Mine Blasting & Mining Drilling
Mine blasting and mining drilling are two of the most hazardous operations conducted in the mining industry. The primary purpose of blasting and drilling is to prepare a deposit of ore to be mined and processed in a variety of ways. Blasting and drilling can create very dangerous working environment due to their explosive nature and potential for large rocks and pieces of ore to become dislodged from their positions. The most important factor to consider when conducting blasting and drilling is the safety of the workers involved and of any inhabitants nearby.
When mining a deposit, blasting or blasting and drilling together are often used to create working conditions that allow access to ore safely and efficiently. Blasting is often the first step as it is less expensive and less time consuming than mining and generally can remove large amounts of ore quickly. Generally a single blast can remove 2 to 3 feet of ore in an area when done correctly .Drilling is generally the second step in mining ore as it helps to create a skip pattern that is followed to more accurately remove ore from the primary deposit. As with blasting, there are potential hazards when drilling, including rock bursts, dust, noise, and vibrations which must be mitigated in order to protect workers and nearby inhabitants.
In order to achieve a successful blast or drill, it is necessary to calculate the drilling, blasting, and breaking ratio. This is done by first measuring the dimension of the ore deposit and the distance between the blasting holes. From this information, the blasting ratio, which is the amount of ore that is removed by blasting relative to the ore deposit, and the breakage ratio, which is the amount of ore that is actually broken by the blasting, can be calculated.
It is important to ensure that the ratio between drilling and blasting is correct in order to obtain the desired results. If the ratio between drilling and blasting is too low, there may be large chunks of ore that remain in the deposit. Conversely, if the ratio is too high, there is a danger of over-blasting, which can cause unnecessary air-borne dust and debris, as well as potential ground instability in the area surrounding the deposit. The ideal ratio between drilling and blasting is generally considered to be 1:3 for primary deposits and 1:2 for secondary deposits.
Another important factor to consider in blasting and drilling operations is the burden, which is the distance between the last hole that is drilled and the blast face. This distance is important as it affects the fragmentation of the ore when blasting. Generally, the greater the burden, the greater the amount of fragmentation that will occur and the more ore that will be removed from the deposit. As with the ratio between drilling and blasting, the ideal burden for a particular deposit must be calculated in order to achieve the desired outcome.
In conclusion, blasting and drilling can be hazardous operations and a great deal of thought and preparation must go into a successful blasting or drilling operation. Factors such as the ratio between drilling and blasting, the burden, and safety efforts must all be taken into consideration in order to ensure a successful result without any disruptions or damage. With proper planning and preparation, blasting and drilling can be safely and successfully conducted without putting workers or nearby inhabitants at risk.
