Rate of oxydesulfurization of coal-derived pyrite in hot alkaline solution. [MS Thesis; 50 references]
The rate of oxydesulfurization of coal-derived pyrite with hot dilute sodium carbonate solutions in a fixed bed tubular reactor was investigated. Pyrite used in this study was obtained in the form of nodules from the refuse produced in cleaning coal. The major areas studied included the difference in leaching characteristics of acid cleaned pyrite and uncleaned pyrite, the degree of sulfur removal from pyrite at different locations in the tubular reactor, the effect on sulfur conversion of the gas to liquid volume ratio in the reactor, and the effect of various operating conditions including temperature (100 to 175/sup 0/C), oxygen partial pressure (3.13 to 13.33 atm.), average particle size (114 to 332 ..mu..m.), and reaction time. With the fixed bed tubular reactor, acid cleaned pyrites gave more consistent results than uncleaned pyrites. The degree of sulfur extraction decreased from the point where the leaching solution entered the reactor to where it left and this change appeared to be related to the drop in oxygen partial pressure across the bed. Also, the gas to liquid volume ratio in the reactor affected the sulfur conversion, and at 125/sup 0/C and 13.33 atm. oxygen pressure the optimum ratio was found to be about 0.17. Furthermore, the rate of sulfur extraction increased significantly with increasing temperature, increasing oxygen partial pressure, and decreasing particle size. The shrinking unreacted core model was used to analyze the leaching process. The results showed that diffusion through a hematite shell which forms around a shrinking core of unreacted pyrite controls the overall rate of extraction of sulfur from the pyrite particles.
- Research Organization:
- Ames Lab., Ames, IA (United States)
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 5206324
- Report Number(s):
- IS-T-905
- Resource Relation:
- Other Information: Thesis
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
OXYGEN
CHEMICAL REACTIONS
PYRITE
SODIUM CARBONATES
AQUEOUS SOLUTIONS
CHEMICAL REACTION KINETICS
CHEMICAL REACTORS
COAL PREPARATION
DESULFURIZATION
EXPERIMENTAL DATA
GRAPHS
HYDROMETALLURGY
LEACHING
MATHEMATICAL MODELS
PARTICLE SIZE
REMOVAL
TABLES
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
ALKALI METAL COMPOUNDS
CARBON COMPOUNDS
CARBONATES
CHALCOGENIDES
COMMINUTION
CRYOGENIC FLUIDS
DATA
DATA FORMS
DISPERSIONS
DISSOLUTION
ELEMENTS
EXTRACTIVE METALLURGY
FLUIDS
INFORMATION
IRON COMPOUNDS
IRON SULFIDES
KINETICS
METALLURGY
MINERALS
MIXTURES
NONMETALS
NUMERICAL DATA
ORES
OXYGEN COMPOUNDS
PYRITES
REACTION KINETICS
SEPARATION PROCESSES
SIZE
SODIUM COMPOUNDS
SOLUTIONS
SULFIDES
SULFUR COMPOUNDS
SULFUR ORES
TRANSITION ELEMENT COMPOUNDS
010402* - Coal
Lignite
& Peat- Purification & Upgrading