DE1281683B - Process for the extraction of nickel and other non-ferrous metals from rich ferrous nickel stone - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

C22b

German class: 40 a -23/04

Number: 1 281683

File number: P 12 81 683.0-24 (S 97925)

Filing date: July 1, 1965

Opening day: October 31, 1968

The invention relates to a method for treating rich ferrous nickel stone, the also contains at least one noble metal and arsenic and / or antimony.

Nickel stone is seen in the processing of sulfide Contain nickel ores and can be composed of a wide variety of components. By means of the method according to the invention, nickel stones are preferably used which have a have a relatively high content of nickel, between about 60 and 75%, and iron, lower Amounts of cobalt and copper, some precious metals and also contaminants, albeit proportionately contain small amounts of arsenic and / or antimony.

Several methods are already known for the extraction of nickel and other metals from nickel stone. This subheading includes pyrometallurgical processes, such as melting with various aggregates, in order to clean the nickel stone so far that it can finally be subjected to electrolysis. Hydrometallurgical processes essentially include leaching in a basic or acidic medium, Purification of the solution and extraction of the metals. These hydrometallurgical processes point against the older procedures have considerable advantages. They are relatively versatile and allow that Treatment of rich nickel stones, which among other things also contain valuable metals, the can be separated individually. Rich nickel stone can under oxidizing conditions in basic or acidic medium to make the valuable metals soluble and the impurities to be left as an insoluble residue. The basic leaching is for relatively simple ones Nickel stone is generally useful and satisfactory. However, if higher quality nickel stone, which contains precious metals to be extracted and / or a relatively large amount of cobalt, for example is to be carried out, an acidic leaching must be carried out.

In a known process for the extraction of nickel from finely divided, iron-free copper-nickel stone, work is carried out in two stages. Each of the two digestion stages is carried out with an excess of sulfuric acid, the first stage taking place at normal pressure and temperatures up to the boiling point, while the second stage is carried out in a closed stirred vessel and the temperature is increased until pressures between 1 and 10 atmospheres, but preferably a pressure of about 5 atmospheres. Starting product for processes for the extraction of nickel and
other non-ferrous metals from rich
ferrous nickel stone

Applicant:

Sherritt Gordon Mines Limited, Toronto, Ontario (Canada)

Representative:

Dipl.-Chem. I. Schulze

and Dipl.-Ing. E. Gutscher, patent attorneys,

6900 Heidelberg, Gaisbergstr. 3

Named as inventor:

Vladimir Nikolaus Mackiw,

Wasyl Kunda, Fort Sasketchewan »Alberta;

David John Ivor Evans, Edmonton, Alberta

(Canada)

Claimed priority:

Canada, July 8, 1964 (906 694)

this method is a crushed copper-nickel stone blown free of iron, since this method is satisfactory is only suitable for this material. It has been found that when treated, ferrous Concentration stones with sulfuric acid, the iron and the nickel go completely into solution and must be removed again from the nickel sulfate solution. However, such a procedure is cumbersome and associated with difficulties, because this results in nickel-containing sludges that are particularly processed Need to become.

809 629/1206

3 4

Another serious problem occurs with the amount used to bind the non-ferrous digestion present A rich ferrous nickel stone requires metals as sulfates. Another one on, the very small amounts, down to 0.1%, is the control of the pH, because the characteristic Arsenic and / or antimony. These metals become first stage at a pH in the range of which is easily dissolved and contaminated in the lye bath 5 3.5 to 5.5 ended. The second leach takes place at as a result, the nickel obtained as the end product, so a pH value of 1.5 to 2.5 and is so long that it may not be useful at all. Continued until practically all of the nickel and The problem becomes particularly serious when the non-ferrous metals accompanying nickel are removed from the residue extracted from the lye solution by hydrogen reduction at. The caustic solutions of both Lauerhöhter Temperature and increased pressure recovery processes can be combined and, from this, the coupling because the arsenic falls under the fer and iron are removed. This will also be same conditions as the nickel. But since all the slightest amounts of arsenic removed during for commercial nickel powder, an arsenic content from which leaches were dissolved. The purified lye less than 0.005% and special powder of less solution can be achieved by known hydrogen reduction than 0.001% is required, the used must of course be treated further to produce nickel and codete Lye solution must be very low in arsenic. bait as an essentially pure metal powder of the invention is a method of obtaining.

