Gamsberg Zinc – Design to Implementation

Location & Client

Aggeneys, Northern Cape, South Africa

Vedanta – Black Mountain Mining

Mining Method

Open pit truck and shovel and Underground Sub Level Caving

Study Accuracy

PFS (+15% -25%) and DFS (+5% -10%)

V-Cut and North Access Ramp Design

Introduction

ABGM was requested by Black Mountain Mining Pty Ltd (“BMM”) to undertake LOM scheduling and capital and operating cost estimations for their Gamsberg Zinc Open Pit Project.

In 2014 BMM intended to establish the new Gamsberg zinc mine, ore beneficiation plant and associated infrastructure near the town of Aggeneys, Northern Cape Province, South Africa. Gamsberg is located between the towns of Aggeneys and Pofadder, approximately 120 km east of Springbok, along the N14 highway. The proposed site is characterized by an oval shaped Inselberg approximately 220 meters above the surrounding plains.

The Gamsberg deposit is a low grade deposit with average zinc content of 6% Zinc associated with deleterious Manganese. Lead is an associated metal and may be of economic value. ABGM in conjunction with TCE (Tata Consulting Engineers) completed a techno economic PFS and then DFS accuracy study at +5%-10% during the 3rd quarter of 2014 for the Gamsberg Zinc Project.

Challenge

Finding an effective mining strategy to ensure low mining costs are achieved throughout the LOM. Due to the nature of the deposit within the Inselberg, access is restricted and a new ramp or roadway had to be constructed to facilitate ore transportation to the plant.

Solution

ABGM in conjunction with the mining team of BMM further developed and refined the V-Cut concept to facilitate reducing the amount of tramming and thereby reducing the overall cost per tonne. ABGM completed a detailed design of the V-Cut and also of the North access ramp that connects with the V-Cut which allowed ore to be transported to the plant more economically.

The V-Cut and north access ramp designed was successfully implemented in 2016 and are currently seen on-site and online.