The Evidence Guide provides advice on assessment and must be read in conjunction with the Performance Criteria, Required Skills and Knowledge, the Range Statement and the Assessment Guidelines for the Training Package.

Overview of assessment

A person who demonstrates competency in this unit must be able to monitor blast furnace operations. Critical aspects for assessment and evidence are required to demonstrate competency in this unit.

Critical aspects for assessment and evidence required to demonstrate competency in this unit

It is essential that competence is demonstrated in the ability to:

use OH&S practices

explain the general principles of iron making

monitor the operation of a blast furnace under direction and consistently achieve required furnace output specification

Relationship to other units

This unit may be assessed concurrently with other relevant units.

Assessment method and context

Assessors must be satisfied that the person can consistently perform the unit as a whole, as defined by the elements, performance criteria, skills and knowledge. A holistic approach should be taken to the assessment.

Assessors should gather sufficient, fair, valid, reliable, authentic and current evidence from a range of sources. Sources of evidence may include direct observation, reports from supervisors, peers and colleagues, project work, samples, organisation records and questioning. Assessment should not require language, literacy or numeracy skills beyond those required for the unit.

The assessee will have access to all techniques, procedures, information, resources and aids which would normally be available in the workplace.

The method of assessment should be discussed and agreed with the assessee prior to the commencement of assessment.

Resource implications

This section should be read in conjunction with the range of variables for this unit of competency. Resources required include suitable access to an operating plant or equipment that allows for appropriate and realistic simulation. A bank of case studies/scenarios and questions will also be required to the extent that they form part of the assessment method. Questioning may take place either in the workplace, or in an adjacent, quiet facility such as an office or lunchroom. No other special resources are required.

This describes the essential skills and knowledge and their level, required for this unit.

Required skills:

Carry out all work according to OH&S practices

Read, interpret and follow information on work specifications, standard operating procedures and work instructions and other reference material

Maintain accurate records

Meet specifications for furnace output

Communicate within the workplace

Apply techniques for Increasing Blast Furnace Productivity including:

blast temperature

blast humidity

blast volume

hydrogen injection

oxygen enrichment

top pressure

burden control/raw materials

size control

Required knowledge:

Competency includes sufficient knowledge of:

Coal

Proximate and ultimate analysis classification of coal for metallurgical coke

Coke

coal carbonisation

technical aspects of coke making

coke model, coke manufacture

by-product ovens

sequence of battery operations

coke properties - caking and swelling

quality control tests for coke

(crucible swelling number and Gray-king coke type)

coke strength and abrasion, resistance CRS - reactivity tests.

Other Fuels

blast furnace gas - uses

coke oven gas - uses

fuel oil - injection of auxiliary fuels

tar and pitch

IronOre

mineralogical characteristics

sources of iron, locations of ore

chemical analysis - ore quality desirable, unwanted impurities

desirable properties for iron making

mining/preliminary treatment (ore beneficiation)

ore handling

blending/stacking (chevron/step stacking)

essential characteristics of iron ore -

reducibility/strength size distribution -

lump ore - direction charging

fine ore - need for agglomeration for good permeability

testing and quality control of iron ores for iron making resistance to fines generation

drying handling and charging resistance to decrepitation

low temperature reduced degradation

(Nagoyal test) height temperature

reducibility (Gakushin test)

softening under load

cohesive zone of (BF)

