Energy Efficiency Processes and Measurement: Ausenco’s Perspective

Mike Daniel and Greg LaneEnergy Efficiency in Mining & Minerals

Increasing Energy Efficiency: Measure, Assess & Audit24 - 25 September, 2008

Introduction

A leading engineering and project management services provider to the resources industries

Delivers innovative solutions across the full project lifecycle,from preliminary scoping studies, through innovative engineering

and effective project management to project operation

Global Operations

The Ausenco SolutionAn established global reputation for the delivery of innovative solutions across the project lifecycle for mining industry from pit to port … the Ausenco Solution

Technical Solutions

Design and supervision of metallurgical test work programs

Feasibility study preparation

Process engineering

Engineering design

Capital & operating cost estimates

Project financial models

Engineering & Process

Innovative design

Efficient plant performance

Process, mechanical, civil / structural, electrical & instrumentation engineering

Multi-discipline

Project & Construction Management

Project management

Cost control

Scheduling

Procurement

Construction management

Commissioning

Operations & Management

Process plant operations

Plant start-up/ramp-up

Maintenance project management and evaluation

Laboratory Services

Training

OPERATIONS & MAINTENANCE

ENGINEERING, PROJECT &

CONSTRUCTION MANAGEMENT

FEASIBILITY STUDYPRE-FEASIBILITY STUDY

CONCEPTUAL STUDY

Understanding Energy Efficiency

Energy Efficiency is not only about “SAVING ENERGY”.

Energy Efficiency is not only about “MAKING MONEY”.

Energy Efficiency is about making use of finite energy resources in the best possible way.

Economic principles are still the driving mechanismsHuman progress and well being is still the quest.

?

?

Economies of scalehttp://www.fcx.com/inrl/annlrpt/2002-FCX-AR/operations%208-20.pdf

Understanding Energy Efficiency

“Energy speaking” at current rates of consumption will we be able to ensure sustained economic and social prosperity in the future ?

What can the mining industry do ?

Understanding Energy Efficiency

PART I Traditional practice: projects driven within monetary systems

Most activities are economically drivenSafety, environment, social, ecology all play vital roles

Current practice: projects getting more complexClimate change, GHG, Carbon trading ERU’s, Carbon taxes, energy costs Energy in engineering design – Where energy is used?.

PART II Future method includes monetary and energy accounting

Integrating energy and economicsExample

Product (t/hr)

Re-circulating load

Classifying cyclone

Ball Mill

SAG Mill

Primary Gyratory

20 MW

20 MW

Conventional Comminution circuits SABC (last 25 years)

What is Grinding Efficiency ?

A 10% improvement in energy efficiency

= 3% reduction in opex for small plants, and

= 5% reduction in opex for large concentratorsA 10% reduction in manning levels

= 5% reduction in opex for small plants, and

= 1% reduction in opex for large concentrators

Media for a large plant comprise 20% of operating costs

Grinding efficiency should be measured as a function of labour requirement to operate and maintain, as well as energy and consumables costs

SAG mill throughput and efficiency optimisation ongoing

•Charge motion

•Ball load

•Lifter design

•Grate size

•Pulp lifters

•Trommel size

SABC + pebble crusher option

Product (t/hr)

Re-circulating load

Classifying cyclone

Ball Mill

SAG Mill

Primary Gyratory

Pebble crusher

More energy

efficient ?

Comments on SAG Milling“energy and economically speaking”

SAB, SABC, ABC circuits are not often the most energy efficient solution

SAG circuits are relatively easy to operate and maintain and are often the lowest cost solution

Media costs are high

http://www.infomine.com/publications/docs/InternationalMining/Chadwick2007g.pdf

Finer grind driving up energy requirements

Ore’s are more competent “Hard rock” applications

Energy costs upMedia costs up

Bond Eqn. Exp. (fine grinding)

Matrix of Competency & Capacity

< 0.5 Mt/a 0.5 to 2 Mt/a 2 to 6 Mt/a > 6 Mt/a

Low Single stage SAG

Single stage SAG

Single stage SAG

SAB

Single stage AG,

Single stage AG,

SAB & ABC SAB & ABCSABC &

SABC Stage crush/HPGR/

ball mill

Competency Grinding Circuit Throughput

Moderate Single stage AG

ABC

High Two stage crush/ball

mill

Stage crush/ball

mill & SABC

Some Examples of Energy Efficiency

Project Circuit % of “Bond” Comment

Hellyer AG/BallSAG/Ball

125 %115 %

130 %

110 %100 %105 %

100 %

135 %100 %

Low/moderate competency, fine

grindCadia SABC Competent

Kambalda Rod/ballS.S. AG

Mod. competency

Macraes SAG/Ball Low Compet.

Forrestania AG/Pebble Mod. Compet.

