Patent EA-004259-B1 (EA)
Title: Method for producing glass nd glass produced thereby
Inventor: JUUL MARTIN
IPC: C03C6/02
Filed: 2000-12-06
Abstract: 1. A method for producing a glass produced on basis of a raw material in form of a mixture of mainly mineral containing components, and where the raw material after initial pretreatment is pressed to dry briquettes that are hardened and subsequently melted in e. g. a blast furnace under oxygen supply, and the melt is quenched and dried, characterised in that the pretreatment comprises the steps of: -producing a mixture of mineral-containing components from sludge from e. g. purification plant and one or several other mineral-containing waste products and/or natural rocks, -thermically decomposing the content of the mixture of soluble organic material, and -adjusting the water content of the mixture to between 20-35 wt%, and preferably between 27-33 wt%. 2. A method according to claim 1, characterised in that the briquettes are melted under additional energy supply from combustion of a fuel in a quantity of max. 10 wt% of the quantity of briquettes to be melted. 3. A method according to claim 1 or 2, characterised in that the briquettes have a density of 1.2-1.3g/cm<3>. 4. A method according to claim 1, 2 or 3, characterised in that the briquettes are hardened at a temperature of between 75 degree C and 110 degree C to a water content of 15-20wt% 5. A glass according to claim 1, characterised in that the glass contains more than 30 wt% inorganic components from sludge. 6. A glass according to claim 5, characterised in that the mineral content of the glass is in oxide form and that the weight percentages of the mineral oxides silicon dioxide (SiO2), dialuminium trioxide (Al2O3), diferritrioxide (Fe2O3), calcium oxide (CaO), magnesium oxide (MgO) and diphosphorus pentaoxide (P2O5) together constitute at least 90 wt% of the glass. 7. A glass according to claim 6, characterised in that the ratio of the weight percentages of the mineral oxides calcium oxide to diphosphorus pentaoxide in the glass is determined by the inequation wt% CaO >= 1.33 * wt% P2O5 8. A glass according to claim 6 or 7, characterised in that the weight percentages of the mineral oxides calcium oxide, diphosphorus pentaoxide, and magnesium oxide in the glass relate to the weight percentage of silicon dioxide in the glass such that the relation is between 0.15 and 0.5. 9. A glass according to any of the claims 6-8, characterised in that the ratio of the weight percentages of the mineral oxides diferric trioxide to dialuminium trioxide in the glass is between 0.56 and 1.00, and that the ratio of the weight percentages of silicon dioxide to dialuminium trioxide in the glass is between 2.2 and 3.2. 10. A glass according to any of the claims 5-9, characterised in that the specific density of the glass is between 2.7 and 3.1g/cm<3>, preferably between 2.8 and 3.0g/cm<3>, and especially 2.9g/cm<3>. 11. A glass according to any of the claims 5-10, characterised in that the glass has a hardness of HV100 >= 600. 12. Use of the glass according to any of the claims 5-11 and where the glass is graded, characterised in that the graded glass is used for sand blasting.