JPS6044379B2 - Methods for extraction and separation of metals using liquid cation exchangers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Liquid organic cation exchangers, such as fatty acids, naphthenic acids and other carboxylic acids, and alkyl-phosphoric acids such as di(2-ethylhexyl) phosphoric acid, are used between metal ions and organic components. It is known that metal ions can be used for the extraction and separation of metal ions from aqueous solutions by complex formation.

When the organic active extractant is dissolved in an organic solvent (diluent) that is insoluble in hydration, contact between the organic phase and the hydration forms an organometallic complex between the active organic extractant and the metal ions in the aqueous phase. causes the formation and formation of This metal complex is soluble in the organic phase, but not soluble in hydration, and the metal is extracted into the organic phase in this way. The formation of the metal complex occurs by cation exchange, whereby an equivalent amount of protons is released from the organic acid corresponding to the amount of metal extracted from the aqueous phase.

This leads to a corresponding decrease in the pH of the aqueous phase. The formation of metal cation complexes mainly depends on the pH of the aqueous phase and
Occurs only above the value. Generally, in the case of carboxylic acids,
The lower limit for the extraction of metal ions can be estimated to be slightly lower than the pH at which each metal is precipitated as a hydroxide. This trend with respect to pH allows extraction to occur selectively and separation of metals is obtained by adjusting the pH in the aqueous solution.

Regarding alkyl phosphoric acids, these are generally capable of extracting metal ions at lower pH values than carboxylic acids.

Furthermore, a special interaction occurs during the conversion of carboxylic acids to alkyl phosphates as cation exchangers: a reversal of selectivity towards copper and zinc. However, as a rule, the extraction of metal ions by cation exchangers in acid form causes an equivalent amount of protons to be released and therefore only a limited amount of metal can be obtained before a low pH value is obtained and the extraction stops. Only ions can be extracted.

This can be countered by neutralizing the released protons by supplying alkali to the system. The pH is thus kept at a value that allows continued extraction of metal ions. However, in practice this prohibits the use of said cation exchangers for the extraction of metal ions in many cases (PrOhi
Depending on the amount of metal that is present or extracted, this method requires the addition of an equivalent amount of alkali, which means that it does not offer any pharmaceutical advantages compared to precipitation reactions. In accordance with the present invention, a method is provided which utilizes the advantages of the described liquid-liquid extraction using a cation exchanger without requiring the addition of equivalent amounts of alkali, which would normally be considered prohibitive or a significant pharmaceutical burden. Served.

This is because metals are leached from solid metal raw materials mainly with organic acids (
This is done by what happens with the above-mentioned cation exchanger). As is known, the conventional technique for extracting metal values by leaching consists in using mineral acids, such as sulfuric acid, to provide an aqueous solution of metal salts. This inventive concept is based on organic acids (
It is based on a combination of leaching of the metal-containing raw material with a cation exchanger) and subsequent use of the metal cation complexes formed therein in a liquid-liquid extraction process. In this liquid-liquid extraction method,
Organic solutions of metal complexes are used to recover and separate metal ions from aqueous solutions of metal salts. Aqueous solutions of metal ions are typically derived from leaching metal-containing raw materials with mineral acids, such as sulfuric acid, in which many metals can be dissolved. Reference is made to FIG. 1, which illustrates the principle of the described method.

For simplicity of description, it is assumed (in the figure) that only two metals are dissolved by leaching of the metal raw material. However, in principle there is no limit to the number of metals that can be recovered and separated using the present invention. In the reaction between a solid metal-containing raw material and a liquid cation exchanger, preferably the most basic metal/metal (Mel) in the raw material reacts with the cation exchanger (KH) to form a metal cation complex (K.Mel).
) to form.

A subsequent liquid-liquid extraction method extracts the least basic metal (Mel,)
is extracted into the organic phase by exchange with metal Mel, and metal ■!
is sent to the aqueous phase. Thus, during extraction the aqueous phase is metal r! 4
Enriched with E1, MEll is simultaneously exchanged into the organic phase. If the aqueous phase also contains other metals, in addition to the metal MEll, the metals can be grouped separately and optionally by appropriate partitioning of the organic phase and adaptation of the number of extraction stages within the technical process of the extraction method. Extracted.

If the aqueous phase contains free mineral acids, said free acids can be neutralized to an appropriate extent by a corresponding increase in the amount of organic phase brought into contact with the aqueous phase during the extraction step.

The protons in the aqueous phase are then extracted by exchange with basic metals from the organic phase. It is also pointed out that it is usually beneficial to dissolve as much metal as possible during the initial leaching of the solid material in the organic phase.

