Głąb ◽  
Dariusz Foszcz ◽  
Daniel Saramak ◽  
Tomasz Gawenda ◽  
Damian Krawczykowski
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Raw Material ◽  
Grinding Process ◽  
Key Factors ◽  
Copper Ore ◽  
Factors Affecting ◽  
Grinding Media ◽  
Grinding Efficiency ◽  
The Impact

Article describes issues related to the assessment of raw materials grinding efficiency in an electromagnetic mill. Application of such type of mill in grinding processes can result in measurable benefits of more efficient raw material grinding by reducing time needed to produce a product of a suitable particle size compared to conventional mills. The expected effect of application of a system based on an electromagnetic mill is to achieve a lower energy consumption of grinding process for raw material processing compared to the existing equipment used for the fine grinding. A key element of correct design of comminution circuits in processing of particular feed mineral is to identify the impact of key factors affecting the efficiency of the grinding process. The most important factors determining the efficiency of the grinding process are the time, the construction parameters of the machine, the type of grinding media used in grinding process, as well as the parameters of the feed, among others the crushing resistance or particle size. The paper presents the results of kinetic study of copper ore grinding in electromagnetic mill for variable feed particle size distribution of and different sizes of grinding media.

Microstructural characterization of laser-melted/roller-quenched dicalcium silicate

1988 ◽  
Vol 46 ◽  
pp. 582-583
Author(s):  
C. J. Chan ◽  
K. R. Venkatachari ◽  
W. M. Kriven ◽  
J. F. Young
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Shape Change ◽  
Microstructural Characterization ◽  
Particle Size Effect ◽  
Dicalcium Silicate ◽  
Laser Melting ◽  
Uniform Size ◽  
Cell Shape Change ◽  
Wide Range

Dicalcium silicate (Ca2SiO4) is a major component of Portland cement. It has also been investigated as a potential transformation toughener alternative to zirconia. It has five polymorphs: α, α'H, α'L, β and γ. Of interest is the β-to-γ transformation on cooling at about 490°C. This transformation, accompanied by a 12% volume increase and a 4.6° unit cell shape change, is analogous to the tetragonal-to-monoclinic transformation in zirconia. Due to the processing methods used, previous studies into the particle size effect were limited by a wide range of particle size distribution. In an attempt to obtain a more uniform size, a fast quench rate involving a laser-melting/roller-quenching technique was investigated.The laser-melting/roller-quenching experiment used precompacted bars of stoichiometric γ-Ca2SiO4 powder, which were synthesized from AR grade CaCO3 and SiO2xH2O. The raw materials were mixed by conventional ceramic processing techniques, and sintered at 1450°C. The dusted γ-Ca2SiO4 powder was uniaxially pressed into 0.4 cm x 0.4 cm x 4 cm bars under 34 MPa and cold isostatically pressed under 172 MPa. The γ-Ca2SiO4 bars were melted by a 10 KW-CO2 laser.

scholarly journals Leaching Behaviour of Construction and Demolition Wastes and Recycled Aggregates: Statistical Analysis Applied to the Release of Contaminants

2021 ◽  
Vol 11 (14) ◽  
pp. 6265
Author(s):  
Alessandra Diotti ◽  
Giovanni Plizzari ◽  
Sabrina Sorlini
Keyword(s):  
Particle Size ◽  
Statistical Analysis ◽  
Raw Materials ◽  
Primary Source ◽  
Recycled Aggregates ◽  
Critical Parameters ◽  
Material Particle ◽  
Analysis Methodology ◽  
Construction And Demolition Wastes ◽  
Leaching Behaviour

Construction and demolition wastes represent a primary source of new alternative materials which, if properly recovered, can be used to replace virgin raw materials partially or totally. The distrust of end-users in the use of recycled aggregates is mainly due to the environmental performance of these materials. In particular, the release of pollutants into the surrounding environment appears to be the aspect of greatest concern. This is because these materials are characterized by a strong heterogeneity which can sometimes lead to contaminant releases above the legal limits for recovery. In this context, an analysis of the leaching behaviour of both CDWs and RAs was conducted by applying a statistical analysis methodology. Subsequently, to evaluate the influence of the particle size and the volumetric reduction of the material on the release of contaminants, several experimental leaching tests were carried out according to the UNI EN 12457-2 and UNI EN 12457-4 standards. The results obtained show that chromium, mercury, and COD are the most critical parameters for both CDWs and RAs. Moreover, the material particle size generally affects the release of contaminants (i.e., finer particles showed higher releases), while the crushing process does not always involve higher releases than the sieving process.

