Design

Gold Fields Granny Smith Mine.

Introduction

Gold Fields Australia is part of the global Gold Fields group, a globally diversified gold producer with nine operating mines in Australia (including the Gruyere JV), Peru, South Africa and West Africa (including the Asanko JV), and a joint venture project in Canada and another in Chile.

Our four Australian mines – Agnew, St Ives, Granny Smith and Gruyere– are located in the Goldfields region of Western Australia where nearly 4,000 people are employed on a residential and fly-in, fly-out basis.

To reduce underground secondary fan power consumption, Gold Fields Australia decided to trial a 260kW 1000V VVVF Drive Fan Starter with a twin stage 110kW fan. The 6-month trial was implemented at Gold Fields Granny Smith mine located in Western Australia, operating on an isolated power system, to gather sufficient data to evaluate potential realised savings, with a view to return or purchase the 260kW 1000V VVVF Drive Fan Starter.

SMEC Power & Technology supplied and commissioned on site, a 260kW 1000V VVVF Magnetek GP1000-E Drive in a custom-built enclosure, complete with on board PLC remote accessibility and an independent PC to remotely access the Magnetek’s VVVF Drive G7 control board which allowed for drive parameter monitoring and changes to be carried out remotely.

The TLT Turbo Air twin 110kW fan and 1000V VVVF Drive were installed on both development declines and inclines during mid-summer when intake temperatures were at their highest during the year.

The 260kW 1000V VVVF Fan Starter is a standalone enclosure design – utilising a closed loop liquid cooling system, negating the requirement for expensive dedicated air-conditioned container rooms.

Outcome

Over the six-month trial the realised power saving averaged at 30 % with individual months achieving powers savings around 50 %. The realised savings exceeded Gold Fields expectations and the decision was made to purchase the 1000V VVVF Drive, at an agreed cost, and to place future orders for the Magnetek GP1000-E VVVF Drive, to allow Gold Fields to enjoy ongoing increased power savings.

Custom Built, standalone, Enclosure designed for harsh underground applications.

Magnetek 260kW GP1000-E 1000V VVVF Drive, being tested and commissioned prior to delivery to Gold Fields Australia.

1000V VVVF Drive enclosure c/w with an Inline Reactor, Tuned harmonic filter and DC Bus choke as standard features.

Component cooling is via a closed loop, maintenance free, liquid to air cooling system.

Grydale is a global leader in dust control solutions, operating in multiple countries.

Grydale hold international patients for manufacturing the only self-propelled, track mounted, mobile dust collector on the market. The mobile dust collectors boast world class operating efficiency, along with regulated air volume using a variable speed drive (VSD). Air flow is controlled via a velocity probe – regulating a VSD can result in a 40 % reduction in power consumption.

Grydale approached SMEC Power & Technology in 2019 to provide a custom-built enclosure to suit their dust collecting rigs utilising a 1000V variable speed drive, enclosure design was required to operate in extreme dusty and harsh environments throughout the Sydney tunnelling projects.

SMEC Power & Technology designed a custom enclosure, utilising forced cooling keeping the enclosure positively pressurised to negate dust entry and offering a high degree of enclosure cooling and IP rating.

The Magnetek GP1000-E 1000V VVVF  260kW and 450kW drives were utilised for this project.

Over the last 4 years SMEC Power & Technology have supplied Grydale multiple 450kW & 260kW Magnetek GP1000-E 1000V Drives in custom built enclosures, providing continuous operation today throughout the Sydney tunnelling projects.

Magnetek 450kW GP1000-E 1000V VVVF drive controlling 450kW motor & centrifugal fan to regulate air flow via velocity probe.

Magnetek 450kW GP1000-E 1000V drive with inbuilt line reactor, tuned harmonic filter, DC bus choke and forced cooling – installed on the JMS-60 M series dust collectors.

SMEC Power & Technology underground division, Southern Mining Electrical Contractors recently completed the manufacture & supply of our Underground 11kV 2MVA 1000V Substations for the recently opened Khoemacau Copper project in Botswana.

Working with the team at Khoemacau Copper, SMEC designed a project specific specification for the substations utilising industry leading components from ABB and in-house fabrication to ensure a long-term asset solution for the project.

Safety & production are a high priority and Southern Mining Electrical Contractors continues to work with high demand mining clients who require quality electrical products. Through innovative engineering, SMEC provides Remote Operating HV solutions with every Underground Substation that we manufacture.

Providing complete mining electrical services, Southern Mining Electrical, design, manufacture and install underground electrical substations, starter panels and switch boards that will ensure your project mining production schedules are maintained by maximum electrical uptime.

Khoemacau Copper Project in Botswana, Southern Africa.

Scope: Supply of underground substations, underground starter panels and underground

Switch boards for underground mine set up.

Client Name: Khoemacau Copper

Location: Botswana, Africa

Start Date: March 2020

Khoemacau, is in Botswana’s prospective Kalahari copper belt. It holds an overall sulphide resource of 502 tonnes at 1.4% copper and 17 grams of silver a tonne. This project comprises of three underground mines generating around 1.2 million tonnes during the initial five years of operations.