Mine Ventilation & Environmental Hazards: Selected Short Answer Questions from AMIE Exams
What are the major sources of noise in underground mining, highlighting the permissible levels of noise in those?
The ambient noise level of the underground mining area is affected by the operation of the cutting machines, tub/conveyor movement and blasting of the coal. The movement of coaling machines and transport units-conveyor, tubs and transfer points caused audible noise which becomes disturbing underground because of the poor absorption by the walls.
Classify mine fires.
Fires underground can be classified into two broad groups, open and concealed fires. Open fires occur in airways, faces and other openings that form part of the active ventilation system of the mine and, hence, affect the quality of the mine airflows quickly and directly.
As the term might imply, open fires are often accompanied by flaming combustion because of the availability of oxygen and offer the possibility of a direct attack by fire fighting teams. Conversely, concealed fires occur in areas that are difficult or impossible to access such as caved or abandoned zones. These are usually, but not necessarily, initiated as a result of spontaneous combustion and can occur in both coal and sulphide ore minerals as well as within any imported organic matter such as paper, discarded fabrics or timbering in abandoned areas.
Write the physiological effect of carbon monoxide.
The toxic character of carbon monoxide has been well known for many centuries. At low concentrations, carbon monoxide may cause nausea, vomiting, restlessness, and euphoria. As exposure increases, a person may lose consciousness and go into convulsions. Death is a common final result.
Explain homotropal and antitropal ventilation.
Homotropal ventilation Ventilation by a current of air travelling in the same direction as the flow of mineral out of a mine.
Antitropal ventilation Ventilation by a current of air travelling in the opposite direction to that of the flow of mineral out of the mine.
Nystagmus is a condition of involuntary (or voluntary, in rare cases) eye movement, acquired in infancy or later in life, that may result in reduced or limited vision. Due to the involuntary movement of the eye, it has been called "dancing eyes".
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