Pentlandite phase relations in the Fe–Ni–S system and notes on the monosulfide solid solution

1970 ◽  
Vol 7 (1) ◽  
pp. 67-85 ◽  
Author(s):  
R. W. Shewman ◽  
L. A. Clark
Keyword(s):  
Solid Solution ◽  
Interplanar Spacing ◽  
Weight Ratio ◽  
Solid State Reactions ◽  
Monosulfide Solid Solution ◽  
Modulated Structure ◽  
X Ray ◽  
Nickel Ores ◽  
Iron Nickel ◽  
Approximate Composition

A curve relating composition of synthetic pentlandite with interplanar spacing was determined experimentally as follows: d115 = 1.9407 – 0.0023x + 0.0077x2, where x represents the iron to nickel weight ratio with d115 measured in Å and the sulfur content is fixed at 33.05 wt %. The following iron, nickel, and sulfur solid solubility limits of pentlandite were determined:[Formula: see text]X-ray powder patterns of monosulfide solid solution heated at 500 and 400 °C with a composition (wt %) of 18.8 Fe, 43.8 Ni and 37.4 S showed a modulated structure. A solvus interrupts the monosulfide solid solution at 275 ± 10 °C and the approximate composition in wt %: Fe = 22.5, Ni = 40, and S = 37.5.The relatively common occurrence of the pyrite–pentlandite assemblage in nickel ores shows that the solid state reactions attendant upon cooling of these ores, proceed to temperatures at least below 200 °C.

An Approach to the Solid Solution Problem Using a Computerized Identification Technique

1969 ◽  
Vol 13 ◽  
pp. 539-549
Author(s):  
Gerald G. Johnson ◽  
Frank L. Chan
Keyword(s):  
Solid Solution ◽  
Powder Diffraction ◽  
Lattice Parameter ◽  
Powder Diffraction File ◽  
X Ray ◽  
Complete Solid Solution ◽  
Vegard’S Law ◽  
Identification Technique ◽  
Approximate Composition ◽  
End Members

Since for most real systems, solid solution effects influence the position and intensity of the x-ray powder diffraction pattern, it is desirable and necessary to have an automatic system which will identify standard reference phases regardless of the amount of solid solution. Using the system CdS-ZnS, where the lattice parameter a0 changes from 4.136 to 3.820Å, with complete solid solution over the entire range of composition, an illustrative study was made. This work presents the results obtained from a computer analysis of the powder pattern obtained. It has been found that if the starting chemistry is known and the end members of the series are in the ASTM Powder Diffraction File, that the solid solution can be identified. Once the phases present are identified, a plot following Vegard's law yields the approximate composition of the sample under consideration. These two methods of compositional determination agree quite well. Examples of the computer system and description of the program input and output with interpretation of the results will be discussed.

scholarly journals Processing of Sulfide Copper-Nickel Ores from the Deposits in Murmansk Region by Heap Leaching

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 820
Author(s):  
Elena Yanishevskya ◽  
Nadezhda Fokina ◽  
Ekaterina Selivanova ◽  
Alena Kompanchenko ◽  
Dmitriy Makarov ◽  
...  
Keyword(s):  
Solid Phase ◽  
Copper Ions ◽  
Low Grade ◽  
Sulfide Ores ◽  
Acidophilic Microorganisms ◽  
X Ray ◽  
Copper Nickel ◽  
Murmansk Region ◽  
Nickel Ores ◽  
Iron Nickel

The feasibility of processing low-grade copper-nickel ores by heap bioleaching was investigated. It was found that an iron-oxidizing strain of acidophilic microorganisms, Acidithiobacillus ferrivorans, is effective in the leaching of sulfide ores from the deposits in Russia’s Murmansk region. Sulfide mineralization of the studied mineral feeds was described using the methods of X-ray phase analysis and optical microscopy. In the process of leaching, the pH and Eh values and the concentrations of ferric and ferrous iron, nickel, and copper ions were monitored. By the end of the experiment, 16.5% of nickel and 7.5% of copper was recovered from the ore of the Allarechensk technogenic deposit, while 22.5% of nickel and 12.7% copper were recovered from the ore of the Nud II deposit. By silicate analysis of the solid phase, patterns of ore chemistry change were described during the process of bioleaching.

scholarly journals Determination of adhesion stages of the Fe-Ni ore at the Ferronikeli plant in Drenas

2020 ◽  
pp. 37-42
Author(s):  
Zarife Bajraktari-Gashi ◽  
Muharrem Zabeli ◽  
Erard Morina
Keyword(s):  
Point Of View ◽  
High Moisture Content ◽  
High Moisture ◽  
Economic Point ◽  
X Ray ◽  
Nickel Ores ◽  
Iron Nickel ◽  
Rotary Kilns ◽  
The University

