The activated Minerals Extraction System, or aMES® is an innovative process technology that enables the treatment of concentrated aqueous solutions to recover a range of valuable minerals, reagents and fresh water. The technology has applications in the desalination, energy, mining and other industrial sectors.


The aMES® technology incorporates several innovations into an integrated process delivering significant advantages over conventional technologies. The ability of the aMES® technology to dewater (remove water from) extremely concentrated (TDS >150 g/L) solutions including brines, and concurrently recover fractionated products, is highly desirable.


The aMES® process utilises a range of processing steps involving dewatering and crystallisation in a variety of proprietary flowsheets, in order to produce a range of valuable products. Mineral extraction is facilitated by systematically concentrating minerals in brines through a proprietary multi-staged process incorporating the innovative use of membranes.


Advantages of the aMES® technology include:

  • Improvements in mineral recovery and product quality
  • Opportunity for substantial project capex & opex savings
  • Highly efficient use of energy and production of pure water as a by-product
  • Reduced water consumption
  • Improved project footprint
  • Environmental sustainability

The ability of the aMES® technology to dewater extremely concentrated solutions including brines, and concurrently recover fractionated products, is highly desirable in a range of applications including

  • Energy – dewatering coproduced waters (recovering minerals)
  • Mining – natural brine & solution mining (lithium and potash bearing deposits)
  • Mining – downstream refinery wastes (cobalt, copper, nickel, REE’s and/or reagents)
  • Wastewater – dewatering (to recover dissolved solids, TDS, as product/s)

In order to demonstrate the significant advantages of the aMES® technology in developing a brine-based mining operation, in late 2020, Parkway, with the support of study manager Worley, completed a pre-feasibility study focused on the Karinga Lakes Potash Project (KLPP).


The KLPP is located approximately 230 km to the southwest of Alice Springs in the Northern Territory, Australia. The production of various salt products from the brine resources in the vicinity of the KLPP was proposed as early as the late 1980’s. More recently, the KLPP project operator (Verdant Minerals) published a scoping study in 2014, which was followed by a more recent scoping study in early 2019, based on a more innovative process route, incorporating the aMES® technology. In contrast to prior studies, the aMES® based process route, provided sufficient encouragement for the project operator and Parkway to commence a pre-feasibility study (KLPP-PFS) in May 2020. Parkway assembled an integrated project team, led by study manager Worley, supported by leading industry consultants and a range of key equipment vendors. The KLPP-PFS was completed in Nov 2020 and concluded that based on the adoption of the aMES® technology, the KLPP represents an attractive opportunity to develop a specialised brine mining operation, to produce a high-quality, soluble grade, sulphate of potash (SOP) product, targeting key domestic markets, in Australia.


Parkway owns a 15% interest in the KLPP and expects this interest to increase to 40% imminently as a result of completing the KLPP-PFS. Parkway also holds a conditional option to increase this interest to 50.1%, under certain circumstance.


KLPP - Introduction

The Karinga Lakes Potash Project (KLPP)

  • An extensive brine lake system that covers approximately 1,109 km2 over pastoral land in the Northern Territory, Australia.
  • Consists of a chain of dry salt lakes and is located within the Central Australian Groundwater Discharge Zone.
  • Extensive resource appraisal studies have been performed by JV partner Verdant Minerals since 2010.
  • Ideally located, with major road and rail infrastructure located in close proximity to the project, with regional gas options also available. 


Extensive Resource Appraisal Status

The potash brine investigations including those utilised for the purposes of resource appraisal and reporting were based on data acquired over several years, including:

  • 93 brine samples from hand dug pits
  • 4 small backhoe trenches which were pump tested
  • 8 vibracore drill holes, 73 sonic drill holes & 200 aircore drill holes
  • 42 installed 50mm piezometers around drill holes & 48 piezometers around trenches
  • 47 installed 100 mm wells
  • 10 pumping tests from 100 mm wells
  • 4 long term pump tests from 3 trenches and a well
  • 142 porosity samples.


