Silica Natural Resources Lands, Minerals and Petroleum Division Mineral Commodity Profile No. 2 ilicon (Si) is the second most common element on Earth after World Production and Reserves Soxygen. Si does not occur naturally in its pure state but instead is found chiefly in mineral form as either silica (SiO2) or silicates. Silica Silica deposits occur, and are mined, in most and/or silicate minerals are a constituent of nearly every rock type in countries. Global silica output is estimated at Earth's crust. roughly 120 Mt to 150 Mt per year (Dumont 2006). The most familiar silica mineral is quartz. In commodity terms, silica About 5.9 Mt of ferrosilicon were produced also refers to geological deposits enriched in quartz and/or other silica worldwide in 2006. The major contributors were minerals. Silica resources include 1) poorly consolidated quartzose China, Russia, United States, Brazil and South sand and gravel, 2) quartz sand/pebbles in consolidated rock (e.g. Africa (U.S. Geological Survey [USGS] 2006). quartzose sandstone), 3) quartzite , and 4) quartz veins. Global production of silicon metal reportedly Uses approached 1.2 Mt in 2006, almost half of which came from China (USGS 2006). Other important Silica is hard, chemically inert, has a high melting point, and functions producers are the United States, Brazil, Norway, as a semiconductor—characteristics that give it many industrial France, Russia, South Africa and Australia. applications. Silica deposits generally must be processed to remove iron, clay and other impurities. The most valuable resources contain Silica Consumption in Canada (Total = 2.57 Mt) >98% SiO2 and can be readily crushed into different sizes for the various end products. Nonferrous smelting and refining Silica is used primarily by the metallurgical, cement/construction, Cement industry glassmaking, water treatment, ceramics and chemical sectors. It is also Glass (including the raw material needed to produce ferrosilicon and silicon metal. containers and glass wool) Speciality Silicas Iron and steel manufacturers Foundries consume most of the world's Chemical industry Speciality silicas include ferrosilicon, using it as a deoxidizer, Other precipitated silica, fumed silica alloying agent, and additive. and silica gel. They represent a 2005 preliminary figures (from Dumont 2006) growing new market for Silicon metal is vital to the Raw silica is mined and/or quarried in most ultrapure silica (polysilicon). aluminium and chemical industries. Uses for precipitated silica Canadian provinces. Quebec and Ontario are the Light alloys for automotive include the production of only provinces currently producing ferrosilicon and manufacture represent the largest footwear and “green” tires. silicon metal. In 2005 Canada consumed 2.57 Mt of market for silicon metal, followed by Silica in tires helps to reduce silica, 1.8 Mt of which came from domestic sources; silicone production (Kulikova 2007). wear, improve traction and the American market absorbed about 95% of decrease rolling resistance. High-purity silica is processed into Canadian silica exports (Dumont 2006). Solar-Grade Silicon silicon for electronic (e.g. computers), photovoltaic and Worldwide demand for S i l i c o n p l a y s a c r u c i a l r o l e i n Polysilicon, refined from silicon speciality silica applications. Global silicon is expected to rise making computer metal, is the most important sales of speciality silica products dramatically through microchips—hence semiconductor material used in alone total about $2000 million per 2012, driven largely by the name "Silicon making solar cells. Polysilicon year (Harris 2003). increased consumption of shortages are currently a speciality silicas and other Valley." Microchips or integrated circuits limiting factor in solar energy The rubber industry consumes silica-based chemical are etched onto the growth. Research is ongoing to about half of the world's speciality products such as solar- surface of a thin develop more cost-effective silicas (Harris 2003). They are also g r a d e s i l i c o n f o r ways of manufacturing solar- “wafer” of ultrapure used in making inkjet paper and photovoltaic cells (CRU grade silicon. (>99.99%) silicon. other high-end paper products. 2008). Mineral Commodity Profile No. 2 Silica / 1 Silica Exploration and Mining in New Brunswick New Brunswick's quartzose sandstones were quarried for decades as dimension stone, millstone and grindstone material. Quartz veins in the province were (and still are) prospected regularly for gold. However, siliceous rocks in New Brunswick received little attention for their silica potential until the mid-1960s. In the early 1960s, the planned opening of a base-metal smelter at Belledune in northeastern New Brunswick prompted developers to examine a silica deposit at nearby Bass River (Fig. 1) in anticipation of selling smelter flux. The Bass River quarry was opened in 1974 and two years later was acquired by Chaleur Silica Inc. The company supplied >90% SiO2 flux to the Belledune smelter from 1976 until 1986. As well, it regularly shipped other silica products to local