HUE034265T2

HUE034265T2 - Eljárás alumínium-trihidroxid õrléses szárítására

Info

Publication number: HUE034265T2
Application number: HUE10173296A
Authority: HU
Inventors: Dr Alfred Reimer; Dr Carsten Ihmels; Christian Beer
Original assignee: Nabaltec Ag
Priority date: 2010-08-18
Filing date: 2010-08-18
Publication date: 2018-02-28
Also published as: MX2013001852A; BR112013003520A2; KR20130098338A; MX336101B; US20130296466A1; JP5916727B2; RU2013111858A; EP2420474A1; EP2420474B1; WO2012022692A2; JP2013540675A; CN103221342A; WO2012022692A3; SI2420474T1; PL2420474T3; KR101861874B1; ES2628088T3; US9038931B2; CN103221342B

Description

Method:fhr mitl-drying aluminium trlhydroxíde iftesmifriton IM iösvtmlöß: listes te « process Ibr m5Íisíg<liflng of tte «w tetemre cosnaiuing aluminum ítririydfoídda,

Polymers are: «sei: as ..materials ta rite 1teriteing,: furniture, ^transport, electrical and: ifelW». industries.: For marig applications, rite polyrners: bave te nteet national and iotermUlonui flame retardant Mmáikvik* fiuee most peiyriiers, .¾¾ particular those which can be obtalried from monomers having a hydrocarbon basis, tee :ÍaÉteable^:i; ts necessary ip: equip fölypers- svidr flame reim-drima in órást to bo able te achieve: classifietterim ef the plymer es flame-resistant. in general, this Is achieved by the addition of organic or ritetgante flame retardants, Flame retardants used; atteler example, η-eîai hulratea.. with tee metes hydrates of aluminum having arte ined particular imperianee (G. KuseKhaum, :!£tmxtntofre; 1%. 1¾¾ IÄ· * 1208 and; R, Schmidt, Rmrststofte, :M, 1#!, 2058 - 2061).

The trihydroxide is based on the thermal elimination of the eftendeatiy bpimd tester in the -flm :ite'Äe jptge- from £0(1 to 400¾ This of rite almmuom tnhydroxMe consumes energy, as a result of which the surface of the plastic is cooled, in addition, the liberated water vapordilutes the eririshustlftle organic depadatpn products of the polymers, The alumlmftft: oxide which remains as residue has a high specific surface area ahd ahsorhs polycpite: and aromatlO lydtoearbon compounds teteted in the munbustion of the poiymew As a result, these compounds: are withdrawn Rom the combustion process, Siriee pfyeplio arid aromatle hydrocarbon compounds are constituents of blacfr smoke from a lire, aluminum trihydroside also contributes to reducing the smohe density in the case of fire, The: use of alumiriurit: thur realms it possible to produce halogen-free flame- redistant: polymem, with the use of iteiogsa-eontaming fire retardants being able to be dispensed: with.

However, l.t is necessary to use large amounts of aluminum trihydroxidex In plastics in order to ensure sufficient:: frame-resistance and meet the Iamb pmteifiri» Ätdards* % iNri Mgh degree of fill, the processing process for such :iteUteresistsr«: piymcr mixtures is often difficult, especially when ihe aluminum friipdtexide is: used iuligntd resins, and the mechanical properties of the plastics obtainable therefrom are often unsatisfactory. in principle, high teteshos edtetiveness, hut these make lásötp&mfiöö Into, the polymer astd its subsequent lartte processing significantly more difficult because of a greater viscosity increase. Although to BIT smlkso ms'oas are advteëptrus because of the easier incorporation into polymers, they are at the same time disadvantageous sine® glummum f t&ydrox ide hay tag a low a» uösaMaoiory Baosa reiarrlanes effect. lor ins reason, a dsstiaetiott Is pnerdify made, iepndlog op fbe ose and incorporation technology, between relatively coarse, milled pate and very fme precipitated aluminum tribybroxide grate,

