Gel Stemming Material for Blast Hole Pressure Control

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Solution Overview

Problem

Conventional stemming methods using aggregates or control plugs in the mining industry often fail to consistently control explosive blasts, leading to inconsistent rock breaking, safety issues, and increased downstream processing costs due to the ejection of stemming devices and subsequent re-blasting requirements.

Innovation Solution

A method involving the use of a gel-type substance, created by transforming water into a gel using Super Absorbent Polymers (SAPs), which is pumped into blast holes to form a gelled column above the explosive charge, reflecting pressure waves and exerting hydrostatic pressure to control blast gases and reduce detonation pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional stemming devices (aggregates or control plugs) are used in blast holes, then stemming operation is simple, but blasting consistency deteriorates and safety issues arise

Engineering Contradiction:
Improvestemming operation simplicityVSAvoidblasting consistency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the physical state of the stemming material from solid (aggregates or control plugs) to gel (semi-solid). This parameter change provides continuous material that can adapt to the blast hole geometry and maintain consistent stemming pressure, eliminating the inconsistency associated with discrete control plugs while retaining operational simplicity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite material system consisting of gel material that may include water, polymers, and other additives. This composite gel formulation provides both the simplicity of a single-phase material for easy insertion and the reliability of engineered properties for consistent blasting performance.

Inventive Principle:
Principle #40Composite materials

2Productivity

If control plugs are used to control blasting, then explosive efficiency may be improved, but stemming devices are ejected causing safety issues and re-blasting requirements

Engineering Contradiction:
Improveexplosive efficiencyVSAvoidstemming device ejection
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the mechanical properties of the stemming material by using gel with specific viscosity and elasticity parameters. This allows the stemming material to contain the explosive force effectively (maintaining efficiency) while preventing ejection because the gel deforms and absorbs the pressure rather than being shattered and ejected like rigid control plugs.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The gel material acts as an intermediary between the explosive charge and the surrounding rock. It transmits the explosive energy uniformly to the rock while absorbing pressure spikes that would otherwise eject stemming material, thereby eliminating the safety hazard of ejection while maintaining blasting efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If gel type substance is used as stemming material, then blasting consistency and safety are improved, but device complexity increases

Engineering Contradiction:
Improveblasting consistencyVSAvoidstemming material complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The gel stemming material is designed to be self-setting and self-adjusting. Once inserted into the blast hole, the gel automatically adapts to the hole geometry and maintains its stemming function without requiring additional equipment or complex installation procedures. This self-service capability offsets the increased material complexity by simplifying the overall stemming process.

Inventive Principle:
Principle #25Self-service

4Ease of operation

If conventional stemming methods are used, then stemming operation is straightforward, but downstream processing costs increase due to inconsistent rock breaking

Engineering Contradiction:
Improvestemming operation straightforwardnessVSAvoiddownstream processing costs
Core Design Contradiction:
Ease of operationVSLoss of substance

Solution Approach 1:

The patent changes the stemming material parameters to achieve more uniform stress distribution during blasting. This results in more consistent rock fragmentation patterns that are better suited for downstream processing, reducing the need for additional crushing and sorting operations while maintaining operational straightforwardness.

Inventive Principle:
Principle #35Parameter changes

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 gel stemming system effectively reduces detonation pressure and velocity, enhances blast control, and allows for safer and more efficient blasting operations by reducing the need for explosive material and enabling easier access to unexploded charges, while also providing a cost-effective and environmentally friendly solution for managing waste water.

Implementation Method 1

providing a gel type substance as a gelled length in the blast hole to increase the efficiency of an explosive during blasting with the explosive being located in the blast hole

Methodology Applied
Scientific EffectPressure wave reflection: Reflection

Implementation Method 2

The gelled column of water fills a column of a desirable height above the explosive charge for the blasting conditions

Methodology Applied
Scientific EffectHydrostatic pressure: Pressure Increase

Data Source

PatentEP3011261B1Blasting systems and methods
Publication Date: 2019.01.02 PARK ALLEN
  • EP3011261B1 patent drawingFigure 1
  • EP3011261B1 patent drawingFigure 2
  • EP3011261B1 patent drawingFigure 3

AI summary

In one preferred form of the present invention there is provided a method of stemming a blast hole with a super absorbent polymer. The method includes providing a super absorbent polymer substance as a gelled length in the blast hole. The gelled length provides a pressure wave reflecting stem, to increase the efficiency of an explosive during blasting, with the explosive being located in the blast hole.