PROCEDURE FOR LAEUTERN OF GLASS

The invention concerns a new procedure for the Läutern by glass, with which it is possible, a waste material, which so far due to his toxicity on special refuse dumps had to be deposited, in an environmentally friendly manner and profitably to begin. The new Läuterungsverfahren according to invention is applicable for glazier-witnessing enterprises, in particular Kristallund Bleikrlstallglashersteller, which polish polished glasses by means of hydrofluoric acid sulfuric acid mixtures. Other glazier-witnessing enterprises can naturally likewise use the Läuterungsverfahren according to invention, if they refer the raw material of such factories, with which it when polishing the polished glasses result. The invention brings distributes in two different regard: First of all it is possible erstle according to invention of mark, the polluting waste material “neutralization mud”, as it with the today predominantly usual procedure of polishing cross section-glass with a hydrofluoric acid sulfuric acid mixture inevitably results, completely and damage-free to eliminate. The second advantage of the procedure according to invention is in that thereby a Läuterungsverfahren is created, which represents a substantial technical progress in relation to the procedures used at present, by avoiding the problems of the latters. After the today's state of the art polishing polished Artlkeln from Kristalloder lead crystal glass takes place predominantly by means of baths from hydrofluoric acid or sulfuric acid, this either separately for changing immersing or as mixture. These Säurebäder become useless after repeated use by dilution with washing water, enrichment also from the glass cleared away materials and losses at HF (Zeitschr. “Speech hall” Loburg 1973 No. 10/12/15/18/17, J.C. Keusch, “the acid polish of crystal glass”). They must be led then in catchment basins and neutralized therein with calcium hydroxide. The developing thin mud or breaking into thickened by presses can be deposited afterwards only on Sandermülldeponien. It is however even also this handling today already disputed, there the contents of few PbO and about 9% F, related to which, groundwater impurities let Trockensubstanz fear. The remaining components are on the average about 40% sulfate (when SOs computes, from the principal part of the polishing acid being due), 41% calcium oxide (from the neutralization means) and about 10% earlier glass components (PbO, Siez, AIzO3, alkalis etc.). Läuterungsmittel are to bring in a Glasschmelze inevitably existing vesicles to ascending. Their lift speed is not sufficiently increased ago alone by the temperature of the melt, since the viscosity of the glass does not drop under 30 to 40 Poise. Therefore the Läuterungsmittel is to as only as possible develop gases, which up-tear the smaller in form of larger blisters also at the highest temperatures of the Glasschmelze (Oldenbourg Verl. Mchn. 1957, Kitaigorodski “technology of the glass”, part of IL, chapter IV, exp. 2,1, 2,2 and 2,3 “Läuterung”). As Läuterungsmittel so far admits " a) oxygen-delivering Steffkombinationen is, prefers Kaliumoder Natriumnitrat as well as arsenic tri oxide or antimony tri oxide. The nitrate component develops free oxygen, that by its decay between 800 and 1100 K from Arsenbzw. Antimony tri oxide under formation of the Pentoxyds to be taken up is. At approximately 1559 K then the arsenic (antimony) begins - Pentoxyd with oxygen delivery under recovery to the tri oxide. These oxygen quantities cause the “chemical Glasläuterung” when their ascending, in particular from crystal (lead crystal) - glass ones. b) Sodium sulfate, preferentially assigned with N1assengläsern, melts at 1157 K and reacts with the sand starting from approximately 1250 K, whereby it delivers Schwefeltriexyd. This läutert partially in undecomposed form or splits - particularly at high temperatures - into sulphur dioxide and oxygen, which take over then for their part the Läuterungsaufgahen. c) Barium sulfate is used very rarely for bariumoxydhaltige glasses. d) Chloride and fluorides not as exclusive, but only Läuterungsmittel to a) or b), additional as, assigned, since their relevant effect is weaker and forbids themselves larger additives because of turbidity of the glass. e) Additionally ammonium salts are also only used because of their to early dissociation (very rarely). (Springer publishing house 1959, Jebsenarwedel “glass-technical factory defects”, chapter IV, exp. 4, “Ohemi Läuterung”) Nr.365546 (HVG = hut-technical. Combination D. German glass industry Frankfurt 1, Mendelssohnstr. 