recovery of nickel and other non-ferrous metals It was surprisingly found that the

to create that the utilization of a rich iron in the caustic solution extracted and dissolved arsenic Nickel stone allowed, which is also at least 20 amount very much reduced when the acid Noble metal as well as arsenic and / or antimony is leached in two stages. The result is in the case of a satisfactory selective mood are here essentially different than in the case of the entrance and separation of the individual components possible step-by-step process. This is all the more astonishing since the is borrowed and the effect of the digestion is carried out as a result of the second leaching under conditions it is increased that no arsenic and / or antimony is added, which is essential in a single-stage leaching impurities occur. Extract amounts of arsenic. Furthermore, the

The subject matter of the invention is therefore a process for the arsenic content of the Rückzur leached in the second stage Extraction of nickel and other non-ferrous stands because of the concentrating effect of the metals from rich ferrous nickel stone, the first leach significantly higher than that of the furthermore at least one noble metal, such as palladium, pia-30 nickel stone.

tin, silver or gold, as well as arsenic and / or antimony It is known that in a direct simple

contains an excessive amount of arsenic due to digestion with dilute sulfur-oxidizing leach acid in two stages, in which the stone is dissolved in finely divided form, which can only be achieved by time-consuming and costly Form under oxidizing conditions at a playful and therefore uneconomical process temperature above 120 ° C and increased pressure in 35 steps to be brought to an acceptable level leached with an aqueous sulfuric acid solution and that can. With the two-stage process according to the invention, precious metals being concentrated in the caustic residue, on the other hand, only becomes one due to the caustic solution the one which is characterized in that a relatively small amount of arsenic is extracted and Sludge of finely divided stone dissolved in aqueous sulfur, which quickly and satisfactorily from the solution of the acidic acid is formed, the content of 40 solution can be removed. It was very general Total sulfur in the sludge is determined to be less in the two-stage process that it is equal to or slightly greater than that used to dissolve than a fifth of the amount of arsenic than in the Formation of the non-ferrous metal sulphates required one-step process, even if in both processes Amount, this sludge a first leach under the same conditions are observed. Like one Oxygen partial pressure above 0.35 atm 45 times the effect of leaching in two stages is subject And this first leaching in one process is 30% greater than the usual one-pH value of the sludge between 3.5 and 5.5 times the work process.

ends, the caustic solution of the first leach of The invention is based on the schematic

separated undissolved residue, the residue of the representation in the drawing described in more detail, first leach a second leach at a 50 After the first leach, the solids are Oxygen partial pressure above 0.35 atm for so long separated from the liquid. Then the second follows is subjected to practically all of the nickel leaching, in which the residue of the first leaching and the other non-ferrous metals in the stone are treated separately. After this second leaching are hiert, the lye solution of the second leaching again separated into a solid and a liquid phase separated from the undissolved residue and together 55 and then the copper and then the iron separated with the filtrate from the first leaching for the purpose of removing and remaining arsenic. Eventually the treatment of copper and iron removal and then adjusted solution and recovered the nickel, Practically pure Nik from the purified caustic solution. The extraction of copper and nickel is in the

kel and cobalt can be extracted. known to the individual and is not a feature of the

In the case of the oxidizing twig according to the invention. The operations are only for understanding Stage digestion is carried out in each stage at one temperature of the entire process for the digestion of a reiperatur of over 120 ° C and an oxygen particle described by nickel stone, pressure of over 0.35 atmospheres, preferably over 0.7 atmospheres, for the sake of simplicity, the process steps

worked. An excess of acid is not required, only in connection with the contaminant since the amount of sulfuric acid used is so difficult to explain arsenic. Of course that corresponds measure is that the total sulfur content of the behavior of arsenic corresponds to that of antimony, so Sludge of the first digestion stage either the same as the processes for the last-mentioned metal or just slightly higher than the stoichiometric apply.

