scholarly journals Influence of grain size on chalcopyrite ore leaching in acidic medium

2007 ◽  
Vol 72 (8-9) ◽  
pp. 911-919 ◽  
Author(s):  
M.M. Antonijevic ◽  
G.D. Bogdanovic ◽  
S.M. Serbula ◽  
S.M. Milic
Keyword(s):  
Grain Size ◽  
Dissolved Oxygen ◽  
Sulphuric Acid ◽  
Acidic Medium ◽  
Raw Material ◽  
Leaching Rate ◽  
Acid Consumption ◽  
Leaching Solution ◽  
Chalcopyrite Ore

This work presents an investigation of column leaching of a chalcopyrite ore using sulphuric acid where dissolved oxygen and iron(III) ions play the role of oxidants. The investigations were carried out in PVC columns, diameter 110 mm and height 1000 mm, by percolation of the leaching solution through the ore layer. The influence of ore grain size on the degree of leaching and acid consumption was examined. The formation of gypsum on limestone results in the comminution of the initial raw material during leaching. The grain size of chalcopyrite was found to have no important influence on the leaching rate of copper. A higher consumption of sulphuric acid was found for the fractions (-3+1) mm, (?5+0) mm and (?5+3) mm than for the fractions (?10+5) mm, (?20+10) mm and (?20+0) mm. .

Experimental Study on Sulfuric Acid Leaching Behavior of Chromite with Different Temperature

2011 ◽  
Vol 361-363 ◽  
pp. 628-631 ◽  
Author(s):  
Cheng Jun Liu ◽  
Jie Qi ◽  
Mao Fa Jiang
Keyword(s):  
Sulfuric Acid ◽  
Acid Leaching ◽  
Raw Material ◽  
Leaching Rate ◽  
Sulfuric Acid Leaching ◽  
Leaching Process ◽  
Pollution Problem ◽  
Environmental Pollution Problem ◽  
Leaching Solution ◽  
Leaching Residue

Utilizing Pakistan chromite as raw material, the rapid leaching of chromium and iron could be realized by the sulfuric acid leaching process on the condition of atmospheric pressure and the addition of oxidant A. And the leaching rate of chromium and iron would be 98.5% and 71.9%, respectively. The sulfuric acid leaching processes with different temperature were systematically studied by chemical analysis and phase analysis. The results showed that, with the increase of reaction temperature, the leaching rate of chromium would increase gradually, but the leaching rate of iron increased at first and then decreases and reached its maximum at 140°C. When the temperature > 160°C, the phases of the leaching residue were magnesium iron silicate and a few of silica, no chromohercynite, chrompicotite and magnesioferrite existed in the chromite. The leaching solution of sulfuric acid leaching process could be used for preparing the basic chrome sulfate, and there is no Cr6+ in the leaching residue and solution. The results would provide theoretical guidance for solving environmental pollution problem of Cr6+ in traditional chromate production process.

scholarly journals Grain Size Distribution and Clay Mineral Distinction of Rare Earth Ore through Different Methods

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 353 ◽  
Author(s):  
Lingkang Chen ◽  
Xiongwei Jin ◽  
Haixia Chen ◽  
Zhengwei He ◽  
Lanrong Qiu ◽  
...  
Keyword(s):  
Grain Size ◽  
Rare Earth ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Solution Concentration ◽  
Low Ph ◽  
Low Grade ◽  
Leaching Rate ◽  
Leaching Solution