Excess metal complex in the organic phase can be stopped directly with mineral acids. The ideal system would thus obtain quantitative leaching of valuable metals by the organic phase, after which the metals are separated by selective stripping from the organic phase with a mineral acid, such as sulfuric acid. From FIG. 1, it can be assumed, for example, that the metal is deposited in its metallic form from the stripping solution by electrolysis.

Many alternatives are possible for producing aqueous solutions of these metal salts by reduction and precipitation methods and each has to be evaluated in a single case. By carrying out the stripping step with an excess of strong mineral acid, it is possible to obtain a direct precipitation of the metal salt by the stripping step. It is also possible to precipitate metal salts directly from the organic phase by contacting and stripping with gaseous phases such as hydrogen chloride, carbon dioxide and sulfur dioxide.

Thus, the present invention utilizes a liquid cation exchanger dissolved in a suitable organic solvent by leaching the metal-containing raw material with the liquid cation exchanger in combination with a subsequent stripping step and/or a liquid-liquid extraction step. relates to a process for the extraction and separation of metals from solid metal-containing feedstocks and from aqueous solutions with or without the presence of free mineral acids, in which a liquid cation exchanger in an organic phase is contacted with a solid metal-containing feedstock. and react, whereby a sort or more metal cation complex is formed, which is contacted with a mineral acid for stripping the metal from the metal complex, or an organic phase containing the metal complex is removed from an aqueous solution of the metal. It is characterized in that it is used in a subsequent liquid-liquid extraction process for recovery and separation of metal ions.

As is evident from FIG. 1, the present invention leads to a closed process with the possibility of quantitative recovery of valuable metals in metal-containing feedstocks, and some of the feedstocks that do not react with the liquid cation exchanger are Lead to final leaching with another aqueous leaching solution.

Subsequently, how the present invention falls within the scope of the wet metallurgical production of zinc when the metal-containing raw material is present in the form known as calcine, which is produced by roasting a sulfide concentrate. Examples show how it can be used.

In this case the zinc oxide content in the power roast reacts with the organic acid during the formation of a zinc metal complex, which is then used to remove ferric ions from the acidic zinc sulfate solution within the thermal leaching stage of the process. be done. However, the general principles of the invention may be utilized within any wet metallurgical process capable of producing organometallic complexes by reaction of solid metal-containing raw materials with active liquid organic ion exchangers.

In existing wet metallurgy processes, reference is made by way of example to the refining and purification of metals such as copper, nickel, cobalt and zinc from sulfide or oxide ores. For sulfide ores, the raw material is most often pre-roasted to metal oxides (force-fired products). This is the most obvious starting material for this invention. oxidation of this material if the metal-containing raw material is a metal waste product, for example an alloy of various metals, or a cementation product of the metal, such as that obtained from a refining step within the wet metallurgical production of zinc; The processing gives a mixture of metal oxides, which can be extracted and separated according to the invention.

When the process according to the invention is used, for example, as is known, in the wet metallurgical production of zinc, in which the zinc oxide in the power-fired product is dissolved in sulfuric acid and the bad lead is deposited electrolytically, the process can be carried out using alkaline or other It can be used for the removal of iron from zinc sulfate solutions without the use of additives.

This further applies, for example, to liquid cation exchangers such as "Versatic 91r (shell)" (9, 10 or 1C), described below as Versatic (trade name).
a mixture of carboxylic acids containing secondary and tertiary acids and no primary acids in a ratio of approximately 1:9)
and commercially available carboxylic acids such as ShellsOl (boiling point 187.5-210
(2) A mixture of acyclic aliphatic hydrocarbons in the range C) is clarified in the following case where it is assumed to exist as a solution in a suitable organic solvent. Referring to FIG. 2, this illustrates the principle of the method described below.

In the figure, it corresponds to the acid of KH Paversachi. In the acid form, Versace is reactive to solid zinc oxide (power-baked).

