DE2106978C - Process for the production of low-iron nickel stone by suspension melting of sulphidic nickel ore concentrates - Google Patents

Description

2! 06 978

The resulting iron and nickel oxide do not interfere with the Stein process. For pure nickel-t.isensihkaterze slag separation of the lower furnace arrives. of the Garnierite type - (Mg. Ni) ₃ Si ₂ O ₇ · 2 H ₂ O -

The procedure is based on the Steieeruns of this procedure, however, not to be recommended Sulfur potential of the oxidation following then a very large heat requirement for the process The gas phase results in the lowering of the oxygen pressure 5 to such an extent that the selective sulphidation carried out in the shaft furnace in the suspension state nickel oxide or ferrite present in a metallic suspension state also in this case without Nickel disintegrates and / or that the nickel sulfide- further possible. It is noteworthy that also Dissociation pressure corresponds to sulfur pressure, although extremely low-nickel sulfide concentrates are good for the is exceeded, but at the same time below the disso- io concentration according to this method is suitable ciation pressure of the iron sulphide is processed, resulting in the processing of poor nickel-copper stone

lktie sulphidation d Nikl Fl h using suspension melts

largely the extraction of copper stone. Irn reaction shaft can with very steep oxygen pressure d d d Stem

ciation pressure it iron sultids is processed what a selective sulphidation of nickel. At the same time there is a reduction of a sufficient large amount of unstable trivalent Elsen. Rdkti d i hll

oross amount of unstable trivalent Elsen. tion shaft can be filled with very steep oxygen For this reduction, a rapid 15 gradient is used, and the one from the system Acting carbonaceous substance e.g. Slag phase which is easily discharged is low in metal and has

reactive carbonaceous substance, e.g. B. mineral spirits and or gaseous elemental sulfur. In this process, the oxidation takes place at about ^: 0C higher temperature (ie at 1350 to 1450 C) ^! s carried out the manufacture of poor nickel stone. The reduction process has no effect on the temperatures of the system, provided that only the roasting takes place normally, that is, provided that there is no longer any free oxygen in the reaction shaft after the oxidation.

According to the invention, the low-iron nickel -., One of concentrates with a low content of Mckel or nickel and copper extracted. This process is initiated by a highly effective Rös.en

outgoing slag phase is poor in metal and has only small amounts of trivalent iron. The solidified stone consists of ai · - iron-rich copper- and cobalt-containing pentlano- (FcNt) ₉ S, - »ο nickel- and iron-containing copper sulfide - Cu ₂ S
Cu _{1 M} S - and the equilibrium nickel-containing iron ferrite - (FcNi) ₃ O ₄ Beim

Try the content of the stone by increasing the amount of roasting air and slightly increasing the normal 25 temperatures in the reaction chamber (1350 to 1450 C) to increase, one finds that the process don. where the pyritic and pyrrotitic iron is rusted, has a turning point. As soon as the

juices vciiaiiicuuuiLiiciiiiiuL.iciiciuivci im ^ .cii pentlandite bound iron begins to oxidize. Concentrate in the suspension state in the reaction shaft operates in relation to the ux> ,, after the suspension smelting plant, whereby it is no longer used in the same way as in the oxidation of iron and part of the nickel Right copper stone. Now comes the following: the oxidation does not result in selective iron oxidation, but in the lower part of the same reaction shaft that also part of the nickel is oxidized, and trivalent iron and iron produced during the oxidation become more considerable Part of - predominantly bivalent - nickel oxide is reduced so that a higher oxidation level is transferred to stone and iron
of the stone as well as the transfer of nickel oxide
: n the slag phase can be prevented. With the
Invention, a method is to be created that 40
technically and economically cheaper
is than the previously known, for the production of
Stein used suspension melting processes.