70, HVG Kursberichte, number 1962, page 14-17 and number 1975, lecture VI, chapter 3,2 “chemical Läuterung”) (HVGFrankfurt, Glashfittenhandbuch, chapter F 40, Wickert “Läuterungsmittel”). The criticism of the state of the art is directed against the following points: To the produced quantity of glass improved by cross section is allotted a portion from about 1.5 to 3% of part-drained mud or about 1 to 2% drying material, this waste must be collected at present and occasionally with tankers or in plastic bags to special refuse dumps be removed. lg those admitted Läuterungsmittel at present show all certain weaknesses; A} the combination alkali nitrate + arsenic (antimony - Trfoxyd because of the too early oxygen delivery of the first a substantial overdosing of it, so that still sufficiently O.ù can become to the tri oxide “handed over”, the two latter are required of extraordinary and/or, high toxicity. In addition arsenic tri oxide makes the glass sensitive to sunlight () and antimony tri oxide shows somewhat slower Läuterung and a decreased “chemical decolorization” of the glass (Akad. Verlagsgesellsch. Leipzig, R. Schmidt “the raw materials for glazier generation” 1958, S.393, “antimony oxide”). b} sodium sulfate can rise after melting and form on the glass bath swimming “Galle”, which disturbs the fusion process in many respects much. Likewise disturbing, at least with the port glass melt with their only small free glass surface the Sehaumbildung is caused, by around approximately 20 {} K to early gassing with simultaneous reduction of the Oberfläehenspannung of the melt. A further, theoretically more clarified, practically however observed again and again disadvantage of the sodium sulfate the easy Grünstich of the glasses geläuterten thereby is not completely. Probably also thereby the too early gas delivery plays a role, with which the further dismantling of the sulfur tri oxide in sulphur dioxide and oxygen runs too slowly and is not present from there from the latter sufficient in the melt, in order the “chemical decolorization” to let run off (oxidation of the bluish green FeO to the yellow Fe2 03} completely. Sodium sulfate could not become generally accepted straight for the Läuterung of Kristallund lead-crystal-glass from there so far. c) Barium sulfate can be used only for glasses, which are bariumoxydhaltig also from the composition. In addition barium sulfate behaves as relatively heavy melting. d) and e) Chloride, fluorides and ammonium salts are too weak as exclusive Läuterungsmittel in their effect. The invention is the basis the task to use the disturbing and polluting waste product “Neutralisationsscblamm from the acid polish of glass ones” profitably as Läuterungsmittel for glass (Kristallund prefers lead crystal glasses) with technical distributing opposite used the so far. Article this task of solving invention is a procedure for the Läutern of glass, which is characterized by it that one adds the Glasscbmelze in place of all or the largest part of the Läuterungsmittel used so far neutralization mud from the acid polish of glass, these contains analysis in accordance with 35 to 45% of the dry weight CaO, 7 to 11% fluoride, 35 to 45% SO3 and residue parts from the polished glass. The following distribute obtained: The disturbing waste material “neutralization mud” is completely used up, thus on the one hand the removal of a noticeable quantity of garbage, on the other hand the critical (poisonous) portion of this garbage, the fluoride, to the all-largest part is void in a very stable form into the glass is built. In the long run still the part arriving into the atmosphere is in contrast to this minimum (estimated 1/12 to 1/10 of on the average 9% fluoride in the Trockenschlamm, thus not even 1% of the material, which is added to the glass again according to invention with 1 to 2%), this extremely small Sehadstoffmengen is thus by far under those, e.g. with production of mass-glass, like board, mirror or bottle glass, with its substantial mixture