Coal Preparation

Economic Effect of Low Amounts of Non-Magnetics in the Correct Medium

Coal Preparation » Gravity Separation

Published: November 16Project Number: C23046

Get ReportAuthor: Michael O’Brien and Bruce Firth | CSIRO

This project has developed a methodology by which the economic loss incurred in a plant when processing a coal through a Dense Medium Cyclone (DMC), operating with a correct medium relative density less than 1.4, when the non-magnetics concentration in the correct medium is varied due to plant stoppages, feed changes, clay breakdown or bleed valve setting changes can be determined. The genesis for the project came from several previous ACARP projects which examined the effect of the non-magnetic material concentration in the magnetite medium. The results of those projects showed that instability can occur with mediums that contain less than 20% by weight of non-magnetic material with a particle size less than 0.200 mm and with a correct medium relative density (RD) below 1.4.

The concentration the of non-magnetics in the medium can depend on the feed rate to the plant, the amount of clays in the feed, the breakdown of particles in the DMC circuit and the setting of the bleed to the magnetic separator. Sherritt, in ACARP C20045, found that if everything else was held constant and the feed rate to the plant changed then the amount of non-magnetics in the correct medium is directly proportional to the feed rate.

The use of a model to describe the washability of a coal was considered for this project as it would allow a quantitative description of the washability with a limited number of variables and facilitate the calculation of coal recovery when a partition curve was applied to it. Washability curves relate the mass and ash value of a density separated coal fraction to the density at which the corresponding separation was made. Only two basic relationships are required to characterise washability, the first relates ash value to relative density, and the second defines the distribution by mass % of the relative density fractions.

Two models were developed that described the ash value to relative density relationship and the distribution by mass % of the relative density fractions for the 39 Australian washability's provided by Armstrong that covered the "good" the "bad" and the "ugly" range of washability's over six categories.

An e-newsletter has also been published for this project, highlighting its significance for the industry.


Health and safety, productivity and environment initiatives.

Recently Completed Projects

C8005Impacts Of Mine Subsidence On The Strata & Hydrology Of River Valleys: Management Guidelines For Undermining Cliffs, Gorges & River Systems


C24024Drilling For Outburst Risk Determination

This project's purpose was to determine parameters that may be indic...

C24066Development Of An Alternative Electronic Spark Test Apparatus

Since a high profile incident in 1998, where two widely deployed IS cert...


Open Cut

Safety, productivity and the right to operate are priorities for open cut mine research.

Recently Completed Projects

C16007Development Of A Smart Condition Monitoring Sensor System For Variable Speed Machinery

The objective of this project was is to design and develop a wireles...

c21033Modelling The Water, Energy And Economic Nexus

The mining industry faces three long term strategic risks in relation to...

C18033Assessing The Ecotoxicology Of Salinity On Organisms In Seasonally Flowing Streams In The Fitzroy Catchment

Stage One Report: Development Of Ecosystem Protection Trigger Values ...

Open Cut

Coal Preparation

Maximising throughput and yield while minimising costs and emissions.

Recently Completed Projects

C21045Fine Coal Agglomeration Using A Novel Economic Binding Agent

In this project a novel economic binding agent was investigated for use ...

C24041Improving Coal Flotation With Oscillatory Air Supply

This report provides detailed information on coal flotation with osc...

C22031Investigation Of The Graviton Separator At Pilot Scale

Vast quantities of fine coal, worth hundreds of millions of dollars, are...

Coal Preparation

Technical Market Support

Market acceptance and emphasising the advantages of Australian coals.

Recently Completed Projects

C12004Coke Reactivity Test: Critical Parameters

A Draft International Standard ISO/DIS 18894 has been prepared title...

C12073Accurate Instrumental Determination Of Carbon In Coal

Traditionally, thermal coal has been traded with its value being pri...

C13067Factors Affecting Coke Size And Fissuring During Cokemaking Part 2

This work addressed the mechanism of fissuring during metallurgical ...

Technical Market Support

Mine Site Greenhouse Mitigation

Mitigating greenhouse gas emissions from the production of coal.

Recently Completed Projects

C19054VAM Enrichment With A Two-Stage Adsorption Process

Treatment of ventilation air methane (VAM) with cost-effective technolog...

C24017Improving Methods For Quantifying Fugitive Emissions From Open Cut Coal Mining

Fugitive emissions from open cut coal mines are usually estimated fo...

C21065Flame Arresting Mechanisms And Flameproof Device For VAM Mitigation

The overall goal of this project was to study the gas flammability limit...

Mine Site Greenhouse Mitigation

Low Emission Coal Use

Step-change technologies aimed at reducing greenhouse gas emissions.

Recently Completed Projects

C17060BGasification Of Australian Coals

Four Australian coals were trialled in the Siemens 5 MWth pilot scale ga...

C17060AOxyfuel Technology For Carbon Capture And Storage Critical Clean Coal Technology - Interim Support

The status of oxy-fuel technology for first-generation plant is indicate...

C18007Review Of Underground Coal Gasification

This report consists of a broad review of underground coal gasification,...

Low Emission Coal Use

Mining And The Community

The relationship between mines and the local community.

Recently Completed Projects

C22029Understanding And Managing Cumulative Impacts Of Coal Mining And Other Land Uses In Regions With Diversified Economies

The coal industry operates in the context of competing land-uses that sh...

C23016Approval And Planning Assessment Of Black Coal Mines In NSW And Qld: A Review Of Economic Assessment Techniques

This reports on issues surrounding economic assessment and analysis ...

C19025Governance Strategies To Manage And Monitor Cumulative Impacts At The Local And Regional Level

ACARP levy contributors should order this report in the normal manner – ...

Mining And The Community


National Energy Research,Development & Demonstration Council (NERDDC) reports - pre 1992.

Recently Completed Projects

1609-C1609Self Heating of Spoil Piles from Open Cut Coal Mines

Self Heating of Spoil Piles from Open Cut Coal Mines

1301-C1301Stress Control Methods for Optimised Development...

Stress Control Methods for Optimised Development and Extraction Operations

0033-C1356Commissioned Report: Australian Thermal Coals...

Commissioned Report: Australian Thermal Coals - An Industry Handbook