Grade control
Grade control drilling in open pit mines
A tight pattern, a clean sample and a rate that holds on a continuous regime: grade control governs dilution, the tonnage sent to the plant and the margin of the site.
Grade control drilling means drilling a tight pattern of shallow holes, usually in reverse circulation, to define the actual ore grade ahead of blasting. It traces the boundary between waste and ore, feeds mine planning and directly governs dilution and plant recovery.
A grade control campaign is not judged on rig power but on the number of hours that rig produces a usable sample. Our organisation is built for that.
Production organisation
What we commit per rig
| Regime | 24 hours a day, 7 days a week, in 12-hour shifts; four crews per rig on a 4-days-on / 4-days-off cycle, giving 42 hours per week per person |
|---|---|
| Manning | 18 people per rig: site supervisor, drillers, offsiders, mechanics, electrician, welder and HSE officer |
| Maintenance | Senior mechanics, electrician and welder embedded in the shift, to repair on site |
| Logistics autonomy | Service trucks, light vehicles, air compression and water supply integrated into the drilling spread |
| Technical supervision | Geologists, surveyors and safety technicians mobilised as the programme requires |
| Supervision experience | More than twenty-five years of exploration drilling for our most senior supervisors, including diamond and gold programmes and deep holes beyond 900 metres |
Out of respect for our people's privacy, individual career histories are not published. Named curricula vitæ for the proposed crew are attached to each proposal.
Standards
Quality, safety and dust exposure
| ISO 9001:2015 | Written procedures, sample traceability, non-conformity handling |
|---|---|
| ISO 14001:2015 | Hydrocarbon and mud management, rehabilitation of drill pads |
| ISO 45001:2018 | Pre-task risk analysis, work permits, near-miss reporting |
| BS EN 16228 | Rotating part guarding and drill string interlock devices |
| Respirable crystalline silica | 50 µg/m³ eight-hour exposure limit: dust suppression, respiratory protection, crew rotation at the cyclone |
Elohim Drilling is not certified to these standards to date: they are the basis of our procedures, not an acquired title. We claim no certification we do not hold.
FAQ
Frequently asked questions about grade control drilling
What is grade control drilling in open pit mining?
Grade control drilling means drilling a tight pattern of shallow holes, usually in reverse circulation, to define the actual ore grade ahead of blasting. It traces the boundary between waste and ore, feeds mine planning, and directly governs dilution and plant recovery.
What shift regime does Elohim Drilling run on a grade control contract?
24 hours a day, 7 days a week, in 12-hour shifts, with four crews per rig on a 4-days-on / 4-days-off cycle, giving 42 hours per week per person. The reference manning is 18 people per rig: site supervisor, drillers, offsiders, mechanics, electrician, welder and HSE officer.
How is rig availability maintained far from any workshop?
Senior mechanics, an electrician and a welder are embedded in the shift, with service trucks, light vehicles, air compression and water supply integrated into the drilling spread. The aim is to repair on site rather than wait for a workshop several hundred kilometres away.
Will Elohim Drilling accept a contractual availability target?
Yes. A monthly measured rig availability target, a sample recovery and quality target, and a firm mobilisation deadline can be written into the contract with symmetrical penalties.
Which safety and quality standards are applied?
Field procedures are built on ISO 9001:2015, ISO 14001:2015, ISO 45001:2018, BS EN 16228 for rotating part guarding and drill string interlock, and on the 50 µg/m³ eight-hour exposure limit for respirable crystalline silica. Elohim Drilling is not certified to these standards to date: they are the basis of its procedures, not an acquired title.
A grade control programme to cover?
Pattern, average depth, monthly metreage and schedule: we price it and commit to a rate.