Although clay mineral content in ion-absorbed rare earth ores is crucial for migrating and releasing rare earth elements, the formation, distribution, and migration of clay minerals in supergene rare earth ores have not been fully understood. Therefore, this study analyzes the characteristics of clay mineral type and content, soil particle size, pH value, leaching solution concentration, and leaching rate. This analysis was performed using different methods, such as regional rare earth mine soil surveys, in situ leaching profile monitoring, and indoor simulated leaching. The results showed that the grain size and volume curve of rare earth ore have unimodal and bimodal shapes, respectively. X-ray diffraction showed the differences in clay mineral types formed by different weathered bedrocks. The principal clay minerals were kaolinite, illite, chlorite, and vermiculite, with their relative abundance varying with parent rock lithology (granite and low-grade metamorphic rocks). In the Ganxian granite weathering profile, the kaolinite content increased from top to bottom. The decomposition of feldspar minerals to kaolinite was enhanced with an increase in the SiO2 content during weathering. The in situ leaching profile analysis showed that the kaolinite content increased initially and then decreased, whereas the illite/mica content exhibited the opposite trend. Under stable leaching solution concentration and leaching rate, clay mineral formation is favored by lower pH. Low pH, low leaching rate, and highly-concentrated leaching solution (12 wt%) resulted in a slow increase in kaolinite content in the upper part of the profile (30 cm). A lower concentration of the leaching solution (4 wt%) resulted in rapid enrichment of kaolinite after 15 days. Low pH, leaching solution concentration, and leaching rate promoted the formation of distinct kaolinite horizons. We suggest that by disregarding other control factors, rare earth recovery of over 90% can be achieved through leach mining with solutions of 8 wt% and a pH of 5 at a leaching rate of 5 mL/min.

scholarly journals Rheological Characterization of a Concentrated Phosphate Slurry

Fluids ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 178
Author(s):  
Souhail Maazioui ◽  
Abderrahim Maazouz ◽  
Fayssal Benkhaldoun ◽  
Driss Ouazar ◽  
Khalid Lamnawar
Keyword(s):  
Flow Behavior ◽  
Continuous Phase ◽  
Raw Material ◽  
Rheological Characterization ◽  
Phosphate Ore ◽  
Insoluble Particles ◽  
Experimental Protocols ◽  
Solid Liquid

Phosphate ore slurry is a suspension of insoluble particles of phosphate rock, the primary raw material for fertilizer and phosphoric acid, in a continuous phase of water. This suspension has a non-Newtonian flow behavior and exhibits yield stress as the shear rate tends toward zero. The suspended particles in the present study were assumed to be noncolloidal. Various grades and phosphate ore concentrations were chosen for this rheological investigation. We created some experimental protocols to determine the main characteristics of these complex fluids and established relevant rheological models with a view to simulate the numerical flow in a cylindrical pipeline. Rheograms of these slurries were obtained using a rotational rheometer and were accurately modeled with commonly used yield-pseudoplastic models. The results show that the concentration of solids in a solid–liquid mixture could be increased while maintaining a desired apparent viscosity. Finally, the design equations for the laminar pipe flow of yield pseudoplastics were investigated to highlight the role of rheological studies in this context.

scholarly journals Contribution of Cyanotoxins to the Ecotoxicological Role of Lichens

Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 321
Author(s):  
Dobri Ivanov ◽  
Galina Yaneva ◽  
Irina Potoroko ◽  
Diana G. Ivanova
Keyword(s):  
Research Methods ◽  
Raw Material ◽  
Modern Times ◽  
Effective Application ◽  
The World ◽  
The Common

The fascinating world of lichens draws the attention of the researchers because of the numerous properties of lichens used traditionally and, in modern times, as a raw material for medicines and in the perfumery industry, for food and spices, for fodder, as dyes, and for other various purposes all over the world. However, lichens being widespread symbiotic entities between fungi and photosynthetic partners may acquire toxic features due to either the fungi, algae, or cyano-procaryotes producing toxins. By this way, several common lichens acquire toxic features. In this survey, recent data about the ecology, phytogenetics, and biology of some lichens with respect to the associated toxin-producing cyanoprokaryotes in different habitats around the world are discussed. Special attention is paid to the common toxins, called microcystin and nodularin, produced mainly by the Nostoc species. The effective application of a series of modern research methods to approach the issue of lichen toxicity as contributed by the cyanophotobiont partner is emphasized.

Study on leaching kinetics of hexavalent chromium from aged calcium-free chromium slag

2021 ◽  
pp. 1-13
Author(s):  
Quan Qi ◽  
Liang Li ◽  
Liangyu Wei ◽  
Baoming Hu ◽  
Zheng Liu ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Resource Utilization ◽  
Scientific Basis ◽  
Diffusion Reaction ◽  
Leaching Kinetics ◽  
Leaching Rate ◽  
Chromium Slag ◽  
Leaching Solution ◽  
Main Components ◽  
Kinetics Of