Due to this reaction, a metal complex is formed between zinc and versatility (Zn-versatility). Subsequent contact between the zinc-containing organic phase and the iron-containing aqueous zinc sulfate solution results in an exchange between zinc and iron. This transfers the iron to the organic phase, where it is present as the metal complex Fe-versatility. This exchange transfers an equivalent amount of zinc from the organic phase to the aqueous zinc sulfate solution. In this way, iron is quantitatively removed from the zinc sulfate solution by contact between two immiscible phases in one or more stages depending on the technical steps of the liquid-liquid extraction process. Following extraction, the iron may be stripped from the organic phase by contacting with sulfuric acid or other mineral acids in one or more stages. Again it is easily loaded with zinc on contact with solid zinc oxide (power-fired).As is clear from the method described above, the raw material in this case the zinc oxide serves as an alkali in this method and the use of extra chemical agents. is not necessary at all. Due to the reaction of Versace Tug with the power-fired product, the zinc is dissolved in the organic phase and transferred to the aqueous phase by a liquid-liquid extraction step and subsequently deposited as metal by electrolysis.Norwegian Patent No. 1O8O47 A method for the decomposition of iron from metal sulfate solutions and a wet metallurgical process for the production of zinc is described in 1999. Reference is made to this patent for conventional processes for the wet metallurgical production of zinc. It is described that leaching of power roasted products with sulfuric acid occurs in two stages, the first stage is characterized as neutral leaching, and the second stage is characterized as acidic leaching.In the first stage, power fired products are added in excess, Leaching is therefore relatively mild.In this method, the iron does not dissolve;
An iron-free zinc sulfate solution is then obtained. However, the calcined residue contains a significant amount of zinc bound to the iron in the form of zinc ferrite. To increase the total zinc yield, the residue is subjected to intensive leaching, heating with excess sulfuric acid,
undergoes so-called acid leaching. This dissolves the remaining amount of zinc, but a significant amount of iron goes into solution. Norwegian patent no. In lO8O47, how does the above iron become K+,
It is shown that it is precipitated as a basic sulfate in acidic solutions due to the presence of cations such as Na+ or NH4+.

This deposited product is called dialosite and the above-mentioned patent provides the basis for the so-called dialosite process within the wet metallurgical production of zinc. This process is used in many zinc plants, and one of the advantages of this process over the previous processes is that acid treatment of the ferrobabies is not a limiting factor on leaching yield. The process according to the invention, which is based on the reaction of the power roast with a liquid cation exchanger and a combination of a subsequent liquid-liquid extraction for the removal of iron from zinc sulfate solutions by means of the organometallic zinc complexes formed, is particularly suitable for zinc Wet treatment. Suitable for gold production.

The starting point of the invention is based on the two-stage leaching process that forms the basis of the dialosite process. The method according to the invention, however, has clear advantages over the dialosite method, since it is not necessary to add any chemical agents such as ammonia to form the deposited product.

Furthermore, in this method it is possible to remove iron from the process cycle in other ways. Stripping of the loaded organic Fe-versatile is a very flexible step;
It is then possible to produce suitable starting materials for the subsequent processing of iron, for example up to valent iron powder or electrolytic iron.

Iron can be crystallized as iron sulfate directly within the stripping stage where the concentration of iron sulfate can be kept close to saturation concentration. If the crystals are further useful as a sulfate of divalent iron, the iron can be reduced with, for example, sulfur dioxide before deposition. In principle there is no limit to the amount of iron that can be removed from a zinc sulfate solution.

It is also emphasized that excess free sulfuric acid from strongly acidic solutions can be neutralized as a single step in a liquid-liquid extraction process. This means that prior partial neutralization with force firing, which is the usual practice in the dialosite method of iron deposition, is no longer necessary. Zinc yield and recovery of the metal remaining in the ore is limited only by the extent to which the metal can be dissolved by the leaching process. A particular advantage of the method according to the invention is that it has no negative environmental impact.

It is also emphasized that metals other than iron can be easily removed and separated from zinc sulfate solutions by extraction methods.

It is specifically mentioned that copper can be extracted according to the same principles described above for the extraction of iron. A mixture of copper, zinc and iron can thus be separated in that an organic solution with zinc as metal complex is first used for the extraction of the iron and then for the extraction of the copper. This will further be evident from the field of application mentioned above for the treatment of mine water.
When copper is the main component of the metal-containing feedstock, it is reacted with an organic cation exchanger and used in the same way as an organozinc complex for the liquid-liquid extraction of iron from metal salt solutions. The method according to the invention is not limited to the wet metallurgical production of zinc and copper, but also includes aqueous solutions produced by leaching metal-containing solid raw materials with liquid organic cation exchangers and conventional leaching of raw materials with mineral acids. It is emphasized that it includes all fields in which it is possible to use the above-mentioned combination with subsequent liquid-liquid extraction for the recovery and separation of metals from.

The aforementioned combination of leaching and liquid-liquid extraction can also be used in connection with the separation and recovery of metal ions from solutions that are not directly related to the production of metals from solid raw materials.

