•'
`
`1h' 53 7 3 ? . 2/ i 0
`
`Chimica Chronica, New Series, 23, 21-29 ( 1994)
`
`RECYCLING OF CULLET AND FitTER DUST· CHALLENGES TO THE MELTING
`OF GLASS
`
`Helmut A. Schaeffer
`Huttentecbnische Vereinigung der Deutschen Glasindustrie (HVG)
`Deutsche Glastechnische GeseUschaft (DGG)
`Frankfurt am Main, Gennany
`
`Increasing ecological constraints linked with economic advantages have induced the
`recycling of cullet predominantly in the container glass industry as well as the recy(cid:173)
`cling of filter dust in various branches of glass production. The recycling of cullet
`originating from non-rerumable glass packaging was introduced more than 20 yeats
`ago, whereas the recycling of filter dust originating from waste gas treatment was
`started only a few years ago. The transition from ew.ploying basically constant raw
`materials to utilizing increasing amounts of recycled glass as the major batch material
`and the introduction of .filter dust as an additive (refining agent) have imposed new
`challenges on glass melting. Difficulties result from the incorporation and possible en·
`richment of impurity components such as metals and halogens and furthermore from
`the unknowu and changing contaminations of organic additives and/or reducing
`agents. Special effons are required to ensure a reproducible glass quality, e.g. an in
`situ conttol of the redox state dwing glass melting by means of eleetrochentical meas·
`urements. Finally, variations of glass properties due to the utilization of recycling
`glass and filter dust will be discussed.
`
`\.
`
`INTRODUCTION
`
`The remelting of ,glass cullet has been employed very likely since the early days of glass llWlU(cid:173)
`facturlng. By using cullet in the batch the melting process is facilitated due to the saving of the
`reaction enthalpies of the primary raw materials when forming the glass melt. Thus an ener·
`getic advantage is gained by ew.ploying cullet. The lllelting of glass using 100% cullet would
`theoretically result in an energy saving in the order of30% for soda-lime-silica glasses (1).
`
`A further advantage in utilizing cullet consists in reducing the primary raw materials 1n the
`batch which is of particular interest for the more expensive raw materials such as the alkali
`o,Qdes (2).
`
`The recycling of domestic (in· house) cullet is traditional practice in glass Jllelting; the recycling
`of foreign 'CU!let, however, was started only 20 years ago. Ecological constraints, in particular
`the l.imited availability of land.6ll sites, initiated the large scale recycling of glass packaging
`prOd\tctS such as bottles and jars The development of glass r-ecycling is sho'\-\<n in Table 1 for
`the case of Germany. The recycling rate in Germany bas reached a value of 63% (in 1991)
`correspondmg to 2.3 x 1()6 tons of recycled cullet. In terms of absolute tonnages of recycled
`,glass the German glass industry is leading, but with respect to national recycting rates it is sur(cid:173)
`passed by The Netherlands (73%) and Swit%erland (72%), see Table 2.
`
`As compared to the recycling of cullet, the recycling of filter dust was started only a few years
`ago. Filter dust is generated as an undesirable by-product as a result of waste gas treatment
`with the help of an absorption medium and by employing either electrostatic precipitators or
`bai filters. Utilizing calcium hydroxide as absorption medium the filter dust consists basically
`of calcium sulphate and unreacted calcium hydroxide. It turned out that the most elegant way
`
`O-I Glass, Inc.
`Exhibit 1039
`Page 001
`
`

