The effect of individual production factors on the heat tolerance of glass containers is studied. It is shown that the use of quartz raw material distinguished by its fineness from the material adopted for a technological process in a given glass-making furnace can result in massive production rejects, consisting in the appearance of seeds and heat intolerance. The phenomenon is explained from the standpoint of oscillations of the heat tolerance index of molten glass.
The formation of the equilibrium Cu(I) « Cu(II) in colored optical glasses under the combined action of several factors is examined. It is shown that the oxidation of copper intensifies with increasing total copper content by weight, increasing content of carbonates in the mix, and increasing basicity of the matrix and depends primarily on the ratio of chromium, arsenic, and copper oxides. A factor is proposed for making a quantitative assessment of the combined effect of the chromium and arsenic oxides on the copper equilibrium.Colored optical glass is used in instrument building to produce color filters that regulate light transmission in the visible and nearby IR and UV regions of the spectrum. To obtain the require spectral characteristics copper oxide is introduced into the mix for blue (BG), blue-green (BGG), and violet (VG) glasses and copper oxide together with chromium oxide is introduced into green (GG) and yellow-green (YGG) glasses (OST 3-4375-79). Up to 0.1% As 2 O 3 (molar content) is introduced into individual compositions in order to correct the optical and operational properties.The following expression is used to evaluate the specific index of absorption c l of a coloring element in glass in order to make a quantitative evaluation of the intensity of absorption by the element:, where t l is the light-transmission of the glass sample, fractions of unity; D rm is a correction for reflection, calculated according to the relation [1] D rm = -2log(1 -r ); l is the thickness of the sample, cm; and, m Me(total) is the content by weight of the coloring element in the glass in terms of metal, %. The scattering index r is related with the index of refraction n of the glass by the expression [1] r = ( ) ( ) n n -+ 1 1 2 2 .Copper and chromium are d elements. In silicate glasses each element coexists in two valence forms: Cu(I), Cu(II) and Cr(III), Cr(VI). Their spectral curves of the specific absorption index c l are presented in Fig. 1 [2]. Univalent copper has no absorption bands in the visible and closest adjoining regions of the spectrum, and Cu(II) forms two complexes with oxygen -a quadruply coordinated "yellow" complex absorbs in the short-wavelength region and a "blue" complex [Cu(II)O 6 ] possesses an intense band at 750 -800 nm.Hexavalent chromium intercepts radiation in the blue part of the spectrum, while tetravalent chromium has two strong bands in the visible region near 460 -480 and 660 -680 nm.It is evident that the spectral curve and the light transmission of glass colored with copper or with a combination of copper and chromium will depend considerably on the ratio of the oxide forms of these elements, i.e., on the equilibrium Cr(III) Cr(VI), Cu(I) Cu(II).The equilibrium between the oxidized and reduced forms of the d elements has been studied in greatest detail for the iron impurity most often encountered in glass and depends on the set of parameters of the technological process: amount of d element, acid -base properties of the glass matrix, oxidation -reduction and temperature -time co...
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
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