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Salt Lake Potash Ltd - Harvest Salt Results at Lake Way

RNS Number : 1600O
Salt Lake Potash Limited
28 May 2020

28 May 2020








Salt Lake Potash Limited (SO4 or the Company) is pleased to announce results of chemical analysis on a bulk sample from its Kainite harvest ponds at the Lake Way Project, showing above the modelled average Potassium grades.


§ A bulk sample of Harvest Salt from the Stage 1 Kainite Ponds was collected in March to confirm plant feed grades and produce mass samples of premium quality SOP for end user customers.

§ Chemical analysis of these Harvest Salts has indicated potassium salts kainite and schoenite (as modelled) are present with a potassium concentration of 7.5%, above the modelled assumed plant feed of 6.8%. Sulphate concentration of 20.9% also matched expectations.

§ Results for other compounds, namely Sodium and Magnesium align with the anticipated plant feed grade.

§ The bulk sample confirms the Lake Way operation is precipitating plant feed Harvest Salts suitable for conversion to premium quality SOP in the designed flowsheet. This will be further confirmed via process testwork at Saskatchewan Research Council (SRC) in Saskatoon, Canada.

TONY SWIERICZUK, Chief Executive Officer

"These positive results confirm our Stage 1 ponds are operating within design parameters and are producing high grade potassium feed salts which can be converted to premium quality SOP. Following the strong results from pumping our first brine abstraction bore reported last week, today's results further highlights the extent to which the Lake Way Project and our on-lake production process has been de-risked over the last twelve months."


harvest salt chemical testwork                      

In March 2020 the Company harvested a bulk sample (277kg) of Harvest Salts from a single point location in Kainite Pond 1, Cell C4 (Figure 2) in the 125ha Stage 1 pond network. Brine feed to the Stage 1 ponds is from both the on-lake trenches and the Williamson Pit.

Following collection, the Harvest Salts were de-brined and homogenised. A representative 0.25kg sample was sent to the Bureau Veritas laboratory in Perth for chemical analysis.

The chemical composition of the sample is outlined in Table 1 and aligns with SO4's evaporation model, based on a series of comprehensive evaporation trials undertaken in 2018 and early 2019. The potassium grade of 7.5% is within the range of expected outcomes and is above the average BFS feed grade of 6.8%. Readings for all other elements were within the range of expected outcomes. XRD results are pending.


Harvest Salt element

Wt %
















Table 1: Table of Bureau Veritas sample results chemistry


Having confirmed that the chemical composition of the bulk sample aligns with SO4's modelling and the grades are within the expected ranges, the remainder of the bulk sample of Harvest Salts is now being shipped to SRC in Canada for confirmatory testwork to produce premium high grade SOP to generate further samples to provide to offtakers.

The Stage 1 pond network commenced commissioning in May 2019 and has been in operation for 12 months, with the continuous inflow of brine into the Halite Pond. Brine evaporates and increases in concentration as it flows through the pond cells. Halite salts form in the early cells prior to the higher concentrate brine being pumped into the Kainite harvest pond cells for the precipitation of the potassium rich harvest salts.

At the end of April 2020, 2.7GL of brine has been pumped into the Stage 1 pond network.


For further information or to view a full version of this announcement, please visit www.so4.com.au or contact:


Tony Swiericzuk / Richard Knights

Salt Lake Potash Limited

Tel: +61 8 6559 5800

Colin Aaronson / Richard Tonthat / Seamus Fricker

Grant Thornton UK LLP (Nominated Adviser)

Tel: +44 (0) 20 7383 5100

Derrick Lee / Peter Lynch

Cenkos Securities plc (Joint Broker)

Tel: +44 (0) 131 220 6939

Rupert Fane / Ernest Bell

Hannam & Partners (Joint Broker)

Tel: +44 (0) 20 7907 8500


This announcement has been authorised for release by the Company's Managing Director, Mr Tony Swiericzuk.

The information contained within this announcement is deemed to constitute inside information as stipulated under the Market Abuse Regulations (EU) No. 596/2014. Upon the publication of this announcement, this inside information is now considered to be in the public domain.

Appendix A - Competent Person Statement and Disclaimer

Competent Persons Statement

The information in this report that relates to Process Testwork Results is based on, and fairly represents, information compiled by Mr Bryn Jones, BAppSc (Chem), MEng (Mining) who is a Fellow of the Australasian Institute of Mining and Metallurgy. Mr Jones is a holder of shares and performance rights in, and is a Director of, Salt Lake Potash Limited. Mr Jones has sufficient experience, which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking, to qualify as a Competent Person as defined in the 2012 Edition of the 'Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves'. Mr Jones consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.