`

`I
`4
`
`I
`(
`
`o • '
`'...,,.;
`
`22
`
`H. A. Schaeffer
`
`Table 1.
`
`Recycling ofPackagins Glass in Germany (J)
`
`-----····-·-···············~-~
`F. 3 . · 1 o
`
`~{ o. 5 e ·n
`
`year
`
`1974
`1980
`1985
`1990
`1991
`1992
`
`domestie sale
`in 106 t
`
`recycled glass
`in 106 t
`
`recycling rate
`%
`
`2.3
`2.5
`2.4
`3.3
`3.6
`3.8
`
`0.1.5
`0.57
`1.0.5
`1.8
`2.3
`2.5
`
`6.5
`23
`43,5
`54
`63
`6S
`
`Table 2, Recyclina ofPackaging Glass in Europe for 19.92 (4)
`
`country
`
`recycled glass
`in 103 t
`
`recycling rate
`%
`
`~rmany
`Franoe
`Italy
`United Kingdom
`Netherlands
`Spain
`Belgium
`Switzerland
`Austria
`Sweden
`Denmark
`Porrugal
`Greece
`
`'.l4.S9
`1100
`786
`459
`378
`312
`216
`212
`17.5
`16
`75
`62
`30
`
`65
`44
`53
`26
`73
`27
`54
`72
`64
`58
`48
`30
`20
`
`to disengage from the filter dust is its addition to the glass batch where it can substitute the
`refining agent. The quantity of Biter dust ax:aounts to about 3 k&'t glass, which corre&J>onds
`e:g. for the German glass U:ldustty to about 18 x 103 t of filter dust per year. Therefore the
`recycling of 6Iter dust is an economical relevllllt step since it relieves the glass industry ftom
`provicl..ing high costs for the storaae of special waste.
`
`2.
`
`2.1.
`
`UTILIZATION OF RECYCLED CULLET FOR GLASS MELTING
`
`IMPU1U1'1ES IN .RECYCLED CULLET
`
`For primacy raw materials the &J>ecifioations are well established and their quality control is as(cid:173)
`sured by various analytical tools. In the case of recycling foreign cullet for the container _g!ass
`industry the situation is much more -~o~cated. In order to ensure stability in glass homoge(cid:173)
`neity and coloration the recycled cullet bas to be separated from impurities such as ferrous and
`non-ferrous metals, ceramic materials (porcelain, stones, slags etc.) a:cd organic components
`
`;
`
`~ : .
`'
`'
`'
`
`' r·. 1 ti
`
`O-I Glass, Inc.
`Exhibit 1039
`Page 002
`
`

`

`17: 2 4
`
`WORLDWIDE SEARCHES
`
`No.5875
`
`P. 4/! 0
`
`Recycling of cults& and filter dust
`
`23
`
`(plastics, paper, food residues etc.) This kind of cullet processing has reached an advanced
`stage of automation (5).
`Furthermore the foreign cullet has ~o be separated according to colour (flint, green, amber).
`Unsep~ated ~~et (SQ:~a.!Je~_~_ed. -~~ll~)._can be introduced to green and to a certain extent
`~_&-~ut __ !!~- .flli:t! __ s!~~~· :!Vith a tj-pical production of flint containerglass in the
`order of 50% of total packaging glass production in Germany, therefore not even a ~0%
`recycling rate can be attained with unsepatated cuRet. Thus colQ_ur separa~ of recycled cullet
`is manda~in order to achieve high recyclb?.g percentages. Various systems with optical
`detecting devices are now available for the automatic separation of cullet according to colour
`(6), however, the first and .main approach is the collection of non-refillable ("one-way") glass
`packaging products according to colour.
`Table 3. Average Annual Data of Impurities in Processed Foreign Cullet According to
`Colour (7, 8)
`
`[glt] ~ppm
`
`1981
`
`cps •>
`Al
`Pb
`Fe
`
`cps •>
`Al
`Pb
`Fe
`
`cps •>
`At
`Pb
`Fe
`
`115
`54
`18
`1.6
`
`197
`234
`98
`1.6
`
`234
`173
`87
`0.4
`
`1987
`
`51
`9
`2
`0.5
`
`46
`69
`12
`0.05
`
`57
`36
`8
`0.1
`
`1993
`
`27
`2
`4
`1.8
`
`28
`l9
`18
`2.5
`
`34
`11
`14
`1.9
`
`flint glass
`
`green glass
`
`amber glass
`
`•)cps ~ ceramics, porcelain, stones
`
`Table 3 shows that even though remarkable improvements in the elimination of impurities were
`achieved over a time period of 12 yeats, yet, no absolute 11purifieation" of the foreign cullet can
`be r-ealized. Thereby in many cases the achieved level of impurity concentrations determines the
`percentage of eullet wbieh can be introduced into the batch without affecting the required
`r~producibiliey of the melting and forming properties attdlor the properties of the final ptoduct.
`Besides tbe separable impurities which are listed in Table 3, the recycled foreign euUet contains
`non-sepacable impurities which were incorporated during the melt history of recycled cu.llet
`due to different origins of the primary glass products, otber glasses not based on soda-lime·
`silica (e.g. opal glasses, lead oxide containing glasses etc.) and due to enrichment eifects in the
`course of recycling (e.g. filter dust recycling, interaction with combustion atmosphere and with
`refractory materials of the glass tank). n~ r~f}:fled cull~t~in various amounts of iron
`
`O-I Glass, Inc.
`Exhibit 1039
`Page 003
`
`