This objective is achieved according to the invention icmpciaiuitu ^^ - - · ■ - -.

in that the atmospheres with an oxidizing effect are those that are valid in a state of equilibrium sphere of the reaction created trivalent stability areas of (Cu, Ni, Fc MgK> -U-bysieme Iron and nickel oxide even before they were used with the im and the corresponding slag systems as a radio sub-oven : n located. Slag layer in contact with the pressure prevailing in the gas phase components, i.e. sulfur and oxygen, are exposed to a reducing atmosphere will. It turned out to be 50 prints. With regard to the stone forest that the nickel oxide does not fall sufficiently immediately the (in relation to the | dissociation pressures) is reduced if, with the reduction, only in the closely adjacent mutual position of hisenuna Lower furnace is started, as is the case with the nickel sulfide process in techmsch aemaß the main patent 2001 450 is the case. Oxygen pressure (10 "to 10» Atm.) And sulfur

The method according to the invention enables the pressure range (10 · to 10 · Atm.). Because of this extraction of rich nickel stone according to the Suspen-Grund, it is difficult to prevent, in a new way, connection with the process, so that even in the absence of high copper contents, iron-selective oxidation of the iron sludge leads to poor stone melt At the same time sufficient metal sulphide is oxidized. The calculation of poor corresponding slags can also be produced 60 the stability ranges of the oxyda ^ c. The process thus enables the economically - the mutually soluble substances NiO · FC ₁ O ₈ and Hch profitable processing of nickel concentrate under FeO · Fe ₁ O ₉ - to be very close together. Comparing using conventional technology. the areas mentioned end with the »« g ^

The process can be used with advantage on pentlandite areas of copper, so it is clear that in the containing - (Ni, Fe),.?. - Use nickel sulphide ores, the system of which can fluctuate from a sulfur pressure of around 10 atm. Copper content. Often containing Cu ₁ S is stable, so that as en * selective iron, the ores hold small amounts of oxidic and oxidation with respect to copper without further silicate nickel minerals, which are, however, soft. Copper oxide. Cu ₁ O, however, only becomes

iron wiru cmc nunnv w / vrum. ^ ... ».—

(i.e. the quantitative rate of oxidation also decreases when the iron bound to the pentlandite participates in the process).

Below are some detailed considerations of the test results in the reaction shaft. In A b b. 1 is the situation to be expected after the reaction with regard to the components for the layer furnace temperatures 1350 and 1450 ° C calculated. By doing

Oxygen remains stable: eg at 135O ° C, the difference in the stability limits of FeO ■ Fe ₁ Oi and Cu _x O is about 4 decades, and this difference increases with increasing sulfur pressure.

According to the diagram, in the oxy- S dation of Ni-Cu-Fe sulfides, based on the oxygen pressure of the gas phase at the beginning of roasting, Pot - 0.21 atm. In the upper part of the shaft furnace, up to the gas phase oxygen ^{pressures corresponding to the reaction products, Po »■ = · 10 ~ 4} to 10- * Atm., a simultaneous oxidation of iron and nickel (especially when roasting pentlandite, with Fe and Ni sit in the same lattice) to ferrites - of course according to the amount of oxygen supplied - as well as a persistence of copper in the corresponding range of activity as sulfide or metal is to be expected.

If one looks at the corresponding slag systems, one recognizes that nickel olivine and fayalite are stable under approximately the same conditions, μ Since both nickel olivine and pure oxides in the molten state have a gapless mutual Having solubility, the emergence of such a solution is an inalienable fact. The diagram According to this, magnesium orthosilicate is present throughout the as Effective range stable, so that, taking into account the melt solubility ratios, are to be expected. that the nickel oxide in a dissolved state, especially in Silicate solution of the form 2 (Fe, Ni ₁ Mg) OSiO ,, occurs. Experience has shown, and also on the basis of theory, that Cu, 0 occurs _{only very rarely at the Po 1} - Ps "pressures of the above-mentioned range, even in an unstable form.

Following the process in the reaction shaft, under the conditions prevailing during melting in the lower furnace, a silicate melt formed by the components Fe, Ni and Mg is to be expected, in which in dissolved form the charge components CaO and Al ₁ O ₁ and a trivalent equilibrium Amount of iron either in dissolved form or, in the case of oversaturation, in the form of Ni, Fe) ferrite deposits. The copper occurs in the slag, depending on the stone and sulfur content of the slag, as sulfide - Cu _{t> M} S - or in metallic form.

Considerations on the process-related nickel · concentrate oxidation and · oxidation-reduction process in iron slag in the pentlandite range.

Let us consider two examples in which the iron in the nickel concentrate was partly roasted from pentlandite. 199 kg of sand were fed into the plant per ton of concentrate, so that the following composition, expressed in percentages by weight, resulted for the feed: 0.85 Cu, 3.6 O Ni, 34.22 Fe, 23.75 S, 1.28 O , 25.03 SiO ₁ and 9.36 other oxides.