Forward Looking Statements

This announcement may include forward-looking statements. These forward-looking statements are based on Salt Lake Potash's expectations and beliefs concerning future events. Forward looking statements are necessarily subject to risks, uncertainties and other factors, many of which are outside the control of Salt Lake Potash, which could cause actual results to differ materially from such statements. Salt Lake Potash makes no undertaking to subsequently update or revise the forward-looking statements made in this announcement, to reflect the circumstances or events after the date of that announcement.


Section 1 - Sampling Techniques and Data


JORC Code explanation


Sampling techniques

·     Nature and quality of sampling (e.g.  cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as downhole gamma sondes, or handheld XRF instruments, etc.).  These examples should not be taken as limiting the broad meaning of sampling.

·     Include reference to measures taken to ensure sample presentively and the appropriate calibration of any measurement tools or systems used.

·     Aspects of the determination of mineralisation that are Material to the Public Report.

·     In cases where 'industry standard' work has been done, this would be relatively simple (e.g.  'reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay').  In other cases, more explanation may be required, such as where there is coarse gold that has inherent sampling problems.  Unusual commodities or mineralisation types (e.g.  submarine nodules) may warrant disclosure of detailed information.

Sampling involved extraction of a small sample of harvest salt from the Stage 1 kainite harvest ponds (C4) at Lake Way.  The harvest ponds are large solar evaporation ponds which receive brine from the surrounding lake aquifer. 

Brine is pumped into the solar evaporation ponds and the chemistry is monitored and controlled to ensure the potassium salts are formed in the harvest ponds.  A salt sample was taken from a single point location in TK1C4, approximately 10m in from the centre of the western edge of the pond, on 28 March 2020.

The salt sample was taken from the surface of the salt pavement to a depth of approximately 5cm.  The salt sample was drained and placed into a total eight buckets (277kg gross) and shipped to Perth for analysis. 

Once received at the SO4 laboratory in Perth, the salt was further de-brined by draining the harvested salt through a strainer, then the drained salts were crushed by hand using hand tools (shovels and paving tamper) to nominally all passing ~25mm, where the typical particle size is <5mm.

The crushed salts were homogenised (overturned and mixed using shovels on a tarpaulin, then coned and quartered multiple times until a 1kg representative salt sample was obtained.  A 250g sub sample was provided to Bureau Veritas for ICP-OES and XRD analysis.

In addition to the salt sample, brine samples are taken from each solar evaporation pond regularly and routinely to monitor the solar evaporation process.

Brine samples were taken manually by initially rinsing out the sample bottle with brine from the source then filling the bottle. Samples were analysed for K, Mg, Ca, Na, Cl, SO4, TDS and specific gravity.

The temperature and pressure in each pond were logged electronically with piezometers.

Brine is a homogenous fluid below the surface, while salt samples are cone and quartered to provide a homogenous sample.

Drilling techniques

·     Drill type (e.g.  core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc.) and details (e.g.  core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc.).

No drilling was undertaken during sampling. The salt sample was taken manually by shovel from the surface of the salt pavement.



Drill sample recovery

·     Method of recording and assessing core and chip sample recoveries and results assessed.

·     Measures taken to maximise sample recovery and ensure representative nature of the samples.

·     Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material.

No drilling was undertaken during sampling.

Brine samples taken from the ponds, were sampled from beneath the surface of the ponds, thus were representative of the entire pond as the ponds are small enough to act as a homogeneous liquid bodies.

Salt samples were crushed, coned and quartered to ensure sample representativeness. The crushing and homogenisation lowers the risk of preferential loss/gain of one size fraction over another.


·     Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies.

·     Whether logging is qualitative or quantitative in nature.  Core (or costean, channel, etc.) photography.

·     The total length and percentage of the relevant intersections logged.

No logging was undertaken during sampling.


Sub-sampling techniques and sample preparation

·     If core, whether cut or sawn and whether quarter, half or all core taken.

·     If non-core, whether riffled, tube sampled, rotary split, etc.  and whether sampled wet or dry.

·     For all sample types, the nature, quality and appropriateness of the sample preparation technique.

·     Quality control procedures adopted for all sub-sampling stages to maximise representivity of samples.

·     Measures taken to ensure that the sampling is representative of the insitu material collected, including for instance results for field duplicate/second-half sampling.

·     Whether sample sizes are appropriate to the grain size of the material being sampled.

Not applicable, no drilling was undertaken during sampling.