`

`- ----- .. --- ----
`---- . ~
`-
`WORLDWIDE SEARCHES
`17:26
`13. Jan. 1999
`
`.. ...
`
`H. A. s~.·haeffer
`24
`oxide, cb.r.o.mium o'9d..e, sulphur, fluorine an~ chlorine, as well as lead oxide, barium oxide, tin
`-
`-
`
`~.
`
`Table 4. Average Annual Data ofFe203 and Cr203 Concentrations in Pl:ocessed Foreign
`Cutlet (8)
`I wt%
`
`1987
`
`1990
`
`1993
`
`1984
`
`Fez03
`Crzo,
`
`Fe203
`Cr203
`
`0.077
`0.008
`
`-
`.
`
`0.076
`0.005
`
`-
`-
`
`0.0776
`0.005
`
`0.353
`0.196
`
`0.0723
`0.005
`
`0.361
`0.216
`
`flint glass
`
`green glass
`
`0.309
`0.043
`
`0.319
`0.044
`
`amber glass
`
`0.300
`0.026
`
`0.30
`0.033
`
`F~03
`Cr203
`Table 4 displays data with respect to colouring impurities such as iron oxide and chromium
`oxide. The requirements for the production of ''pure" flint glass are very stringent with respect
`to the concentrations of iron and cbtomiwn oxide. To illustrate this sensitive dependeuce it can
`be stated that only 50 g of wrongly coloured glass can be tolerated in I t of'recycled tlint ,glass
`(ie. 50 ppm). Such requirements can probably not be fulfilled with colour-separating
`technology. The high pwity of recycled flint cullet can only be achieved by carefUl hand sorting
`or by mechanical negative selection .6:om colour-separated cullet (6).
`It was proposed to initiate an international quality standard for recycled cutlet (9). However,
`the outlined variations of the cullet impurities, the different collecting and handling procedures
`ofthe cuUet represent a technical and economical barrier to assess such an endeavour. Never·
`theless, on the company level such quality requirements with respect to separable impwities
`and grain size do exist.
`CULLET AS MAJOR. BATCH COMPONENT
`2.2.
`In many glass plants of Western Europe the introduction of8Q to 100% ofrecy~~.!_~!Jllet fo!
`the melting of green container &lass is nowadays common practice. Thus recycled cullet has
`becotne the major raw material component in tbe ,glass batcb. This "novel" bat<:h formula gives
`rise for reinvestigating the various aspects of glass 1118.l1ufacturing as compared to a batch
`·
`comprised predominantly of primary raw materials.
`2.2. l. CHEMICAL COMPOSITION
`With increasing amounts of foreign -eullet in the batch only few options are left for the
`realization of patticular target compositions. In countries with a high recycling rate the glass·
`composition becomes almost indistinguishable among glass plants. There are interesting
`con$equences to be noted: ingredients added to the glass will be· also recycled and remain in
`the glass composition of the cullet for long periods. A beneficial additive e.g. would be lithium
`oxide as a flux agent in the melting process (''chemical boosting"), or boron oxide for the im·
`
`O-I Glass, Inc.
`Exhibit 1039
`Page 004
`
`