Ore Agglomeration

Need for agglomeration, sources of fines, aims for agglomeration

Pelletising

use of pelletising; size and quality of ore

pelletising process

quality control needs for pellets

abrasion index, RDI index

Sintering

sintering process

proportioning of raw materials

size of ores, blending, moisture

limestone and coke

mixing and granulation

sinter characteristics, sinter quality

size, strength, reducibility

chemistry (basicity ratio)

quality control tests for sinter

sieving and sizing

sinter tumble test (abrasion test)

low temperature reduction, degradation (reduction

degradation index - RDI), high temperature reducibility

Miscellaneous Raw Materials

Fluxes: Limestone, fluorspar, quartzite

manganese ore, air/tonnage oxygen, water

Iron Blast Furnace Operations

general description and function of blast furnace including charged materials

blast furnace terminology

blast furnace chemistry (reduction chemistry and gaseous v's solid reduction)

thermodynamics of iron making (physio chemical principles)

free energy charges; Ellingham

diagram/oxygen potential

equilibrium/equilibrium

constant/activity

dependence of coke/oxygen reaction and gas composition

Blast furnace slags

slag/metal reactions

slag formation reactions

Construction and Design of Blast Furnaces

furnace construction/furnace profile layout and function of processing units associated with the blast furnace

charging and distribution

ore blending, raw material bins

raw material control and charges

furnace filling

use of moveable armour

refractories and cooling systems

choice of refectory materials for furnace lining

method of cooling/under hearth

cooling/stave cooling

campaign life determinants - link between refractories and cooling system

blower stations:

hot blast stoves, tuyeres

gas cleaning equipment , dust extraction

cast house layout

slag/metal

flow-slag disposal

blast furnace sensors

computer control

sensors and interpretation

human eye

tuyere/casting condition

thermocouples

hot metal

stoves

brickwork

tip temperature probes

pressure tapping

level detectors

flow meters

flow rate of gases/hot blast

chemical analysis

composition of metal slag and waste gases

Principles of Iron Making

furnace filling

mechanism of charging and of distribution segregation effects

blast furnace zones of operations

physical movement through the furnace

counter current process

solids/gas and temperature profile five internal zones lumpy/granular zone, cohesive zone, active coke zone raceway

hearth and deadman

lumpy/granular zone-zone formation

cohesive zone-zone formation

active coke zone-zone formation

importance of coke properties

zone chemistry - effects of metal, coke, alkalis and fluxes/slag.

raceway

physical structure,

raceway model-factor affecting shape-blast parameters

combustion in raceway,

importance of coke additives to replace coke to improve control and production.

hearth and deadmen-zone formation

(deadman boundary residence time of coke)

gas/liquid flow, liquid levels

floating levels, floating of coke bed

liquid permeability

effect of casting rate

fluidity of slag and metal

liquid flow: effect on lining wear.

hot metal and slag chemistry

hot metal - optimisation of hot metal

composition control of carbon, silicon, manganese, sulphur, phoporus

slag - mechanism of slag formation

optimisation of slag chemistry

requirements of a good slag -melting point, basicity, viscosity

ability to remove unwanted materials, (de sulphurising power)

slag volume

requirements for effective and efficient operation

importance of raw material quality and quantities

burden distribution , tuyere injectants, fuel rate

elimination of irregularities

Post Iron making Practices

reasons for post iron making productivity

control of unwanted elements

control of hot metal, composition for BOS

steelmaking and balance of exothermic reactions

de sulphurising, dephosphorisation, desiliconising

lime, magnesium, aluminium

importance of injectants and slag formers, significance of slag partitioning

The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.

SCADA system

System Control and Data Acquisition is a general term applied to a number of systems which automatically collect critical process data, perform required mathematical manipulations on it and then make control decisions and/or give required information to personnel for action.

In the continuous manufacturing sector, the SCADA system may be integrated into other sophisticated computer control systems such as DCS (Distributed control system). Organisations may simply refer to their SCADA as the DCS or other similar term (such as the proprietary name of the computer system).

SCADA systems may provide information from outside of the process, such as stock/material levels in a location. This information may all be accessed by the SCADA system and the employee using it in order to make production rate and other control decisions (either automatically or human assisted) about their own process.

Metallurgical principles relate to

preparation and selection of raw materials

characteristics of iron ore

pelletising

sintering

iron blast furnace operations

blast furnace slags

principles of iron making

techniques for increasing blast furnace productivity