scholarly journals Mining Wastes of an Albite Deposit as Raw Materials for Vitrified Mullite Ceramics

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 232
Author(s):  
Pedro J. Sánchez-Soto ◽  
Eduardo Garzón ◽  
Luis Pérez-Villarejo ◽  
George N. Angelopoulos ◽  
Dolores Eliche-Quesada
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Phase Evolution ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Mining Wastes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value

In this work, an examination of mining wastes of an albite deposit in south Spain was carried out using X-ray Fluorescence (XRF), X-ray diffraction (XRD), particle size analysis, thermo-dilatometry and Differential Thermal Analysis (DTA) and Thermogravimetric (TG) analysis, followed by the determination of the main ceramic properties. The albite content in two selected samples was high (65–40 wt. %), accompanied by quartz (25–40 wt. %) and other minor minerals identified by XRD, mainly kaolinite, in agreement with the high content of silica and alumina determined by XRF. The content of Na2O was in the range 5.44–3.09 wt. %, being associated with albite. The iron content was very low (<0.75 wt. %). The kaolinite content in the waste was estimated from ~8 to 32 wt. %. The particle size analysis indicated values of 11–31 wt. % of particles <63 µm. The ceramic properties of fired samples (1000–1350 °C) showed progressive shrinkage by the thermal effect, with water absorption and open porosity almost at zero at 1200–1250 °C. At 1200 °C, the bulk density reached a maximum value of 2.38 g/cm3. An abrupt change in the phase evolution by XRD was found from 1150 to 1200 °C, with the disappearance of albite by melting in accordance with the predictions of the phase diagram SiO2-Al2O3-Na2O and the system albite-quartz. These fired materials contained as main crystalline phases quartz and mullite. Quartz was present in the raw samples and mullite was formed by decomposition of kaolinite. The observation of mullite forming needle-shape crystals was revealed by Scanning Electron Microscopy (SEM). The formation of fully densified and vitrified mullite materials by firing treatments was demonstrated.

scholarly journals Evaluation of Marblewood Dust’s (Marmaroxylon racemosum) Effect on Ignition Risk

2021 ◽  
Vol 11 (15) ◽  
pp. 6874
Author(s):  
Miroslava Vandličkova ◽  
Iveta Markova ◽  
Katarina Holla ◽  
Stanislava Gašpercová
Keyword(s):  
Particle Size ◽  
Dust Particles ◽  
Wood Dust ◽  
Sieve Analysis ◽  
Granulometric Analysis ◽  
Analysis Measurement ◽  
Risk Research ◽  
Minimum Ignition Temperature ◽  
The Impact

The paper deals with the selected characteristics, such as moisture, average bulk density, and fraction size, of tropical marblewood dust (Marmaroxylon racemosum) that influence its ignition risk. Research was focused on sieve analysis, granulometric analysis, measurement of moisture level in the dust, and determination of the minimum ignition temperatures of airborne tropical dust and dust layers. Samples were prepared using a Makita 9556CR 1400W grinder and K36 sandpaper for the purpose of selecting the percentages of the various fractions (<63, 63, 71, 100, 200, 315, 500 μm). The samples were sized on an automatic vibratory sieve machine Retsch AS 200. More than 65% of the particles were determined to be under 100 μm. The focus was on microfractions of tropical wood dust (particles with a diameter of ≤100 µm) and on the impact assessment of particle size (particle size <100 µm) on the minimum ignition temperatures of airborne tropical dust and dust layers. The minimum ignition temperature of airborne marblewood dust decreased with the particle size to the level of 400 °C (particle size 63 μm).

Enrichment of a Nigerian chromite ore for metallurgical application by dense medium flotation and magnetic separation

2019 ◽  
Vol 116 (3) ◽  
pp. 324 ◽  
Author(s):  
Kuranga Ibrahim Ayinla ◽  
Alafara Abdullahi Baba ◽  
Bankim Chandra Tripathy ◽  
Malay Kumar Ghosh ◽  
Rajan Kumar Dwari ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Separation ◽  
Organic Liquid ◽  
Size Fraction ◽  
Dense Medium ◽  
Chromium Alloy ◽  
Magnetic Separator ◽  
Electro Deposition ◽  
Chromite Ore ◽  
Wet Chemical