consumers. Silica extraction at Bass River ended in 1992, five years after Chaleur Silica lost its smelter contract. L.E. Shaw Limited of Nova Scotia acquired the property in 1992 but has yet to reactivate the operation (Webb 2006). Silica products from the Atlantic Silica Inc. plant at Cassidy Lake range from quartz In southern New Brunswick, the noted in the late 1970s when a potash pebbles to fine-grained sand. Burchill Road quartzite deposit exploration drillhole intersected 150 m of southwest of Saint John (Fig. 1) was white quartzose material. When the silica Sizing Silica investigated in the late 1960s as raw unit was drill-tested and analyzed, results Silica is processed according to three size indicated a reserve of 16.7 Mt of high- material for smelter flux, concrete categories, each with specific industrial whitener and sandblast sand. grade (98–99%) SiO2 in the form of poorly applications. Lump silica (3 mm–15 cm) consolidated Cretaceous sand and gravel is obtained from vein quartz, quartzite, A New Brunswick Department of (Lockhart 1984). and quartz pebbles. Silica sand (3 Natural Resources (NBDNR) survey mm–75 ųm) is derived from sandstone of provincial silica resources The Cassidy Lake operation started or unconsolidated sand deposits. Dry (Hamilton and Sutherland 1968) production in 1986 under what became grinding of silica sand yields silica flour encouraged work on the deposit, Sussex Silica Inc., and a processing plant (<75 ųm). including sample analyses and was erected on site. Atlantic Silica Inc. Silica Use in Canada b e n e f i c i a t i o n t e s t s . L e g a l acquired the Sussex Silica assets in 1993 2005 preliminary figures (from Dumont 2006) complications over land tenure and currently manages the quarry and Lump silica 28.9% facilities. Nova Scotia-based interests emerged in 1971, however, and Sand 68.6% development ended around 1974. took ownership of Atlantic Silica in early Silica flour 2.5% 2003. In the mid-1970s, silica deposits on Nantucket and White Head islands in Silica resources at Cassidy Lake comprise southwestern New Brunswick (Fig. about 20 Mt of material averaging >99% 1) were considered as a potential SiO2, 0.06% Fe2O3, <0.01% CaO and source of ferrosilicon feedstock. The 0.2% Al2O3 (Atlantic Silica Inc. 2003). The deposits underwent some mapping, processing plant sells its silica products sampling and drilling, but efforts across eastern Canada and the ceased in 1975. Around the same northeastern United States. time, a similar, short-lived exploration program took place on a End uses of the sand- and pebble-sized quartz vein east of Saint John. materials include silicon metal, silicon carbide, glass, recreational sand, The Cassidy Lake deposit near decorative stone, filtration sand, foundry Sussex (Fig. 1) is New Brunswick's sand, refractory sand, smelter flux, most productive and longstanding cement additive, landscaping material Cassidy Lake silica operation. silica operation. The silica was first and construction sand. Mineral Commodity Profile No. 2 Silica / 2 Geology of New Brunswick Silica Deposits Silica deposits generally consist of quartz particles Mabou groups. The silica-rich material comprises quartzose derived from the weathering of igneous and metamorphic sand and quartz-pebble to quartz-cobble gravel within a sandy rocks. After being redeposited elsewhere, the granular to argillaceous matrix. sand and/or pebbles can either 1) remain as poorly The Cassidy Lake deposit is interpreted as a thick remnant of consolidated quartzose sand and gravel, or 2) become Cretaceous sand and gravel preserved in a narrow, fault- compacted into sandstone or quartzite. Less commonly, bounded basin. The silica-bearing material is truncated to the silica deposits occur as hydrothermal quartz veins. east but continues westward along the fault trend, possibly Silica in New Brunswick occurs in a variety of geological becoming finer grained to the southwest. environments (Fig. 1), some of which favour the Cretaceous sand and gravel deposits resembling those at formation of high-grade deposits. Available data suggest Cassidy Lake have yet to be located elsewhere in New that several areas of silica-enriched rocks in the province Brunswick. However, remnant deposits may exist in merit thorough exploration and testing to determine their structurally similar settings—that is, on the down-ice side of industrial silica potential. down-faulted blocks in horst-and-graben terrain. Other potential New Brunswick's silica deposits are divided into four deposit sites could include the area immediately south of the categories, based on their geological setting. Harvey–Hopewell Fault in southeastern New Brunswick. 1. Cretaceous quartzose sand and gravel: poorly consolidated sedimentary material, weathered from older siliceous rocks and deposited in ancient lakes and rivers. 2. Late Carboniferous quartzose sandstone and quartz-pebble conglomerate: quartz grains and/or need Cassidy lake photo here pebbles bonded loosely or firmly by a matrix of clay, (preferably geological, not industrial) calcite, iron oxide and/or siliceous material.