Tailings and mine waste reprocessing for production of the foamed glass

The activity of some mining enterprises is accompanied by accumulation of a huge quantity of the fine-dispersed wastes since at exploitation the country rocks of ore deposits are crushed up to 100 microns. Only after that the ore components are extracted with content varying from 1 to 50 % for different types of deposits. The rest 99–50 % of unproductive rock are stored as slime occupying the wide land areas and requiring significant financial expenditure for the keeping. The technology is suggested to utilize such slimes from alumosilicate rocks to obtain the building foamed glass. Theoretical and experimental data show that for production of the foamed glass the slimes of those rocks are appropriate whose melts viscosity is 10 3 – 10 5 Pas at their liquids temperature since such viscosity is optimal for generation and conversation of the foam structure of the melts. This requirement is satisfied by such widespread rocks as granites, syenites, rhyolites, andesites, trachytes, phonolites and some other. To obtain the building foamed glass the slimes are mixed with foaming agents. This mixture is used to form granules or blocks which are heated later up to nearly 1150°C. There is a partial melting of the slime and intensive decomposition of foaming agents with emission of gas which foams the slime being in pyrqolastic state due to its partial melting. As a result, the alumosilicate froth forms which produces the material of foamed glass type at cooling. This foamed glass has a volume weight of 300–600 kg/m 3 . Its compressive strength is 8–10 MPa and heat conductivity is about 0.15 Wt/ (m·K). Thus, this material may be used as light weight and thermal insulation building material. Its production is much cheaper than the production of foamed glass from the specially prepared glass.