5 6

The nickel stone is first ground in the usual way. Cobalt and a small amount of arsenic, generally ground, at least about 80% of the particles containing less than 0.05 g / l, may be less with the caustic solution than 325 Tyler screen fineness. The solution of the second stage will be combined and then Ground material is mixed with water and sulfuric acid to extract copper and remove it Stirred and prepared a slurry of a density 5 iron. If the dissolved copper from about 20 to 40 percent solids by weight is not so large that it represents the nickel-eride. The optimum density of the slurry is dukt contaminated, can - as from the dashed lines from the nickel lines desired in the lye solution can be seen - the copper recovery excess as well as the working conditions, how to go.

The size and shape of the reaction vessel as well as the an- 10 The second oxidizing acidic leaching is dependent on the skillful stirring technique. The same general temperature and pressure The added amount of sulfuric acid must be carried out in sufficient conditions as the first leaching. The amount to make up the total sulfur content of the slurry residue is slurried with water to a density of 20 to 40% solids to convert the non-ferrous metals into suI. To be obtained if necessary. It is preferable to use a little more draft, to warm up, in order to set the oxidation in motion. Of course, the one to be added depends on the set. The reaction starts at a temperature with the amount of sulfuric acid from the sulfur already present in the nickel stone from 121 to 176 ° C and under an oxygen component. The pressure of over 0.35 atm according to the invention continued around the entire turned nickel stones generally have a nickel and the accompanying non-ferrous metals from a lack of sulfur, so that the missing amount 20 of the first leaching can be extracted. The pH value in is replaced by the addition of sulfuric acid. The molar of this stage depends on the molar ratio of the Ge ratio of total sulfur content to non-ferrous total sulfur to non-ferrous metals in the first low-grade metal is at least 1.0: 1.20, preferably from the supply residue, which is preferably 1.05: 1.20 be-1, 05: 1.20. wearing. If this molar ratio is obtained by adding the first leach is at a temperature of 35 sulfuric acid before the first leaching correctly-121 to 176 ° C, preferably 135 to 15O ⁰ C, transit and sets out the first leaching to the corresponding. The oxidizing conditions are terminated at the point in time when the residue, which is fed into the second Laud by the addition of oxygen or a free acidification, has created a ratio of gas containing sulfur, such as air, to metal in the desired range of 1.05: 1 , 20. Sufficient pressure is applied to achieve a 30 It is therefore generally not necessary to add further acid, preferably to the second leaching, when the oxygen pressure is 0.34 atm. Should maintain 1.36 to 6.8 atm. It is also possible to use higher temperatures and higher pressures, however, for whatever reason, this ratio may have dropped below 1.0, which can also be used in the setting. The associated higher costs will be added to the second stage acid,
however, in general, by the increased extraction 35 on the second leach, essentially that will not come in. The reaction is exothermic, and all of the nickel, cobalt and copper within, once set in motion, is normally about 3 hours from the first leach residue, an external heat supply only at the beginning of the extracted and dissolved in the caustic solution. A reaction required. A small amount of arsenic, generally less than 40 0.1 g / l, is also extracted in this stage and the control of the pH value during the first leaching is solved. Most of the arsenic as well as the precious metals are seen to be such that the resulting metals remain in the residue. The extra slurry in this case has a pH value of 3.5 to 5.5, the amount of arsenic mentioned is only a small fraction of preferably 4.5 to 5.0. This depends on the amount required for an economical Nik leaching time, since the oxidation in the first stage requires kel, cobalt and copper extraction, causes the free sulfuric acid to be dissolved first with conditions in a one-stage leach ,
the metallic nickel connects. The alkali solution of the second leaching decreases as the content of free acid, and the pH value increases. the separation of the residue either alone or as the oxidation progresses, the sulphides are oxidized together with the caustic solution of the first stage of the nickel stone. Subjected to purification by oxidation of iron.

sulfides and the hydrolysis of ferric sulfate to basi- In the leaching according to the invention, the With ferric sulphate, the free acid content rises, precious metals concentrated in the residue. Hence can on again, and the pH value drops accordingly. this residue, which besides the precious metals still In this way it is very easy to control the pH of the main amount of arsenic and iron as well as a small amount of restim to control the desired area and to reduce the amount of nickel and accompanying non-ferrous metals. It is essential that the first leaching contains talen immediately for the extraction of the noble liquor, before the oxidation has progressed so far, metals, for example by cyanidation,. used the pH value can be reduced to below the minimum by free acid.