To provide a scientific basis for the resource utilization of chromium slag, this article studies the release law of hexavalent chromium in the aged calcium-free chromium slag. XRD (X-ray diffractometer) and MLA (Mineral Liberation Analyzer) were used to analyze the composition of the chromium slag; using sulfuric acid-nitric acid as the leaching solution, the release law of hexavalent chromium in chromium slag and the leaching kinetics were studied. The results show that main components of the chromium slag are magnesioferrite, chromite, hematite, hydrargillite, and spinel; chromium is mainly present in chromite and magnesioferrite; the leaching rate of hexavalent chromium increases with the increase of temperature or the decrease of pH. The analysis of leaching kinetics shows the leaching rate is controlled by the internal diffusion reaction, and the apparent activation energy is 11.93 kJ·mol–1. The chromium slag is aged in high temperature seasons, which is conducive to the precipitation of hexavalent chromium in the chromium slag, can increase the yield of chromate in the roasting kiln, and is conducive to resource utilization; chromium slag should be stored in order to prevent acid rain erosion which leads to environmental pollution risk (e.g. drinking water).

scholarly journals On the role of grain size on slurry erosion behavior of a novel medium-carbon, low-alloy pipeline steel after induction hardening

Wear ◽  
2021 ◽  
pp. 203678
Author(s):  
Vahid Javaheri ◽  
Oskari Haiko ◽  
Saeed Sadeghpour ◽  
Kati Valtonen ◽  
Jukka Kömi ◽  
...  
Keyword(s):  
Grain Size ◽  
Pipeline Steel ◽  
Induction Hardening ◽  
Slurry Erosion ◽  
Medium Carbon ◽  
Erosion Behavior

Characterization and A Preliminary Study of TiO2 Synthesis from Lampung Iron Sand

2020 ◽  
Vol 849 ◽  
pp. 113-118
Author(s):  
Yayat Iman Supriyatna ◽  
Slamet Sumardi ◽  
Widi Astuti ◽  
Athessia N. Nainggolan ◽  
Ajeng W. Ismail ◽  
...  
Keyword(s):  
Food Packaging ◽  
Xrd Analysis ◽  
Major Elements ◽  
Raw Material ◽  
Solid Residue ◽  
X Ray Diffraction ◽  
X Ray ◽  
Leaching Solution ◽  
Ti Content

The purpose of this study is to characterize Lampung iron sand and to conduct preliminary experiments on the TiO2 synthesis which can be used for the manufacturing of functional food packaging. The iron sand from South Lampung Regency, Lampung Province that will be utilized as raw material. The experiment was initiated by sieving the iron sand on 80, 100, 150, 200 and 325 mesh sieves. Analysis using X-Ray Fluorescence (XRF) to determine the element content and X-Ray Diffraction (XRD) to observe the mineralization of the iron sand was conducted. The experiment was carried out through the stages of leaching, precipitation, and calcination. Roasting was applied firstly by putting the iron sand into the muffle furnace for 5 hours at a temperature of 700°C. Followed by leaching using HCl for 48 hours and heated at 105°C with a stirring speed of 300 rpm. The leaching solution was filtered with filtrate and solid residue as products. The solid residue was then leached using 10% H2O2 solution. The leached filtrate was heated at 105°C for 40 minutes resulting TiO2 precipitates (powder). Further, the powder was calcined and characterized. Characterization of raw material using XRF shows the major elements of Fe, Ti, Mg, Si, Al and Ca. The highest Ti content is found in mesh 200 with 9.6%, while iron content is about 80.7%. While from the XRD analysis, it shows five mineral types namely magnetite (Fe3O4), Rhodonite (Mn, Fe, Mg, Ca) SiO3, Quart (SiO2), Ilmenite (FeOTiO2) and Rutile (TiO2). The preliminary experiment showed that the Ti content in the synthesized TiO2 powder is 21.2%. The purity of TiO2 is low due to the presence of Fe metal which is dissolved during leaching, so that prior to precipitation purification is needed to remove impurities such as iron and other metals.

Ivory in the Chalcolithic enclosure of Perdigões (South Portugal): the social role of an exotic raw material

2015 ◽  
Vol 47 (3) ◽  
pp. 390-413 ◽  
Author(s):  
António Carlos Valera ◽  
Thomas Xaver Schuhmacher ◽  
Arun Banerjee
Keyword(s):  
Social Role ◽  
Raw Material ◽  
The Social ◽  
South Portugal
Sign in / Sign up

Export Citation Format

Share Document