합성니켈광 기반 Fe-Ni-S matte 제조 = Production of Fe-Ni-S matte from synthetic Ni ore

다국어 초록 (Multilingual Abstract)

This study investigates the production behavior of Fe–Ni–S matte using synthetic
nickel ore designed to replicate the chemical and mineralogical characteristics of
low-grade saprolitic laterite. The synthetic ore was formulated based on XRF and XRD
data from magnetically upgraded laterite concentrate, and thermodynamic modeling—
phase stability analysis, Ellingham evaluation, viscosity prediction, and sulfidation
equilibria—was employed to establish suitable smelting conditions. Carbon reduction
behavior was evaluated with respect to the carbon reaction ratio, its control over FeO
evolution in slag, and its influence on slag basicity and viscosity. Selective reduction of
NiO and FeO at 1550 °C resulted in the formation of Fe–Ni alloy droplets, which then
reacted with FeS to produce Fe–Ni–S matte. The optimal carbon ratio was found to
be 0.2–0.4 mol, which maintained slag viscosity within the industrially favorable range
(approximately 2–5 poise) and simultaneously mitigated crucible dissolution.
Thermodynamic assessment confirmed that FeS is the only stable sulfide phase at high
temperatures and dissolves fully into the Fe–Ni melt, enabling stable matte formation.
Under optimized carbon and FeS addition conditions, the maximum nickel recovery
achieved in this study reached approximately 88%, driven by favorable slag composition,
controlled basicity, and reduced viscosity that enhanced matte–slag separation. These
findings demonstrate that simultaneous carbothermic reduction and sulfidation is a viable
method for producing Fe–Ni–S matte from saprolite-derived oxide feed, and that
controlling carbon ratio, FeS addition, and Al2O3 flux is essential for achieving stable
matte formation and efficient metal–slag separation.

목차 (Table of Contents)

• 1. Introduction 1
• 2. Theoretical Background 4
• 2.1. Nickel Resources 4
• 2.1.1. Nickel Reserves and Production 4
• 2.1.2. Nickel Surfide Ores 6
• 2.1.3. Nickel laterite Ores 7
• 2.2. Major Ore Processing Technologies 9
• 2.2.1. Magnetic Separation 9
• 2.2.2. HPAL (High Pressure Acid Leaching) Process 10
• 2.2.3. RKEF (Rotary Kiln – Electric Furnace) Process 12
• 3. Experimental 14
• 3.1. Materials 14
• 3.2. Apparatus 17
• 3.2.1. Kanthal Tube Furnace 17
• 3.3. Analysis 18
• 3.3.1. Synthesis Ni Ore 18
• 3.3.2. Fe-Ni-S matte 18
• 3.4. Procedure 19
• 3.4.1. Manufacturing of Synthetic Ni Ore 19
• 3.4.2. Smelting of Fe-Ni-s Matte 21
• 4. Results and Discussion 23
• 4.1. Thermodynamic Consideration 23
• 4.1.1. Synthesis of Ni Minerals 23
• 4.1.2. Carbonation Reaction 28
• 4.1.2.1 Standard Gibbs Free Energy 28
• 4.1.2.2 Carbon Reaction Ratio 30
• 4.1.2.3 Viscosity of the Overall Slag as a Function of Increasing Carbon Ratio 32
• 4.1.2.4 Al2O3 Solubility with Increasing Carbon Ratio 34
• 4.1.2.5 Viscosity Changes of the Slag System with Increasing Al2O3 Content 36
• 4.1.3 Sulfidation 38
• 4.1.3.1 Selection of Sulfurizing Agent 38
• 4.1.3.2 Solubility of FeS in Fe–Ni Alloy 39
• 4.2 Experimental Results 41
• 4.2.1 Nickel Recovery 41
• 4.2.2 Matte composition 43
• 4.2.3 Slag Composition 49
• 4.2.4 Basicity 51
• 5. Conclusion 53
• 5.1. Conclusion 53