This is what tim mcveigh used to bomb the oklahoma fbi building. It is your classic diesel fuel explosive or diesel oil explosive
For useless information he says the diesel oil is a catalyst that allows the ammonium nitrate to explode. he says ammonium nitrate is a high explosive by its self.
| Chemical |
Parts by weight |
Parts by Volume |
| diesel fuel or diesel oil |
1 | 1 |
| ammonium nitrate | 3 | 4 |
Also my friend says this explosive is much more powerfull then the fuel oil, or diesel fuel explosive mix. Even on top of that this mixture is more stable and easier to handle.
| Chemical | Parts by Volume |
| ammonium nitrate | 70% |
| powdered aluminum | 15% |
| Bulls eye Pistol Powder | 10% |
| carbon black | 5% |
Carbon black is not carbon. It is made from the incomplete combustion of matural gas or petroleum oil and used in making rubber and ink.
http://todo_todo.tripod.com/news/anfo.htmlhas some interesting info about ANFO which is a big word
Ammonium Nitrate Fuel Oil Explosives
These are a few other sites that deal with the subject:
http://www.cdc.gov/niosh/mining/pubs/pdfs/faafp.pdf
http://www.google.com/search?q=cache:7ilQMF5ZQKIC:www.cdc.gov/niosh/mining/pubs/pdfs/faafp.pdf+%22anfo%22&hl=en&ie=UTF-8 --------------------------------------------------------------------------------
Page 1 FACTORS AFFECTING ANFO FUMES PRODUCTIONJames H. Rowland III and Richard MainieroABSTRACTFor many years there have been small scale tests available for evaluating the toxic fumes production by cap-sensitive explosives (DOT Class 1.1), but these could not be used with blasting agents due to the large chargesizes and heavy confinement required for proper detonation. Considering the extensive use of blasting agentsin construction and mining, there is a need to determine the quantities of toxic fumes generated by blastingagents. At the International Society of Explosive Engineers Twenty Third Annual Conference on Explosivesand Blasting Technique in 1997, the authors reported on a facility for detonating large (4.54 kg), confinedblasting agent charges in a controlled volume that had been constructed at the National Institute forOccupational Safety and Health's Pittsburgh Research Lab's Experimental Mine. Since 1997, this facilityhas been used to collect data on toxic fumes produced by the detonation of various ammonium nitrate/fueloil (ANFO) mixtures and several cap-sensitive explosives. ANFO composition ranging from 1 to 10 percent (pct) fuel oil have been studied. As expected from previousstudies, with an increase in fuel oil content the carbon monoxide production increases, while nitric oxide andnitrogen dioxide production decrease. The detonation velocity varies from 3,000 to 4,000 m/sec for the 1to 10 pct range of fuel oil content, suggesting that ANFO mixes with improper fuel oil content may appearto detonate properly, while their fume production differs significantly from optimum. The study alsoconsiders such factors as degree of confinement, water contamination, and aluminum content on blastingagent fume production. Results indicate that water contamination of the ANFO has little effect on carbonmonoxide production, but causes significant increase in nitric oxide and nitrogen dioxide production.Decreasing confinement from Schedule 80 steel pipe to 0.4-mm thick sheet metal also has little effect oncarbon monoxide production, but significantly increases nitric oxide and nitrogen dioxide production. Adding5 and 10 pct aluminum to the ANFO had no clear effect on carbon monoxide, nitric oxide, or nitrogendioxide production. --------------------------------------------------------------------------------
Page 2 INTRODUCTIONIn February of 1997 a paper entitled "A Technique for Measuring Toxic Gases Produced by Blasting Agents"was presented at the 23rdAnnual Conference on Explosives & Blasting Technique in Las Vegas, Nevada.That paper discussed a method for measuring toxic fumes produced by detonation of blasting agents. Theresearch reported here is a continuation of that work.Detonating ANFO in steel pipe in the Pittsburgh Research Lab (PRL) mine fumes chamber yields a baselinefor comparing relative fumes production for blasting agents, but is by no means a predictor of what willhappen in the field. In actual blasting operations, the confinement of the detonating ANFO will probably beless than that offered by the 4-in, Schedule 80 steel pipe employed in most tests. Additionally the ANFOevaluated in the PRL mine chamber is carefully mixed the day before and care is taken to preventcontamination. In practice, ANFO may not be exactly the 94/6 ammonium nitrate/fuel oil ratio desired ormay be loaded into boreholes weeks before it is shot, exposing the explosive to water seeping into loadedboreholes and possible fuel oil evaporation. The current research looks at these factors and others in an