`

`Recycling of culler and fi/Jer dust
`
`25
`
`provement of chemical resiStance. On the other hand lead oxide in the recycled cullet is
`presently strongly debated. Lead oxide has entered the recycling process either intentionally
`(by exploiting the melt accelerating effect oflead oxide containins cullet) or unintentionally via
`the mridation of lead metal iolpurities in the recycled cuDet. The average lead content in the
`recycled glass in Western Europe amoW2ts to about 200 ppm. Unexpectedly this low level is in
`conflict with a regulatory bill passed by the Coalition of Notth Eastern Governors in the US
`restricting the sale of packaging materials containing impurities of heavy metals at the ppm
`level. The regulatory bill foresees limits of less than 100 ppm for the sum of lead, cadmiutn,
`mercury and hexavalent chromium ( 10). Unintelligibly this bill is also used as the basis for the
`.European Comnmnity Directive on Packaging which is presently before the Parliament.
`This example illustrates the susceptibility ofthe recycling process to intricate after-effects and
`it should lead to a Illore pronounced responsibility to prevent the incorporation of potentially
`detrimental components.
`
`2.2.2. REDOX STATE
`As eotnpared to glass melting with primary raw mat~als the melting 'With !.~~led cullet gives
`rise to al~erat~~~- of the redO?( .state of the. glas~ ~~t ~e_ t_()~~~~-~~t~ o~_organic ma~
`rials which are p.att of the recycled glass products. Whereas a cullet-ffee 6itcn can be charac(cid:173)
`terized by the redox number or by the chemical oxygen demand of the different components, it
`is very difficult to assign such characteristics to cullet which fluctuates locally and with time
`Vlith respect to its organic impurities. Nevenheless, successful attempts for the characterization
`ofthe redox state ofcullet are reported (11).
`The reducing power of the organic impurities lowers the oxidation state of the &lass melt and
`thereby has an inlpact on the coloration of the glass. In order to ~ain __ ~e target colours,it
`becomes neces~ to provide ad:c:!itives with oxidising power which compensate the reducing
`_grganic impurities. Due to the lack of feasible oxidising agents ttcan becOme attractiVe to ex(cid:173)
`ploit the higher oxidation state of flint glass cullet in order to adjust the required redox state of
`green or amber glass. On the other hand, however, the introduction of a mixture of differently
`coloured recycled cullet gives rise to the release of sol and thus to foam fonl1.ation. Therefore
`the oxidation of eullet which is contaminated Vfi.th orgallic materials represents a challenge to
`glass melting and various approaches are being discussed to overcome this problem, e.g.
`''weathering" of recycled cullet, preheating of the cullet batch and bubbling of the glass melt
`with oxygen.
`
`UTfi..IZA TION OF FU.. TER DUST IN GLASS MELTING
`3.
`The dry absorption of gaseous species $Uch as S02, S03, HCl, Hf and Se-containing eour
`pounds (decolorizing ag.en.t for flint glasses) which are present in the waSte gas requires the
`employment of either calcium hydroxide or sodium ¢atbonate (in the form of light soda). The
`absorption products are collected by means of an electrostatic precipitator ( 12) or a bag filter
`( 13). They consist of calcium sulphate, calcium carbonate, calcium chloride, calcium fluorid.e
`and unreacted calcium hydroxide or of sodium sulphate, sodium chloride, sodium fluoride and
`unreaoted sodium carbonate, respectively.
`In the case of high fluorine concentrations in the waste gas it is advantageous to utilize calcium
`hydroxide as absorption medium which forms calcium fluoride with a high absotption rate of
`up to 90%, whereas the utilization of soda results only in an absorption rate of 30% in the fonn
`of sodium fluoride (calcium fluoride i.s thermodynamically more stable than sodium fluoride).
`
`O-I Glass, Inc.
`Exhibit 1039
`Page 005
`
`

