Modern Quarrying Q1 2019

AT THE QUARRY FACE

Bell articulated haulers tip directly injto the primary Osborn 47x60 jaw crusher.

About 35% of Eikenhof’s total sales go into AfriSam’s own readymix plant located on site.

Velapi Vilakazi, maintenance superintendent at Eikenhof quarry.

Innovative haul road design is key to safety on site.

material better than the previous one,” says Mgxekwa. Following the design interventions, jaw crusher life has been extended from the previous five years to an 8-10 year lifecycle. Mgxekwa says the manner in which Osborn has cooperated with the AfriSam team at Eikenhof to respond to the andersite rock challenge has already set a blueprint for other operations with comparable drawbacks. The quarry recently hosted a delegation of visitors from Indonesia who came to witness the equipment and operational solutions that have been implemented at Eikenhof to get the better of the tough rock. The Indonesian delegation also operates a quarry with the same rock formation. Another key operational challenge is that the overburden material at Eikenhof contains a lot of clay, and cannot be used as a base material for road construction. Consequently, the spoil ratio at the quarry is very high. Mgxekwa reasons that spoil costs a lot of money. However, in a rare deal, the quarry recently supplied 18 000 t of overburden material to a customer who wanted fill material containing a mixture of rock and clay. When tested, the Eikenhof overburden material worked out wonders for the particular customer. Quality matters Eikenhof generally recovers the unusable overburden costs through its high qual- ity material. Despite its large spoil ratio, the quarry remains one of the largest in the country, with a capacity to produce 800 000 t/year. When we visited the site

Yedwa Christopher Mgxekwa, works manager at Eikenhof quarry.

The previous crusher also suffered frequent flywheel breaks, translating into unwanted downtime. “To get the better of this setback, we no longer use a spoke-type flywheel in our primary jaw crusher. We have since migrated to a dis- type flywheel, which handles the

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MODERN QUARRYING QUARTER 1 - 2019