SE190373C1

SE190373C1 -

Info

Publication number: SE190373C1
Authority: SE
Publication date: 1964-01-01

Description

Uppfinnare: F A Fischer Prioritet begiird fran den 1 augusti 1952 (Storbritannien) Att tillampa fluidiseringstekniken vid rostning av sulfidronlmer f6r framstallning av S02-gas eller vid forgasning av fasta branslen etc. är val kant f6r fackmannen. Vid detta forfarande matas de finfordelade, fasta materialen med en kornstorlek, som mOjliggor deras fluidisering, dvs. frau damm och upp till 1,cm, in i en reaktionszon, i vilken de vid reaktionstemperaturen 1 form av en tat turbulent suspension av finfordelade fasta partiklar hallas svavande i en uppatriktad gas-groin. De uppatstigande gasernas hastighet mates linjart sona om gaserna skulle passera genom en pa fasta material tom reaktor. Ett hitt utrymme eller dammavskiljningsrum är anordnat ovanfOr baddens Ovre niva, sO. att den tato suspensionen av fasta partiklar antager formen av en ganska val avgransad badd med en distinkt skiljeyta mellan bidden och det ovanfor befintliga fria utrymmet, i vilket en utspadd suspension av gasburna, fina partiklar finnes. Inventor: F A Fischer Priority requested from 1 August 1952 (Great Britain) To apply the fluidisation technique in the roasting of sulphidrone films for the production of SO2 gas or in the gasification of solid fuels etc. is an option for those skilled in the art. In this process, the finely divided solids are fed with a grain size which allows their fluidization, i.e. frau dust and up to 1, cm, into a reaction zone, in which, at the reaction temperature in the form of a tat turbulent suspension of finely divided solid particles, they are kept floating in an upwardly directed gas groin. The velocity of the ascending gases is measured linearly as if the gases were to pass through a solid material empty reactor. A hot space or dust separation room is arranged above the upper level of the bath, sO. that the tattoo suspension of solid particles assumes the form of a rather selectively delimited bath with a distinct dividing surface between the bite and the existing free space above, in which a diluted suspension of gas-borne, fine particles is present.

Kontinuerlig drift resulterar i en utmarkt varmediffusion genom den fluidiserade bad-den och Or darfor sarskilt val lampad for be-handling av fasta material vid hogre temperaturer. Typiska forfaranden aro exotermiska reaktioner, sasoin t. ex. sulfidrostning, dar temperaturen uppratthalles medelst reaktionsvarmet, och endotermisk kalcinering av kalksten, dar varmet tillfOres genom att branna bransle direkt i den fluidiserade badden eller genom att tillfora varma gaser och eller gasburna fasta partiklar till badden. Continuous operation results in an excellent heat diffusion through the fluidized bath and therefore special choice lamped for the treatment of solids at higher temperatures. Typical processes are exothermic reactions, sasoin e.g. sulphide roasting, where the temperature is maintained by the heat of reaction, and endothermic calcination of limestone, where the heat is supplied by burning fuel directly in the fluidized bath or by supplying hot gases and or gas-borne solid particles to the bath.

Temperaturen regleras i sadana baddar, ddr exotermiska reaktioner dga rum, medelst vilket som heist vanligt organ f6r utvinning och absorbering av varme frail badden, t. ex. genom att samtidigt genomfora endotermiska reaktioner eller fOranga vatten dari, tillfora badden atercirkulerade, avkylda fasta partik lar eller gaser eller genom anvandning av kylslingor eller dylikt, etc. The temperature is regulated in such baths, where exothermic reactions occur in rooms, by means of which is the usual means for extracting and absorbing heat from the baths, e.g. by simultaneously carrying out endothermic reactions or evaporating water therein, supplying the baths with recirculated, cooled solid particles or gases or by using cooling coils or the like, etc.

