Coal carbonization include the reform process with the state of anaerobic (without oxygen) at low temperatures 459-700 Celsius and at high temperatures produces 900-12000 Celsius and porous solid materials which are residues carbonization process called coke or charcoal and volatile gases (Tsai, 1980 ).
In general, the solid material consists of semi-coke is formed from the coal that is not experiencing maturation and coke derived from coal that has undergone maturation.
During the carbonization of coal through several stages of physical and chemical changes. Physical changes of softening, the flow of material, and hardening of the merger, while the chemical changes of cracking polymerization and evaporation. The factors above may affect the quality of coal in terms of petrography composition.
Coal type is characterized by variation maceral and mineral content in coal (Cook, 1975; Stach, 1985). The formation of this type are controlled by various factors, including the spatial and temporal variation of the ancient climate, geological age, tectonic processes, the ecological conditions of sedimentation environment and the coal-forming plants in its community. Type of coal occurs in phase biochemistry.
Rank or rank of coal is the maturity level of organic material that starts from the lowest level of lignite, sub-bituminous, bituminous, semi-anthracite, anthracite to meta-anthracite. Carbonization stage is dominated by geochemical processes, so that the most important factor in the formation of coal rank is the temperature, pressure and time.
Observations by petrography in coal basically covers two things namely the identification maceral abundance and composition of maceral vitrinite, inertinite and liptinite. Coal with high inertinite composition and low vitrinite will tend to produce low-power one while if vitrinite high and low inertinite it will have the moderate-power, but coal with high strength obtained when the composition shows inertinite content and vitrinite was balanced. Strength of coal can also affect the rank of coal. Through petrography, coal rank can be known through its vitrinite reflectance value. The best range of vitrinite reflectance value is 1.2-1.4. The coal with good vitrinite value obviously can produce coal with high strength quality.
Observations by petrography in coal basically covers two things namely the identification maceral abundance and composition of maceral vitrinite, inertinite and liptinite. Coal with high inertinite composition and low vitrinite will tend to produce low-power one while if vitrinite high and low inertinite it will have the moderate-power, but coal with high strength obtained when the composition shows inertinite content and vitrinite was balanced. Strength of coal can also affect the rank of coal. Through petrography, coal rank can be known through its vitrinite reflectance value. The best range of vitrinite reflectance value is 1.2-1.4. The coal with good vitrinite value obviously can produce coal with high strength quality.
0 comments:
Post a Comment