Procedimentos técnicos adotados no processo de rebaixamento do nível freático nas minas N4 e N5, Serra dos Carajás – PA

Abstract

The hydrogeology evaluates the forms of interaction between water and geological system. In open pit mining the presence of water in the pit is undesirable for several aspects, among which we mention: Jam excavation equipment and transportation, increased cost of using explosives to dismantle special, more expensive maintenance of roads and excavation sites; a shorter shelf life of truck tires off-road production delays, risk of accidents with power cables, unhealthy work environment with plenty of moisture, instability of slopes of cava with risks of accidents, etc.. The draining of groundwater is therefore an integral part of mine planning and should allow the mining plans may be developed, considering the water level lowered enough so that production walk normally. From the moment that defines the need to effect the dewatering of mines by wells so that we start the process on the basis of the mine geology and mining plans, both long and short term. The philosophy of work in lowering the water level in mining, where feasible, should be called "pre-downgrade" where a smaller number of active wells for a longer interval of time to perform the task of lowering the water level. With this decreases the cost of drilling wells and the impact of the mining operations.