Hittills kanda och praktiserade fluidiseringsfOrfaranden ha viclladit den begrdnsningen, att bandtemperaturen icke far overstiga de i badden ingaende fasta partiklarnas smaltpunkt, om icke fluidiseringen skall upphora. Denim begransning liar medfort, att fluidiseringstekniken endast kunnat anvandas vid hantering av sadana fasta partiklar, som icke mjukna eller sintra vid den onskade reaktionstemperaturen. Hitherto known and practiced fluidization procedures have obviated the limitation that the belt temperature must not exceed the melting point of the solid particles entering the bath, unless the fluidization is to cease. Denim limitation means that the fluidization technique could only be used in the handling of such solid particles which do not soften or sinter at the desired reaction temperature.

Manga sulfidmalmer, t. ex. vissa zinkblanden, speiss, blyglanskoncentrat och liknande, vilka, ph grund av vid lag temperatur smaltande bestandsdelar eller fororeningar, tendera att mjukna eller smalta vid reaktionstemperaturen, har darfor hittills mots-Mt alla fOrsok till behandling i fluidiserat tillstand. Manga sulfide ores, e.g. certain zinc mixtures, spice, lead gloss concentrates and the like, which, due to low temperature melting constituents or impurities, tend to soften or melt at the reaction temperature, have hitherto been opposed to all attempts at fluidized bed treatment.

Det Or saledes ett andamal med foreliggande uppfinning att astadkomma ett forfarande for behandling av sadana sulfidmalmsmaterial, som tendera att mjukna eller smalta vid reaktionstemperaturen yid vilket behandlingen kan utforas med de fasta sulfidmalspartiklarna standigt i fluidiserat tillstand utan att de defluidiseras pa grund av att de smdlta. It is thus an object of the present invention to provide a process for treating such sulphide ore materials which tend to soften or melt at the reaction temperature at which the treatment can be carried out with the solid sulphide ore particles constantly in a fluidized state without being defluidized due to melting.

Ytterligare ett andamal med uppfinningen Or att astadkomma ett forfarande for att under behandlingen overfOra partiklarna till for-men ay sma kulor och darigenom till ett minimum nedbringa dammforlusterna saint Oka reaktorkapa.citeten, medan samtidigt en latt hanterbar produkt produceras, vilken Or lamp-hg for ytterligare behandling. A further object of the invention is to provide a process for transferring the particles into small spheres during the treatment and thereby minimizing the dust losses in the reactor capacity, while at the same time producing an easily manageable product, which Or lamp-hg for further treatment.

Uppfinningstanken bakom foreliggande uppfinning grundar sig pa upptackten att partiklar av sulfidmalmsmaterial, -vilka tendera att smalta yid reaktionstemperaturen, icke desto mindre kan hallas fluidiserade genom att Oka fluidiseringsgasens hastighet och dar- Dupl. kl. 12 i: 21 2— igenom giva badden st8rre tnrhulensenergi. Denna &ale gashastighet forhindrar helt ovantat en fullstandig smaltning av partiklarna i hadden och bringar materialet att agglomerera till kern, varigenom saledes dammforlusterna genom medryckning i bortstrommande gaser nedskaras. The inventive concept behind the present invention is based on the discovery that particles of sulphide ore material, which tend to melt at the reaction temperature, can nevertheless be kept fluidized by increasing the velocity of the fluidizing gas and then. at 12 i: 21 2— through giva badden greater8nr tnrhulensenergi. This gas velocity completely unexpectedly prevents a complete melting of the particles in the heat and causes the material to agglomerate into a core, thus reducing the dust losses by entrainment in escaping gases.

Foreliggande uppfinning avser ett fOrfarande for rostning av finfordelad sulfidmalm och .uppfinningens omffing och innehiird aro bestamda av det efterfoljande patentanspraket. The present invention relates to a process for roasting finely divided sulphide ore and the scope of the invention and are to be determined by the appended patent claim.

Ehuru de for tillampningen av foreliggande uppfinning erforderliga gashastigheterna variera fran fall till fall, kan man generellt saga att tillfredsstallande resultat kunna erhallas genom att Oka gashastigheten sh att den blir tva till fyra ganger sá stor som den minsta hastighet, som fordras for fluidisering av enbart de finfOrdelade, orostade sulfidmalmpartiklarna. Although the gas velocities required for the practice of the present invention vary from case to case, it can generally be said that satisfactory results can be obtained by increasing the gas velocity so that it becomes two to four times as large as the minimum velocity required for fluidizing only the finely divided, unroasted sulfide ore particles.