`

`! J, o U 11.
`
`i :J :J j
`
`] I , j ,
`
`JO. :)Oij
`
`r.
`
`tiiU
`
`26
`
`H. A. Schal.!fer
`
`On the other hand the opposite holds for high chlorine concentrations i.n the waste gas: soda is
`more effective to absorb ehlorlue as compared to calcium hydroJdde, because sodium chloride
`is more stable than calcium chloride.
`
`For waste gases which contain simultaneously high levels of fluorine and chlorine it is advisable
`to use a mixture of calcium hydroxide and soda as absorption tnedia or to proVide a two stage
`absorption process, first with calcium hydroxide, then with soda. The practical experience has
`shown that filter dust can be added to the batch and thus ca:o. be recycled pro\'ided that
`respective batch composition corrections are canied out, taking panicularly into account that
`sodium sulphate and calcium sulphate act as refining agents (14). It has been reported that
`calcium sulphate is a less effective refining agent for glass melts containing Olore than 90%
`recycled cullet. This is not swprising because the capability of calcium sulphate to act as re.fin·
`ing agent depends on the reaction with soda in the batch to form sodiulll mlphate. This reac(cid:173)
`tion Jl.\echa.tlism disappears 'With batch compositions consisting of hardly any raw materials.
`Therefore, the use of ligbt soda as absorption agent is of advantage provided that the fluorine
`concenttatio.a. in the waste gas is sufficiently low.
`
`3.1.
`
`IMPURITIES JN mE FILTER. DUST
`
`The recycling of filter dust requires a careful study of the compositional changes of the filter
`dust (15). Besides sulphur, especially heavy metals and halogens are incorporated in the filter
`dust ud thus can lead to enrichments of certaht elements' in the glass (16), see Table 5. Poten·
`tial candidates are nickel and vanadium ill the case of firing with heavy oil, furthennore lead,
`cadmium, selenium, chlorine, .tluoril1e, titanium and tin fro.t1l the raw materials and/or recycled
`cullet; the latter elements can also originate from the b.ot end treatment using SnC4 or TiC4.
`
`Mass balances 9fthe elements being added (via fue~ batch, filter dust) and being released (via
`emission, filter dust and glass product) have to be performed and discussed with respect to
`potential enrichment effects. So far no alai1l\iu.g enrichments have been detected which could
`be attributed to the recycling of the filter dust ( 12). The filter dust recycling will be jeopardized
`when the glass melt is saturated with the eles:nents in question. It Call not be excluded that this
`case will occur eventu.ally.
`
`3.2.
`
`OXIDAnON STATE OF FILTER. DUST
`
`Only recently it was recogniz;ed that the filter dust originating from electrostatic precipitators
`( 12) or bag filters ( 13) not necessarily acts as a refining agent, but ea:o. possess reducing prop·
`erties. In terms of the chemical.oxygen demalld (COD) values for filter dust were reported ( 17)
`which correspond to reducing agents such as calumite. This observation has raised the question
`for the parameters detetolining the oxidation state of the filter d~, i.e. which are the parame(cid:173)
`ters favouring the formation of sulphites or even sulphides instead of the expected sulphate
`fotnllltion. Which sulphur compound is formed depends e.g. on the type and grain size of the
`absorbents, the partial pressure of oxygen and water in the waste gas, and on the temperature
`and time in the reactor of the absorption stage. Presently an investigation is carried out to elu·
`cidate the parameters which have an il:npact on the oilidation state of the filter dust (18).
`
`· - - -.. ---------
`
`O-I Glass, Inc.
`Exhibit 1039
`Page 006
`
`

`

`13. jan. !999
`
`!7:33
`
`WORLDWIDE SEARCHES
`
`Recycling oj c:tUet and filler du.rt
`
`No r'73
`' :Jd'
`
`P. 81! 0
`
`27
`
`Table 5. Average sulphur and impurity concentrations with their deviation ranges
`of tilter dust and glass as monitored at a single regeneratively heated flint
`treatment: dry absorption with calcium
`glass furnace (waste gas
`hydroxide, electrostatic precipitator) over a period of 2 years with
`continuous recycling of filter dust ( 16)
`
`Component
`
`rllter Oust
`[mglkg] .Q ppm
`
`Glass
`
`TiOz
`VzOs
`Crz03
`MnO
`Fe203
`CoO
`NiO
`CuO
`SeOz
`Zl'02
`CdO
`Sn02
`PbO
`
`f•
`Cl·
`S03
`
`7.100
`580
`200
`159
`1.700
`96
`100
`90
`5.100
`so
`60
`1.600
`6.300
`
`::1:
`.:1::
`:1:
`:1:
`:t
`::1:
`::1:
`::1:
`::!:
`::1:
`::1:
`::1:
`:!::
`
`4.000
`336
`110
`87
`600
`93
`67
`83
`2.063
`78
`31
`1.490
`. 5.270
`
`7.400
`14.500
`261.000
`
`2.230
`:1:
`5.370
`:1::
`:1: 86.000
`
`497
`8
`45
`94
`630
`3
`6
`7
`9
`71
`6
`130
`186
`
`315
`460
`1.400
`
`;!;
`;I;
`;I;
`;I;
`:i:
`::1:
`:1:
`:1:
`:1:
`:!::
`:!::
`:l::
`::1:
`
`::1:
`::1:
`:l::
`
`197
`s
`25
`47
`90
`1
`5
`3
`7
`45
`s
`127
`107
`
`275
`40
`100
`
`REDOX CONTROL IN GLASS MELTS
`4.
`Th.e vU}'ing organic impurities in recycled glass as well as the partially reducing behaviour of
`filter dust have a negative effect on glass 11\elting and consequently on the homogeneity and
`reproducibility of the final glass product. Therefore it is desirable· as a fitst step- to determme
`continuously by means of in situ measurements the "oxidation state" or the "redox state" of the
`glass melt.
`Electrochemical methods can be exploited in order to monitor the oxygen activity ud the
`quantities of p9lyvalent ions in the sJ,ass melt. The oxygen activity measurements can be car·
`ried out with the help of a:o. electrochemical cell based on an oxygen ion • conducting solid
`electrolyte (yttrium-stabilized zircottia) as reference electtode (19). For SOll\t years experience
`has been gained m the container glass industxy by plaoins the oxyaen activity sensor in contact
`with the glass melt in the foreheanh ( 1200-1250 C), a location of measurement optimally
`suited to characterize the conditioned glass melt prior to the feeding procedure (20, 21) ..
`For the determination of the quantities of polyvalent ions in situ voltam11'letric measurements
`can be utilized. Especially the square-wave voltamrneuy has proved to be a powerful tool to
`characterize the glass melt with respect to polyvalent ions (22). First studies have shown that
`also under industrial conditions polyvalent -elements, especially iron, ean be detected (23 ).
`Both electrochemical sensors are appropriate to establish an i.e siru redox control system which
`providfli an early wanting for deviations of the oxidation state. Furthermore sucb sensors \:an
`
`O-I Glass, Inc.
`Exhibit 1039
`Page 007
`
`

