Resource World Magazine

66 www.resourceworld.com A P R I L / M A Y 2 0 1 8 Developments in Green Technology by Jane Bratun GREEN TECHNOLOGIES SILICA – THE HEART OF GREEN TECHNOLOGIES Silica, where Green Technologies begin, is a common oxide form of silicon. Silicon is commercially prepared by placing silica in an electric arc furnace. Silica is an abundant mineral in the earth's crust and it exists in sand, as quartz, and as other minerals such as amethyst. Silica doesn't conduct electricity and has a very high melting point. When it is exposed to high temperatures and cooled at a certain rate, melted silica will solidify to form glass. Silica is widely used in the ceramic, glass and cement industries. Silicon is part of group 14 on the periodic table and is con- sidered a metalloid. Silicon has many of the aspects of metal, meaning it bends but does not break, does well under heat, is malleable and has a high melting point. The lack of conductivity in silicon keeps it from being fully classified as a metal. While silicon is the second most abundant element in the Earth's crust, it is harder to find as a valuable, pure, free element. While quartz does not conduct electric current, it has some unusual characteristics related to electricity, namely the piezoelec- tric effect. Mechanical pressure on a quartz crystal produces an electric spark. That's why it is used in cigarette and barbeque light- ers. The opposite is also true. In a quartz clock or watch, the battery sends electricity to the quartz crystal through an electronic circuit. The quartz crystal oscillates (vibrates back and forth) at a precise frequency, enabling the watch to keep time. Quartz crystals rubbed together create yellow-orange light, called triboluminescence. One of the most important roles that silicon plays is in other forms of modern technology. Purified silicon (high-purity quartz, SiO 2 ) is used in semiconductor electronics and makes up many inte- grated circuits in computers, meaning that much of the technology we use is dependent upon silicon. Various forms of silicon are the basis for solar cells, which turn light into power in solar modules. Solar modules absorb sunlight as an energy source to generate elec- tricity or heat. A single solar module produces a limited amount of power; most installations contain multiple modules. A photo- voltaic system typically includes an array of photovoltaic modules, an inverter battery pack for storage, and interconnection wiring. Costs have continued to fall so that in many countries solar power is cheaper than ordinary fossil fuel electricity from the grid. EXPLORING FOR SILICON RESOURCES HPQ Silicon Resources Inc. [HPQ-TSX] is implementing a busi- ness plan to revolutionize solar grade silicon metal (SoG Si) metallurgical production. The company aims to become a pro- ducer and manufacturer of multi and monocrystalline solar cells of the P and N types, required for production of high perfor- mance photovoltaic conversion. HPQ uses its PUREVAP™ Quartz Reduction Reactor (QRR), developed by its partner, PyroGenesis Canada Inc. [PYR-TSXV], a leader in the design, development, manufacturing, and com- mercialization of advanced plasma processes. HPQ owns the PUREVAP™ intellectual property (patent pending) through a binding agreement with Pyrogenesis, and HPQ provides the stra- tegic direction, marketing, and funding for the project. The PUREVAP™ QRR is a second generation carbothermic process for reducing quartz (SiO 2 ) in one step into high-purity silicon metal (Si) and solar grade silicon metal (SoG Si) for use in solar panels. Until now, a traditional three-step process trans- forms quartz in SoG Si and is the biggest contributing source of CO 2 emissions and chemical pollution related to producing the solar cells needed to convert the sun's energy into electric- ity. HPQ's new one-step process promises to drive down the cost of solar cells and greatly improve the carbon and environmental footprint of SoG Si production. According to HPQ, their unique one-step process eliminates aggressive chemical use and dangerous by-product produc- tion during the refining phase and reduces the energy carbon footprint for producing SoG Si by a least 75%. This number is justified because the process eliminates emissions by not using chemicals, and deletes the additional purification step, eliminat- ing energy consumption for that step. According to the company, the PUREVAP™ process promises to reduce capital expenditure costs for new SoG Si capacity by as much as 95% and the operat- ing expenses for making SoG Si by as much as 80%. HPQ also owns 11 high-purity silica projects in Québec, two of which have substantial historical resources – Roncevaux (414,700 tons) and Martinville (1,092,000 tons). The company plans to spin out its Beauce gold project to a subsidiary, Beauce Gold Fields Inc.

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