Our Mining Method


                                                        

 Mining Methods 

 Below is a typical example of a mining method used to excavate Bentonite from a farm in the Kinderwys block.

 Securing the mining rights lead to the mining activities that commenced on August,12th 2011.

 The area has been classified as the best Bentonite development in the Southern hemisphere.

 Due to the uniqueness and the thickness of the clay at this location, an area of 4900 square meters was identified for the new mining area. We estimate that  approximately 27 200 tons (16 000 cubic meters) of Bentonite will be produced from the first 4.5 meters.

 Equipment Used

 – Hitachi Zaxis 400 LCH Hydraulic Excavator

 – 3 x 10m³ Dump Trucks

 We employ the services of a subcontractor who provides the necessary equipment. The operators are well trained and excavations and loading the dump trucks  are done at optimum efficiency.

 An excavator and 3 dump trucks conduct the open cast mining operation.

Site Preparation

A conveniently located stock piling area approximately 200m from the mining site (quarry) was scraped with a scraper.

The different layers of Bentonite mined are stockpiled here by the dump trucks from where it will eventually be transported to the customers premises.

Soil

Removal of +/- 600mm of overburden

The excavator carefully removes and stockpiles the dark and grey overburden of 600mm separately until the first grey bentonite is exposed. This is called the first commercial zone suitable for the sealing slimes dump floor and for the A.M.D activities and the first sale able collection of bentonite mined.

Excavation

Excavation of +/- 1m greyish clay

The Mining of Bentonite on Mooiplaats

After the overburden has been removed by the excavator, the fist zone of grey bentonite (average layer thickness of 1m) is mined. Each dump truck carries approximately 10 cubic meters of bentonite. A competent driver of the excavator is of vital importance as he has to have the ability to distinguish and excavate the different layers of bentonite separately. This ensures that the different zones are stockpiled correctly.

Excavated

Yellow clay of +/- 2m excavated

The second zone is distinctly yellow in colour. The layer is on average 2m thick (total depth of 3.6m from surface including overburden). Once again, this zone gets stockpiled individually.

Safety has to be considered with open cast mining and the different depths of mining is clearly visible from the ‘steps’ created by the excavator. This minimizes the risk of injury and the collapse of the side walls in the quarry.

Excavation Green Clay

Excavation of +/- 1m greenish grey clay

The third layer has a greenish grey colour with an average thickness of 1m (second and third zone) referred to as the ‘Main Zone’, followed by the fourth zone (yellow with increased brightness) with a thickness of 2.8 meters.

Stockpiling

Stockpiling

Loading Dump Truck

Excavator loading dump truck

Safety Steps

Safety steps and evacuation

Excavator and Dump Truck

Excavator and dump trucks in operation

Rehab Process

Rehabilitation in process (backfilling method)

 

Logistics

Chemical toilets
Portable diesel cart
Portable fresh water cart (500 litres)
Container for housing
4 Operators
2 Site supervisors
Staff welfare (food operators)
1 Project manager
Total mining and rehab days used = 40 days
Summary of excavations and loading capacities

Excavator: 1 scoop = 2 cubic meters
Dump Trucks: capacity of 5 scoops (10 cubic meters = 16 tons)
Loads Per Hour: 8 (80 cubic meters per truck per hour)
1 Dump Truck Per 9 Hour Day: 720 cubic meters (1152 tons with SG of 1,6)
Total Tons Per Day For Three Trucks: 3456 tons

 

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