Tabeiie A Material balances of the oxidation and reduction process

sample

crowd

Analysis of the sample in percent by weight Ni I ft I Fe "I S I O

Oxidation: IH-a Oxydic shaft product

Pit sulfide

stone

slag

Reduction: lll-b Manhole product Pit sulfide

stone

slag

100.0

11.4

8.4

91.1

99.2

12.4

9.1

90.7

1.00

10.6 03

1.01 8.05 10.9 0.14 4.30 27.54 434

0.72

443 28.19 44.2

043

40.2 31.58 16.6 42.6

40.5 3240 15.8 42.8

174

0.9 5.8

12.1

0.9 4.0

3.6 31.58 27.0

0.58

3.8 30.58 26.9

0.6

(13.4)

0.6 (13.0)

(12.5)

0.6 02.7)

Table B. The distribution of the components on the oxide and jacket phase

sample

Oxide phase of the input mixture

- oxidation

Oxydic shaft product .. Oxide phase of the stone Oxide phase of the slag Slag phase

reduction

Manhole product Oxide phase of the stone Oxide phase of the slag Slag phase

Ni Distribution in percent by weight Fe " Fe 0
27.0 Approx 0.8
43.0 0.8
91.4 117.5
100.0 0
5.0 0.2 0.3 14.9
153 0.0 134
13.1 96.0
96.5 91.1 18.5
0.0 0.0
22.8 29.9
0.2 90.0
0.3 99.2 6.5
6.9 0.0
0.0 94
9.1 93.9
96.4 90.7 0.0
11.5

In the first stage of the experiment the concentrate was thus oxidized. Dalj a portion of the bound to the Pentlandil f.iscns was oxidized (Jas ratio Pcnllanditciscn: (iesamtcisengehalt the concentrate br \ ug about 0.1) where about 1.ViI Nm ³ of air per ton of concentrate were (1% H, T) and 10.2. kg heavy fuel oil / top-up filler. In the second stage of the experiment, the reduction of the suspension took place in the lower part of the reaction shaft by introducing 2 Below the reaction, there is no statistical rcprisenl.iti \ c. deterred Ρη> Κ · η vntnonnven. which served to analyze the concentration oxidation process in the shaft furnace Slags were analyzed in the same way. The test substances are assembled and analyzed, as well as the distribution of the components in the individual phases, are compiled in the attached dragonflies and H his r totality, to which the value lim.O was assigned

Experiment III-2: Oxidation

The (iasniengc (Fig. 4. Point K, l) obtained during the hydration in the reaction shaft was! '18 Nm 'per ton of concentrate. The dry analysis of the gas phase, expressed in percent by volume, was: 0.09 H _1. 0.1X to O, and! V 44 Sn. The _{SauerMoff pressure calculated from the ratio CO 1} CO was at a temperature \ on UOt) CP _{(> 1} 2 · 1 <> ^: At>". The corresponding sulfur pressure P * ti calculated from the material balance · ⁷ · Ό '\ tm Im stability * · Diagram. Fig. 1. the gas phase is marked by dse / aitl purple. According to this figure mihI hu cinder block (Ni. Fe) I e, O _4. Ic ₁ SiO _1. Ni SiO, and MgSiO, stable, so that the composition of the slag phase with a suitable amount of silica has the formula ( _{Ic. Ni. Mg) 1} SiO ₁ ; in the case of oversaturation the phase (Fc. Ni) O-Fc ₁ O, present

Fig. 2 shows a typical microprobe analysis of an oxidic sample from the reaction shaft. The basic material distribution of the phases ah <and d marked in the positive speckle image can be seen from the corresponding X-ray photographs. The spherical phase α contains the components Ni. Fe and O in abundance, while the components Ch. S and Si are absent. This phase, which has a spherical shape typical of (Fc. NihFertite mixtures, evidently originated as an oxidation product of pentlandite. The phase ^ is a nickel- and iron-containing sulfide of the pentlanclite type and copper sulfide, which separated from one another during freezing t consists of fisenovyd containing calcium acid - signs of slag formation which has already begun. Phase d consists of quartz which is not in contact with the reaction.