portions of calcium fluoride fluor-spar) and (or) sodium aluminum fluoride (cryolite), release. According to invention used the material represents in its combination of predominantly calcium sulfate with little calcium fluoride beside glass Bestanteilen a favourable Läuterungsmittal: Opposite the Läuterungsmittelkombination alkali nitrate arsenic (antimony) - tri oxide permits it complete omitting of the combination or the first Antei] it and a reduction of the latter portion particularly problematic by its toxicity on for instance a third D r to usual quantity (0.15 to 0.2 opposite so far 0.5 to 0.6%, related to finished glass). Opposite sodium sulfate leave themselves distribute by comparison of the characteristics between this and calcium sulfate to make clear: Thus the latter splits thermally around nearly 200 K more highly, thus at the most favorable glass temperature (starting from 17Q0 K). The blisters formed thereby are more oxygen-rich, since the dismantling of the sulfur tri oxide in sulphur dioxide and oxygen runs at high temperatures more rapidly. Thus again the Läuterung beside-going “chemical decolorization” (oxidation of the bluish green FeO to the yellow Fe 03) is perfect with the Calciumsulrat. Furthermore also no Galle can occur with calcium sulfate, since this melts only at 1670 K and also exhibits a substantially higher leg density (2.96 opposite 2,70). Specific warming (99.6 opposite 127,7 J/Mol.K) and fusion warming (28.0 opposite 28,7 J/Mol) beiS favorable likewise the Calciumsu] fat opposite the sodium sulfate (Lit.: D'Ans Lax, paperback for chemists). Finally calcium sulfate foam does not arise with the use ven, since the gas delivery takes place at higher temperature and thus smaller viscosity of the melt. All mentioned distribute (opposite the sodium sulfate) are equally valid for approx.] oiumsulfat as for the material according to invention. - With the past Läuterungsmitteln the sodium sulfate and/or. 2e Salpeter existing F] ußmittelwirkung is taken over with the material according to invention to the Te 1 by the portion of calcium fluoride. In addition will, in order to hold the earth composition of the glass, with application of the invention anyway the portion of Kaliumbzw. Sodium carbonate increased and at limestone reduces. The degree of purity of the neutralization mud according to invention will under normal conditions be sufficient by the relatively small auxiliary quantity, which is called that the portion of coloring metal oxides (z.Zt. for instance under 0,1% lies) does not disturb. It would be however even possible in case of higher requirements to take the invention in requirement since the quality of the neutralization mud can be increased to a large extent by the treatment of the waste in the Neutralisationsbecken and by use of a purer calcium hydroxide. 3e Ausführungsbeispie] e: The neutralization mud in the GLS factory by Fi] terpressen of the larger part of the water released - which already happens frequently at the purpose of the more comfortable refuse disposal. The damp material (the water contents lie between 30 and 40%) then, if possible dried using unused waste heat, since the quantities which can be mastered thereby are on with 3S small glassworks in the order of magnitude of 10 kg and approach only with the largest factories of the ton border per day, represents the acquisition or the self's building of such a drying device no economic or technical problems. The dried material will afterwards grind, whereby the run unit does not need to go under the natural granulation of the Glassandes (Kcrngrößen of up to 0.4 mm to have 0 as perfectly usable proved). It is important that the grinding tools are non-metallic (corundum, Mullit od.