Research on Industrial Explosives Detonation Performance Testing Standards and Quality Management Systems

I. Theoretical Basis of Industrial Explosives Detonation Performance Testing

1. Relationship Between Detonation Performance and Blasting Efficiency

The detonation performance of industrial explosives determines their effectiveness in practical blasting operations. The energy released during an explosion manifests through several mechanisms such as rock fragmentation, medium compression and deformation, and shock wave propagation. The proportion of these energy forms directly affects both the economic efficiency and engineering quality of blasting operations.

The total useful work generated by an explosion is referred to as total work, which corresponds to the part of the total reaction energy that contributes to engineering tasks, known as work capacity. To fully utilize explosive energy, blasting design must select appropriate charging methods and explosive types according to rock mass characteristics.

2. Classification of Industrial Explosives and Performance Variations

Industrial explosives include powdery ANFO, emulsion explosives, and water-gel explosives. Significant differences exist among these types in terms of detonation characteristics, application scope, and safety properties. Based on density and velocity-of-detonation (VOD) measurements, industrial explosives exhibit a wide performance range:

• Low-VOD explosives:

Porous granular ANFO: VOD 2,500–3,300 m/s, density 0.90–0.95 g/cm³

• Medium-VOD explosives:

Expanded ammonium nitrate explosives: VOD 3,200–3,800 m/s, density 0.95–1.20 g/cm³

• High-VOD explosives:

Rock powdered emulsion explosives: VOD 4,000–4,400 m/s, density 1.05–1.25 g/cm³

Different formulations have a strong influence on detonation performance.

II. Testing Methods and Standards for Key Performance Indicators

1. Density and Moisture Content Measurement

Density and moisture are fundamental parameters influencing explosive detonation behavior.

Industrial explosives typically involve two density definitions:

1. Cartridge density: Includes packaging; determined using direct measurement or graduated cylinder methods.

2. Explosive density: True density excluding packaging; measured using density cups or weight–volume methods.

Moisture content directly affects stability during storage and use. Common methods include:

Vacuum oven method (operated at 65–70 °C and vacuum ≥0.8 MPa), and Moisture meter method (operated based on azeotropic distillation).

2. Measurement of Toxic Gases After Explosion

According to GB 18098, the concentrations of toxic gases (CO and NOx) produced after detonation must be assessed due to their impact on health and the environment. The test procedure is as follows:

110 g of explosive is detonated inside a test chamber; after cooling to room temperature, total gas volume and composition are measured. To account for toxicity, NO₂ is converted to CO-equivalent based on relative toxicity due to the cor-relationship between both.

Oxygen balance is a key factor. If Negative oxygen balance occurs, higher CO will be generated, and if positive oxygen balance occurs, more NOx will be generated.

This is critical for environmental evaluation and formula optimization.

3. Compatibility and Safety Assessment

Compatibility refers to the stability between explosive components and between the explosive and packaging materials, which can be divided into:

1. Internal compatibility: Between components within the explosive
2. External compatibility: Between the explosive and materials it contacts (e.g., metal casings, packaging films)

Poor compatibility may reduce stability, lower the explosion point, alter mechanical or initiation sensitivity, or corrode the packaging. Standard evaluation methods include:

• Vacuum stability test (mercury manometer) —- test the amount of gas released

• Differential thermal analysis (DTA) —-examine thermal decomposition characteristics

• Differential scanning calorimetry (DSC) —- measure exothermic reaction

• Gas chromatography (GC) —- analyze the product of decomposition

• Metal corrosion testing —- evaluate the corrosiveness to metals

III. Inspection Standards in the Quality Management System

1. Physicochemical Testing System

Physicochemical testing serves as the “eyes” of quality control, covering raw materials, intermediates, and finished products.

Key indicators include:

1. Density measurement: Directly related to VOD and work capacity
2. Moisture measurement: Must remain within specified limits (e.g., 0.08–0.12% for expanded AN explosives)
3. Component analysis: Verifies raw material ratios comply with formulation requirements

2. Standardized Detonation Performance Testing

Industrial explosives are evaluated across multiple performance dimensions using standardized testing methods such as the lead cast expansion test method and the ballistic mortar test method

Each method has defined acceptance criteria and forms a complete performance evaluation system to ensure consistency and reliability of product quality.

IV. Role of Standardized Management in Blasting Safety

Standardization provides scientific technical norms for civilian blasting operations. By establishing unified testing standards, quality indicators, and management procedures, the industry can:

1. Ensure stable performance within the same explosive product category

2. Provide accurate parameters for blasting design

3. Enable performance benchmarking across different suppliers

4. Supply a scientific basis for blasting safety evaluation

Frequently Asked Questions (FAQ)

Q: Why differentiate between cartridge density and explosive density?

A: Cartridge density includes packaging and is relevant to logistics and product delivery. Explosive density reflects the true detonation performance and is used for engineering design. Distinguishing the two enables accurate evaluation of actual blast energy.

Q: What factors influence the amount of toxic gases after detonation?

A: Primarily the explosive’s oxygen balance.

• Negative oxygen balance → higher CO

• Positive oxygen balance → higher NOx

Appropriate formulation design can effectively reduce toxic gas generation.

Q: What are the consequences of poor compatibility?

A: Decreased chemical stability, lower explosion point, increased sensitivity, potential decomposition during storage, heat release, and even self-ignition or accidental explosion.

Q: Why must test conditions be specified when measuring VOD?

A: VOD is affected by charge diameter, density, initiation method, and confinement. Without specifying conditions, performance comparisons become inaccurate.