`

`- --- i 3~ j ~ n~ i 999~-i 7:35 · · ------- woRiowJ DE- sEARcHEs
`
`········=····· ----~---··············------
`N k873
`P. q;'lO
`• 0, .J
`
`•
`
`'
`
`28
`
`H. A. Schaeffer
`
`be used to control batch additions and/or furnace parameters in order to achieve the required
`redox state and thereby to accomplish those glass properties which depend on the redox state.
`
`S.
`
`CORRELATIONS BETWEEN GLASS PROPERTIES AND .RECYCLED CULLET
`
`The extensive recycling of glass raises the question whether specific glass properties can be
`maintained in a reproducible fashion. It is a widespread assumption that high portions of cullet
`in the batch can result in glasses of poor "workability'' or increased ''brittleness". So far no evi(cid:173)
`dence was found that su.ch a direct correlation exists. However, as was pointed out, the ad<Ji..
`tion of recycled cullet has an i.l:npact on the o,Qdation state ofthe glass melt and thus in turn on
`a variety of glass properties. Therefore indirectly a complex property such as "workability'' can
`become dependent of the amou.nt and type of recycled cullet. It has to be recalled that vari·
`ations of the oxidation state cause glass property variations in the viscous, viscoelastic and
`solid region (24). Of special importance are variations of the ferrous/ferric ratio which lead e.g.
`to variations in viscosity, infrared absorption and emission. These property changes give rise to
`changes of process ptoperties such as convective flow and heat transfer in the glass melting
`furnace or heat radiation and heat removal in the glass forming moulds.
`
`It was shown by Hessenkemper and Bruckner (25) that soda-lime-silica glass which was
`melted under reducing conditions possesses
`lower elastic lllOduli and a lower relaxation
`modulus and therefore is less stiff and less brittle, and displays moreover a larger high
`temperature tensile strength as compared to oximed glass. This tneans that a reduced glass
`· · (.&teen and especially amber glass) should show a better workability than an oxidized flint
`glass. However, workability can depend on further parameters w.hich are either redox-depend·
`ent (e.g. solubility of gases) or suuctu.re-dependa (e.g. phase separation, clustering. micro(cid:173)
`crystals, mhomogenities) (26). Nevertheless, it can be stated that the ~or source for property
`variations is due to unstable redox states of glass melts. Therefore the installation of an in situ
`redox control system is an important measure to improve the reproducibility of glass melting
`md _glass fomring properties as wen as glass product properties.
`
`6.
`
`CONCLUSIONS AND OUTLOOK
`
`The recycling of foreign cullet and of filter dust represents an evolutionary process in glass
`manufacturing. The inttoduction of recycled cullet as a major batch component has caused a
`new awareness in the melting of glass. New challenges occurred in order to mamta.in the glass
`quality requirements. These challenges were and ~ be met by providing an improved data
`aequisiton of the chemical analyses, by improving computer-aided process control systems
`corobined with a redox control system. and by enlarging the experience in the identification of
`glass defects and assessing their cause-and-eWect relationships. Considering moreover the
`ecological and energetical optimizations which were accomplished, it becomes obvious that the
`state-of·the-art of glass melting in the container glass industry has reached a higher level of
`efficiency.
`
`From the point of view of materials science, glass is an outstanding inorganic packagin&
`material ·with respect to ch~mical resistance and inemess when in contact with food or
`beverages. Glass is optimally suited for recycling not only in the case of retu.mable and
`.refillable glass containers, but especially for the internal recycling, i.e. remelting of recycled
`eullet. n·e material glass is free of any inherent effect of "down-cycling" in the recycling
`process.
`
`O-I Glass, Inc.
`Exhibit 1039
`Page 008
`
`