Not applicable, no drilling was undertaken during sampling.

The brine samples were taken in sterile plastic bottles of 50ml or 250ml capacity. Brine is a homogenous fluid below the surface, while salt is cone and quartered to homogenise and sample.

Brine was diluted (1:50 in de-ionised water) at the lab to ensure accurate determination by ICP.

Salt was crushed to <25mm and homogenising to ensure that the 250g subsample taken is representative for the grain size. 50g of the wet homogenised sample is air dried at ambient temperature and sent for XRD. Following this the sample is crushed with a mortar and pestle to <120um. It is then packed into a pellet to undergo XRD analysis.

10g of the wet homogenised sample is air dried at ambient temperature. Residual moisture is determined by acetone-displacement wash followed by drying at a temperature of 60 degrees Celsius. Following this drying, the salt sample is dissolved in 100ml of de-ionised water, and is sent for ICP analysis.

Quality of assay data and laboratory tests

·     The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total.

·     For geophysical tools, spectrometers, handheld XRF instruments, etc., the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc.

·     Nature of quality control procedures adopted (e.g.  standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (i.e.  lack of bias) and precision have been established.

The brine and salt samples were sent to Bureau Veritas (BV) Laboratories in Perth, WA. ICP and XRD preparation undertaken at BV.

ICP analysis to determine the chemical ion analysis, and wet chemistry titration to determine chloride content was performed by Bureau Veritas, Canning Vale, WA.

Sub samples prepared at BV were sent for XRD analysis to determine the salt crystal mineralogy at Microanalysis in Perth, WA.

No laboratory analysis was undertaken with geophysical tools.

All BV laboratories work to documented procedures compliant with ISO 9001 Quality Management Systems. Rigorous quality control and quality assurance measures are applied throughout the entire process in their laboratories.

Standard quality assurance procedures include:

• Analysis of blanks within each batch.

• The routine testing of suitable certified reference materials from national and international suppliers, in addition to in-house and client supplied standards. Standards will be selected based on the elements of interest, expected range of concentration, and the analytical method used.

• Duplicate samples are included in each batch to ensure that reproducible results are being achieved. Duplicate samples may be solutions, pulps or coarse splits as requested.

• Re-assay of anomalous results by our quality control staff using techniques considered appropriate for the level of analytes encountered.

• All sample results are reported. All blanks and standards are reported on request.

Microanalysis uses XRD, which is semi-quantitative, as it does not take into account preferred orientation, strain or crystallite size. The amorphous content is estimated using the background ratio rather than an internal spike. All procedures are internally validated. Microanalysis Australia has an established QA/QC system of procedures for receipt, preparation and analysis of samples. All instruments are calibrated monthly with a certified reference standard. They run a calibration check using a certified Panalytical silicon standard monthly and monitor source decay. Repeatability studies have been undertaken to verify subsampling procedures. Every tenth sample is repeated to verify repeatability and consistency of results.

Verification of sampling and assaying

·     The verification of significant intersections by either independent or alternative company personnel.

·     The use of twinned holes.

·     Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols.

·     Discuss any adjustment to assay data.

Not applicable, brine is a homogenous fluid below the surface.

Not applicable, brine is a homogenous fluid below the surface.

All sampling and assaying is well documented and contained in SO4's internal databases.

No adjustments have been made to assay data.

Location of data points

·     Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation.

·     Specification of the grid system used.

·     Quality and adequacy of topographic control.

Location data is not relevant for this process test and so was not taken.


Data spacing and distribution

·     Data spacing for reporting of Exploration Results.

·     Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied.

·     Whether sample compositing has been applied.

Brine samples were taken at appropriate time intervals, either weekly or biweekly, to gain sufficient resolution on the brines' evaporation pathway.

The salt sample was taken from cell 4 of 5 cells in the Stage 1 harvest pond, whilst the brine chemistry of the cell was within the targeted "harvest zone" (where potassium salt is expected to be produced).  The sample is therefore is indicative of the type of harvest salt produced in the potassium harvest ponds.

Sample compositing has not been applied.

Orientation of data in relation to geological structure

·     Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type.

·     If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material.

Not applicable as harvest salts were homogenised.

Drilling orientation is not applicable. The entire mass of the salt sample produced by the solar pond was harvested, homogenised and sent for assay.


Sample security

·     The measures taken to ensure sample security.

SO4 operations personnel and engineers were responsible for sampling and homogenising all brine and salt samples prior to shipping to the BV lab in Perth and the SO4 lab/warehouse.  The security measures for the material and type of sampling at hand was appropriate.