limit of 3.5 drops. At this point in time, the schematic representation of the entire Verden essentially 70 to 75 percent by weight of 60 driving can be seen that the combined first and Nickel content of the nickel stone be leached, and second caustic solution initially for copper extraction the bulk of the copper as well as the arsenic remains in the process. Here the copper is treated as a SuI residue. fid concentrate obtained that contains less than 1% nickel Residue that contains all precious metals and the main 65 0.005 g / l copper. The copper can get through contains amount of copper and arsenic, precipitate from the solution can be removed with hydrogen sulfide, separated in the usual way and the second Lau- whereby preferably temperatures of 87 to 126 ° C, supply. The caustic solution, the nickel and a pH-Wejt of 1.5 to 2.0, a molar ratio of

1 2δ1 683

Sc | iwefeiwässerstorr to copper of έ, 5: 3.0 and a 3 ^ 5 f ^ ier7§§§§§§§§§§feinh "Sit ground. 1200 g of the milling

Boiled nickel plus cobalt alf less than girtes ^ were hammered out with 61 water, so that

X20 g / l can be used-. ₄ ... Eifie Jöhlärnmäichte from 2ö ^s / o of the solid material weight

The solution freed from copper is retained for removal. Then 786 g of sulfuric acid would be produced

pH adjusted to 4.0 to 5.5. The solution being Dids'e slurry was made in a power plant

sufficiently long at a temperature of 78 to equipped kofrdsiöüsfesjEen ÄütoKläv at 135; * 'G

93 ° C stirred and ventilated to keep the main irons and five an oxygen pressure of 1.38 ∆fi8 as Eisenhyäröx ^ d z_u fall. During this Behaiid- io leached, flat istüfidigerii leaches became the jÄ. | Iiö-

The arsenic content of the solution is slightly cooled to a low level and the solution, the pH value

Certain släß lowered if in the output range of 1.4 äüfwlesj in front uögelostSii Mucksiänä düjch

Curtain up a little, preferably under 50 g / l, of oxen. Oils Läügelosiing Ji $ tte aB ^ u-

Anäerniäils a complete removal of this composition of Ii3 g / l nickel 08 gyl KöÜ5 | it

gy. |,

Mets d & ggaß v ir g E 5 0 ^ 3g / l itpfer ,, i, 4g7 iron nd Ö, 2 ^ g7l Ärseii. Üie

quantity to be carried out. . In this case, however, occur ßÜter- Exiraktionsäusijeüte afi a uögewascJienen fuels' ¹ on schwierigkeiteri and ^ larige residence. fis depends on stancj revealed. ^ ö | 7 Ve, "Niökelj 77 ^ 8 ^ / 0 feörJält, i'2,1 * / * demnaSh from the arsenic concentration of the feehandel- copper and 58.6 ^ / O arsenic, th solution; SeHkuhg des

Sleeve shells aui ₀ a maximum before about Q ₅ ÖÖ5 g7l äö Example %

or whoever can be achieved.

.. pas in accordance with the requirements. In the example \, it emphasizes, on, mfächer, ₍ Woise put a Hiclelstein lie, outside of the 24Ö0 g nickel steel and .12 "Wasiösuüg to get,. -that only a, minimum of caustic was used .Sulphuric acid is added to the draft :, the lelcHi by adjusting the pH value is ben and the molar is added to total sulfur. . 13: ί eing6 $ .teilt The Auflöhläinreichend is ^ there are gesenfct -τ Kaiin Elsen mung wuräg in fine nut a J ^ ührSr AEU | gestäiteieö example, iE I ^ QRM yög Bisenoxid ziigege- UNAE koSrosioösbestäriälgen autoclave tiei Ϊ3§ ⁶ Ö. vM ψη in order to äasÄrsenzu ßüe ± _t The required- jmter eüdem _i iaüefstbfiuterdruGk'.vSn 1; M. $ M so

ÄTsemnenge; .. ',, ... ..... & ΒΦ ^ ^eni - Abbot fenneii in front yhgelöstetl Rüpliständ

