South Africa’s largest diamond producer, the opencast Venetia operation, in Limpopo province, is on track to produce three-million carats before year-end, shrugging off the impact of the flooding of the pit earlier this year.

De Deers Consolidated Mines (DBCM) CEO Phillip Barton said the mine had come through “the big dry” after being set back by a one-in-200-year flood event earlier this year.

Venetia, in the north-east corner of South Africa, near Musina, consists of 12 kimberlite pipes and is currently mining two of the largest pipes in a single, opencast operation.

DBCM’s total South African third-quarter production grew 9% year-on-year to 1.36- million carats, which includes output from DBCM’s two remaining mines, Voorspoed, in the Free State, and the Kimberley surface operations, in the Northern Cape.

Mining Weekly watched from the pit side last week as overburden was removed from the Venetia openpit’s Cut Four, which will be mined out in 18 months.

At that point, stripping will move to the southern portion of the pit, where only opportunistic activity is currently under way.

The Cut 3 portion of the K1 orebody, which is at a level of 330 m below surface, will be mined to 450 m below surface, representing another eight years of mining before the new Venetia underground project begins accessing the same orebody from the bottom.

The K2 orebody is currently 250 m below surface and will be mined down to 350 m below surface.

“Those two orebodies are the future of the mine,” DBCM Venetia GM Ludwig von Maltitz explained to Mining Weekly from the viewing platform overlooking the activities.

The opencast mine is operating with seven 600 t shovels that take four passes to load the huge trucks that carry payloads of between 180 and 225 t.

Venetia’s 26 large trucks are to be fitted with lighter bowls, allowing the vehicles to carry 4 t more load and use 6% less fuel.

The 13 smaller trucks, which are close to the end of their lives, will not be subjected to any change.

New shovels will be introduced and old ones retired as pit mining ends in 2018.

Barton said R600-million had already been spent on the Venetia underground project, where President Jacob Zuma, Anglo American plc chairperson Sir John Parker and Anglo American CEO Mark Cutifani this week turned the first sod.

In all, the underground project will absorb an investment of R20-billion, the biggest single investment in diamonds in decades, which demonstrates investor confidence in South Africa.

Opencast mining will continue to 2021 and the conversion to underground mining will extend the life of the mine to 2046.

So far, shaft terraces and decline portals have been built, electricity laid on and long-lead items ordered.

The underground mining is expected to take the output to 4.5-million carats a year, which represents the average yearly production from the openpit.

It will feature the latest technologies and future technologies and continue to employ 1 300 people for the next 20 years.

“It’s a fantastic orebody and the grades continue at depth,” Barton said.

Venetia is located near the spectacular 36 000 ha Venetia Limpopo Nature Reserve, where the company is involved in a variety of ecological conservation activities, including the relocation of plants and animals affected by mining activities.