2013 INSENSITIVE MUNITIONS AND ENERGETIC MATERIALS TECHNOLOGY SYMPOSIUM
October 2013
Reclamation and Reformulation of TATB from PBX-9502 and LX-17
Dr. Jacob Morris*
R&D Synthesis Manager
jacob.morris@baesystems.com
BAE Systems; OSI
Holston Army Ammunition Plant
Kingsport, TN 37660
423-914-9960
Mr. Crane Robinson
US Army PDJS
Picatinny, NJ 07806
Mr. Tim Mahoney
US Navy NAWCWD
China Lake, CA 93555
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Abstract
The insensitive explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) is a critical ingredient in a number
of different DoD and DoE booster and fuze weapon assemblies including US nuclear warheads. Since
1993, no domestic manufacturing source has existed within the US for this explosive, causing the
strategic stockpile to dwindle. A joint DoD/DoE initiative was created to restore US TATB manufacturing
capabilities, with BAE Systems at the Holston Army Ammunition Plant (HSAAP) downselected as the
contractor of choice.
Considering the amount of time that is required to develop a synthesis process and scale it up to
production quantities, including facilitization, it was proposed that an alternate source of TATB be
developed to bridge the gap until newly produced TATB comes online. A process was developed by the
team at HSAAP to recover TATB from DoE explosives and reuse this TATB in existing DoD weapons
applications. This reclaimed TATB will potentially be utilized in a number of applications even after the
new Benziger TATB becomes available due to its low cost. The alternate source proposed and evaluated
in this program comes from recovery of TATB from surplus PBX-9502 and LX-17 explosives. Both of these
formulations contain TATB coated with Kel-F 800 polymer binder.
This paper describes the development and optimization of the lab- and production-scale reclamation of
TATB from PBX-9502 and LX-17 at HSAAP, as well as the successful reformulation of the reclaimed
material into PBXN-7 and W-14, meeting all of the Mil-Spec requirements. Once final qualification has
been completed, this program will provide an additional CONUS source of TATB through the recovery
from LX-17 and PBX-9502. The TATB will support a number of DOD defense applications at reduced cost
from newly procured material.
Background
A joint DoD/DoE initiative was created to restore US TATB manufacturing capabilities, with BAE Systems
at the Holston Army Ammunition Plant (HSAAP) downselected as the contractor of choice. Considering
the amount of time that is required to develop a synthesis process and scale it up to production
quantities, including facilitization, it was proposed that an alternate source of TATB be developed to
bridge the gap until newly produced TATB comes online. A process was developed by the team at
HSAAP to recover TATB from DoE explosives and reuse this TATB in existing DoD weapons applications.
This reclaimed TATB will potentially be utilized in a number of applications even after the new Benziger
TATB becomes available due to its low cost.
The alternate source evaluated in this program comes from recovery of TATB from surplus PBX-9502
and LX-17 explosives. Both of these formulations contain TATB coated with Kel-F 800 polymer binder.
PBX-9502 contains 95% TATB and 5% Kel-F 800 binder whereas LX-17 contains 92.5% TATB and 7.5% KelF 800 binder along with a red dye to help differentiate it from PBX-9502. The two products are shown
below in Figure 1.
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Figure 1: PBX-9502 and LX-17
Program Overview and Results
This program had three phases: lab-scale reclamation development, TATB reclamation and
reformulation prove-out, and production-scale TATB reclamation and reformulation. The three phases
are described below:
Phase 1: Lab-Scale Reclamation Development
In the first phase of effort, the TATB recovery parameters developed and optimized on the lab-scale. A
3-L still was used for this effort (Figure 2). The process parameters for reclamation that were
investigated as part of this effort included solvent type, temperature, solvent:PBX ratio, and extraction
time. The key measurements for analyzing the reclaimed TATB included particle size and residual Kel-F
800 binder. The particle size was determined by Malvern laser diffraction. The residual Kel-F 800 binder
percentage was determined by combusting the TATB in a Parr bomb and measuring the residual
fluoride.
Figure 2: TATB Reclamation in 3-L Still
The TATB reclamation process was found to be very solvent dependant for the amount of residual
binder. A number of different solvent systems was studied, with clear differences seen in the binder
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removal ability between solvent systems. The particle size of the reclaimed TATB was a consistent size
for each of the input materials under all reaction conditions. Virgin Benziger-type TATB has a
monomodal distribution with an average particle size of 50-60 µm (Figure 3). The TATB reclaimed from
PBX-9502 had a bimodal distribution with an average particle size of 15-20 µm (Figure 4). The TATB
reclaimed from LX-17 had a monomodal distribution with an average particles size of 11-12 µm (Figure
5). As is shown, the reclaimed TATB has a smaller particle size than the virgin Benziger-type TATB. This
attrition of crystals is indicative of the TATB crystals being fractured during the processing and pressing
of the PBX formulation. The TATB from the LX-17 is smaller than the TATB from the PBX-9502 because it
comes from a softer crystal (wet-aminated TATB).