The slag resulting from the oxidation process has a columnar structure in solidified form under the conditions described. These pillars consist of fayalite-containing silicates, whereas the Columns / wipe spaces from different elements in terms of their composition. Al-, Ca-Siiikdten exist, in which just like with the Fayaliten often extremely finely divided sulphide suspensions and metallic copper can be found.

In the picture in A b b. 3 is a typical one Saw structure-0 \> dationspro / eB; the Basic material distributions of the individual phases can be seen from the corresponding X-ray images. The column phase α contains the lilemcnie le. Ni. Si. Mu and of course O and thus represents a typical Silicate solution of the i'aya'it-i'orm (Jar. The prism-like phase h consists! Of stainless steel, in which the components Si and Mg are absent. The phases c and ι / consist of copper; in phase c there is Sulphide deposited in the krusientcil on staring.

ίο the Ph.isc (/ however hoMc'ii entirely of metal Nickel- and iron-containing sulphides were found at the merging point nijit

The values given in table Λ can be used before. because the proportion of third parties is Shaft product tcc'u high is 17.Hicwu.hls prozcni. Furthermore, the bottom part of the shaft product has a .iiil-ci-rdentlieh high nickel and Fiscn salary on. "A" leads to the conclusion that cmc selective oxidation do I isens extremely difficult

jo rig i> i derives from the widths given in I.iKlleH. dall because nickelanieil at the oxide phase of the shaft sample with 27 ° _v . in relation to the achievable, relatively Stem (Cu Ni) 53 °), is already quite high

aj slag phases - \\ ertc. both the analyzes al% also the distribution wcrtc. lie in this attempt a little cheaper than this is usually the I.ill The 1 m stand also deserves attention. that. based on the roof of the targetable stone in which Oxvd phase des Schach'.priiiV.sktc * brr.Mis <) 1 ·. and accordingly in the resulting Schlackcnphasc ^ ^0, the Gesamtcisens are included.

Microanalysis of the solidified stone showed that this almost as much SaltidpUascn (Ni. lc », p.

Impurities O. '>" ₀ tu and Co and NijSj Impurities: 2. (>""Ic. 1.0 ·', Cu and 1.2 ° o ^to contains The copper was in the stone as sulphide Cn," S impurities: 1 ', Ni and Fe contained The oxvdphasc of the stone consisted of nkkel-

Containing magnetite Overall, the stone contained 2.1 * ₀ metal, primarily nickel, but also the metals Fe in a precipitated form. Cu and Co and a minor amount of sulfur.

The results of the oxygenation search III-a show.

that the oxidation mechanism preceded the corresponds to the statements made, but obviously has an even more complicated construction.

Experiment III-b: Reduction

The gas phase obtained during the reduction and oxidation in the reaction shaft was a total of 1351 Nm ^s , ton of concentrate. The dry analysis of the gas phase, expressed as a percentage by volume, was 0.32H ₁ . 0.68 CO, 2.59CO ₁ and 11th WSO ₁ . The au < The oxygen pressure of the gas phase, calculated from the ratio of CO _{1 CO, was Po 1} 4 10 * Atm at a temperature of 1400 C. the corresponding sulfur pressure Ps ₁ 7-10 Atm calculated from the material balance sheet. The gas phase obtained is stable The diagram is identified by the number III-b According to the diagram, "-" at the temperatures used, Ni-ferrite in the shaft (ofcn) produle no longer in stable form. so that with d <reduction the leakage \ on (Ni. Fe) - "erupted partly in the metallic, partly in the sulphidic study, * is to be expected. The stability range of F.isenoxyi corresponds to that of Wüsli: or at least it is! close to this, so that the shaft product e

309 630 / Ί

9 10

Decrease in the proportion of trivalent iron in reaction shaft stems, the duration of the processing, the is expected. Since fuel distribution and the like obviously depend on factors in the reaction process; the the equilibrium is not reached and the acti- attempts, however, will be carried out vitätswcrtc of the components are not known. of the process on a technical level the compulsory state of contemplation employed here is reached, the extraordinarily inctallarnie running of only a trend-setting nature. The Schlak-Schlacken delivers.