When shuwioinn trihydroxide is used so liquid resins. sprite coarse aluminum trihydroxide which is obtained from crude aluminum hydroxide by milling is usually employed, 'Ibis achieves: not only a reductlonin tbs average paridle aiae .:¾ but also a significant increase in the spelilb ÄT surface area. The aluminum- triydroxife obtained by snilhhi processes neeotdmg to fhe prior art fiierelire have as improved flame Retardant effbekllbwever, such alursdnum fíilyítroxite c;m be used only to a limited extent: as Harne retardants sro.ee when Isteorporaiod rate lipid rétes they lead to a drastic merease in viscosity of the liquid:: rés in mixture, wbiefe makes the processing of such liquid tpsin tuMoras dlfiSetdt or impossible, The miitltsg process is therefore usually sfcpped at average particle sizes above 5 #tn because îpæepiabie are still obtained bote, A greater degree of milling produces a significant increase In the surface area and makes the processing of the resulting aluminum tribydftede sad the compounds produced therefrom more difficult to an unacceptable degree, lie which lower surface areas eats in principle be laohleveÄ theirefâiéfïÂkîeii for the preparation of finely divided aluminum trihydroxide.

In the ease of thermoplastic and rubber applieatibns, very Bne preelpltated alnmihnm tribydroxide grades are generativ nsed.

For this purpose, coarse: crude alnodmnn trihydroxide is dissolved in sodium hydroxide solution and subsequently precipitated la a controlled manner. This process gives aluminium trihydroxide·· tvhtch puemliy bas :an average particle size 0.¾ significantly below 3 pm. The aluminum: ulhydroxides obtained in this way have a relatively low specific BBT surface area, usually in the rangs from 2 to 12 mVg, rarely higher. When aluminum trihydroxides haying such particle sixes are prepared by complicated nulling processes, fids leads to aluummm tnhydroxides having significantly higher BBT surface areas.

Afepnatöp trihydroxtde & high specific BEf'fuefaea area Is thus, on thei.omSià, advantageuas since the flame sxstardanf effect increases with increasing spécifié BBT sferface area, bet unfiié other haad such aluminum trihydroxKles kad, when incorpotsled info liquid resins, to a drastic increase in viscosity. which snakes she processing of the resins difficult or even impossible. EP 1 555 286 describes a process ns which:.aiunnnuo> ©«hydro* Uie which has been obtained by precipitation and filtration and hasi qn average panicle si?e 0¾ in the :l|&rh 0,8 to 1.5 pm gpÉ#Ilgfe- SIÄ^ßfüfeglÄpf ' 50% by weight, based on trihydroxide*.É·Äf PdM't© a milling-drying process af temperatures In the range fern 150 to 450eC. liessÉttfdonm trilrydroxide which can fee obtained by this process has good viscosity properties in liquid resins, hut them is still room tor improvements. A disadvantage of the process described in BB 15$ 286 isq in particular, that an aluminum trihydroxide which can be obtained by precipitation and had an average particle size D« in the range from 0.8 to IJ pps fees to'fee used. á thither possible way of avoiding the disadvantapous viscosity properties of aluminum; trihydrOKidc in ilptd msk\ systems has been desoilM In. Ä· pifef «i-tdri .fdhsprists coating aluminum MhydiMdde particles with organic additives such as silanes, felly acids and/or titauafes.

It is therefore an object of the invention to provide a process for preparing aluminum trihydroxide which has a high specific BET surface area and ean Ifeé·.resins and.

In particular does not lead to the: aboveadascribed drastic ifecfeáaea in viscosity, tte process sltodM: fee less expensive than the processes described In the prior art and, ist p&rtk tbÄg; processes sfeoulifee avoided and aiutfeialum trihydroxides Jtaving significantly feiger averap particles sizes :¾ should also he able to be used as stariing materials.

