Coal Preparation

Evaluation Of Ultra-Dynamics Non-Nuclear Density Gauges

Coal Preparation » Process Control

Published: June 12Project Number: C19043

Get ReportAuthor: Peter Purdon, Laurie Gibson | ALS Coal Technology NSW

The objective was to directly determine the measuring efficiency of a pilot Ultra-Dynamics density gauge. Direct comparisons were obtained by installing the non-nuclear gauge immediately after a standard nuclear gauge within the ACIRL Pilot Plant. That provides a direct comparison of the gauge's accuracy, reproducibility and suitability for use in dense media and tailings circuits. The gauge's initial calibration, drift with time, drift with temperature, influence of media contaminants and sensitivity to magnetics content were assessed.


The "as developed" Ultradynamics magnetic susceptibility density gauge housed the measurement device in a 25mm diameter high alumina sheath. This sheath was inserted into the dense media pipework though a valve/gland arrangement.


The effectiveness of the nucleonic gauge was confirmed with further testing, and the gauges were then recalibrated against the nucleonic gauge data. Testing was completed to determine the gauge accuracy with the new calibration.


Temperature effects on the arrangement within the system were also investigated. By controlling other variables, it was found that temperature was affecting the magnitude of the non-nuclear gauge error. That was tracked to an incorrectly applied formula within the gauge software, and a correction was applied.


A number of tests were then carried out to determine the accuracy of the non-nuclear gauges. The tests ranged from 1.3 to 1.8 in density, and the mode of altering density changed from stepwise to continuous & increasing to decreasing. Tests were also completed at constant density to assess short term drift.


The tendency of the non-nuclear gauges to over or underestimate the nucleonic density was also shown to change depending on whether the density of the system was increasing or decreasing. That was demonstrated in a number of sub-tests.


The effects of contamination on the ability of the gauges to read density were also tested. Three types of contaminants were added to the system at three concentrations. The error in the non-nuclear gauges was shown to increase with increasing system contamination. That error was of the magnitude of 0.015 RD for every 10% of contamination added to the system.


Another test was arranged to investigate the ability of the non-nuclear gauge to detect small changes in magnetite concentration. 1.6 kg of magnetite was added in 1, 0.5 and 0.1kg increments. The gauge identified these changes in magnetite concentration, and this is visible in the following chart. However, the gauge had little success in identifying the density of the mixture without that mixture containing any magnetic material.


Marcy gauge densities and normalised DMC cut-points confirmed the accuracy of the nucleonic gauge. The negatives of the non-nuclear gauges were the occasional erratic jump in signal, and the tendency of the calibration to drift with time. The positives were their ability to pick up small quantities of magnetite (0.01%) and reasonable resilience to contamination. When compared to a nucleonic gauge, the typical error from the non-nuclear gauges was +/- 0.015 RD. This figure of 0.015 RD was also the figure generated as the average increase in error for every 10% of contaminant added to the medium.


The project has proved that the concept of using magnetic susceptibility to measure medium density within a typical dense medium circuit is sound.


Health and safety, productivity and environment initiatives.

Recently Completed Projects

C27039True Triaxial Strength Of Coal Measure Rocks And Its Impact On Roadway Stability And Coal Burst Assessment

Rocks in the ground are subject to a range of stresses. The stresses...

C3063Underground Vehicle Design Standards And Statutory Implications

The Australian underground diesel vehicle fleet has evolved since di...

C3064Conveyor Belting And Lagging Shear Characteristics - Drive Drum Slip

The primary aim of this project was to investigate the relationsh...


Open Cut

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

Recently Completed Projects

C26029Geological Controls On Fluorine And Phosphorus In Bowen Basin Coals

Increasing global restrictions on fluorine in product coal prompted ...

C28033Raw Ash To Yield Relationships

Correct outcomes in yield predictions for product ash from coal bore...

C27038Establishing Self-Sustaining And Recognisable Ecological Mine Rehabilitation

In recent years an increasing interest has been placed on mining ope...

Open Cut

Coal Preparation

Maximising throughput and yield while minimising costs and emissions.

Recently Completed Projects

C27064Dry Beneficiation Using FGX And X-Ray Sorters

Conventional dry processing methods engage a single beneficiation de...

C26010Multi-Sloped Screening Efficiency With Changing Strokes, Frequencies, Feed Solids And Feed Rates-Pilot Plant Study

Optimising multi-sloped screens is often described as an art and the...

C28059Impact Of Water Quality In Coal Handling And Preparations Plants

The objective of this project was to deliver a concise reference do...

Coal Preparation

Technical Market Support

Market acceptance and emphasising the advantages of Australian coals.

Technical Market Support

Mine Site Greenhouse Gas Mitigation

Mitigating greenhouse gas emissions from the production of coal.

Recently Completed Projects

C23052Novel Stone Dust Looping Process For Ventilation Air Methane Abatement

This multi‐phase project is concerned with the mitigation of m...

C27054Optimisation Of A Thermal Flow Reversal Reactor For Ventilation Air Methane Mitigation

Ventilation air methane (VAM) generally accounts for 50-85% of the t...

C28076Selective Absorption Of Methane By Ionic Liquids (SAMIL) - Phase 2 Demonstration In A Packed Bed Reactor

An alternative approach to high temperature oxidation of ventilation...

Mine Site Greenhouse Gas 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

C16027Assessing Housing And Labour Market Impacts Of Mining Developments In Bowen Basin Communities

The focus of this ACARP-funded project has been to identify a number...

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 ...

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