The ken phase continues to move in the fayalite area: For the extraction of low-iron nickel sticks, these calculations show that the nickel suspension smelting plant of industrial silicate has also lost its stability. The inatia of activity. In Λ h h. 4 is the complete Anlajv with conditions but should be of this kind, i.e. di to Ausruhme.! Es f lekir.> Tilters to see The Rc.iMions-Nickel also continues as SiIiI.tt in the Schlaek.'n Schacht 2 des Ofi.ii> ii.nt. · a height of HO in and remains a D'irclimesser \ on Vi m. The I lnter> »fi * n 3 Table A shows. Since the <ichalt at three- had a height \ of 1.7 m. a Hrcile of Mimwertiprm F.iscn in the chess product as I olge der and a long of Ι'ί.5 ri Der DiirchnK ^ v des reduction by Ή ° ₀ on the value 12.1 "sunk isi 15 riser shaft 4 is true 2.x ni. its maximum height phase of the shaft protlukt went from 27.0 ° "to executed in chrome. Both the Re.ikn> ns-18.5 ° o. The s'illi.ltcil of the shaft 2 .ds the nickel (and iron) part of soluble places causes overcooling

with, however, very slight changes in atulv ao from Kon / entr.i !, Sjnd and surcharges, in: 1 lilfc

slightly increased in terms of volume. At the stone there was a usual concentrate burner 1 under

Significant increase in volume / u. Turn before \ *, itmier (450 C) air in the '' fen

likewise its content (Cu t Ni) was suspended. The / un tt / ßfuel des Schait '^ 2

55.I ⁰ Z ₀ easy / 11. In the case of the nickel and copper, in Ruhcm /ust.inj over the vault

Quantities of the slag was a sharp decline / u 45 manhole fed in for the reduction \.;, - c-

Discrimination: Compared to the starting values, the fuel was compared to the one in the remedy

the decrease in copper is 51.9 ° ₀ at Nkkcl the pipeline II shown in the shaft is inserted> r ^ '

54.5 ⁰ O. The Nickel and Kiipfcranieile (-distributions) Each of the three muscles could also be cin / cin bc: .- t

at the slag phase are only 6. ')

fc'w I! .5 · _d and «« mil mn 55.0 h. ». '.. 4«?. 5 * _e ge-.yr.kcn, 3 ^ Dk ί lu.uiu-c J. _r (, asprobe and the knife 'or

which undoubtedly happened as an excellent result / u rate temperature \ .τη or in the shaft A ·> 4th

is Hmsic! i: lich the structure of the solidified stone ar, d.r V;.; 'cA', or bcdarfsf.ills lotreci .: u

Are, with the exception of a minor analysis swamp, this point The riser shaft were at .r

kungen. opposite the stone of the oxidation stage position Λ \ Ι'γ, κ, π taken The intake τ

no significant changes occurred The 35 samples aiu .! a reaction layer happened with H-fe

The metallic phase of the stone is quantitatively light to a mirror specially constructed for this / »corner

increased (about 24 ° _e ). shows, however, with the exception of the chamber sampling channel, the cooling

a slight increase <ks copper value, the same amount and speed in one quenching: .r

Analysis values as matched to your samples. The system was subjected to ulwr

The results of the reduction test III ο show 40 the vault of the lower furnace with the help of a ν-r-

cindividual. that the multi-chamber sampling device which can be lowered into the Osydphase during the oxidation

The nickel that has passed through the reduction is selectively taken from stone and slag samples

sulfided or reduced to metal. A note of both the slag and the star

The samples in a Λα also decrease in trivalent iron in layers of the furnace melt

the reduction obtained before the impingement of the suspension to 45 as a function of the altitude were Ms the

The melt surface in the inter-furnace can be seen in the steady state at which Versuchsperh.de was reached.

The length of the metallization and sulfidation was also obtained from the corresponding tapping

naturally representative of the kinetic conditions of the stone and slag samples.

