Accession Number:

ADA288783

Title:

Hazard Evaluation on ANFO Charges.

Descriptive Note:

Project officer's rept. 16 Jun-31 Dec 93,

Corporate Author:

NEW MEXICO UNIV ALBUQUERQUE BUREAU OF ENGINEERING RESEARCH

Personal Author(s):

• Olson, Doug
• Banks, Marvin

Report Date:

1994-12-01

Pagination or Media Count:

54.0

Abstract:

The purpose of this work was to determine the potential thermal hazards from self-heating of large ANFO charges. To accomplish this objective, the thermal stability of ANFO was determined from measurements of the critical temperature at three sample sizes 40 mg, 25 g, and 25 kg. The effective thermal conductivity of solid ANFO at density 0.85 gcm3 was measured as 0.11 Wm K using a specific heat value of 1.5 Jg K. The cook-off data were used to determine the decomposition rate coefficient from 168 to 297 deg C-a range covering over five decades in reaction rate. The resulting Anhenius rate constant expression was determined. These data were compared with previous studies on ANfuel mixtures. The Experimentally-determined ANFO parameters were incorporated into two models to investigate the potential for thermal runaway of 2,400 and 4,800 ton charges. Overall, the work reported here showed ANFO to be a highly thermally stable energetic material, suitable for use in large conventional explosive charges. The data measured in this work allow predictions of minimum thermal runaway conditions for ANFO charges of various sizes and for various initial conditions. If the initial temperature

Descriptors:

• *THERMAL PROPERTIES
• *HAZARDS
• *HIGH EXPLOSIVES
• TEST AND EVALUATION
• MATERIALS
• REACTION TIME
• EXPLOSIVE CHARGES
• RATES
• THERMAL STABILITY
• CRITICAL TEMPERATURE
• COEFFICIENTS
• THERMAL CONDUCTIVITY
• ENERGETIC PROPERTIES
• DECOMPOSITION
• COOK OFF
• SPECIFIC HEAT

Subject Categories:

• Ammunition and Explosives
• Thermodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE