All About Coal Flashcards
a naturally-occurring inorganic substances that have physical and chemical characteristics that can be mined at a profit.
Ore
a natural-occurring substance that have physical and chemical characteristics.
Mineral
an organic remain formed from accumulation of plant material buried beneath the surface that has undergone incomplete oxidation.
Coal
stratum of coal parallel to rock stratification
Coal Seam
a coal measures 81 hectares
Coal Block
toxic waste material derived from internal combustion of coal
Coal Ash
heating value of coal
British Thermal Unit (BTU)
a bed or bank of waste material dividing veins or beds- soft thin sedimentary layer following a surface of separation between thicker strata of different lithology
Parting
an arrangement or deposition of sedimentary materials in layers or of sedimentary rock in strata
Stratification
rock or sediments composed of clasts which have been transported from their place of origin like sandstone and shale.
Clastic Material
processed and purified coal
Clean Coal
formation of coal from plants by the process of diagenesis and metamorphism.
Coalification
chemical and physical changes occurring in sediments during and after their deposition but before consolidation.
Diagenesis
sequence of sedimentary rock formation
Bedding
sequence of igneous rock formation
Layering
a surface mine working place where coal is mine by open-pit method.
Coal Pit
History of Coa
- In primitive time, coal was used mainly for cooking and heating during cold weather
- The Chinese recorded the use of coal 1,100 years before the Christian Era
- Evidences of use of coal by the Romans in England (100-200 AD) were found
- Americans used coal for cooking, heating and in pottery (1300)
- Expanding of use of coal during the Industrial Revolution period (1760 - 1840)
- More application of coal in making steel during the Civil War (1875)
- Use of coal to generate electricity for homes and factories (1880s)
- Coal became the major fuel used to generate electricity in USA (1961)
Other Use of Coal
- Transportation
- Cement Manufacturing
- Road Construction
Markets of Coal
- Industries (cement plants, etc.)
- Shipping & Railway
- Transportation
- Power Plants
- Iron and Steel
- Oil Refinery and Chemical Plants
- Gas Utility
Origin of Coal
Coal was formed from accumulation of plant material buried beneath the surface that has undergone incomplete oxidation.
Origin of Coal (Condition Necessary for Coal Formation)
- Swamps or marsh environment and climate favorable to plant growth;
- Some subsidence (sinking) of the area during accumulation of vegetal debris, or compaction of deposited plant material, permitting further
accumulation; - Sufficiently wet conditions to permit exclusion of air from much of the vegetal material before it decays, and sufficiently rapid accumulation to thwart bacterial action, even in water of the swamp;
- Proximity to the sea or a subsiding area so that vegetal material can be buried by sediments when the sea level rises or the land subsides;
- Site of accumulation such that removal by erosion does not subsequently occur
Coal
a term applied to vegetable matter (trees, grasses, etc.) which was subjected to heat and pressure through geologic ages resulting to change in both the physical and chemical properties. Peat represents the initial, unconsolidated stage in the development of coal. This coalification process continues with time and the application of temperatures and pressure from lignite to anthracite. Coal contains Carbon, Hydrogen, Nitrogen, Sulfur, Oxygen, mineral matter
Geologic Factors Affecting Coal Formation
- Erosion
- Water or Wet Zone
- Sediments Deposition
- Vegetation
- Temperature and Pressure
- Bacteria
- Faulting
- Folding
- Geologic Contacts
Soil/Rocks in Coal Formation
- Clay
- Sediments
- Sandstones
- Shale
- Mudstone/Claystone
- Limestone
Factors that Affect Coal Quality
- Vegetal Origin
- Time
- Calorific
- Thermal Components
- Impurities
- Processing Methods
Ranking of Coal
- Factors to consider for usage of coal include the heating value, ash melting temperature, sulfur and other impurities, mechanical strength, and many other chemical and physical properties
- The carbon content of coal supplies most of its heating value, but other factors also influence the amount of energy it contains per unit of weight.
- The amount of energy in coal is expressed in British thermal units per pound. A BTU is the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit.
the carbon residue of the organic material that involves the removal of volatile constituents (as a gas) of the organic matter by heat without combustion.
Fixed Carbon (FC)
refers to that portion of the organic matter which is driven off as a gas.
Volatile Matter (VM)
the heat produced by combustion of coal. The British thermal unit (Btu), commonly used to express heating (calorific) value, is the amount of heat required to raise 1 lb of water 1 degree Fahrenheit and is normally reported as Btu per pound of coal.