Figure 3: Virgin TATB
Figure 4: Reclaimed TATB from PBX-9502
Figure 5: Reclaimed TATB from LX-17
Upon completion of Phase I, the data was assessed by the Joint TATB team with a decision made to
proceed forward and reclaim TATB on the kilogram scale in order to be able to reformulate the material.
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Phase 2: TATB Reclamation Scale-Up and Reformulation
In Phase 2 of the program, the optimized reclamation parameters were scaled-up in the laboratory to
the kilogram scale. Two 1-kg samples of TATB were reclaimed at this scale from both PBX-9502 and LX17 using an 18-L still (Figure 6). The reclaimed TATB had a particle size and residual binder amount
(<0.5%) that was similar to the Phase I effort.
Figure 6: Phase II TATB Reclamation
The reclaimed TATB was then reformulated into PBXN-7 and PBXW-14 using standard Holston
laboratory equipment and procedures. A total of four samples were produced: 1 kg of PBXN-7 from both
PBX-9502 and LX-17 TATB as well as 1 kg of PBXW-14 from both PBX-9502 and LX-17 TATB. The
formulations processed the exact same as when virgin Benziger TATB was used despite its smaller size.
All four batches passed the standard Mil-Spec testing, including composition, granulation, bulk density,
pressed density, impact, and VTS. A picture of PBXN-7 using reclaimed TATB is shown next to PBXN-7
from virgin Benziger-type TATB is shown below in Figure 7. The two samples are indistinguishable.
Figure 7: PBXN-7 Formulation
PBXN-7 from Benziger TATB
PBXN-7 from Reclaimed TATB
Small scale gap testing (SSGT) was performed on PBXN-7 using reclaimed TATB to compare relative
performance with PBXN-7 made with Benziger TATB. This testing by performed at Reynolds Systems Inc.
Due to the limited amount of shots available, the testing was performed at -60 oC in order to provide
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worst-case shock initiation data. It was found that the difference in shock sensitivity was less than 1%,
which is well within lot-to-lot variation. This implies the shock initiation characteristics of both PBXN-7
samples are the same and would perform in initiation systems with the same degree of reliability.
The data from the SSGT was reviewed by the Joint DOD/DOE team along with the other spec testing
results of the PBXN-7 and PBXW-14. A decision was made at this point to move forward with the
program to Phase III, which was full production scale reclamation and reformulation of the TATB.
Phase 3: TATB Reclamation and Reformulation in Production
The TATB reclamation process was scaled to the Agile Manufacturing Facility at HSAAP (G-10), with the
reclamation performed in a 6,000 gallon still. TATB was reclaimed from both PBX-9502 (8,000 lbs) and
LX-17 (6,500 lbs) in high yield. The solvent used to remove the binder was distilled between batches and
reused with no loss or effect on binder removal. The TATB reclamation process flow is shown below in
Figure 8.
Figure 8: TATB Reclamation in Production
A total of 7,000 lbs of TATB was recovered from PBX-9502 (3 Batches) as well as 5,200 lbs of TATB from
LX-17 (3 Batches). The TATB particle size and residual binder amount was the same as the lab-scale
effort. The reclaimed TATB was also tested by the new military specification including: purity analysis by
HPLC and GC, Chlorine content by ion chromatography, particle shape by SEM, safety data (impact,
friction, ESD), and thermal analysis (DSC and VTS). The collection of the reclaimed TATB from the plateand frame-filter press is shown below in Figure 9.
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Figure 9: Reclaimed TATB
PBXN-7 and PBXW-14 was formulated using the reclaimed TATB a standard formulation production
building for these products. The batches were produced using a 500-gallon vacuum still. For PBXW-14
1,500 lbs of material was produced (3 batches) using both PBX-9502 TATB and LX-17 TATB. For PBXN-7,
1,500 lbs of material was produced (3 batches) using only TATB reclaimed from PBX-9502. The
reformulated PBXN-7 and PBXW-14 underwent standard material qualification including normal
acceptance testing and initial first article testing. The bulk density, granulation, and pressed density
were excellent for all of the batches, despite the smaller size of the TATB. The PBXN-7 and PBXW-14 was
then sent to the DoD for further evaluation and formal qualification including 6-month aging and coldtemperature small-scale gap test evaluation. The formulated and pressed PBXW-14 is shown below in
Figure 10.
Figure 10: PBXW-14 with Reclaimed TATB
Conclusion
The process for reclaiming TATB from PBX-9502 and LX-17 was initially developed and optimized on the
lab-scale at HSAAP. After testing out the process on the kilogram scale, the process was then scaled to
full-scale production. The developed reclamation process was optimized to use existing infrastructure at
HSAAP. The reclaimed TATB was formulated into PBXN-7 and PBXW-14 on the production scale, again
using existing procedures and infrastructure. BAE Systems and DOD conducted full qualification testing
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on both materials. Reclaimed TATB is available and can be provided at a reduced cost compared to
Benziger TATB. DOD customers have already expressed interest for some applications.
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