There are a number of isolation methods that can be used to isolate pure silicon; which method that is used depends on what the silicon is going to be used for, and how pure it needs to be.
Large scale isolation of silicon to be used for commercial purposes is isolated from silica. Silca minerals such as sand, quartz, rock crystal, and agate, all contains high amounts of silicon dioxide in various crystalline forms. Through the isolation process, silica minerals that contain high purity silica are reacted with charcoal, coal, and wood in an electric arc furnace Carbon electrodes are used, and the furnace is heated to over 3452 °F. An electric arc furnace uses the electrical breakdown of gas through heat charged materials. Through the isolation process, liquid silicon is drained from the bottom of the furnace and then cooled. One another isolation reaction that results in pure silicon uses the reaction between silicon chloride with hydrogen.