The object là achieved "by a process in Milch a raw mixture containing alaminum trihydroxide having an average particle size in the raage from SO to 13(1 pm is subjected to. a mllllng-drylng; process. The invent!©« therefore provides a process for the milling-drying of a raw mixture: containing;:, álhrpifefefev iÉhyipfextde having an average parttele size Β*$ in the range from:; #S· Id 130 pm and a specific BET surface area in the fange from O.Ui to 0,5 m'Vg and epntalalng :ä|öib 1,1 to 20% by weight of water, based on the nm mixture, wStich comprises the steps i) mtrodnetlsn of the raw mixwre imo a milling-diving apparatus, i>: irmndueiion pfa höfalr Stream h&¥Í5:g:3::tS®pgm»8:ÍS> llt®: ?a.njp ltom 10 to ÎS9eÇ fUtO fi®' miUsng»dryln| apparatus so asléiÉow through the

Hi) comminution of the aluminum trihydroxide present, in the raw mixture In the miliiqgfetyiag apparatus, the grocess of the Invention is cheapo than the processes Known in the prior art, Ahtmlnetn frlhydfnxMes having an ayerap pastteie iae D50 in the range tram 50 to 130 am can be used la the process of the invention,: in addition, the process of the invention cam. compared to processes according to the^ prior art (EP 155 286. from ! 50 to 450"C), be carried can at sigmlicandy lower femperattaeSs: which leads to an energy saving and also miss: oat dehydration of ahrmimrm iribydroxida to ahmrinmn oxide.

Out aluminum trihydfaxide: winch can be obtained by the process of the mvendors has a high specific BET surface area and therefore ars excellent flame retordant etted:, fhe aluminum trihydroxide which can be obtained by 11½ process of the inventionrcan t'esdily he incorporated Into liquid resins and, in particular, does nos lead to a drastic inctoasc ih Ée viscosity of the liquid resin mixture ohtatnedy ax i$ ohserved in the ease of alam hrnm trlhydroxldes Sorts the prior art.

The raw mixture used in the process of the invention contains front SO to 99.9% by weight, preferably fenn SO to 99.85% by weight, ofahoninuot irlhydroxida. Änt to 20% bv weighf of water and optionally from 0 to 30% by weight of further substances such ax boehmhc, magnesium hydroxide, Stannates, silanes, poiyco.nden.sed silanes, slioxanes, borates, fatty acids, fatty acid esters, sails of tatty acids, polymer emulsions, polymer solutions and/or titanatex.

The raw mixture contains aluminum trihydroxide having an average particle size 1½ in the range from 50 to 130 pm, preferably m the ranp fe>m SO to 120 pm, more preferably in the ranp fenn 99 to i 10 pm and parifeniarly preferably In the ranp fenn 95 to 195 pm, The average partie is sixes Dja indicated in fie present invention have been determined by means of laser light scattering (laser light scattering instrument CUas 1964, evaluation by fee Fraunhofer method).

The aluminum fehydroxlde has ajSpecific Hi: 1 .surface area in the raupe from 0.91 to 9.5 mVg, preferably from OJS to 9,4 nfTg, more prefemhh írom 0.0ο m 0.35 mVg and parilcuisrly preferably from 9.07 to OTS fehg. The specific: BÍt'F sorisee: areas indicated in the present Inyenion have been determined by the ISO 9277. based

The raw mixture |Ä:lf weiigbb more preferal% from: 4 to-12% by weight and particularly preferably feml to Ifefefey weight, of water, based on fed td# mfedne. in a preferred enibafeiMdt, fee raw felgiare contains^. ahtmlmtm trihydroxide which as a result of fee niefeöd bf pscpäraicn containsifeath 1 to 20% by weight,: preferably frpmfrfe 15% by wetgife more preferably from 4 to 12% by weight and· is : ptficulsr 'fifes» 5&tö:.l»%":wö||hh of water, based on aluminum trihydroxide. In this casc^feoo^atsr presejh in fee raw miyfere originafes solely from the aluminum trihydroxide present in the raw mixture. It is also pdsdlhfe to hse aluminum trihydroxides having a fewer water content and add Wafefdn themw mMtm iBhwduer, this is not; feeferred,