effortto determine how they affect fumes production. Fumes measurements in the mine chamber were carried outfor ANFO mixtures other than 94/6, ANFO contaminated with up to 10 pct water, ANFO detonated withless confinement than that offered by Schedule 80 steel pipe, and ANFO contaminated with limestone rockdust. Additionally, several cap-sensitive explosives, as well as ANFO containing up to10 pct aluminum werealso studied to gain an understanding of how detonation behavior affects fumes production. In each casecarbon monoxide, nitrogen oxides, and ammonia were the toxic gases of primary interest.EXPERIMENTAL APPROACHDetonating large blasting agent charges and confining the fumes requires a larger experimental chamber thanwas employed in past work on cap-sensitive explosives. Towards this end, a chamber was created in theexperimental mine at PRL. The facility consists of a portion of mine entry enclosed between two explosionproof bulkheads. Each bulkhead is 40 inches (1 m) thick, constructed of solid concrete block hitched 1 foot(30 cm) into the roof, ribs, and floor. On the intake side, the bulkhead is fitted with a submarine mandoor anda small port for control and sampling lines. On the return side, the bulkhead is fitted with two sealedventilation ports. Total volume of the chamber is 9,666 ft3(274 m3). The chamber volume was determinedby releasing a known quantity of carbon monoxide into the chamber and sampling the atmosphere after it hadmixed. Following the shot, a fan mounted at one end of the chamber mixes the chamber atmosphere at 3,500ft3/min, after which the chamber is vented using the mine's airflow. The layout of the chamber is illustratedin Figure 1. Up to 10 pound (4.54 kg) charges can be detonated in the chamber using a variety ofconfinements.EXPERIMENTALA 28-inch (71-cm) length of 4-inch (20-cm) Schedule 80 seamless steel pipe was chosen to provideconfinement in most tests of blasting agents and cap-sensitive explosives. Prior to loading the pipe withexplosive, a continuous velocity probe of the type described by Santis is taped to the inner surface of the pipealong its length1. In conducting a test of a blasting agent, the commercial blasting agent minus its wrapper,or premixed ANFO are loaded into the pipe to a weight of 10 lb (4.54 kg). Initiation is provided by a 2-inch(5-cm) diameter, 2-inch (5-cm) thick cast pentolite booster, initiated by a number 8 instantaneous electric --------------------------------------------------------------------------------
Page 3 1Reference to Specific products is for informational purposes and does not imply endorsement by NIOSH.blasting cap. In conducting a test of a cap-sensitive explosive, the cartridge explosive is loaded into the pipeto a weight of about 10 lb (4.54 kg). Cap-sensitive explosives are initiated by a number 8 instantaneouselectric blasting cap. Following detonation of an explosive in the chamber, the fan is run for about 10 minutes to uniformly mixthe chamber atmosphere before fumes samples are taken out of the chamber through 1/4-inch (0.6-cm) Teflonor polyethylene tubes for analysis. Teflon sample lines are used for nitrogen oxides and ammonia to minimizeloss of these constituents to absorption on the tube surface. Vacutainer1samples are taken and sent to theanalytical laboratory for analysis; this technique is appropriate for components that are stable in theVacutainer, namely hydrogen, carbon monoxide, and carbon dioxide. Nitrogen dioxide, nitrogen oxides, andammonia are not amenable to analysis by the Vacutainer technique and are instead absorbed in chemicalsolutions in bubbler trains using the technique described by Santis2. That method was modified by eliminatingthe purging of the system with helium and using a gas meter to measure the volume of fumes bubbled throughthe solutions rather than measuring gas flow rate. An electrochemical carbon monoxide monitor was alsoemployed to act as a backup to the analytical lab's carbon monoxide analysis of the Vacutainer and to allowmonitoring of the mixing of the chamber atmosphere. RESULTSAn ANFO mixture of 94 pct ammonium nitrate, 6 pct fuel oil is close to optimum from the perspective ofminimum toxic fumes production. Previous research and theory show that the detonating ANFO willproduce excessive levels of nitrogen oxides if the fuel oil content is too low and will produce excessivelevels of carbon monoxide and ammonia if the fuel oil content is too high.3,4,5This behavior is supportedby data collected in the current research, as illustrated in Figures 2, 3, and 4.In Figure 5 the data from figures 2, 3, and 4 is presented in terms of oxygen balance. Figure 5 is a plot ofcarbon monoxide production versus oxygen balance for ANFO and several cap-sensitive explosives. Asthe oxygen balance is increased for ANFO the carbon monoxide production decreases. This