`

`l3. Jan. l 9 9 9 l 7 : 3 8
`' .
`
`WORLDWIDE SEARCHES
`
`No. 5873
`
`P.
`
`!0/iO
`
`Recycling of culllt and }filer dust
`
`29
`
`Furthemore, the material glass • as a frozen-in, undercooled silicate liquid • possesses a high
`solubility for most elements which might be taken up as impurities during the recycling
`procedure. High solubility means that the impurity elements become part of the glass network
`structure and thus are protected against chemical attack or leaching phenomena. Nevertheless,
`enrichment effects of certain elements should be carefully morutored and their increase should
`be prevented by further improved cullet separation techniques. The ~sting l~ls of colouring
`funher increase of recycled cullet ~~~~-~f_tijnt ~-~ss. An
`a~tly · ·
`increase_will depenJlQn a change m the customer attitude to acc_ept also flint glass with a'Slight -
`tint.
`
`The container glass industry has demonstrated very successfully the realization of the recycling
`concept and therefore can serve as a IX!.Odel for other branches of the glass industry.
`
`Moreover, the experience which has been gained with the recycling of cullet can be exploited
`by the glass industry in becoming active in the field of waste glass melting, i.e. vitri:Bcation of
`hazardous and toxic wastes such as tly ashes, filter dusts and slags from incinerators. The glass
`industry has the expertise also to tackle these novel challenges successfully.
`
`7.
`
`REFERENCES
`
`W. Trier, J. Lauter, L. Schumacher, DGG, FA·Bericlit No. 71 (1978)
`(1)
`A. Reynolds, Proc. First ESG Coni. Sheffield (1991) 247
`(2)
`BV Glas und Mineralfaser, Diisseldor.( personal communication
`(3)
`CPIV-INFO. No.70 (1993) 26
`(4)
`K.-H. Gitzhofer, Tagungsbd. VDM .. Tag. (1992) 209
`(5)
`K-H. Gitzhofer, Glastech. Ber. 64 (1991) 9
`(6)
`P. Buchmayer, HVG-Fortbildungskurs (1988) 147
`(7)
`P. Buchmayer, personal communication
`(8)
`J. K Edington, Proc. First ESG Con£ Sheffield (1991) 232
`(9)
`( 1 O) Model Toxics Legislation I CONEG ( 1989)
`(11) M. Nix, H. P. Williams, Glastech. Ber. 63 K(l990) 271
`(12)
`U. Kircher, Glastech. Ber. 66 (1993), to be published
`(13)
`B.M. Scalet, C. Ferrero, Proc. 2nd ESG Con£ Venice ( 1993), to be published
`G. Bachmann, H. Drexler, Glastech. Bet. 65 (1992)N 61
`(14)
`( 15) W. Trier, Glastech. Ber. 60 ( 1987) 225
`( 16)
`J. Kappc~ FhG-Berichto 3 ( 1990) 36
`J. Jansen; personal communication
`( 17)
`HVG/ AiF research project
`( 18)
`H. Miiller-SimoD, K. W. Mergler, Gla&tech. Ber. 61 (1988) 293
`(19)
`H. Miil1er·Simon. K W. Mergler, H. A. Schaeffer, Proc. XV. ICG Conaress, la
`(20)
`(1989) lSO
`H. MUller-Simon, K. W. Mergler, H. A. Schaeffer, Proe. First ESG Conf. Sheffield
`(1991) 148
`C. Monte~ C. Riissel. £. Freude, Glastech. Ber. tH (1988) 59
`M. Zink, C. Russe~ R Miil1er·Simon, K. W. Mergler, Glastech. Ber. 65 (1992) 25
`A. Lenhart, H. A Schaeffer, Proc. XIV.ICGCongress, 1 (1986) 147
`H. Hessenkemper, .R. Bliickner, Glastech. Ber. 63 (1990) 244
`F. Geotti·Bianchini. Glastech. Ber. 65 ( 1992) 306 & 329
`
`(22)
`(23)
`(24)
`(25)
`(26)
`
`(21)
`
`O-I Glass, Inc.
`Exhibit 1039
`Page 009
`
`