Use of captured cement dust for making mass-use glass

Abstract

It is shown that there is promise in using dust from electric filters, which are used in cement production, for making sheet (heat-insulating) and container glass. Adding 5 -15% dust to the batch makes it possible to decrease or eliminate the use of natural and artificial material without degrading the quality of the glass with respect to gas-containing inclusions. As the dust fraction increases the equilibrium of the oxide forms of iron in the glass shifts in the direction of higher degree of oxidation, which is explained by the presence of sulfur containing compounds.Key words: salvaging of wastes, cement dust, mass-use glass, spectral characteristics, equilibrium oxide forms of iron, chemical need for oxygen in the batch.The problem of reducing the cost of mass-use glass (sheet, container) while preserving or improving its equality is a key problem in a market economy. The best way to reduce the production costs is to use in the technological process wastes from other industries [1].It is well known that cement production generates large quantities of dust. Dust formed during the preparation of the initial mix, calcination of clinker and pulverizing cement, is ordinarily returned into production. However, this is a forced step, as a result of which the properties of the material can be degraded because of the accumulation in it of alkali-metal oxides which have a negative effect on the strength of concrete block [2].Successful use of wastes requires that their composition be close qualitatively and quantitatively to that of the products from industries where the use of wastes is planned. On this basis it is desirable to use the dust from cement production in glassmaking technology.The present work studies the possibility and prospects for using captured dust from cement production for making glass.Considering the high content of iron oxide in cement dust, compositions of sheet heat-insulating (composition 1) and container (PT glass -composition 2) (Table 1) were chosen for this study.The batch was made using raw materials with the following content (%) 5 of iron oxide (III): sand -0.022; feldspar concentrate (FSC) -0.3; dolomite -0.2; chalk -0.08; soda -0.006. In addition, 5, 10, or 15% cement dust was added to heat-shielding glass and 5% electric-filter dust from cement product (CD) in Novorossiisk was added to container glass. The composition of the dust in terms of dry matter was a follows (%): 21.91 SiO 2 , 4.41 Al 2 O 3 , 4.01 FeO 3 , 63.60 CaO, 0.68 MgO, 2.28 SO 3 , 0.53 Na 2 O, and 2.58 K 2 O.Marl was used at the enterprises in Novorossiisk to obtain clinker -carbonate -clayey sedimentary rock to which pyrite cinders were added.The calculations showed that using such a product in the preparation of glass batch will make it possible to decrease partially or completely the use of conventional materials with