We are all too familiar with the destructive power of ammonium nitrate when mixed with gasoline or diesel fuel. At the same time we know it as a common fertilizer needed to ensure good agriculture yields. Is there a way to neutralize the stuff so that people like Timothy McVeigh (the Oklahoma City bomber) and the Tsarnaev brothers who last week killed 3 in Boston and maimed over 200, can’t improvise explosives that kill?
Well it turns out that folks at Sandia National Laboratories in Albuquerque, New Mexico, have come up with a revised formula for a fertilizer that works well with plants but fizzles as a bomb ingredient. Sandia has no intentions of applying for a patent on their new formula and plans to make it widely available to manufacturers.
Although ammonium nitrate is outlawed in theaters of war like Afghanistan because of its bomb making properties, it does get smuggled into the country from neighbouring Pakistan. As a result, in 2012 approximately 1,900 American troops were wounded or killed by improvised explosive devices like the one being detonated in the picture below.
So the motivation to find a new formula for chemical fertilizer is there. What the researchers did is add a compound to the ammonium nitrate to change it at the molecular level. The compound that works best is iron sulfate. The iron ion grabs the nitrate and the ammonia is attracted to the sulfate. The result is ammonium sulfate and iron nitrate. Both even when mixed with a fuel like gasoline or diesel will not blow up.
And the iron sulfate is good for the soil as well, particularly alkaline soils like those found in dry climate zones. The iron also gets taken up by the plants and infuses them with iron which improves the health of those who consume the crops.
The new formula is no more expensive to produce than the old one. Current producers of ammonium nitrate fertilizer can switch over to the new formula. If they do then fewer will die from fertilizer bombs, and more will live because an improved formula will increase crop yields.
Hard to argue with the potential of these results.
Imagine how many lives would have been saved in West, the town in Texas that experienced the fertilizer factory explosion on April 17 which left a crater 30 meters (93 feet) wide and 3 meters (10 feet) deep, if the ammonium nitrate had been treated with iron sulfate. With more than 250,000 kilograms (540,000 pounds) of ammonium nitrate on site, investigators are speculating that the existence of another chemical at the facility, anhydrous ammonia, could have contributed to the explosion.