Integrating drilling, blasting, load and haul, materials handling and rehabilitation can improve productivity, cost control and operational efficiency at opencast mines, says contract mining company Zizwe Opencast Mining social responsibility and strategic development director Andre Pruis.

The role of contract miners is increasingly extending beyond providing equipment and people, to taking responsibility for defined production outcomes, safety, environmental execution, cost control and local participation, he adds.

Mining companies want flexible access to specialist skills and fleets, while cost inflation, variable commodity markets and increasingly complex deposits, as well as tighter regulatory and environmental requirements, are increasing the demands on contractors.

An integrated opencast operation starts with translating the geological model, mine plan and production targets into an executable plan covering site establishment, access and haul roads, water and stormwater controls, drilling, blasting, waste stripping, ore mining, load and haul operations, run-of-mine management, crushing, screening and materials handling activities.

“The principal benefit is alignment,” Pruis adds.

Meanwhile, the interconnected nature of these activities means that decisions made at one stage of the operation can have a direct effect on downstream productivity.

Drill and blast design, for example, affects fragmentation, which, in turn, influences loading rates, equipment wear, crushing performance and the cost of every tonne of material handled.

Coordinating these activities enables an opencast operation to optimise the full value chain, rather than one activity at the expense of another, says Pruis, adding that it can also reduce handover delays by better linking mine planning, production, maintenance and rehabilitation.

Opencast mining productivity starts with converting life-of-mine and yearly plans into practical monthly, weekly and shift targets that reflect actual geology, haul distances, road conditions, loading units, truck payloads, maintenance capacity and operating hours.

“Fleet optimisation involves matching loading and hauling systems to the material, bench geometry and haul profile. Factors such as payload, queue and spotting time, cycle time, equipment availability, idle time, fuel burn and tyre performance can help identify the causes of lost production,” he elaborates.

Telematics, survey data, production dashboards and maintenance alerts can also help identify bottlenecks and exceptions earlier. Zizwe combines original equipment manufacturer telematics and machine health information with production, fuel, maintenance, survey and planning data where client and equipment systems permit.

Pruis adds that technology should support operational decisions with accurate data, clear ownership of corrective actions and regular reviews to turn information into safer and more productive shifts.

Managing Pressures

Contract miners are also facing pressure from fuel volatility, exchange-rate exposure on equipment and parts, long lead times, tyre and component costs, skills shortages and wage escalation, acknowledges Pruis.

Ageing fleets can increase maintenance and downtime risks while project delays or changes in scope can leave equipment underused, he notes.

Pruis says contractors can manage these pressures with appropriate equipment selection, payload compliance, road-condition management, idle time control, operator coaching, preventive maintenance and component-life planning without compromising on safety-critical expenditure.

“Forward planning for critical spares and strong original equipment manufacturer relationships can also help reduce avoidable downtime.”



Pruis confirms that Zizwe plans to strengthen its South African base while pursuing selective growth in Southern Africa, particularly in Botswana and Namibia.

As a result, the company is evaluating opportunities across coal, chrome, hard-rock and selected critical and precious mineral projects where its opencast, underground, materials handling, crushing and screening, and rehabilitation capabilities can add value.

“Our aim is not expansion for its own sake. We want to build a diversified project portfolio in which Zizwe can provide an integrated solution, improve production reliability and create lasting local value,” he concludes.