Sulfidmalmpartiklar, som kunna rostas enligt foreliggande uppfinning, aro sadana, vilka bli klibbiga eller vidhaftande och saledes latt agglomereras vid eller under reaktionstemperaturen. Det exakta skeendet vid forfarandet är annu icke fullstandigt utrett, men teoretiskt kan tankas att under behandlingen de okade gashastigheterna strava att bryta sonder eller forhindra bildning av for stora agglomerat i badden, medan de gynnsamt paverka bildning av relativt sma kulor. Dessa sma kulor aro storre On de inmatade partiklarna, vadat- materialforlusten i form av av gasen medryckt damm Or nedbringad till ett minimum. Okade gashastigheter minska med andra ord i verkligheten. dammforlusterna i stallet for att Oka dem som man normalt skulle vanta sig. Sulfide ore particles which can be roasted according to the present invention are those which become tacky or sticky and thus easily agglomerated at or below the reaction temperature. The exact course of the process has not yet been fully investigated, but theoretically it can be thought that during the treatment the increased gas velocities try to break probes or prevent the formation of excessive agglomerates in the bath, while they favorably affect the formation of relatively small spheres. These small spheres are larger on the particles fed in, the loss of material in the form of dust entrained by the gas is reduced to a minimum. In other words, increased gas velocities decrease in reality. the dust losses in the stable to increase them as one would normally expect.

UppfinningsfOrfarandet Or sarskilt val lam-pat far behandling av finfordelade material, I. ex. flotationskoncentrat, dar starsta delen av de fasta partiklarna passera genom en 100 mesh Tyler-sikt. INVENTION PROCEDURE A special choice of lam- pat for the treatment of finely divided materials, I. ex. flotation concentrate, where most of the solid particles pass through a 100 mesh Tyler screen.

Uppfinningsforfarandet kan genomforas i varje konventionell reaktor for behandling av material i fluidiserat tillstand. The inventive process can be carried out in any conventional reactor for treating material in a fluidized state.

Exempel I. Ett flotationskoneentrat av My-glans rostas i fluidiserat tillstand i experimentell skala, varvid den kemiska sammansattningen av det inmatade materialet var: Pb 68% Cu 4,3 % Zn 4,7 % Fe 3,3 % 14% Rostningen utf8rdes medelst den exotermiska reaktionen mellan svavel i de fasta materialen och syre i den uppalstigande fluidiseringsgasen. Preliminara prov i kallt till-stand angavo att gashastigheten (den linjara hastigheten for fluidiseringsgaserna genom en tom reaktor) horde vara 30 cm per sekund. Emellertid smalte de fasta materialen i bad- den och hallos icke langre fluidiserade, da temperaturen hade stigit till 525° C. Hastigheten okades till 90 cm per sekund I enlighet med foreliggande uppfinning, varvid de fasta partiklarna Milos fluidiseradeaven fast-On rostningstemperaturen steg till 650° C. Example I. A flotation concentrate of My-gloss is roasted in a fluidized state on an experimental scale, the chemical composition of the feed material being: Pb 68% Cu 4.3% Zn 4.7% Fe 3.3% 14% The roasting was performed by the exothermic reaction between sulfur in the solids and oxygen in the ascending fluidizing gas. Preliminary tests in the cold state indicated that the gas velocity (the linear velocity of the fluidizing gases through an empty reactor) should be 30 cm per second. However, the solids melted in the baths and were no longer fluidized when the temperature had risen to 525 ° C. ° C.

De fasta partiklarna okade i storlek under rostningen, sa att 95 % av produkten kvarholls pa en 150 mesh Tyler-sikt, medan det annu icke rostade materialet, dO det inmatades, hade en sa. liten kornstorlek, att mer On 85 % passerade igenom en 200 mesh Tylersikt. The solids increased in size during roasting, so that 95% of the product was retained on a 150 mesh Tyler screen, while the as yet unroasted material, when fed, had one. small grain size, that more On 85% passed through a 200 mesh Tyler screen.

