The Lake Disappointment Project is located in the Little Sandy Desert, Western Australia, approximately 320km east of Newman. Access via the Talawana Track. The Project is made up of over 5,000km2 of granted tenements covering the Lake Disappointment playa and surrounding Palaeovalleys. The whole of the project area lies within the Martu Native Title Determination area.
In 2015, exploration was carried out over LD using a purpose built rig, transported over the lake by helicopter. The core retrieved from the lake was collected in sealed tubes that recover the lake sediments as well as the entrained brine for the interval. Drilling was carried out over the entire lake surface area (accommodating the Traditional Owners restricted areas) at drill spacings required for a JORC (2012) compliant resource carried out by Pendragon Environmental Solutions Pty Ltd.
Reward proposes to abstract potassium-rich brines from sediments associated with Lake Disappointment to produce sulphate of potash (SOP) by means of solar evaporation of the brine. The Project currently has a JORC compliant recoverable mineral resource of 153Mt SOP from an in-situ brine resource of 596Mt grading 12.5kg/m3.
Approximately 60 million m3 of brine will be abstracted annually to produce 400,000 tpa of SOP. Brine will be collected from a network of shallow trenches across the lake and then pumped into shallow evaporation ponds to concentrate the brine by evaporation and crystallise out approximately 18Mt solid waste salts (halite) per annum and 2.9Mt crude potash salts. The total pond area required is approximately 4,000ha. Ponds will be constructed on the playa and occupy under 3% of the lakes surface area.
The SOP crystallisation plant requires approximately 3 million m3 pa ‘fresh to brackish’ water to separate SOP from the crude potash harvest product. Raw water for processing will be sourced from two bore fields that have been located 16km and 29km north of the lake.
The Talawana track (public road) will require upgrading to enable the transport of SOP products to ports for subsequent shipping.
A number of key milestones have been accomplished in recent years that position the company firmly for transition from exploratory activities through development into operational phases over the next two years
- Mining and Indigenous Land Use Agreement (ILUA) reached and settled with the Martu Traditional Land Owners in Dec 2011
- Completed detailed heritage Surveys over the lake Disappointment Project Area allowing access by late 2012
- Upgrading 43km of the Talawana Track from Cotton Creek and construction of a 29km access track to the northern shore of Lake Disappointment in 2013
- Established 20 person base camp at Lake Disappointment at Lake Disappointment for exploration and pilot scale activities
- Level two flora and fauna surveys initiated in 2013 to underpin environmental submissions for the Project to federal and state authorities (EPA and DoEE) in 2016
- Exploration drilling during 2014-2015 to identify palaeovalley extents and to intercept palaeochannel SOP resources north of Lake Disappointment as well as Lake Dora and Lake Waukarlykarly
- Resource definition drilling and trench test work during 2015-2016 culminating in the JORC compliant resource upgrade to 596Mt in-situ SOP
- Extensive in-house field and laboratory pilot evaporation trials to improve process and plant design parameters
- AMEC scoping study for the processing plant completed in 2015 and incorporated in the company’s Project scoping study
- 250km drone survey for detailed engineering road designs of the Talawana and Willjabu (site access) tracks as well as areas for supporting Project infrastructure (airstrip, village and operations centre) in 2016
- Pilot Pond construction activities in 2016 for pond seepage and geotechnical evaluations on lake Disappointment to establish build methodologies for causeways and pond infrastructure
- First round evaporation pond and brine trench layout design by independent engineers Knight Piesold in 2016
- Collation of civil contractor submissions for construction packages of Project infrastructure – Talawana Upgrade, Airstrip and Bulk earthworks for Village and Operations centre in 2016 and Pond construction and Harvesting (Q1 2017)
- Lycopodium Engineering scoping study for the revised processing plant design completed in 2016 leading into whole of Project feasibility studies in 2017
- Preliminary numerical hydrogeological models developed for the total project Q1 2017 by Strategic Water Management
In 2017, the company is progressing its environmental submissions as well as its Feasibility Studies to definitive status for development. The current areas of focus comprise,
- Completion of exploratory drilling for the raw water bore fields together with flow testing and modelling by Strategic Water Management
- Lake based deep well flow testing and brine recovery work to refine the lake hydrogeological model and establish an SOP Mineral Reserve for subsequent mining
- Ongoing environmental studies to support the environmental submission approval processes
- Updated review of the brine processing infrastructure (ponds through to plant) and Definitive Feasibility Study for the whole of Project by Lycopodium Engineers
- Development of the Mining Proposal and Mine Closure Plans for DMP Project approval