KLPP – Development Concept

The KLPP development concept involves the processing of naturally occurring hypersaline brines from a series of salt lakes at the KLPP, in order to produce 40,000 tonnes per annum (tpa) of high-purity sulphate of potash (SOP), over an initial mine life of 20 years. The development concept is divided into two broad areas of operation, upstream and downstream operations.

KLPP – Upstream Operations

The upstream operations at the KLPP consist of the following key stages:

1 - Brine Harvest – extraction of raw brine from trenches and pumping to evaporation ponds.

2 - Brine Concentration – the raw brine is concentrated, through a i) pre-concentration pond, then pumped to, ii) a Halite crystallisation pond, where waste sodium salts are precipitated, and then pumped to the, iii) final potassium salts crystallisation pond, where the potassium enriched mixed salts are harvested.

3 - Salt Stockpile - the harvested potassium enriched mixed salts, are then transported a short distance to a stockpile, near the processing plant, ready for processing in the SOP processing plant.

4 - Process Plant – the aMES® based process plant, then processes the potassium enriched mixed salts, to produce SOP, which is then packaged on-site.

5 - Site Logistics – packaged SOP is then transported to key domestic markets, via the proposed access road leading to the Lasseter Highway to the north of the project area.

KLPP – Downstream Operations

The downstream operations at the KLPP consist of the following key stages:

 1 - Salt Stockpile – the downstream operations in the processing plant, commence with the potassium enriched mixed salts, harvested from the evaporation ponds, during upstream operations.

2 - Salt Preparation – the potassium enriched mixed salts are screened and milled, to ensure adequate dissolution of potassium minerals.

3 - Salt Extraction – the milled salts are dissolved in warm water, ensuring the transfer of potassium and sulphates from the mixed salts, into the warm leach solution, to form a concentrated brine.

4 - Core aMES® Plant – the concentrated brine from the salt extraction step, is processed through a proprietary aMES® based flowsheet, in order to:

    • Remove impurities (mostly sodium and magnesium chlorides).
    • Recover pure water.

5 - Produce intermediate products:

    • Sylvite (KCl).
    • Leonite (K2SO4.MgSO4.4H2O).

6 - SOP Synthesis - as a result of reacting the Sylvite and Leonite intermediate products, with the addition of recovered process water.

7 - SOP Logistics – the drying, packaging, storage and dispatch of the produced SOP product.


KLPP – Pre-Feasibility Study (KLPP-PFS)

A number of significant advantages of the proposed KLPP-PFS development concept have been established through the KLPP-PFS, including:

  • Strong Financial Performance - Despite the relatively small-scale of the project which would ordinarily be considered sub-economic, the development concept outlined in the KLPP-PFS appears to be financially attractive.
  • High Potassium Recoveries & Grade - The unconventional processing route based on the aMES® technology is capable of achieving high potassium recoveries.
  • Efficient Water Use - As the aMES® technology recovers freshwater during the processing of brines, the development concept outlined in this study, is highly efficient, in terms of water use. In comparison to other major SOP projects, the KLPP-PFS envisages a water use intensity of approximately half that of the peer group, with a realistic pathway to potentially reducing the intensity of water use, by approximately half again.


Additional Information Regarding the KLPP-PFS

Additional Information regarding the KLPP-PFS is outlined in the following documents:

 Sulphate of Potash Resource and Production Plan (KLPP-SOPRPP) 



Karinga Lakes Potash Project - Pre-Feasibility Study (KLPP-PFS) 



Parkway ASX Announcement (5 Nov 2020), incorporating the KLPP-SORPP and the KLPP-PFS.




Additional information regarding the aMES® technology and related water treatment solutions, is outlined in the Parkway Process Technologies, Next-Generation Technologies brochure. 


For additional information, or to discuss how we can provide you with the most suitable technology-based solution to address your water treatment challenges, we invite you to reach out and speak to a Parkway water treatment specialist, today. 


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