Exempel II. En finfordelad speis rued en approximativ sammansattning av: Cu30% Pb5% As35% Sb6% Fe, Ni, Co 18 % rostades i experimentell skala for att driva av arseniken och Ora materialet lampligt for vi-dare behandling. De fasta partiklarna fluidiserades vid en gashastighet av 60 cm per Sekund och temperaturer av upp till 800° C. Partikelstorleken &ode under rostningen, sO att 75 % av produkten kvarholls pi en 100 mesh Tyler-sikt, medan 70 % av utgangsmaterialet passerade genom en 100 mesh sikt. Example II. A finely divided stove rued an approximate composition of: Cu30% Pb5% As35% Sb6% Fe, Ni, Co 18% was roasted on an experimental scale to drive off the arsenic and the Ora material was suitable for further treatment. The solid particles were fluidized at a gas velocity of 60 cm per second and temperatures of up to 800 ° C. The particle size increased during roasting, so that 75% of the product was retained in a 100 mesh Tyler screen, while 70% of the starting material passed through a 100 mesh screen. mesh sieve.

Tidigare forsok att rosta detta material -yid en gashastighet av 30 cm per sekund misslyckades, darfor att det fasta materialet smalte och joke langre hblls fluidiserat vid temperaturer i narheten av 500° G. Previous attempts to rust this material -yid a gas velocity of 30 cm per second failed, because the solid material melted and joke longer hblls fluidized at temperatures near 500 ° G.

Exempet III. Av zink (blande) bestaende flotationskoncentrat rostades i experimentell skala. Koncentratet hade fOljande ungefarliga sammansattning : Zn 50% Cu3% Pb2% Fe5% 31% och rostades med gott resultat i fluidiserat tillstand vid en gashastighet av 60 cm per sekund och temperaturer av upp till 925° C. Ehuru det inmatade materialet var sh finkornigt, att 85 % passerade genom en 200 mesh Tyler-sikt, kvarholls 86 % av den rostade produkten ph en 150 mesh sikt. Tidigare fors& att rosta detta koncentrat vid en normal hastighet av 30 cm per sekund och en temperatur av cirka 850° C ha misslyckats. Example III Zinc (mixing) flotation concentrate was roasted on an experimental scale. The concentrate had the following approximate composition: Zn 50% Cu3% Pb2% Fe5% 31% and was roasted with good results in a fluidized state at a gas velocity of 60 cm per second and temperatures of up to 925 ° C. Although the feed material was fine-grained, that 85% passed through a 200 mesh Tyler screen, 86% of the roasted product ph retained a 150 mesh screen. Previous attempts to roast this concentrate at a normal speed of 30 cm per second and a temperature of about 850 ° C have failed.

Claims

1. Patent claim: Procedure for roasting finely divided sulphide ore, e.g. lead lacquer, cooker or zinc blend, in a conventional reactor for the treatment of material in a fluidized bath, which salt is crenomforced at a temperature exceeding the melting point of the ore and without accumulation of agglomerate or sintered, non-fluidized material at the bottom of the bath, characterized in that finely divided ore one by one is fed. bath of particles, which mainly consist of already roasted maim, and which by agglomeration of the ore into small spheres during the state of continuity of the process erHint a significantly larger average grain size than the maim as -Mores bAdden, that this bath in its entirety is kept fluidized by upflowing, oxygen-containing gases, the rate of which is adapted for complete fluidization of the bit and alash, is significantly greater than the rate required for fluidization of a material with the grain size and specific gravity of the supplied ore, and that a discharge of fluidized material corresponding to the ore supply provides space from the bath . Request publications: Patent application from France 1,012,836; USA 1,310,455. Other publications: Chemie-Ingenieur-Technik 1952: No. 2, p. 105. Mining congress journal 37 (1951); March, pp. 32.