Thu raw mixtum·. can comprise feather substances such as boehmlte, magnesium hydroxide, stanitates, silanes* plycoMehsed silanes, siloxanes, borates, fatty acids, felty aetd eaters, salts of fatty acids, pblynfer emblsibss:, polymer solutions ahdfef titanafes in laddifiuh to aluminum trihydroxlde. present'äd a result of the ntefedbdfpcpratlon in fee aluminum trihydroxide presenton fee raw the raw- mixt tue. in one embodiment, a raw mfefere eompflsing alnminntn trihydroxlde eoufelumg from 0,1 to 20% by weight of wafer, preferably from 3 to 15% by weight of water, more preferably from 4 to 12% by weight and particularly preferably from 6 to 11% by weight of wafer, based on the ahtmlnom trlhydruxidb and having ÄMdPidfpÄii Ätt 1¾ in fee range from M to 1SO: pm, preferably from 80 to 120 μην mom preferably from ID to 110 urn and particularly preferably front OS to I OS urn, andaspeeifioSbT surface area In the range from 0.01 to 0.5 m%. preferably from 0.0S to ö.,4 nf/g* more: preferably from 0.06 to 0.35 mfrg and; pardeuiarly preferably from 0.07 to 0.25 mVg, Is used. id a pfeferred embodiment a raw mlxtttre comprising aluminum trihydroxidc containing frosn 6 to "10% I» vteight of water, based ott aluminum trihydroxide, and having an average particle size 0½ it) the range írom 90 to 110 urn and a specific BET surface area in the range from 0.07 to 0.25 m7g is used. m Ä pnteess oft!« invention, dia raw m!i» b mfrodueed Into ®ppmM$: ö> ·*8$Η fjb lÂÉlfel íxjHHng'^ÖiRg^lláíí-átü^' m kööwrop»ss arai ars described, ÎW example, írs Lueger, Luxikonder Technik- volume 48, page 394. fri a parilbblar embodmlbnh Ibe milling-drying apparatus contains a rotor which is mounted1 in a tkod manner eu a solid shaft and rennes at a circumferential velocity In the range from 20 to 200 m/s,: preferably from 30 to 180 m/s, more preferably from 90 to 120 más and particularly preferably írom 60 to 70 mk.

The invention therefore also provides a process in which thé ndfbhgkryibg aphMafus -eohisins a rotör-SMör system and the rotor has a efreumiersubai veiociry to the range from 20 to 200 m/s.

The infrodtsetion of the ww-M&îm into (he «tillinf^fefs^pp^ífstsp 1)) can be effected: by methods known per se* tbr example conveyor belts, screw eonveyompeccentrie screw pumps: ssá spiral eunueyors, to a preferred enibodtrphb the raw mi2aue is: IhfrOduced into the iosliing-drymg apparatus by means of a screw conveyor. 10 step HV a hőt "to stream having a temperature inihe range -from 2frto 1 Ρ*€2 preferably from 21) to ! W?Q* «tore preferably from 20 io 1007(3 and parfiöttíarfy preferably from 20 to 80¾. is hmpdueed Into the ms|liegsds'yiug:apparamsL:ln a preferred embedimenfr the hot afr stream enters at the lower end of the: nulingnlrylng apparatus through m ihlet opening Jato the mdliogwlfylng apparatus and flows through: tbedaher: front the hofrom upward, with the hot: air stream forming, a MÄte.'-inP".!«, eombinafioh.. *VfÉ the rotary motion of the rotor of die : milling-dry ing apparatus, :ahd leaves: dte ndfilugnitning apparatus: through an outlet opening at the upper end of the milling-drying upparamst In a preferred emhudnoenf, the hot air stream in the sudllng-brying apparatus has & Reynolds number of > 3000. The: hot:: ah' stream generally frows through the ndlbng^dtpng apparatus at an aif dfrpugltpt ht the csnpfrem 3000 to 7001! mVh at operating pressure.

