Materials characterization of the Libyan Ashi-Shibat desert sand

Elemental silicon is produced mainly by the Carbo-thermic reduction of silica sand [1]. This technique produced rather impure silicon, which is termed as metallurgical grade silicon (MG-Si). An upgraded MG-Si, produced from high purity silica, is usually used to produced semiconductor and solar grade silicon tilized in the manufacturing of microelectronic components of integrated circuits, transistors and solar cells. In this paper, sand from one of the Libyan desert formations called Ash-Shibat, will be characterized to explore the possibility of its use in the production of high purity silicon. Such sands are thought to be suitable for the production of silicon used in electronic industry. Chemical analysis, x-ray diffraction, and scanning electron microscopy are the main techniques used to characterize the sand and to asses the type and amount of impurities present. The results indicate that impurities such as B, Na, Ca, K, Mg, Al, Ti and Fe are present in the as received sand in trace amounts. These impurities were found to be contained mainly on the sand particles exterior surfaces, and in the binding material between them. The interior of the form of quartz silica. It is concluded from this study that further purification and processing of Ash-Shibat sand should produce high purity silica that can be used for producing electronic industry grade silicon. (author)