ähnl.). Also here the cutting up device can be kept very small compared with other machines of the glass factory. For the glass components remaining as bay plays specified glass-mixture-corrode a middle analytic Zusam &5 mensetzung the water-free material of 41% CaO, 40% S03, 9% F and 10% (K O, NATO, PbO, BaO, SiG2 among other things) one accepts. Is approx.] ciumoxyd bound to the larger part at S03 (than CaSO), to the smaller at F (than CaF). This would entail a mineralogisehe composition of 19,3% café, 70.3% CaSO and 10.4% glass remainders when total drying process. Since however the drying process will be usually made at temperatures under 403 K, which is also quite sufficient for the invention, one can assume then per molecule CaSO of” still 2 molecules water remain in the material (calcium sulfate dihydrate), while approx.] ciumfluorid no water holds. Then the mineralogical composition with 16,1% CaF2, 75.1% CaSO 2 H O and 8.8% glass remainders would adjust itself. From this middle composition of the material according to invention outgoing, arise (with neglect of the latter, only the glass quantity, but not the glass composition of changing portion) as “glass factors” for the list mixture-corrode: 0.26 GaG, 0.13 CaF2 and 0.09 SOs. (From empirical values a loss of approximately 75% with the SOa and such were accepted of 8% with the F.) I. Production (with Läuterung according to invention) of a crystal glass (lead free] by means of port furnace melt (mixture set and resulderende composition): kg quartz sand 9 kg limestone 6 kg barium carbonate kg of potash calc. 9 kg soda calc. heavily 1.5 kg of borax calc. 0.2 kg antimony tri oxide 1.4 kg according to invention used material 73.42% Si02 5.21% CaO 4.57% BaO 9.81% K2 0 5.53% Na2 0 0.96% BsOs B, 19% Sb2 0s 0.18% CaFs 0.13% SOa 2nd production (with erfindungagemäßer Läuterung) of a lead crystal glass (24%) by means of port furnace melt (mixture set and resulting glass composition): 100 kg quartz sand 43 kg of red lead purely 23 kg of Pottascbe calc. kg soda calc. heavily 3 kg limestone 0.2 kg arsenic tri oxide 1.7 kg according to invention used material 59.26% SiO, 24.94% PbO 9.11% K2 0 5.15% Na2 0 1.24% CaO 0.08% As=Os 0.13% GaF= 0.09% SOs in both remark examples mentioned if necessary (higher accumulation] usable additionally according to invention material can be used, whereby in the exchange the half quantity of limestone is to be omitted in each case. 3. Production of a by machine formed crystal glass (lead free) in a glass tub furnace (computes for l-ton-mixing) (mixture set and resulting glass composition): 590 kg quartz sand 70.05% SiO 2 13 kg alumina hydrate 1.02% Alz 03 12 kg of borax calc. 0.93% B2 0s 170 kg soda calc. easily 11.55% Na2 0 kg of potash calc. 3.97% K=O kg barium carbonate 6.47% J aO kg limestone 5.37% CaO 17 kg according to invention used material 0.26% CaF= 13 kg alabaster gypsum 0.38% SO 4th production of a flat glass (Tafeloder mirror glass) with a maximum portion of according to invention used material, as it can be processed only in a tub furnace melt. In addition theoretically resulting glass composition. (Mixture set computes ffir a 1000-kg-Mischer.) 540 kg quartz sand drying kg of Feldepat (localhook read-rich) 7 62% SiO 1.01% AlsO3 I0 200 kg soda calc. easily kg limestone 130 kg dolomite kg according to invention used material 13.94% Na=O 0.52% K2 0 8.91% CaO 3.35% MgO 0.97% CaF= 0, fi8% S03 Nr.365546 production of a lead, bariumund arsenic-free Kristal] of glass with relatively small, but straight still portion of according to invention used material, sufficient for the exclusive Läuterung. (Mixture set computes sand on 100 kg.) I00 kg quartz sand drying 21 kg of potash calc. 8.5 kg soda calc. heavily 17 kg limestone 1.8 kg according to invention used material 77.40% SiO= I0.86% KzO 3.81% Na=O 7.62% CaO 0.18% CaF= 0.13% SOs PATIENTN FR RÜCH E: I. Procedure for the Läutern characterized by glass, thereby that one the Glasschme] CPU neutralization mud from the acid polish of polished glass ones, containing 30 to 50% of the dry weight CaO, 30 to 50%-Masse SOs, 6 to 12%-Masse fluoride, remainder usual G] asbestos-and-divides, if necessary together with flbliehen Läuterungsmitteln, adds. 2. Procedure according to requirement i, thereby is added characterized that for Hafenglasofensehmelzen the neutralization mud in a quantity from I to 2,5%-Masse as Läuterungsmltts] alone or together with As2 OS or Sb= 03 in a quantity from 0,1 to 0,2%-Masse or together with iron-poor gypsum in a quantity from 0,5 to l%-mass, in each case related to the finished glass. 3. Procedure according to requirement I, thereby characterized that for tub glass furnace melts the neutralization mud in a quantity from i to 3%-Masse mixes as Läuterungsmittel alone or together with iron-poor gypsum in one from 0,5 to 2%-Masse, related to which finished glass is used. Druok: Ing.E.Voytjech, Vienna