Abstract: Purpose. The process of calcine production in rotary kilns at the Ferronikeli plant in Drenas is realized with great difficulties as a result of the formation of large adhesions in the areas of rotary kilns. So far, the removal of load adhesions during the work process inside the rotary kilns is achieved only by their physical removal. The purpose of the paper is to determine the factors in reducing adhesions in the process of calcine production in the areas of rotary kilns, in the Ferronikeli plant in Drenas. Methodology. Chemical analysis of iron-nickel ore. The determination of the composition of the adhesives was performed with the X-RAY device, in the laboratory of the Ferronikeli plant. Method with the software Calphad 2020, at the University of Ljubljana. Findings. From the composition of iron-nickel ore, the composition of adhesives in rotary kilns, we manage to determine the thermodynamic phases and exothermic and endothermic processes that take place in the process of rotary kilns. From the determinations of the composition of the adhesives in the software alphad 2020, we manage to determine one of the factors that affect the formation of adhesives based on the stages during the process, which do not have a stability, as a result of high moisture content of iron-nickel ores. Originality. Based on the study at the Ferronikeli plant, shovels were placed on the walls of the rotary kilns in the three areas, the removal of fireclay bricks, the placement of anchored concrete and the project for the placement of two kilns for kiln ore were started. Practical value.The placement of the shovels has increased the temperature inside the rotary kilns. While the placement of dryers will have an impact on reducing the adhesions inside the rotary kilns and from the economic point of view, we will have a reduction of fuels in the load of the rotary kilns.

Effect Ni Addition of the Cu-Al Powder by Mechanical Alloying

2005 ◽  
Vol 498-499 ◽  
pp. 141-145
Author(s):  
Rodrigo Estevam Coelho ◽  
Ana Cris R. Veloso ◽  
Rodinei Medeiros Gomes ◽  
Tadeu Antonio de Azevedo Melo ◽  
Severino Jackson Guedes de Lima
Keyword(s):  
Solid Solution ◽  
Ball Mill ◽  
Thermal Analyses ◽  
Weight Ratio ◽  
Argon Atmosphere ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ni Addition ◽  
Al Powder ◽  
Diffraction Patterns

In the present work is shown the results for solid interaction of a Cu-13.4Al-2Ni (wt%) elemental powders. Together with this mixture was placed tungsten carbide balls into a cylindrical vial under argon atmosphere. The weight ratio of the balls to powder was 20 to 1. A planetary ball mill (Fritsch Pulverizette 5) was used to perform MA at 250 rpm. The elemental powder was milled at 10min, 5 and 10 hours and a small amount of the powders were collected and analyzed via X-ray diffraction, using Cu Kα radiation (λ=0.15418 nm) and differential thermal analyses from 25 up to 450oC at a heating rate of 25oC min-1. The x-ray diffraction patterns showed that after 10h of milling the phase formation of the mechanical alloyed powders is composed of a Cu, full Cu(Al) solid solution and γAl9Cu4.

The Yttrium Oxide Fluoride Solid Solution Described as a Composite Modulated System

1998 ◽  
Vol 54 (4) ◽  
pp. 391-398 ◽  
Author(s):  
S. Schmid
Keyword(s):  
Solid Solution ◽  
Yttrium Oxide ◽  
Diffraction Data ◽  
Substantial Reduction ◽  
Lattice Parameters ◽  
Group Symmetry ◽  
X Ray Diffraction ◽  
Modulated Structure ◽  
X Ray ◽  
Wide Range

Single-crystal X-ray diffraction data (Mo Kα radiation) are used to determine the structure of the Δ = 0.174 member of a (YO1 − ΔFΔ)F1 + Δ, 0.12 ≤ Δ ≤ 0.22, wide-range non-stoichiometric solid solution in the yttrium oxide fluoride system. The structure is refined as a composite modulated structure composed of two mutually incommensurable Q and H substructures with overall superspace-group symmetry Acmm(0,0,1.174..)0s0. The Q substructure has lattice parameters a = 5.415 (2), bQ = 5.534 (2) and cQ = 5.525 (2) Å, and superspace-group symmetry Acmm(0,0,1.174..)0s0. The H substructure has lattice parameters a = 5.415 (2), bH = 1/2bQ = 2.767 (1) and cH  = 4.696 (2) Å, and superspace-group symmetry Pmcm(0,1/2,0.8518...)s00. Refinement on 338 unique reflections converged to R = 0.025, while a previous conventional superstructure refinement led to R = 0.101. This lowering of the R factor goes hand-in-hand with a substantial reduction in the number of refined parameters.

