This paper presents theoretical calculations and the results of laboratory experiments showing that almost all quartzite, carried away as a fine dust phase in gas removal and gas cleaning, presented spheroidized micro- and nanoparticles of SiO2. It takes the dust of gas purification from the class of "waste" in class "product" if  carbon impurities, which invariably accompanies in a fine dust, will be removed.

As a result of studying the properties of the dust production of silicon revealed that 85% of it represented with spheroidized particles of SiO2, and the resulting amounts of dust makes a promising source for production. The best process for extracting the associated carbon nanotubes is flotation. Floating particles of micro and nano-sized particles should be carried out in a laminar flow of the pulp with the fewest basic flotation cycles. In the  thick layer of watery foam microspheres and nanospheres of silica are washed away in the chamber of the product interbubble channels. Flotation air bubbles should be nano and micro size. Initial bubbles emerging from the aerator must be close to monodisperse distribution. The reagents used need to be more soluble in water than conventional. As the aerator should be used pneumohydraulic aerator. To activate hydrophilized particles of valuable component need to use pressure flotation. To reduce energy consumption and time of flotation need the smallest number of elementary cycles of flotation (ETSF). Before and after the flotation conglomerates of valuable component particles with other particles should be broken, as well as to make the necessary removal of impurities of the sand slurry.

The results demonstrated that as a co-product along with the metallurgical silicon is formed a large amount of dust containing up to 85% of spheroidized micro- and nanoparticles of silicon dioxide and up to 10% carbon nanotube content and other nanoparticles. Enrichment product possible to 99.5%. Further enrichment requires additional research.