For this purpose 2 sheets of drawings

Claims (5)

1 2 working and otherwise in production in large patent claims: scale possible technology is extremely difficult, designed, and sometimes even impossible. in the 1. Process for obtaining low-iron connection with the almost complete oxidation of nickel stone by suspension melting of SuI- 5 of the iron is thus also a considerable part of the fiderzen in a shaft-shaped furnace, with the nickel contained in the concentrate being oxidized. In the case of the reaction material with the oxidizing gases containing nickel-containing sulphide concentrates, the nickel is led from the top to the bottom and the reac- habitably bound to an approximately the same amount or more ionic gases through a horizontally lying iron-containing pentlandi lattice, from the settling hearth (lower furnace) into an upward overall _i0 rich in the manufacture of stone and the iron directed Fuchs be passed must be herausoxydiert according to Patent. Pentlandite ignites 2 001450. characterized, like the other nickel-containing sulphides, that the threefold resulting from the oxidation burns at a higher temperature and more slowly than valuable iron and the nickel oxide in the lower part of the reaction shaft, which makes up the main part of the concentrate, is increased of the sulfur-free iron sulfide (usually pyrite-containing pyrrole partial pressure of the gases obtained and or tii). For this reason, with a highly effective lowering of the oxygen partial pressure in the lower roasting part of the reaction shaft using conventional roasting technology, considerable amounts of trivalent iron are formed before it is introduced, the gases obtained in the lower furnace are reduced while the gases that have already been oxidized (pyrrotite) are reduced Oxidation of the stone in ao iron is further oxidized. During the treatment of the lower furnace and the transition from nickel oxide to the nickel ore concentrates, the slag phase can thus be avoided. sicnsoxydation when working according to the conventional 2. Method according to claim 1, thereby not controlling technology with the same accuracy draws that the reduction of the reaction gases such as. B. in the production of rich copper stone, It is widely carried out that the stones that arise in the slag are 15 The amount of stones resulting from the below-mentioned forms a shaft furnace product made in accordance with oxvdic, e.g. non-ferrous metal conditions, bonds, reduced to the corresponding metals, is small, since a considerable part of the reaction occurs or to the corresponding metal sulfides manhole resulting sulfide in the reduction of the be sulfided. trivalent iron of the slag phase consumed 3. The method according to claim 1, characterized in that it is characterized by a further growing sender that the reduction of the reaction gases transition into the slag phase-related Nickeiso is carried out far that the oxidation of the losses occurs. The iron oxide contained in the oxidation of the stone slag to magnetite in the slag phase is prevented, the resulting Fe ₄ O _{3 is processed} into the iron-magnesium-nickel-silicate melt and the iron is almost completely bivalent weak solution from which it remains. using conventional methods in the lower oven 4. The method according to claim 1, characterized in gas reduction or in a separate slag furnace records that the reaction gases are reduced so far with normal treatment time, temperature and will be that a significant part of the conventional technology such. B. at the Gases contain sulfur in elemental form 40 Manufacture of poor or rich nickel stone is won. Copper stone is common, but extremely difficult 5. The method as claimed in claim 1, characterized in that it can be reduced. draws that the reduction of the gases is controlled in the way described in the main patent 2 001 450 is that the exhaust gases a desired SO ₂ - level process is primarily intended to serve. Have salary. ₄₅ in the manufacture of metallic copper and Spurstein the .Suspension melting process for the To improve copper concentrates. By loading of the lower oven; with raw fuel, the sulfur potential of the The present invention relates to a method after 50 well gases so increased that the in the Patent 2 001 450 for the enrichment of sulphidic system returning fly dust partially or fully concentrates With low nickel content or constantly sulphided, which leads to an improvement in nickel and copper through suspension melting, the degree of autogeneity of the reaction shaft so that the end product is one that is very poor in iron. At the same time, there is a multitude of others but richer in nickel or nickel and copper 55 advantages, of which the following should be mentioned: Stone as well as at the same time one of the mentioned colored extraction of sulfur in elemental form result in low-metal slag. From the so obtained when adjusting the reaction gases according to the almost iron-free, highly concentrated stone, demands of sulfuric acid extraction,
“I use chemical or pyrometallurgical methods in the manufacture of raw metal or trace stone Process easily and cost-effectively nickel in 60 causes a confluence of the in the win iciner form. Slag usually contained as metal or sulfide According to the process of the invention, copper is found due to the increase in sulfur Beginning in the reaction shaft of the suspension potential of the gases in the lower furnace and Imeizanlage an oxidation of the suspended also to a decrease in trivalent iron with Sulfide concentrate instead, with the majority 65 being the result of a decrease in the copper content of the of iron is oxidized. The dissociation pressures of the slag. Iron and nickel sulfides are very close to one another in the process of the present invention that on the basis of selective iron oxidation is prevented, that with strong oxidation