Itt the mil ling-dry lug:: apparatus., the: aluminum f «hydroxide: present: in the raw mixture; is aeeeforated by the hotair sfreinUi iit oombigation with the rotary omtirm of th«: rotor, ills results in comminution of the aluminum trihydroxide present in the raw mixture by Impacts of the -alumim.no frihydroiide partMes with one another andror by impacts of the: almniniurn: frihydrotbde partlnles m. lbs irntoostator aystant of the millin^drylng: apparatds (step |lf»> At; the same flow, water As withdrawn from the raw rniature by means of die ntlliing energy liberated. The shtminum fflbydronide present in flu raw mixture is: subsequently discharged from the mlfimg'dpving apparatus. fua prefefreb embodiment, discharge occurs through the exit opening iluoogh which the iöí sir stream httrodaeed; Isii) te «flBttg^dng apparatus leases* T%e tplxfere eeutahiag. almplrmm trlbydtoxide, iíöf âly sfreap) apd Äs water withdrawn fVos« íi)e simpingmfritsydroxsde of lié aw mixture leaving the reactor b optionally subjected to farther work-up steps. These are, tot exemple,, yepurafi«« of tie ptmmnanted alntifRum trihydroxide particles .feta tebot air sitet«« apd t|e wster withdrawn finnt the raw mixture k step Hi).

Steps I), H) and ni> can be carried opt föő^siy^' M^ÄöltÄPously;, :¾ ^.prnlftr^É^hotUmenîl. steps i), M> and Hi) are carried out simultaneously and the milhstg-drying process is carried out cqtginuously. Ip this embodiment, the raw mixture and the hot ah stream are mtrodneed simultaneously Into the milHugKitviug apparatus, T he residence tithe of the raw mixture In pnefidfy fiot« 0>I1 ίο 1 second,. preferably horn 0 01 to 0,1 second and particularly pefetably from 0.0ä to 0.0S second. A utelfc: <M-.^fÄ!Älly be used â te process of the mveatlom The eipsiftsr is p^llraOly used after $f«f classifier separatee coarse matériát from the raw mixture. The coarse materia! which- áM'feössppmted off Is reelreul&led te the raw mixture, For the purposes of tie present invention, coarse material consists of particles having particle sleds of pm, 'the aluminum trlhydroxitle which can be Obtaissei by the process of the Invention has: a Ugh Specific BÉT surface area and thus an excellent flame protection eltet In plasties. Idle hinminttm trlhydroxide which can be obtained according to the invention can he readily incorporated into liquid resins and, in partieuiär, does not lead to a drastic tnerease ln the viscosity, as Is observed in the ease of the aluminas» trihydroxides whiehste fchowhÉöm iMpfiot: urtisdihave a high Specific BET suttee area.

The aluminum trlhydroxidc which can be obtained by the process of the invention generally has st« average partidé size D-o in the range from 3 to 15 pm, preferably from 4 to 12 urn, particularly preferably in the range from 4 to 6 pm. The aluminum rnhydroxide which can be obtained by the process of the invention has a nas to« pariidé s» v doit>button. The D>(1 values are in the range fions ] U> η μ so and preferably in tire range from :] to i.5 pm,

The D.,0 values are in the range fisam f tp SO pm end pretedbiy in theiràhpSfixuu O td 13 pm.

The aluminum trlhydroxide which: cap be obtained by the process of the hrvenfios preferably has, Dî;> values in the range from 1 to 1.5 png 1½ values in the range from 4 to h pm and 1.½ values in the range Irons 9 to 13 urn.

