There is a backlog of scrap from both active and closed ranges and training areas that have not yet been cleared that will have to be removed in the future. Although the total mass of residual energetics materials remaining on range scrap is likely to be small, there is a potential risk for explosion during recycling or other processing of the scrap. A low-cost, safe, and environmentally benign process to treat energetics residues in-situ on scrap materials found on training/testing ranges is needed as an alternative to conventional recycling measures such as blast furnace melting.
The alternative process relies on mild, base hydrolysis of energetics at ambient temperatures in a lime-water solution. The technical objectives of this project were the following:
- Determine lime solution parameters that increase the speed of solid energetics dissolution and degradation;
- Determine lime solution parameters that provide maximum yield of polymers from degraded energetics;
- Establish an optimum treatment formulation and laboratory-scale procedure for treating energetics residues on scrap material; and
- Perform a preliminary cost analysis of the optimized treatment approach.
Range scrap was soaked in tanks containing either acetone or aqueous solutions of agricultural lime. Organic high explosives (HE) were degraded to non-hazardous inorganic ions and insoluble polymers that could then be readily recovered from the aqueous solution by sedimentation or filtration. Formation of insoluble polymers that can be collected as solids is an effective means to minimize the volume of waste produced from large volumes of contaminated scrap and to facilitate waste handling.
Energetic material was successfully removed from scrap munition through the use of either an acetone or a SuperSolve™/limewater soak over a period of one to two days. This work has established the feasibility for rapid and effective treatment of a variety of critical energetics residues on military range scrap. The technology is an exceptionally low-cost alternative to other approaches and is suitable for implementation at Department of Defense and Department of Energy sites.
The project established the feasibility for cost-effective treatment of a variety of critical energetics residues on range scrap using a lime-water formulation. The need for segregating scrap with visible signs of energetics residues or hidden recesses and treating it with unexploded ordnance could be eliminated by simply treating all scrap in the lime-water tanks. To ensure that HE and degradation products are within specifications for discharge or treatment, simple field colorimetric, conductivity, and ion-selective electrode measurements can be performed on-site with samples pulled from the tank(s).