To. RemovalHg de | ßisdns ünä: the arsenic residues 10J g / l nickel ,. 8 $ g / l Kofeali, _t O, ÖOS g / l ilüpfer, will die.Läugefösungrfüf the opening of Niekel §ffi g / l liien ^ Ö, Öp g / l Äfsen, D'er, unwascMne

ä by the well-known reduction with hydrogen at ig Mckstänä, the 47 ^δ / ο fiickel, · 5.9 ^ö / o, copper, %, Pk

increased temperature and temperature . increased pressure an iron and 1.97 ^ o Afseii eritnieltj would ifi_4, Si wäs-

posed. The caustic solution is leached with water and / or water, after adding a full 78 g of water.

or recirculated final solution from the previous run em molar ratio of Si / NI + OQ 4- Cu

the reduction level had been set yferdünnti around the Mckelhalt ^ 13. This second oil dehydration

to bring aüf 4S to SS gTl. 40 leaching was prioritized under the same temperature and temperature

XJm is the molar ratio of ammonia to acidification conditions as in the efsteri stage, iiäöh

Nickel to 1 ^ 9: 2.5 or the ammonium sulphate content to 1 hour, the pH value was

To amount 35Ög / l becomes Afnmoniäjs: and Äminonmung 1,3. The clear caustic solution mat is an additional

sulfate added. During this solution, the composition of .7 |, ög / l nickel ^ 0.7 g / l Köfeäitj

can also include the remaining, during the previous 45 Qß g / l copper, 0.4 g / i Είέβη and Ö, l <5glt ArsSn. the

Stage nods away iron to be precipitated. This (giesamtaüsbeute amounted to 99-, 6 ⁰ Zo Mbmi, 98.2 ^'o / o

takes place by introducing air, tim das Bisen full cobalt, 13, IVo copper and §, S ^! From arsenic,

to constantly oxidize and fall. In general The results of Examples 1 and 2 show that

With this treatment, "the iron content is rapidly increased in the two-stage leaching process - less work

reduced to below 0.005 g / l. ......,. 5o extracted wixd as in the Bmsiüfenveiiahren. j & wufleri

'The clear solution is then' replaced by the one known from the Nielieistein.in Example 2 8 _S 5 ⁸ Zo arsenic extra-

Hydrogen liberation treated to essentially hlert, while in the example Ϊ 58.8 ° / g arsenic removed

to precipitate pure nickel in powder form. Any were. It can also be seen, for example, that the two-stage

Kobalftfiengen in Reduktioiis-Bndlösung can YerfahreÄ M 'minutes were erförderpcK, | im.über

can be obtained by conventional processing steps. 55 98 «/ 0 nickel and cobalt from 24ÖÖg nickel stone to

The invention is based on the. Withdraw the following, while at one stage, in 60 minutes

games described in more detail. In the tests only 90, -7 ⁵ Zq ^ nickel and 77, S ' ⁰ Vo cobalt from .l2ÖÖ§

ih Nikli d d dh Sh fii üd fü Bi

p n 9, Zq ^ 7, V u. §

Rich nickel stone is used, which has been extracted by melting stone. It would be for every interior from nickel sulfate concentrate. The criterion of reaction in a two-stage process can

percent sulfur and 0.5 weight percent arsenic. _ _ft . . ,.

■ BSi§i> igl 3

Example i ^ 5 JÖie separation of oxen by adding

Iron ni ^ ofm of .BisenOxide would be enough. Nickelsteines solutions of the following were in a ball mill up to 83 ^b / o unier * ■ «'- ■

9 Ni Co Cu Fe 10 S. As PH value Caustic solution
No. 104
116 0.76
0.86 0.022
2.8 0.055
0.33 57.4
64.0 0.071
0.24 2.9
1.9 1 (two-stage leaching)
2 (single stage leaching)

A varying amount of residual alkali from a NiS concentration process containing 47.6% iron as iron oxide was added to 11 solution. Each solution obtained in this way was ^{stirred at 65 °} C., specifically over periods of time ranging from 15 to 180 minutes. After the end of the experiment, the solution was filtered and tested for arsenic. The results of these investigations are summarized in the following table and show that the arsenic content can be reduced within a very short time below an allowable maximum where the initial content thereof is low. This is the case with the solution from the two-stage process. The solution from the one-step process, which is relatively rich in arsenic, is not lowered to the marked level even after a residence time of 2 hours and the addition of 15 g / l residues.

