Break Analyzer Tutorials for Underground Ring Blasting Operations

Welcome to the AEGIS Break Analyzer Tutorials

Operational Guide

AEGIS Break Analyzer - What It Is And What It Does

iRing INC has developed a new technique for analyzing/diagnosing blasting patterns based on a stress reflection principle and a unit charge blasting geometry.  In addition to five analytical blasting calculators, there is one main Blast Design workflow. The intent of providing these tools to underground blasting operations is to allow engineers and planners the ability to see the effect of explosive types, rock/ore parameters and stress generation on ring blasting as well as discovering how varying specific parameters and properties of both explosives and rock/ore types influence blast pattern design.

AEGIS Break Analyzer Objective

AEGIS Break Analyzer is designed to benchmark current blasting practices as well as provide insight into new patterns and practices. Based on dynamic explosive properties and dynamic rock properties, Break Analyzer matches the explosive detonation state (shock - brisance) and explosion state (gas expansion - heave) energies in order to maximize ore recoveries and minimize dilution. As a consequence, target fragmentation is optimized for haulage equipment and potentially minimizing (or eliminating) primary crusher requirements and/or reducing the associated costs.
Aegis Break Analyzer is used on the premise that current blasting operations can be improved through careful control of the application of explosive energy distributed throughout an orebody to provide maximum recovery with absolute minimum dilution. The objective is to recover ALL the ore and LEAVE the support rock.

AEGIS Break Analyzer as an Information and Training Tool

In mining and more specifically regarding day to day operations dealing with blasting and blast design, the focus is to get things right the first time without having to go through an experimental phase searching for what works best. This is pretty much a standard across the board for mining methods including development, open stope, sublevel cave, block caving, vertical retreat mining and Alimak.
More attention is being placed addressing the myriad geometries presented by complicated orebody shapes and grades. AEGIS Break Analyzer software has been specifically designed to enable many ‘what-if’ scenarios to be tested and applied to complex orebodies in seconds to find perfect ring layouts optimized for highest recovery at the lowest cost.  
Break Analyzer is a tool that will provide underground drill and blast engineers and planners with the ability to appraise the effects of different explosive and rock combinations along with shock decay used in designing blasting patterns. It is based on a stress reflection principle as well as an hyperbolic break model. This is a new innovative approach developed using a novel physical model comprising both explosive and rock property components and is called a 'unit charge'.
The unit charge allows traditional two-dimensional models to be extended into three dimensions providing a base for improved accuracies regarding powder factor, energy factors and hyperbolic break and break angle. Hyperbolic break appears to be a much more realistic methodology addressing blasting geometries compared to traditional rectangular and radial break models. Break Analyzer has been developed using comprehensive field testing involving actual field data as part of its evolution.
Model parameters include:
  • Explosive detonation velocity charge diameter curves along with corresponding energies that are measured and curve fitted using AEGIS CurveFit ©.
  • Rock properties using P wave and S wave values that have been computed from field testing using two different orientations (N|S, E|W)
  • Impulse loading from explosives on blasthole walls to obtain shock wave reflection from free faces through a burden distance
  • Shock wave attenuation from blasthole wall to a rock/ore mass for the purpose of determining site factors for ore bodies
Even though AEGIS Break Analyzer utilizes sophisticated mathematical and physical models, the interface is very easy to use. For the Blast Design Workflow, a step-by-step process is used that guides the engineer along each stage in the process. Using each calculated solution will help direct the engineer in deciding which blasting pattern to use for varying or changing situations underground.
Break Analyzer also includes a number of supplementary calculators that can be used to perform very specific calculations or for exploring different parts of the model. Final results using the workflow are presented in a table of statistical results, a sample of which is presented here.
Sample statistical results from the Blast Design Workflow for version above as shown.
Statistical results using the new gauge control Evaluation Table for Blast Design. This presentation is much easier to read and tends to provide an intuitive interface in which to alter input values of blast design parameters.

Use the AEGIS Break Design Workflow to Develop Precision Blasting Operations that May Allow a Blasting Operation to Become a Primary Crusher

The installation of an underground crusher station is a costly and labour intensive process. It involves the construction of a shaft with the crusher at the base of the shaft along with equipment that allows crushed material to descend from an ore pass to be delivered to the crusher through a stage of sizing gates. The first is a Ross Chain Feeder which slows the flow of broken material sized by a grizzly. The blasted ore enters the crusher, that may be of the following types -  cone, gyratory, jaw or other type.

The Possibility of Crusherless Mining in an Underground Mining Environment


There has been significant progress particularly with the development of  gold mines in which a second option for crushing is beginning to attract attention. In order to ensure the profitability of a mine, the focus has been on crushing. If a mine can remove the costs associated with the construction of an underground crusher station as well as infrastructure and optimize blasting operations in such a way as to use the blasting operation itself as a primary crusher, the cost savings would be substantial. Ore passes would not be required since mucking would tram directly to surface (most suitable for shallow mines).

Installation Costs

The installation of a crusher accounts for a significant portion of the capital input required to bring a crusher into operation. This is due to the large amounts of support required to accommodate both geotechnical problems over the course of mine life as well as to resist its own internal forces. The physical installation process is also labour intensive, involving the deconstruction on surface, part by part hoisting and reconstruction in place. Generally, installation can exceed six times the cost of the crusher itself (de la Vergne, 2003) Queen's U.

Other Costs

The above approximation does not account for the many other accessory components that may be required over the course of a mine’s operation, most specifically the motor. In the case of Jaw Crushers, the cost of the motor is generally negligible compared with the cost of the crusher itself due to the significantly smaller power requirements (Infomine, 2008)(Mullar, 1998). Gyratory crushers require larger motors to account for their greater throughput, the cost of which cannot be neglected. Similar methods to those shown above exist for the costing of motors but motor type must also be chosen according to specific operating requirements. Generally large horsepower motors can range up to a million dollars, but considerable variation exists (Mullar, 1998). Queen's U.

Operating Costs

The primary operating costs of a crusher are parts and labour for maintenance, which can vary approximately twice as much as the power for the motor. Gyratory crushers generally cost less than $1500 per hour to run, while jaw crushers cost less than $200, including electricity (Infomine, 2008). Queen's U.

 Rules of Thumb

• A 42-inch gyratory crusher produces approximately 2.4 tons per horsepower-hour (2.9 t/kWh).
• When idling jaw crushers consume approximately 50% of the power of full operation and gyratory approximately 30%.
• Installation of an underground jaw crusher may cost up to six times as much as the crusher itself.
• A 48 by 60 jaw crusher produces approximately 1.8 tons per horsepower-hour (2.2 t/kWh) at a 6:1 reduction ratio. (de la Vergne, 2003) Queen's U.
The above drawing shows a general layout of an underground mine including shaft access, exploration and development. Note how an open pit mine as been constructed on the surface for ore that is accessible with underground working constructs for access to the underground part of the ore body. Queen's U.