This study, focused on the beneficiation of a Nigerian complex chromite ore sourced from Tunga-Kaduka, Anka Local Government of Zamfara State, Nigeria, assaying 45.85% Cr2O4 and 54.15% mineral impurities, was enriched concurrently through sink floatation and magnetic separation techniques. The chromite ore initially analyzed to contain silicate impurities was found not suitable for metallurgical purposes. Thus, enrichment was examined through gravity separation studies using organic liquid with different specific gravities at 2.8, 3.3, and 4.0. The separation of chromite ore with lowest particle size fraction was done using Mozley mineral separator followed by the magnetic separation of the sink product by magnetic separator. The results obtained revealed about 77% of the total material containing 300 μm particle size, 52% ˂ 212 μm and 17% below 75 μm. Subsequent analysis of the beneficiated ore was carried out by wet chemical analysis and atomic absorption spectrophotometer. The results showed that Cr2O4 content increased to 78.34% from initial 45.83% with maximum Cr:Fe ratio of 3.2:1, representing 84.27% of chromium metal present in the ore. The enrichment of Cr2O4 obtained in this study could be found metallurgically applicable in the electro-deposition and ferro-chromium alloy production practices.

scholarly journals Mineralogical and Microstructure Analysis for Characterization and Provenance of Ceramic Artifacts from Late Helladic Kastrouli Settlement, Delphi (Central Greece)

Geosciences ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 36
Author(s):  
Vayia Xanthopoulou ◽  
Ioannis Iliopoulos ◽  
Ioannis Liritzis
Keyword(s):  
Raw Materials ◽  
Analytical Techniques ◽  
Sem Analysis ◽  
Petrographic Analysis ◽  
Ceramic Assemblage ◽  
Thin Sections ◽  
Central Greece ◽  
High Calcium ◽  
Local Geology

The present study deals with the characterization of a ceramic assemblage from the Late Mycenaean (Late Helladic III) settlement of Kastrouli, at Desfina near Delphi, Central Greece using various analytical techniques. Kastrouli is located in a strategic position supervising the Mesokampos plateau and the entire peninsula and is related to other nearby coeval settlements. In total 40 ceramic sherds and 8 clay raw materials were analyzed through mineralogical, petrographic and microstructural techniques. Experimental briquettes (DS) made from clayey raw materials collected in the vicinity of Kastrouli, were fired under temperatures (900 and 1050 °C) in oxidizing conditions for comparison with the ancient ceramics. The petrographic analysis performed on thin sections prepared from the sherds has permitted the identification of six main fabric groups and a couple of loners. The aplastic inclusions recognized in all fabric groups but one confirmed the local provenance since they are related to the local geology. Fresh fractures of representative sherds were further examined under a scanning electron microscope (SEM/EDS) helping us to classify them into calcareous (CaO > 6%) and non-calcareous (CaO < 6%) samples (low and high calcium was noted in earlier pXRF data). Here, the ceramic sherds with broad calcium separation are explored on a one-to-one comparison on the basis of detailed mineralogical microstructure. Moreover, their microstructure was studied, aiming to estimate their vitrification stage. The mineralogy of all studied samples was determined by means of X-ray powder diffraction (XRPD), permitting us to test the validity of the firing temperatures revealed by the SEM analysis. The results obtained through the various analytical techniques employed are jointly assessed in order to reveal potters’ technological choices.

New uses for brick-making clay materials from the Bailén area (southern Spain)

Clay Minerals ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 453-465 ◽  
Author(s):  
I. Gonzalez ◽  
E. Galan ◽  
A. Miras ◽  
P. Aparicio
Keyword(s):  
Particle Size ◽  
Iron Oxides ◽  
Raw Materials ◽  
The Other ◽  
Southern Spain ◽  
Other Hand ◽  
Floor Tiles ◽  
Potential Applications ◽  
Clay Materials

AbstractAn attempt has been made to assess new potential applications for the Bailén clays, traditionally used for manufacturing bricks, based on mineralogical, chemical, particle size, plasticity and firing results. Raw materials and mixtures used by the local factory were selected and tested with the addition of some diatomite, feldspar or kaolin. Based on their properties, clay materials from Bailén might be suitable for making porous red wall tiles, clinker, vitrified red floor tiles and porous light-coloured wall tiles by pressing; the first could be manufactured from the raw materials and mixtures currently used by the local manufactures. On the other hand, stoneware shaped by extrusion, such as perforated bricks, facing bricks and roofing tiles, can be also manufactured from the mixtures used at the factory if they contain 20-25% carbonate and small amounts of iron oxides; lightweight bricks require black and yellow clays with diatomite.

Sign in / Sign up

Export Citation Format

Share Document