Separation of arsenic from the nickel alkali solution by treatment with iron oxide

Conditions: 82 ° C

Examined samples

Amount of added
Residues (60 minutes
Dwell time):

lg / 1

2g / l

5 g / l

10 g / l

15 g / l

Dwell time (10 g / l residue):

15 minutes

30 minutes

60 minutes

120 minutes

Main solution

0.071 g / L As
(Number 1)

0.029

0.030

0.009

0.0055

0.0024

0.0083
0.0052
0.0042
0.046

0.24 g / l As
(No. 2)

0.24
0.29
0.24
0.17
0.12

0.20
0.19
0.17
0.16

30th

35

40

45-

Example 4

Samples of solution 1 and 2 from Example 3 were treated with ammonia to bring the pH to 4.5 up to 5.0. The adjusted solutions were stirred and air was passed through to remove the arsenic to fail. After 2 hours solution No. 1 contained only 0.0057 g / l arsenic, and after 24 hours it had Solution No. 2 still 0.20 g / l arsenic. When the pH of solution No. 1 was increased to 5.5, by To precipitate more arsenic, copious amounts of basic nickel sulfate were precipitated, which could only be achieved with large Difficulties could be filtered.

The method according to the invention has numerous advantages. In particular, it enables the arsenic content to enrich the treated nickel stone in the residue, so that no costly and time-consuming Procedures for removing this metal are needed. The effectiveness of the leach is also increased significantly, and precious metals can be obtained in the form of a concentrate in the residue will. In addition, the caustic solution of the first stage (three quarters of the total caustic solution volume) essentially free of copper and iron and can therefore be directly can be used for nickel recovery with further purification.

Claims (6)

Patent claims: 1. Process for the extraction of nickel and other non-ferrous metals from rich ferrous Nickel stone, which also contains at least one noble metal, such as palladium, platinum, or silver Gold, as well as arsenic and / or antimony, by digestion with dilute sulfuric acid in two stages in which the stone is finely divided under oxidizing conditions at one Temperature above 120 ° C and increased pressure leached in an aqueous sulfuric acid solution and the precious metals are concentrated in the lye residue, characterized in that that a sludge of finely divided stone is formed in aqueous solution, the content of Total sulfur of the sludge is measured so that it is equal to or slightly greater than that of the Formation of the non-ferrous metal sulphates required, this sludge undergoes an initial leaching subjected to an oxygen partial pressure above 0.35 atm and this first leach at a pH of the sludge is terminated between 3.5 and 5.5, the caustic solution of the first leach separated from undissolved residue, the residue from the first leaching of a second leaching at an oxygen partial pressure above 0.35 atm is subjected until practically all the nickel and the other non-ferrous metals of the stone are extracted, the caustic solution the second leaching separated from the undissolved residue and together with the filtrate from the first leaching for the purpose of removal treated by copper and iron and then practically pure from the purified alkali solution Nickel and cobalt can be extracted. 2. The method according to claim 1, characterized in that the first leaching at a Temperature of 135 to 150 ° C carried out and is terminated at a pH of 4.5 to 5.0. 3. The method according to claim 1 or 2, characterized in that the residue of the second Leaching is subjected to a process for the extraction of precious metals. 4. The method according to claim 1, characterized in that the solution of the first leach directly subjected to the extraction of nickel and cobalt without removing copper and iron will. 5. The method according to claim 1 to 3, characterized in that the copper from the caustic solution removed by reaction of the solution with hydrogen sulfide and iron and the remaining Arsenic by adjusting the pH 809 629/1206 U 12 the solution to 4.5 to 5.0 by adding Am- .- amount of arsenic, added and the remainder moniak is felled. Arsenic is removed. 6. The method according to claim 1, characterized indicates that from the solution of the second documents considered: Leaching by adding 10 times the amount 5 Excerpt from German patent applications, Vol. 19, Iron, based on the p. 324 contained in the solution. 1 sheet of drawings 809 629/1206 10.68 © Bundesdruckerei (Berlin