DRILLING ÄND BLASTING OF ROCKS CARLOS LOPEZ JIMENO Project Director for EPM, SA EMLIO LOPEZ JIMENO FRANCISCO JAVIER. Submitted By. drilling blasting rocks filetype pdf free Engineer requires continuous use of drilling and blasting or special power. Facts About: Underwater Drilling. faced with a number of challenges in the area of drilling and blasting such as blasting cost, explosives consumption, airblast, blast induced ground vibration and flyrocks. Sorry, there is no online preview for this file type.
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Only in down the hole hammer drilling is a high pressure compressor used 1 – 7 MPa because the percussion power is increased along with the flushing blqsting cuttings. Therefore, there is no incentive to use high explosives that generate high stresses on the blasthole walls: Hydraulic dewatenng pump Swanson Eng.
Drilling and blasting
Blasting characteristics of large diameter boreholes. These labors with explosives consist in placing small charges in strategic points of the structures, provoking unstableness and fragmentation during the fall in a prefixed direction. The gases produced behind the detonation front come into action, at high temperature and pressure, carrying the Thermodynamicor Bubble Energy.
These are used in underground operations to charge blastholes of 28 to 65 mm in diameter and basically consist drilliing small vessels of polyethylene plastic with Straps for their transport. This blastiny has the folbwing advantages: The placing of the blastholes can be done on a staggered square Pattern which allows better distribution of Concrete walls In the case of reinforced concrete walls that form part of the retaining structure, the patterns used are detailed in Table Another thing to take into account is that energy is lost through the sleeves of the rod couplings, due to reflection and fricton which is converted into heat and wear on the drill steel threads.
The wave travels at high speed and its shape depends basically on the design of the piston. The geomechanic Parameters of the rock which are used in the modelization are: The percussion is delivered directly to the drill bit, whereas fileype rotation is performed outside the hole. Initiation und priming Systems ives, Fig.
Drilling and Blasting of Rocks
In each type of rock there is an optimum rotation speed which produces larger sized cuttings taking advantage of drilllng free area of the hole created with each impact. When excavating inclined ramps or shafts by blasting, it must be checked that the empty blastholes are not be filled with water in order to achieve the benefits of this mechanism of breakage.
The inclined orebodies are divided verticallv into levels, from which drillkng haulage drifts are estakshed along the foot walls. According to the capacity of this loading equipment, the height in meters can be estimated with the following equation: At the Same time, the objectives and contents of this handbook contribute to improved safety in mining.
Supports, undermining, unions with cables or bolts, etc. What are VitalSource eBooks? For an initial classification of sedimentary rocks, their formation process viletype taken into account, later the grain size, the characteristics of their bonding, apart from the types and quantities of their rninerai components.
Rocks are classified as to their hardness by using Friedrich von Mohs’ Scale of Hardnessin which the concept is that any mineral can scratch anything that has a lower or equai number to it, numbering from 1 to Depending upon the fields of application of these drilling ngs, surface or underground, the most comrnon range of diameters are shown in Table 2.
Sublevel stoping in the Stiassa Mine. The evolution of loading 4. On the other hand, the types of work, in surface as wellas in underground operations, can be classified in the following groups: Blsting minimum height of 12 m is recommended, although a lesser height can also be used for cast blasting.
Afterwards, a sensitivity analysis is carried out in order to calculate theoretically blasitng optimum fragmentation, evaluating the System in practice by contrastingthe actual size distribution and yields with those predicted in the calculations, Fig. The resulting product is pumped into the blasthole. The cylinder has charging instruments or integral systems of manufacture an oscillating movement hat is transmitted by the pusher and charge.
Drilling and blasting – Wikipedia
The rounds consist in the instantaneous firing of a group of charges located in the whole base in an homogeneous manner. Optimizing the yield and distribution of effective exploSanmartin, V.
These trucks are similar to concrete trucks with slight modifications to make them safe for mixing and charging bulk blasting agents.
In the majority of hydraulic hammers, the manufacturers indicate the impact energy value, but this is not the case with the pneumatic hammers. The equations that follow refer to a gelatin explosive in plaster charges, but without any special geometry. This influence is significative when the crystal size is under 0. Spherical charge cratering-planeand angle geomeAtlas Copco: Drilling is canied out with a rotary percussive top harnmer rig and a Generally, the mining is divided into phases which begin in the top part with a pilot drift 1 and lateral stope holes 2to follow by benching in the lower part with horizontal or vertical blastholes 3Fig.
E Menendez Atlas Powder Company: Manual de perforacibn de rocas. Rotary Drilling with Cutting Action 7. One inconvenience of the system isthe irregularity and poor condition of the roof after each blasting. Directional Blasting with completefall This is the safest method and the study of its application should be done with priority over the other two methods.
Drilling and Blasting of Rocks – CRC Press Book
In down the hole drilling the piston energy is transrnitted directly to the bit, giving greater performance. Learn More about VitalSource Bookshelf. What now has to be determined is the geometric configuration of the blastholes, the explosive charges, the initiation sequence and the delay timing, which constitute the main problems in blasting practice.
The lower bench is broken once the upper section is finished, or with a certain time difference. In these cases it is recomrnended that the downline be prepared for multiple prirning outside the hole, threading twice each of the pnmers, Rockw.