would beexpected since there is increasing oxygen to convert the carbon monoxide to carbon dioxide. ANFOmixed at 6 pct fuel oil produces approximately the same amount of carbon monoxide as cap-sensitiveexplosives of equivalent oxygen balance. The opposite is true when looking at nitrogen oxidesproduction as a function of oxygen balance, as illustrated in Figure 6. When the oxygen balance isincreased, the nitrogen oxides and nitrogen dioxide production increased. ANFO mixed at 6 pct fuel oilproduced significantly more nitrogen oxides and nitrogen dioxide than cap-sensitive explosives. Figure7 illustrates that as the oxygen balance for ANFO is increased the ammonia production decreases. Withthe exception of a couple data points that may be anomalous, ANFO mixed at 6 pct fuel oil producedabout the same quantity of ammonia as cap-sensitive explosives of equivalent oxygen balance.Figure 8 shows that adding water to an ANFO mixture of 94 pct ammonium nitrate and 6 pct fuel oil hadlittle effect on carbon monoxide production for water percentages from 0 to 10 pct. However thenitrogen oxides and nitrogen dioxide increased dramatically when water is added to the ANFO mixture.This is demonstrated in Figure 9. Figure 10 shows the effect of water on ammonia fumes production;adding water to the ANFO yields an erratic trend, indicating that further study is needed. --------------------------------------------------------------------------------
Page 4 As mentioned earlier, shooting ANFO in 4-inch schedule 80 seamless steel pipe is probably much moreconfinement than seen in the field. To examine the effect of reduced confinement on fumes production,ANFO was tested in sheet metal and PVC pipe. As seen in Figure 11, reduced confinement doesn't havemuch effect on carbon monoxide production. Carbon monoxide production for ANFO shot in the PVCpipe was much higher than that for the steel or sheet metal pipe. The high carbon monoxide might beattributed to burning of the PVC pipe. The degree to which the PVC pipe reacted was not studied indetail, but it is safe to assume that at least some of the PVC burned during the ANFO detonation. Thehigh carbon monoxide production would be consistent with the earlier observation that the higher thefuel content of the explosive, the higher the carbon monoxide production. Explosive packaging is an important consideration relative to toxic fumes production. For example, ablast pattern may contain a number of boreholes that are contaminated with water and the blaster maydecide to insert sleeves into the boreholes contaminated with water to keep the ANFO dry. If the sleevesare made of a combustible material they could add to the carbon monoxide production. Figure 12shows that the production of nitrogen oxides and nitrogen dioxide increases dramatically with lowerconfinement, while Figure 13 shows that with less confinement ammonia decreases.Limestonerock dust (approximately 73 pct through 200 mesh) was added to the ANFO mixture tosimulate drill cuttings being mixed with the ANFO as it was loaded into a borehole. The rock dust hadlittle effect on the carbon monoxide production, as illustrated in Figure 14. Figure 15 shows that theaddition of the rock dust led to an increase in nitrogen oxides production and a decrease in nitrogendioxide production. Since the nitrogen oxides consist essentially of nitric oxide and nitrogen dioxide, thisindicates that nitric oxide production increased significantly. Figure 16 shows that adding rock dust tothe ANFO caused a significant increase in ammonia production .Aluminum is sometimes added to ANFO to increase the velocity and the output energy. Figure 14illustrates that the aluminum added to the ANFO mixture has little effect on the production of carbonmonoxide. From Figure 15 it is not clear whether or not the nitrogen oxides and nitrogen dioxideproduction is affected by the added aluminum. The ammonia increased with the added aluminum, asillustrated in figure 16. It should be noted that the addition of aluminum had no clear effect on theANFO's detonation velocity. The aluminum added to the ANFO mixture was Fine Aluminum PaintPigment Powder, Alcoa # 422 flake.This type was used to give the fastest possible burning rate forexperimental purposes. For commercial explosives, the lowest and least expensive grade of aluminum istypically used, consisting of ground scrap aluminum of various particle sizes.DISCUSSIONSeveral factors that may effect the fumes production of ANFO have been investigated. Probably theeasiest to control is the fuel oil content. To minimize toxic fumes production , the ANFO should bemixed at 6 pct fuel oil. Deviating from the 6 pct will lead to excessive fumes. Water contamination maynot have an affect on carbon monoxide production, but it increases the production of nitrogen oxides andnitrogen dioxide. At the present time in our research it is not clear how the production of ammonia isaffected. The confinement of ANFO doesn't appear to make a difference in the production of carbonmonoxide, but it makes a difference in the production of nitrogen oxides , nitrogen dioxide, and ammonia. --------------------------------------------------------------------------------
