Silica sand in focus: abundant yet critical?

Created

23 Nov 2023

Author

Artem Golev

Category

Cover page - Silica Sand

November 1, 2023

Silica sand (and lump silica) is one of the most abundant resources on the planet, with a variety of known sources widely distributed across the globe. Yet, more recently, silica sand has been attracting attention as a critical raw material. Specifically, silica is needed for solar panels – in the form of crystalline silicon and highly transparent tempered glass, which combined account for up to 80% of a solar panel weight. Silicon metal, produced from silica, is an important alloying element and the basis for all modern electronics.

Queensland has been a major producer of silica sand in Australia and globally for more than 50 years, with several new projects in the pipeline aiming to triple its production in the next few years. This article provides an overview of silica sand market and outlines the status of silica sand mining in Queensland.

Brief market overview

Silica sand is a widely accepted term for sands with high silica (SiO2) content, typically above 95% but in some cases above 99.9%, with very low level of impurities. This is unlike most common construction sand, where silica content is not limited and can vary depending on the rock source (though typically above 80%), and only some specific minerals and elements are of concern – those that can severely affect physical and chemical properties.

Silica sand and lump silica (e.g. quartzite) are considered relatively abundant materials, and there are currently no estimates of global resources and reserves. Nevertheless, high-quality deposits are relatively scarce. As a result, silica sands can be transported over considerable distances, including for export. This is unlike conventional sands, which have a more local market and typically lower price range.

The requirements for silica sand can be met only where the level of impurities in sand (or in lump silica) are naturally low or can be lowered through processing. Typically, extracted silica sands require relatively simple low-cost processing, such as size classification and magnetic and/or gravity separation.

In addition to silica content and level of impurities, grain shape, size and distribution are also important parameters for all sand products, as well as, in many cases, the consistency in quality of supplied materials.

Silica sand has a broad range of applications, with major sectors being glass manufacturing (34%), foundry (22%), and proppant for hydraulic fracturing in oil & gas extraction (20%) (SIBELCO). There are also some other important applications – examples such as crucibles and silicon metal manufacturing can be smaller in volume but attract a premium price.

Global mine production of silica sand was estimated at 380 Mt in 2022 (USGS), worth about US$15 billion. The leading producing and consuming countries are USA and China, both accounting for about a quarter of global total, being relatively self-sufficient.

Global production of silicon ferroalloys and silicon metal is estimated at about 9 Mt per year (silicon content) (USGS), equating to about 5% of global silica sand production. Currently, China accounts for about 70% of global silicon metal manufacturing. Small quantities of silicon are processed into high-purity silicon for the solar and semiconductor industries. 

Australia has significant known resources of silica sand, including some of the highest quality deposits, mainly located in Queensland and Western Australia. The country accounts for about 1% of global silica sand production, mainly in Queensland, but it is one of the major global exporters. Australia is also a silicon metal producer (about 0.6% of global production), with one operating plant in Western Australia. Most produced silicon is exported.

Silica sand in Queensland

All current and prospective large-scale mining operations for silica sand in Queensland are located in or close to Cape Flattery, approximately 40 km north from Cooktown, in Far North Queensland.

The dune fields at Cape Flattery were described by Captain James Cook, who named this headland on 10 August 1770. An interest in the extraction of dune sand at Cape Flattery came in 1960s after identifying potential Japanese markets for glass and foundry industries. The company – Cape Flattery Silica Mines Pty Ltd – was founded in 1967, and mining and first shipments to Japan commenced in the following year.

The Cape Flattery mine was purchased by Mitsubishi Corporation in 1977, and currently is one of the world’s largest silica sand mines, with annual production of about 3 Mt (Queensland Department of Resources).

The average content of silica sand produced at Cape Flattery is 99.93% SiO2 and 0.01% (100 ppm) Fe2O3 (CFSM). This is one of the highest grades available globally, which allows the targeting of premium markets, including manufacturing of extra clear glass for solar panels.

There are two other emerging silica sand miners at Cape Flattery – Metallica Minerals Ltd, developing Cape Flattery Silica project, and Diatreme Resources Ltd with Northern Silica and nearby Galalar Silica projects.

Queensland’s major silica sand mines and projects are also summarised in the table below.

Table

Data sources: companies’ reports and announcements, Queensland Department of Resources.

In addition to the above, co-production of silica sand products in smaller quantities likely occurs at some sand quarries across the State. The potential for silica sand deposits also exists in other areas along the eastern coast of Queensland, as well as on the western coast of Cape York in Far North Queensland.

Apart from silica sand (and potential lump silica) projects, there is also an interest to establish a silicon metal production, including further processing into polysilicon for solar panels and computer chips, in Lansdown Eco-Industrial Precinct in Townsville, currently aiming for the plant(s) to be operational by 2030 (iQ Industry Queensland).

The total resources for silica sand and lump silica in Queensland are not reported, but likely exceed 2 billion tonnes. This would be an equivalent of five years of current global production or more than 600 years of current production in the State. Most important, however, is not the quantity but the quality of available resources, which is undoubtedly one of the highest in the world.

Silica resources and grades for major new projects in Australia are presented in the graph below. Additional information about critical minerals in Australia, including high-purity silicon, can be found at the Geoscience Australia website.

Major new silica sand projects in Australia by silica grade and total resources

Figure

Data source: companies’ reports and announcements.

For further information, please contact Artem Golev: artem.golev@resources.qld.gov.au

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