The aluminum Phydroxide wifieh mm be obtained by the pocegs of the Invention has a specific SET satrime aria m the radge ÄPi 2 to E nrVg, preferably m the range from S to 9 nr/g. The Äpltellt wIÉ os» le #tm«ag$iy *|*&:pqpe**cd::lhe invention generatív contain* trop E to E Eiffev vyelght, pg&raEly fmm íi to 1 M% weight and more ;psllrah|? (Vorn 0.1 to 0.5 % by weight of water, basedon sípolnom tr&

Id ο preleMl eínbolimeoh fie aiunnnunt:ttihydrovkie whtel ean le obtained by the process of the Mmmm has mávetbp particle si-re 0S! itt She range from 3 to 1 S pm, a specific EET surface area in Shew®mÄÜIn the range Eom 0: ioTI« iy weight, basedon the aluminum Edhydfoxide,

The aluminum Irihydroxkie which can be obtained by the process of the invention can be incorporated into crosslinkabie liquid resins. A process tor producing a thermoset comprises the step a) mtmrporailon of an aiomlnndv Elhydroxide witch ears be obtained by the process: of the Invention into p leastode erodsbakabie liquid resin to forth a esnáble tpiafure ofblpmlnum trihydroxlde and liquid resin, and b) .c*ösSSiöb1t#bI:ötslMixtttin:Äfei ned adeoMlhgTd a).

Step b| Is earned bhf by methods teown to those skilled its the art, tor example by means of iSôlç^feilÔeiÈii^Rer-iSâÎ^Êemæ,utilising accelerators and further additives, A proeeas for prodnoing a thermos# comprises the steps a| Incorporation of an aluminum trihydroxide which cad be obtained by Em process of The invention into at least: one crössidlabie liquid resin selected from the group consisting of unsaturdted polyester rosins and epoxy resins to form a curable mixture of aluminum trihydroxlde and liquid resin, and b) crossllnfcing of the mixture obtained according to a).

For the purposes of the present invention, erosslldkable liquid resins are liquid polymer compositions which eontaih Etncticmai groups which are able to tenet with one another and crosslink the components of the crossiinkabie liquid resin with one another. Suitable functions are double bonds, epoxide units and combinations of isocyanate and alcohol units. To produce a therrnosst, it. is possible to use one (1} crosslinkable liquid resin or a mixture of two or mure crosslinfcabie liquid resins.

The aluminum trlhydroxsde which can be obtained according to the process of the invention is used as titane retardant, in particular as flatoe retardant for tfeermosets which can bo obtained itorn the abovementiohed erossl^kalblie-l^ltette

Tbe posent invention m illustrated «$, -mam-Mowing examples, without being restricted thereto.

The Invention Is illnstrated by fte following exampleswithout being restricted thereftg, ISxanrpies

The aluminum frihydroxide which east he obtained by the process of the invention has a high spécifié BET surface area and thns an excellent flame retardant effect in plastics. The aluminum tfihydroxlde which can he obtained accerdihg to the invention can read ily fee ineefpofaied thin liquid resins and, in particular, does not lead in a drastic increase in viscosity, as is observed in the ease of aluminum, frifeydroxides whiefe are known ltom the prior art and have a high specific BET surtMe area.

Tafele I shows slumhnan trltydrosldes wiiltfee heed jpPpaibd fey processes bom lip pior art (comparative examples h and,. 2).: end an alnmlnunv hyÉ^ide winch bas been prepared by the process offhe iff the Invention).

Table 1

The abmtoum trihyiiro^sde prepared by the pööess· of the & signlfíeantly Spar and delays a narrower particle dtstrifeetidn, as .½ made clear by llpre % In addition* the product according to the invention displays a atplSeaátly Mper epeelie BET surface area,

Thé mlaenee m th# degree of fill with aUtminum Inhydroxide On an mtsaiarated polyester resin tEalapfeg PI 7-1)2 fmm. OSM1 vtm expahmd for the aluminum trihydroxide according to the invention (mmotpie 5 aeeotdmg to IP Inyetniony In eopparisop wlp aluod nom trlhydroxlde from tp plor art fenmparape examples 1 arid 2). The dispersed mixtures having Increasing degrees of till were measured in a rheometer (MCR 301 Boar Anton Paar) ai 22¾ «sing a piate/piaie measuring element having a diameter of 40 nun at increasing speeds of rotation. At a speed of rotation of 0.25 min' g a value was extracted and the viscosity obtained In this way was plotted apinst the degree of ill lor each sample*

Fipre 2 shows the viscosity behavior of the alummutn trlhydroxlde «©cording, to the inventlos (example I according to the lovetdloa) and comparative examples 1 and 2.

