Rounded Explosive Particles with Low Shock Sensitivity

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Solution Overview

Problem

Existing methods for producing explosive particles result in high sensitivity to shock, especially for larger particles, and often introduce internal defects and high viscosity issues in formulations, making them difficult to use effectively in cast formulations.

Innovation Solution

A process involving controlled cooling of a saturated solution without seeding to reduce internal defects, followed by crystalline growth to maintain supersaturation and shape modification through mechanical erosion and partial dissolving to create rounded, defect-free particles with a low volume fraction of closed pores, dissociating shock sensitivity from particle size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If particles of very small sizes (0-10 μm) are used to reduce shock sensitivity, then shock sensitivity is reduced, but viscosity of the mixture increases making casting difficult

Engineering Contradiction:

Improveshock sensitivityVSAvoidcasting ease

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The invention changes the physical-chemical parameters of the explosive particles by controlling crystallization conditions (temperature, solvent composition, cooling rate) to produce particles with specific surface characteristics and internal structure that reduce shock sensitivity without requiring extremely small sizes

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates local quality differences within particles by controlling crystal growth patterns and internal structure during crystallization, producing particles with dense cores and controlled surface properties that simultaneously reduce sensitivity and maintain castability

Inventive Principle:

Principle #3Local quality

2Ease of operation

If particles of large sizes (>100 μm) are used to reduce mixture viscosity, then casting ease is improved, but shock sensitivity increases

Engineering Contradiction:

Improvecasting easeVSAvoidshock sensitivity

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The invention changes the physical-chemical parameters of large particles through controlled crystallization to produce particles with internal structures and surface properties that reduce shock sensitivity, allowing large particle sizes to be used without increased sensitivity risk

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If conventional crystallization processes are used to control particle size, then size control is achieved, but internal defects and solvent inclusions increase leading to high shock sensitivity

Engineering Contradiction:

Improveparticle size controlVSAvoidshock sensitivity

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The invention performs preliminary action by carefully controlling nucleation conditions and using controlled cooling rates to prevent the formation of internal defects and solvent inclusions before they can form, resulting in particles with high internal quality

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention maintains continuous controlled cooling throughout the crystallization process to ensure uniform crystal growth without interruption, preventing the formation of defects that would occur with batch cooling or temperature fluctuations

Inventive Principle:

Principle #20Continuity of useful action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The process produces explosive particles with significantly reduced shock sensitivity, independent of size, facilitating easier use and reducing the risk of explosion, while maintaining high performance and safety.

Implementation Method 1

a step of crystallizing particles suitable for reducing populations of internal defects in particles

Methodology Applied

Scientific EffectCrystallization: Crystallisation

Implementation Method 2

maintain supersaturation

Methodology Applied

Scientific EffectSupersaturation: Supersaturation

Implementation Method 3

According to another characteristic that also allows a reduction in the sensitivity of these particles to shock, the particles are rounded in shape

Methodology Applied

Scientific EffectStress distribution:

Data Source

PatentUS8747581B2Particles of an explosive of low sensitivity to shock and associated treatment process

Publication Date: 2014.06.10 INSTITUT FRANCO ALLEMAND DE RES & DEVS DE SAINT LOUIS

AI summary

The invention relates to the field of explosives, and more particularly relates to particles of an explosive, wherein they are in crystalline form, have a rounded shape and a majority of them contain no internal defect. Particles of an explosive in crystalline form include a volume fraction of closed pores of less than or equal to 0.05%. A method for preparing explosive particles includes preparing crystalline particles, a majority of which are without an internal defect; and rounding the crystalline particles.