Page 5 1. Santis, L. D. and R. A. Cortese, A Method of Measuring Continuous Detonation Rates UsingOff-the-Shelf Items, Proceedings of the Twenty-Second Annual Conference on Explosives andBlasting Technique, Orlando, FL, February 4-8, 1996.2. Santis, L. D., J. H. Rowland, III, D. J. Viscusi, and M. H. Weslowski, The Large ChamberTest for Toxic Fumes Analysis for Permissible Explosives, Proceedings of the Twenty-FirstAnnual Conference on Explosives and Blasting Technique, Nashville, TN, February 5-9, 1995.3. Mainiero, R.J., A Technique for Measuring Toxic Gases Produced by Blasting Agents,Proceedings of the Twenty Third Annual Conference on Explosives and Blasting Technique, LasVegas, NV, February 2-5, 1997.4. Blaster's Handbook, Sixteenth Edition, E.I. du Pont de Nemours and Company, 1977, p. 59.5. Explosives and Rock Blasting, Atlas Powder Company, 1987, p. 25-27.In the case of nitrogen oxides and nitrogen dioxide the fumes production will increase, while theammonia fumes production will decrease.Adding aluminum or rock dust to ANFO does not affect the fumes production of carbon monoxide. Theaddition of aluminum does not have a significant affect on nitrogen oxides and nitrogen dioxideproduction, but the addition of rock dust leads to an increased production of nitrogen oxides. Additionally, the rock dust appears to have an effect on the ratio of nitric oxide to nitrogen dioxide. Theaddition of aluminum and rock dust increased the production of ammonia. The effect of rock dust onfume production was based on limited data and requires further study to look at the effect of particle sizeand dust type.Its important to understand that the data reported here applies only to the test conditions under which thedata was collected. For example, the schedule 80 steel pipe may provide more confinement than manyfield blasts. The research reported here shows that the confinement will affect the quantity of toxicfumes produced. In the field the toxic fumes released from a blast will differ significantly from the datareported here. There is a need to collect data from the field to develop an understanding of how datafrom the PRL fumes chamber compare to fumes production in the field. This, in return, will help indeveloping improved tests for evaluating fumes production. --------------------------------------------------------------------------------
Page 6 Figure 1. Research was conducted in a chamber created in the underground mineat the Pittsburgh Research Lab.Figure 2.Effect of ANFO fuel oil content on carbon monoxide production. In all figures,the line is a polynomial fit to the data; it is included for illustrative purposes and does notrepresent a fit of theoretical results. --------------------------------------------------------------------------------
Page 7 Figure 4.Effect of ANFO fuel oil content on ammonia production.Figure 3.Effect of ANFO fuel oil content on nitrogen oxides and nitrogen dioxideproduction. --------------------------------------------------------------------------------
Page 8 Figure 5.Effect of Oxygen Balance on carbon monoxide production for 94/6 ANFO andhigh explosives (cap-sensitive explosives).Figure 6.Effect of Oxygen Balance on nitrogen oxides and nitrogen dioxide productionfor 94/6 ANFO and high explosives (cap-sensitive explosives). --------------------------------------------------------------------------------
Page 9 Figure 7.Effect of Oxygen Balance on ammonia production for 94/6 ANFO and highexplosives (cap-sensitive explosives).Figure 8.Effect of ANFO water content on carbon monoxide productionfor a 94/6 mix. --------------------------------------------------------------------------------
Page 10 Figure 9.Effect of 94/6 ANFO water content on nitrogen oxides andnitrogen dioxide production.Figure 10.Effect of 94/6 ANFO water content on ammonia production.Figure 11.Effect of 94/6 ANFO confinement on carbon monoxideproduction. --------------------------------------------------------------------------------
Page 11 Figure 12.Effect of 94/6 ANFO confinement on nitrogen oxides andnitrogen dioxide production.Figure 13.Effect of 94/6 ANFO confinement on ammonia production.Figure 14.Effect of aluminum and rock dust content on carbonmonoxide production. --------------------------------------------------------------------------------
Page 12 Figure 15.Effect of aluminum and rock dust content on nitrogenoxides and nitrogen dioxide production.Figure 16.Effect of aluminum or rock dust content on ammoniaproduction.