Example: :t according to the invention displays slgmbctsntly better viscosity properties* ip this áhrmlhtsm mbydroxlds brings about a signiieaatly lower increase in viscosity than: does the COnípáfafely fitté akmthwm trlhydroxlde «comparative example 2) and even rhe coarser aitmmmtn trlhydrdxldc toptnparative example fi poptmty to all: expectations at a significantly Increased BET surface area.

The results are shown in figure 2. A team Med with i 5 <> parts of aluminum irihydroxidd per IPO pits of resin ifMapreg PI 2-82) was epred and the IlmiMg oxygen Index <EO§ was snhsetpenily measptud on the opted sample. Whop using the ahooktnm irthydroxide according; to the invention (example 1% a significant Increase in the value ifrom 34.4 to 37,23¾ of Os compared: to aluminum trlhydroxlde according to comparative example I is found This shows a siplfteamly Unproved Batne protection ef&ei of the ahanilmtn tilhpfes'M* j&üe esiipaifid; t& ulumtem tHhydtpMdn from the prior art (with shrndiansoesiy improved processability).

The results ere sho wn ht tahié 2.:

Table 2

labiée

Table '3 shews the particle distribution of a know» aluminum trlhydroxids {comparative· example 3) and an aluminum trihydroxide which has been: prepared by the process of fite invention (example 2 according to the invention),

Here too, a positive viscosity effect Is found despite a finer, narrower particle distribution and a comparable BET surface area.

The results of the viscosity measurements as a function of the degree of fill, are shown in: figure 3.

Claims

SMBálMÉMl IGÉNYPONTOK K Eljárás egy syersfeéverék őrlése s szántására, amely tartalmaz tű^xém^^áánaMaá,. amelynek 11½. átlagos szemcse-mérete SÍM 30 ,um tartományba és BET-féle tzllagos fölös eta #,01-0,3 nvvg tartományba esik, ás 0, ! -20 iömeg% vizet, a nyerskeverekre vonatkoztatva, amely tartalmazza a követező lépésekéit ·) a nverskevereket egy őrléséé SZáritő berendezésbe vezetjük, il) m ârlékas szárítő berendezésbe forr# levegő áramét yMetőbk, amelynek hőmérsékleté: :2<Μ:§#^ és amely átámmiik az őrléses szári!# berendezésen, ás iis.} a oyerskeverékbea jelenítő# alimvínium-tfim#oxidoi azötiéses szárőő berendézáéhén aprítják,
2, Az 1, igénypont szerinti eljárás, ahol a nyerskeverék alrsosínsaor'trihidfoxldot ás 3Ί 5 ίό· meg% vizet tartalmaz, a aprskeverékre vonatkoztatva,
3, Az I. vagy 2. Igénypont szerinti eljárás, alto) a nyerstermékbe]! ahnnmirnn-trihidroxid Iko átlagos szemcsemareie iiNtl 0 am tartományba ®sik>
4, Az 1 -3. igény pontok bármelyike szerinti eljárás, ahol az őrlések szárit# béfondezés taitaímáz egy rotor-stator rendszert, és; & üt kerületi sebessáp 30-:300 ht/s tartományba esik
5, Az 1*4, igéoypontnk bátsnelyike szerini eljárás, # rjye^kev§ü#lt|fee» alüfiíbí* «nt-^ribldrokid átlagos tartózkodási ideje az Örises. szárítő berendezésben 0:,01-1 másodperc tartományba esik. ő> Az í-1 Igénypontok bármelyike szerinti e|járáA ahol óz l)si Irt ás iii) lépéseket egyszerre va-Msítjtik meg, és az eljárás? folyamatosan működtetjük.
7. Az l-ő. igénypontok bármelyike szerinti: eljárás, ahol a: forró levegő áram az őrléses bered' dspsbéó »hslons ármnlási képez, amelynek; Reynoldi száma ttagyobb, mim 3Ö#0