Granüle alüminyumun kayaç boyutuna ve delme patlama maliyetine etkisi

Abstract

Bu çalışmanın amacı anfo içine ağırlıkça değişik oranlarda granule alüminyum ilavesi ile elde edilen karışımın kayaç boyutuna ve delme patlatma maliyetine etkisinin incelenmesidir. Çalışma boyunca 10 deneme atımı yapılmıştır ve sonuçları değerlendirilmiştir. Çalışmada deneme atımlarında kullanılan karışımın hazırlanması hakkında bilgi verilmiş ve karışım için kullanılan granule Al tanıtılmıştır. Anfo ve granule AI+ANFO karışımının termodinamik özellikleri hakkında bilgi verilmiş, hesaplamalar örneklerle açıklanmıştır. Anfo ve granule AI+ANFO karışımının bileşenlerinin oranlarına bağlı olarak değişim gösteren ısı miktarı, sıcaklık, özgül enerji değerleri çizelge ve grafik olarak verilmiştir. Ayrıca patlama hızı ve şok dalgaları basınç değerleri çizelge olarak verilmiştir. Yapılan deneme atımları hakkında bilgi verilmiş ve sonuçlar ayrı ayrı değerlendirilmiştir. Granule alüminyumun delme patlatma maliyetine etkisi incelenmiştir. Sonuç olarak katkı maddesi olarak kullanılan granule alüminyumun kayaç boyutunun küçültülmesi ve delme patlatma maliyetlerinin azaltılması açısından olumlu neticeler verdiği görülmüştür

To survive, mining operations must maintain a high level of mining efficiency. To the end, much attention has been given to drilling and blasting procedure, where direct cost savings can be obtained and where downstream cost can be reduced through improved fragmentation. The use of aluminum in explosive products can play a major role in reducing drilling and blasting costs. The main purpose of this research, is to examine the effect of the aluminum on the rock fragmantation and drilling costs. As long as research, ten test blasting has been blasted. And results of the test blasting has been criticized. Firstly, the working area was introduced. The working open pit is near the Büyükçekmece is produced limestone for Akçansa Cement Factory. In part two, the drilling and blasting working were introduced. Anfo and granule AI+ANFO, gelatin dynamit, water gel has been used for blasting operations. For initation, the shock tube system (the nonel shock tube) which is a nonelectric instantaneous, nondisruptive signal transmission system has been used. In part three, granule Al was introduced. Aluminum is extensively utilized in bulk and packaged anfo, slurries and emulsions. Both as a relatively low cost, high energy fuel and as asensitizer. It is well known fact that the addition of aluminum increase bulk and weight strenght of anfo, the most common blasting agent under dry conditions. As a fuel, aluminum added to an explosive or blasting agent increases the total energy out put. This increased energy allows more work to be performed by the same volume of explosive, permitting greater distance in hole spacing and achieving better fragmentation. The resulding increase in energy is not linear however, as is illustrated in Figure 1. Which shows the energy out put relative to regular ANFO on an equal weight basis for different aluminum additions. The decreasing rate of energy out put increase obtained by the addition of aluminum more than %15 means the economic limit is usualy reached at this amount, however, higher percentages can still be cost effective when drilling cost are extremely high. XII Because the aluminum is acting as a fuel, other fuels added to the mixture, such as fuel oil, must be reduced to maintain maximum energy out put. Figure 2. Illustrades the percentage of fuel oil required in anfo at various levels of aluminum addition to maintain maximum energy out put. Figure 1. How the addition of aluminum anfo increases the energy out put of the explosive on an equal weight basis. 6 5 0s» O 3 £ 2 Granule Al (%) Figure 2. Percent fuel oil by required to obtain maximum energy output in Anfo at various levels of aluminum addition XIII Fuel grade aluminum must meet certain specifications to be reactive, specifications for aluminum used in blasting agents are; General a) b) c) Size : %100 minus 18 plus 150 mesh. A maximum of %1.5 minus 150 mesh can be tolerated if the ideal specifications is not met. Purity : %90 plus aluminum. Magnesium content must be less than %0.5 for slurries and water gels. Flow : The aluminum addition should be free flowing for a bulk truck application. The size of the aluminum particules is important because particles larger than 20 mesh tend to react slowly, not releasing all their energy, while particles smaller than 150 mesh are a dust explosion hazard. Aluminum purity is more important in slurries and emulsions than in dry mixtures. Impurities in the aluminum can introduce the possibility of galvanic action, causing pH changes in the slurry and there by breaking down the slurry gel. The addition of aluminum to ammonium nitrade based explosives not only increases the energy out put but also influences the velocity of detonation, pressures and temperatures generated and volume of gas produced ( Figure 3.). Many explosive products contain aluminum in their formulation or can have aluminum incorporated in to their compositions. Anfo is currently the most extensively used bulk explosive product, and the use of aluminum to increase its energy out put is very common worldwide. DETONATION PtfSSSutlr: -İS22îVO£DEIONAriON 10 15 20 25 PfflCrNI Al UMINUM ADDITION 30 Figure 3. The influence of increased aluminum addition to anfo on the ideal velocity of detonation, detonation pressure, detonation tempereture, volume of gas produced and bulk densitiy. xiv In part four, granule Al which has been utilized as long as in test blasting was introduced. Some of them are : Particle size (0-1.25) mm ( close to 16 mesh/down) FloWability fine granules less 75 microns. Free flowing granules because of a low percentage of Transportation : A nondangerous cargo without any transport restrictions. In part five, termodinamic properties of anfo and granule AI+ANFO which is calorific values, temperature and specific energy values of the gazes released from anfo and granule AI+ANFO mixtures were calculated according to termodinamic laws. The results of these were showed as tables and graphics In part six, the explosion speed of different granule AI+ANFO mixtures were showed. It was found a big difference in the pressure of shock waves calculated from explosion speeds. We can see that pressure of shock waves are decrease according to increase ratio of the granule Al in the granule AI+ANFO mixture(Figure 4.). 10 Granule Al (%) Figure 4. Shock Waves Pressure According to Granule Al xv In part seven, test blastings which has been blasted to learn the effect of the granule AI mixtures on rock fragmentation were reported. As a result, granule Al effects rock fragmentation. If granule AI+ANFO mixture was prepared well (oksigen balanced), maximum fragmentation is obtained at granule AI+ANFO mixture including %15 granule Al. At the end, a blasting cost analysis was made. Granule AI+ANFO has %40 less cost than anfo.