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Industries & applications / Secondary breaking in quarries / Secondary reduction of oversize boulders

Secondary reduction of oversize boulders

Whenever blasted rock is too big to be handled by loading equipment or fed through the crusher, secondary reduction is required.

HB 3600
Even with the most advance blasting techniques, it is inevitable that there will be oversize boulders, and these need to be broken as economically as possible.

Atlas Copco hydraulic breakers can be used to reduce boulders in the rock pile or on the primary crusher. Mounting the secondary reduction breaker on a mobile carrier provides a flexible unit with can be used at several points in the quarry.

Breaking performance depends largely on the operator. The more experienced the operator, the higher the productivity.

The diagram shows guideline figures which can be achieved using hydraulic breakers for secondary reduction.

The characteristics of the rock – brittle or tough – have a major influence on reduction performance. Brittle rock types can be more easily broken by hydraulic breaker than tough types. For majority of secondary reduction applications, blunt tools have proven most effective. The table lists examples of rock types.

Open table
Secondary reduction performanceExamples of rock type
HighShell limestone, sandstone, slate, gneiss, marble
AverageLimestone, dolomite, greywacke
LowLava, porphyry, basalt, granite
The figures are based on performance achieved in practical operations.

For more information about Hydraulic breakers in mining applications, go to Atlas Copco Print shop and search for reference 3390 0513 01