Audits or reviews

·     The results of any audits or reviews of sampling techniques and data.

Data review is undertaken in the report and included an assessment of the quality of assay data and laboratory tests and verification of sampling and assaying.  No audits of sampling techniques and data have been undertaken.

Section 2: Reporting of Exploration Results


JORC Code explanation


Mineral tenement and land tenure status

·     Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings.

·     The security of the tenure held at the time of reporting along with any known impediments to obtaining a licence to operate in the area.

The Lake Way Project comprises tenements held by Piper Preston Pty Ltd, a wholly owned subsidiary of Salt Lake Potash Limited (SO4 or the Company).


Exploration done by other parties

·     Acknowledgment and appraisal of exploration by other parties.

No prior process (solar evaporation) test work has been undertaken by other parties on the brine from Williamson Pit or Lake Way Playa.

The Company has previously reported a brine resource for the Lake Way Project - refer ASX Announcement 11 October 2019.

There has been significant mineral exploration on and around Lake Way.  The primary source for the information is the publicly available Western Australian Mineral Exploration (WAMEX) report data base.

The majority of previous work has been concerned with investigating the bedrock and calcrete for gold and uranium, and it is of limited value in defining the stratigraphy of the lakebed sediments.  The data has been shown to be useful in the determination of the top of the paleochannel basal sand and for the calibration of the passive seismic data.

The data from previous exploration work by other parties has not been used in appraising the results of the process testwork included in this announcement.


·     Deposit type, geological setting and style of mineralisation.

The deposit is a salt-lake brine deposit.

The lake setting is typical of a Western Australian palaeovalley environment. Ancient hydrological systems have incised palaeovalleys into Archaean basement rocks, which were then infilled by Tertiary-aged sediments typically comprising a coarse-grained fluvial basal sand overlaid by palaeovalley clay with some coarser grained interbeds. The clay is overlaid by recent Cainozoic material including lacustrine sediment, calcrete, evaporite and aeolian deposits.

The brine is concentrated in solar evaporation ponds and the salt is precipitated into the evaporation ponds as fine (0.5 - 5mm) crystals that form a single, homogeneous salt bed.

Drill hole Information

·     A summary of all information material to the understanding of the exploration results including a tabulation of the following information for all Material drill holes:

·     easting and northing of the drill hole collar

·     elevation or RL (Reduced Level - elevation above sea level in metres) of the drill hole collar

·     dip and azimuth of the hole

·     downhole length and interception depth

·     hole length.

·     If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case.

No drilling was undertaken. 

The brine source for the Stage 1 solar evaporation pond, was initially sourced from the Williamson pit, and subsequently from an array of trenches constructed on the surface of Lake Way in the vicinity of Stage 1 solar evaporation pond.


Data aggregation methods

·     In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (e.g.  cutting of high grades) and cut-off grades are usually Material and should be stated.

·     Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail.

·     The assumptions used for any reporting of metal equivalent values should be clearly stated.

Harvested salt from the solar evaporation ponds was homogenised, assayed weighed to provide the estimated grade at the time of sampling.


Relationship between mineralisation widths and intercept lengths

·     These relationships are particularly important in the reporting of Exploration Results.

·     If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported.

·     If it is not known and only the downhole lengths are reported, there should be a clear statement to this effect (e.g.  'down hole length, true width not known').

Not applicable to process testwork.



·     Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views.

Maps and sections not included for process testwork. Refer prior ASX Announcement dated 25 February 2020.

Balanced reporting

·     Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results.

All results have been included in the body of the report.


Other substantive exploration data

·     Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances.

All material process data has been reported.

Further work

·     The nature and scale of planned further work (e.g.  tests for lateral extensions or depth extensions or large-scale step-out drilling).

·     Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive.

Brine evaporation from the solar ponds is ongoing, as the brine concentration progresses to the target concentration points.

Downstream metallurgical test work on the harvested salts will be undertaken by a world leading potash research laboratory to convert the harvest salt to a process intermediate (schoenite). The schoenite will then be tested by the crystalliser supplier.

Brine and salt samples will continue to be collected during the establishment of a fully operational solar evaporation pond system.




This information is provided by RNS, the news service of the London Stock Exchange. RNS is approved by the Financial Conduct Authority to act as a Primary Information Provider in the United Kingdom. Terms and conditions relating to the use and distribution of this information may apply. For further information, please contact [email protected] or visit www.rns.com.

Quick facts: Salt Lake Potash Ltd

Price: 30.25

Market: AIM
Market Cap: £111.66 m

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