Boddington (study)

SABCCrush/HPGR/Ball

Very high competency

Understanding Energy Efficiency

PART II Future method includes monetary and energy accounting

Integrating energy and economicsClimate change & GHGEnergy resources & Energy auditsEnergy Accounting: Emergy & EmdollarsApplication within comminution circuits – an example

Energy comes at great cost to our world and societies

Energy comes at great cost to our world and societies

Access to more data via the net

070125

World & Environment are synonymous

MINING is a Large Global business

Diesel oil consumption for Australia's mining industry

Electricity Natural gas Petrol Diesel LPG Black coalTWh TJ ML ML ML kt

Mining 14 52,126 36 2,124 29 377Total 137 378,576 4,469 9,711 1,115 4,205

% of total energy 10% 14% 1% 22% 3% 9%

Ref : 2005, Year book of Australian Statistics

Total electrical energy consumption for Australia's mining industry

Electricity Natural gas Petrol Diesel LPG Black coalTWh TJ ML ML ML kt

Mining 14 52,126 36 2,124 29 377Total 137 378,576 4,469 9,711 1,115 4,205

% of total energy 10% 14% 1% 22% 3% 9%

excludes power conversion losses

Ref : 2005, Year book of Australian Statistics

Forms of Energy

light chemical mechanical heat electric atomic sound

Chemical Energy (hydrocarbons)

World Energy Consumption

Chemical 85%

Chemical Energy (hydrocarbons)

World Energy Consumption

OIL 41%

GAS 22%

Coal 24%

An emerging global event“Peak OIL”

World Energy Consumption

OIL 41%

GAS 22%

Coal 24%Chemical

85%

“Dollar cost”=

= “Dollar cost”

≠ “Energy cost”

“Energy cost” vs “Dollar cost”

Real wealth is not measured by money alone.

Real wealth is what an item can do when it is used.

Accounts for environmental systems cannot be kept in dollars alone. These are based ecosystems, for which no money is paid.

Need an accounting system that determines the balance of real wealth in parallel with monetary accounting.

“EMERGY” a tool that links socioeconomics and environment

“Emergy” is a composite word of “embodied or embedded” and “energy”

Emergy addresses how much energy is embedded in a product (how much energy did it take to build the product)

It represents the “memory” of the energy within whole systems

Emdollars

SourcesSourcesEnvironmentalEnvironmentalProductionProduction

NonNon--renewablesrenewables

EconomicEconomicProductionProduction

Macroeconomic OverviewMacroeconomic Overview

AssetsAssets

ImportsImports

GNPGNP

FuelsFuelsGoods &Goods &ServicesServices

ExportsExports

$$

$$

The SAG Mill, still….

The King of Comminution devices

http://www.industry.siemens.com/broschueren/pdf/mining/simine/en/SIMINE_Completely_Integrated_Solutions_for_the_mining_industry_en.pdf

Process = 53% of total

Comminution circuit 1 SAG mill 1 pebble crusher 2 ball mills

Feasibility studies focus on “Dollar Cost”

72%

What is the “Dollar cost” of running mills?

PowerPower $42m pa $42m pa Cost per ton $2.03/tCost per ton $2.03/t

SteelSteel $27m pa$27m paCost per ton $1.3/tCost per ton $1.3/t

Can we reduce the energy footprint ?

Can we reduce these costs?

“ENERGY COST” of producing SAG and ball mill grinding media

1. How much Energy is consumed to make grinding media ?

Answer : 6000 kWh/tonneConsumption rate of 1 kg/tonne of milled ore6 kWh/t of “embedded energy” or “EMERGY”.

This represents 30-50% of the direct energy consumed by the mills

00.10.20.30.40.50.60.70.8

Moly-Cop/S

caw

China (Vari

ous)

Former

CIS (Var

ious)

Smorgon S

teelMag

otteau

x

North S

tar (Ger

dau)

Santa

AnaAlta

stee

lDelt

a stee

lMep

sa

Energy E

nginee

ring in

tl.

Border

Steel

Forjace

ro

Norcast

Castin

gOthers

Mill

ion

tonn

es

Global grinding media production 2.5 million 2500 kt

(Horsburgh, 2005)

Global grinding media production

Mining group grinding media consumption

650 kt

(Horsburgh, 2005)

Ausenco’s technical solution : HPGR

Reported 20-50 % reduction in comminution energy

No grinding media required

Conclusions

• HPGR is seriously challenging SAG.

• Driven by higher media and energy costs.

• Driven by ENERGY ACCOUNTING.

• Adopting Emergy might attract a strange mix

of economists and energy scientists/engineers.

• The science of “emergy” is obscure and arcane,

“It’s well-known, but only to a few!”

Finally

The dynamics of how we use energy in the future in relation to economics,

resource consumption efficiency and the environment are set to change forever

070125

Questions, comments, condemnations ?

www.ausenco.com