Calorific Value
refers to a standard test made to determine whether a pulverized sample of coal will or will not fuse and form a solid button at an elevated temperature
Agglomerating Character
Physical Properties of Coal
- Specific Gravity – ranges from 1.23 to 1.72
- Hardness – a term related to coal’s structure & rank. Its hardness depends on composition & location of coal beds
- Grindability– determines the relative ease of pulverizing or grinding of coal
- Friability or Size Stability– ability to withstand breakage in handling and shipping
- Fracture and Structure- fractures refers to manner which coal pieces breaks
- Weathering- tendency especially lower ranks, to break apart in exposure to weather particularly when alternately wetted and dried or subjected to hot sunshine.
Chemical Properties of Coal is affected by:
✓Type of vegetation which the coal originates;
✓The extent to which decay was permitted to proceed;
✓The pressure to which the decaying vegetation was subjected;
✓The foreign matter deposited on the decaying vegetation during coal
formation;
✓The heat which the decaying vegetation was subjected.
✓Type of vegetation which the coal originates;
✓Theextent to which decay was permitted to proceed;
✓Thepressure to which the decaying vegetation was subjected;
✓The foreign matter deposited on the decaying vegetation during coal
formation;
✓The heat which the decaying vegetation was subjected.
Physical Properties of Coal ranges from 1.23 to 1.72
Specific Gravity
a term related to coal’s structure & rank. Its hardness depends on composition & location of coal beds
Hardness
determines the relative ease of pulverizing or grinding of coal
Grindability
ability to withstand breakage in handling and shipping
Friability or Size Stability
fractures refers to manner which coal pieces breaks
Fracture and Structure
tendency especially lower ranks, to break apart in exposure to weather particularly when alternately wetted and dried or subjected to hot sunshine.
Weathering
is to search, define and acquire a block of coal which can be mined at a profit.
Coal Exploration
to look or search for something valuable to man.
Exploration
Purpose of Coal Exploration
- To define the extent of the deposit
- To determine its quality and quantity
- To detect the gaseous level and give way to its emission into the atmosphere;
- To determine the ideal processing method;
- To determine the geological characteristic of the coal deposit, such as: geologic
structures present, host rocks, geometry of the deposit, thickness of
overburden, etc. - Hydrologic Conditions
- Engineering Characteristics of coal seam and its surrounding strata.
It is the process of drilling holes through surface and subsurface materials such as rock, clay, sand or boulders, using a bit inset with diamonds, or rock bits for the purpose of obtaining a sample or core for visual examination and laboratory analysis.
Exploration Drilling
Common Drilling Techniques for Coal Exploration
- Rotary Drilling
- Diamond Core Drilling
- Conventional Core Drilling
- Wireline Core Drilling
Factors to Consider in Selection of Drilling Methods
- Size of hole
- Efficiency of the method
- Drilling costs
- Drill Capability (depth, core size, etc.)
- Sampling required
- Terrain condition
This method uses a pump or compressor to circulate a fluid (air, water or drilling mud) through the rods to cool and lubricate the bit and flush the cuttings upward, outside the drill rod to the surface.
Rotary Drilling System
This uses a rotary-type of drill machine and drilling fluids in conjunction with a swivel-type double-tube core barrel. The core barrel consists of inner and outer tubes separate by a narrow annular space. The inner tube holds the core and remains stationary during coring while the outer tube, to which the hollow core but is attached turns around it.
Conventional Coring System
This is modified system over conventional drilling where it also uses a swivel-type double-tube core barrel where the inner tube containing the core can be hoisted through the drill rods while the inner tube and rods remain in the hole. The core sample is extruded from the solid inner tube. However, a third tube may added is required to obtain softer formation. This method is preferred over conventional system due to the time saved in retrieving the core sample
Wire-line Coring System
Performed to confirm the minability of the coal and to provide data required for the preparation of mine design
Gathering of Geotechnical Data
Fracture frequency, RQD, hardness are needed in determining the mechanical competence of the strata.
Rock Mechanic Data
Correlation of aquifers and defining amount, movement, and quality of water in aquifers
HydroGeologic Data
Methane content of coal seam
Gas emission
The type of analysis required for coal reserve depend upon the proposed use of coal.
Coal Analysis
Proper sampling is critical to all coal exploration as it is
designed to determine the general character of the coal and establish a field average for each of the quality parameters. Sampling methods are channel and column.
Coal Sampling
represents the number of tons of coal per acre foot at 1.0 Specigic Gravity
1359
service factors
labor, site, weather.
