Reducing Brine Volume through Membrane Distillation Crystalliser

Underground » Environment - Subsidence and Mine Water

Published: March 22Project Number: C28030

Get ReportAuthor: Ramesh Thiruvenkatachari and Michael Cunnington | CSIRO

Mines prioritise their water use strategies not just because it is a limited shared resource, but also to achieve environmentally safe discharge after use. Water treatment is already adopted in various coal mines and a greater emphasis is placed by the Government for more water treatment and for mines to have positive water balance. Demand for water is also increasing for their use in coal handling and preparation plants and other mine operations.

Generally, the direct reuse or disposal of the mine impacted water is not possible, due to the presence of salt and other ions, without some form of treatment and/or amendment. Reverse osmosis has been one of the leading desalination treatment technologies, which can typically achieve 50-60% water recovery, depending on the feed mine water characteristics. Some mine impacted waters require various pre-treatment such as neutralisation, pre-filtration etc. to make it suitable to treat through the reverse osmosis process. Yet, management of the brine produced as a by-product of RO treatment remains a challenge as a proportion of available storage capacity must be dedicated to brine. Minimisation of brine volume reduces one of the key constrains of brine management for the industry.

So far, evaporation ponds have been used to concentrate the brines, but these are only practical where the right climatic conditions are available and require large surface area and careful management. Besides, with the increasing value of freshwater, water evaporated from the evaporation ponds cannot be collected and reused, thereby making no contribution to improving water usage efficiency. Further to loss of water, additional expense is incurred for the mine to replace this lost water. Most coal mine operations in Australia are located inland and do not have the option of ocean disposal and are looking for alternate methods to handle brine. A portion of the brine generated from the treatment process could be diluted with mine water and used for dust suppression. Runoff from dust suppression would be recaptured, with the increasing salt concentration within the salt management system. Remaining brine is stored on-site, reticulated to mining or waste emplacement areas. Minimising the salt brine volume will significantly minimise the salt disposal cost. It was estimated that in some areas of inland desalination treatment, every 1% reduction of their brine volume offered a savings of about $1M in disposal costs.[1] Hence, developing and adopting an effective brine management option would lower the brine waste footprint for the coal industry.

In this project, a proof-of-concept of a low thermal based membrane distillation process coupled with a crystalliser (MDC) was demonstrated using actual brine and mine water samples. Two coal mine reverse osmosis brines and one mine impacted water were used as test samples in this project to further concentrate and simultaneously recover reusable clean water using the lab scale MDC process operated in a batch mode. The experimental results obtained show that the MDC process was able to concentrate and further reduce the volume of brine produced from the reverse osmosis process and also the acidic mine impacted water, operating at 55°C feed water temperature. This process also recovered a high-quality reusable permeate water both with hypersaline brine and acidic mine water. Under batch mode of operation, water recovery of about 60-90% was obtained with a flux rate of about 15-20 LMH. The solute rejection of the membrane was found to be over 99.5%, recovering clean permeate from the vapour permeating through the membrane. Integrating with a crystalliser, resulted in achieving crystallisation for all three samples tested through the MDC process.


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