Modulated structure in Bi2+xSr2−xCu1+yO6+δ

1991 ◽  
Vol 6 (3) ◽  
pp. 435-445 ◽  
Author(s):  
Zenji Hiroi ◽  
Yasunori Ikeda ◽  
Mikio Takano ◽  
Yoshichika Bando
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Unit Length ◽  
Excess Oxygen ◽  
Structure Model ◽  
X Ray Diffraction ◽  
Modulated Structure ◽  
X Ray ◽  
Transmission Electron ◽  
Modulation Vector

The modulated structure in solid solution Bi2+xSr2−xCu1+yO6+δ (0.1 < x < 0.6, y ∼ x/4) has been investigated by means of powder x-ray diffraction, electron diffraction, and transmission electron microscopy. The [010] component of the modulation vector decreases almost linearly with increasing x, from 5.2b (x = 0.1) to 4.2b (x = 0.5), where b is the unit length of the average structure along the [010] direction, and is little sensitive to excess oxygen content δ. A structure model of the modulation based on a periodic substitution of Sr for Bi and formation of Bi blocks whose size varies with x is proposed. Relations among various modulations appearing in other related phases such as the Pb-substituted 105 K Tc phase are discussed.

The Precipitation of Si in AlCuSi Thin Films

1973 ◽  
Vol 31 ◽  
pp. 34-35 ◽  
Author(s):  
R. M. Anderson
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Heat Treatment ◽  
Solid Solution ◽  
Integrated Circuit ◽  
Copper Film ◽  
Solution Concentration ◽  
X Ray ◽  
Silicon Thin Films ◽  
Before And After

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.

TEM studies of solid-state reactions in sputter-deposited Nb/Al multilayer thin films

1996 ◽  
Vol 54 ◽  
pp. 1020-1021
Author(s):  
F. Ma ◽  
S. Vivekanand ◽  
K. Barmak ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Stoichiometric Composition ◽  
Analytical Electron Microscopy ◽  
Grain Structure ◽  
Solid State Reactions ◽  
Multilayer Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sputter Deposited

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.

Direct Observation of Monolayer Zones in Al-wt 4% Cu

1990 ◽  
Vol 48 (1) ◽  
pp. 14-15
Author(s):  
B. Jouffrey ◽  
D. Dorignac ◽  
A. Bourret
Keyword(s):  
Solid Solution ◽  
Synchrotron Radiation ◽  
Direct Observation ◽  
Supersaturated Solid Solution ◽  
Original Model ◽  
X Ray ◽  
Image Position

Since the early works on GP zones and the model independently proposed by Preston and Guinier on the first steps of precipitation in supersaturated solid solution of aluminium containing a few percent of copper, many works have been performed to understand the structure of different stages in the sequence of precipitation.The scheme which is generally admitted can be drawn from a work by Phillips.In their original model Guinier and Preston analysed a GP zone as composed of a single (100) copperrich plane surrounded by aluminum atomic planes with a slightly shorter distance from the original plane than in the solid solution.From X-ray measurements it has also been shown that GP1 zones were not only copper monolayer zones. They could be up to a few atomic planes thick. Different models were proposed by Guinier, Gerold, Toman. Using synchrotron radiation, proposals have been recently made.

Synthesis of dispersed mesoporous powders solid solution Zr0.88Ce0.12O2 for catalyst carrier of the conversion of methane to synthesis –gas

2020 ◽  
pp. 73-83
Author(s):  
L. V. Morozova ◽  
◽  
I. A. Drozdova ◽  
Keyword(s):  
Solid Solution ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Primary Crystal ◽  
X Ray ◽  
Catalyst Carrier ◽  
Conversion Of Methane ◽  
Deposition Processes ◽  
Zirconia Oxide ◽  
Coprecipitation Of Hydroxides

The xerogels in the system 0.88 mol.% ZrO2 − 0.12 mol.% CeO2 were obtained by the method of coprecipitation in a neutral (pH = 7) and slightly alkaline (pH = 9) medium under the influence of ultrasound with the size of the agglomerates 70 – 230 nm. It is shown that the coprecipitation of hydroxides of zirconium and cerium at pH = 9 with the use of ultrasonic treatment facilitates the formation of a primary crystal is symbolic of the particles in the xerogel, whose size is ~ 5 nm, whereas the xerogel synthesized in a neutral environment consists only of the x-ray amorphous phase. The effect of pH-precipitation on deposition processes of dehydration of the xerogels and crystallization solid solution based on zirconia oxide in the metastable pseudocubic modification (с′-ZrO2) was discovered. It was found that in the temperature range 500 – 800 °C there is a phase transition с′-ZrO2 → t-ZrO2, the size of the crystallites of the formed tetragonal solid solutions is 8 and 11 nm. The method of low-temperature nitrogen adsorption were investigated dispersion properties and characteristics of the pore structure of the powders of the solid solution Zr0.88Ce0.12O2. It is determined that the specific surface area of t-ZrO2 samples obtained after firing at 800 °C is 117 and 178 m2/g, the total pore volume reaches 0.300 − 0.325 cm3/g, the pore size distribution is monomodal and is in the range of 2 − 8 nm. The effect of thermal “aging” at a temperature of 800 °C (40 h) on the structure and dispersion of the solid solution t-ZrO2 powders was studied.

Sign in / Sign up

Export Citation Format

Share Document