INDUSTRIAL USES & MARKETS
The largest single market for industrial garnet is in the USA, followed by Europe and Asia. Some 70-80% of the domestic USA production is used for abrasives, water filtration and jet-cutting. The following exerts are from the current USGS – 2019 Mineral Commodity Summaries and confirm that imports of garnet into the US have increased with Australia, India, South Africa and China being the major importers.
The wild cards are India that are now restricting alluvial garnet mining and China that is subject to a trade war with the US, with both countries seeing future imports into the US potentially decrease. This provides an opportunity for a new entrant, admittedly on a fairly small scale.
The USGS study indicates an average unit value of garnet in 2018 was US$210 per US ton (this equates to US$231 - A$342 per metric tonne) although prices on the ground are substantially higher with the attached wholesale quote from GMA in the US of US$517 – A$765 (ex Tax) per a 2200 lb bulker bag (this equates to 1 metric tonne – see GMA quote below).
Air Blast Abrasives – Domestic Market Australia
The market for garnet within Western Australia is in excess of 25,000 tpa. The total expendable blast cleaning material consumed in Australia is approximately 200,000 tpa, much of which comprises very expensive metal (magnetite) slags as an abrasive product that could be replaced by garnet. The Garnet Hills product offers advantages of providing an exact garnet sizing for various blasting uses and the potential for increased use in outside blasting requirements where visual pollution is a consideration.
Precision Garnet Powders
Garnet powder is used to produce a high-gloss finish on a majority of television and computer monitor screens that are manufactured in the world today. Garnet powder is a natural abrasive that reduces scratches etc caused by artificial abrasives and is highly sort after as a polishing media for high gloss applications.
Garnet Hills - Jet Cutting Garnet
The advantages of a crushed hard rock andradite garnet from Garnet Hills is that it is naturally angular (refer photomicrographs) and can be sized to the tolerances required by computer - driven jet-cutting machinery. Andradite garnet from Garnet Hills is chemically benign and offers colour advantages over GMA almandine garnet (light brown rather than pink) in terms of eventual disposal in landfills.
The Garnet Hills garnet has the advantage of being sized to the requirements of the customer. Standard jet cutting grades of 50 mesh (200 - 600 µm), 60 mesh (200 - 400 µm) , 80 mesh (150 - 300 µm), 120 mesh (150 - 300 µm) and 200 mesh (50 – 150 µm) can be provided with the angularity of the garnet grains guaranteeing fast precision cutting o f materials varying from glass, steel, titanium and dimension stone. Jet-cutting of dimension stone and man-made materials used for bench-tops etc using garnet will minimize the need for diamond – blade cutting that has caused the proliferation of silicosis – related diseases in the industry.
GH Garnet –600+180 μm (50 mesh)
GH garnet grains are angular ensuring maximum abrasive power. Photomicrograph - plane polarised transmitted light. Field of view – 3 mm.
GH Garnet – <180 μm (80 mesh)
GH 80 mesh jet-cutting garnet grains are consistent and angular ensuring maxium cutting power through any medium. Photomicrograph - plane polarised transmitted light. Field of view – 3 mm.
Potential New Garnet Product – High Density Fraccing Proppants
Fraccing or hydraulic fracturing of naturally low permability hydrocarbon – rich sediments under high pressures to increase LNG and oil production currently uses high density (>3.2 g/cc) proppant sands such as garnet.
Retail Garnet Prices - Australia
These prices are indicative only, with premium coarse grained and very fine grained garnet achieving much higher prices. Prices are also dependent on the end use for the garnet. Garnet Hills offers the major advantage of being able to produce a range of garnet fractions that can be tailored for the end user. Export FOB prices are expected to be in US$ although a A$650/tonne price has been used in our calculations to provide a conservative outlook (refer Appendix 5).
Non-slip Surfaces
Research indicates that there is a market for garnet as a non-slip surface for flooring applications. Two Sydney based companies viz Johnson Tiles Pty Ltd and Cementaid Pty Ltd specialize in this application. Testing of product is undertaken by Boral Pty Ltd in Sydney.
Water Filtration
Garnet is finding increased use in the filtration industry particularly with the growth in the need for potable water for cities either from retreated sewrage/waste water or from Reverse Osmosis plants. Water filtration needs various grades of angular garnet, even up to the coarser grades of 2.8 mm. The various grades of angular garnet can be supplied from the Garnet Hills skarn deposit. Current trials of fine (0.3 mm or 300 micron) angular garnet combined with standard filtration material in residential pools has proved highly successful in producing crystal clear water – effectively eliminating any suspended fines that can cloud the pool water. The same principal can be applied on a much larger scale using garnet to filter ground/lake/river water used for reticulation in agriculture (ie vineyards and orchards) to reduce sediment build-up in the fine jets and drippers.
Garnet can be combined with carbon and manganese to provide additional filtration properties particularly for industrial uses. For example, the addition of manganese oxide to garnet in a multi-media filtration plant can extract suspended particles as well as Fe oxides that could be important in cleaning up water extracted from open cut and underground mines.
The Western Australian Water Authority (WAWA) uses various materials, usually silica sand, as filtration media. The WAWA has expressed interest in garnet as a filter medium and require 3mm-7mm size fractions. Garnet Hills will be capable of supplying these garnet grades. Swimming pool filter suppliers currently use white sand between 850 - 1600 micron and garnet may represent a viable, longer lasting alternative. Typical retail pricing for a 25 kg bag of filtration garnet is A$50 per bag.
The current emphasis on water recycling has added new emphasis on the role of filters in producing potable water. Garnet plays a pivotal role in the filtration column and this will ultimately increase in demand for the coarser garnet grades not currently available in Australia. The chemically benign Garnet Hills garnet will be ideal for these filtration applications.