As an example, metal-containing waste water is pumped and dilute acid baths from metal surface treatment are used in the metal industry, and other metal-containing wastes are mentioned, for example from pyrite mines. In these cases, solid materials which are reactive with organic acids (cation exchangers) must, however, be added to the process cycle, for example in the form of a coal.

If the metal solution is based on sulfate, gypsum is deposited in equivalent amounts to the metal being recovered. The process is suitable for example for the recovery and separation of metal values from mine waters, where typical compositions include 0.5-1.0y1' copper, 1-2y
11 zinc and 5-6y1' iron. FIG. 3 shows a process diagram for the recovery and separation of copper, zinc and iron from mine water, where the metals are present as sulfates by way of example.

As extraction component, for example, "versatistic acid" can be used. In the first stage of liquid-liquid extraction, iron is separated from the mixture and
The copper can then be separated from the zinc in the next step. The remaining zinc sulfate solution will have a zinc concentration equivalent to the original total concentration of zinc, copper and iron, and possible free sulfuric acid.
A split stream from this zinc sulfate solution can be treated with coal. At this stage, organometallic zinc complexes are formed which are used in liquid-liquid extraction methods. If the method is used for the treatment of dilute acid baths containing relatively high concentrations of zinc and iron in the mixture, e.g. Can be used in liquid-liquid extraction.

After this treatment, the bath consists of a zinc salt solution from which the zinc can be deposited and recovered in pure form. The invention is further described below by way of example.

Example 1 200 y of technical calcined material produced by roasting zinc sulfide concentrate was dissolved in ``Siersol''.
The mixture was brought into contact with an organic phase 1e consisting of 91% Versatile. After stirring the two powders at 50'C, the solid and liquid phases were separated.

The organic phase then had a zinc concentration of 40yIe. In a stirred vessel, 100 ml of an aqueous sulfate solution containing 120 y1' of zinc and 18 g1f of iron were brought into contact with 317 ml of the 30% versatility solution described above. Gradually add 83 ml of zinc-loaded versatility solution containing 40 f1e of zinc;
After a weaving period of 1 hour at 20° C., the aqueous and organic phases were separated. Analysis of the two phases showed the following results: Aqueous phase: 152qIeZn0.3yI'Fe Organic phase: 0.
4V1eZn4.42f11'Fe Example ■Zinc 12
5 from an aqueous sulfate solution containing 0yIe and iron 18g1e.
Iron was extracted in a continuous operation at a temperature of 0'C in an apparatus consisting of three mixers and a settler in series.

Organic phase: one stream, pure 30% versatility solution (
Zinc loading 30% containing organic phase 1) and zinc 40yIe
Divided into a versatile solution (organic phase 2). The organic solvent (diluent) was "Ciersol TD".Aqueous phase and organic phase 1
One solution was added to each of the first and final stages, while the organic phase two solutions were distributed over the third stage. Relative ratio of feed streams: aqueous phase: organic phase 1: organic phase 2 = 1:2.2:0
．． The resulting zinc sulfate aqueous solution contains Znl52daI' and FeO
．． It contained less than lyle. Example ■ 120 fIe of zinc and 18 iron with 25 daI' of free sulfuric acid
Both iron and free protons were extracted from the sulfate solution containing f1e in a continuous operation in a manner corresponding to that of Example ①.

Relative volume ratio of feed streams: aqueous phase: organic phase 1: organic phase 2 =
1:1.8:1.2 The zinc sulfate aqueous solution produced is Znl6
9fle and FeO. It contained less than lyle.

Although the present invention has been described in detail above, embodiments will be shown below.

(1) The iron-containing organic phase is contacted with a mineral acid following extraction.
2. A method as claimed in claim 1, in which the iron is precipitated as a salt and the regenerated organic phase is recycled to the leaching of the raw solid concentrate.

(2) contacting the iron-containing organic phase, following extraction, with a gas selected from the group consisting of hydrogen chloride, carbon dioxide, and sulfur dioxide, thereby precipitating the iron as a salt and depositing the regenerated organic phase; 2. The method of claim 1, wherein the raw solid concentrate is recycled for leaching.

(3) The method of claim 1, wherein the iron-containing raw material comprises a metal oxide selected from the group consisting of oxides of copper, zinc and iron, and mixtures thereof.

(4) The method according to claim 1, wherein the iron-containing raw material is produced by roasting a concentrate selected from the group consisting of copper sulfide ore, zinc sulfide ore, and mixtures thereof. .

(5) Claim 1, wherein the iron-containing raw material is a metal compound produced by oxidizing a metal material selected from the group consisting of waste metals and metals obtained by refining an electrolytic solution. the method of.

(6) A method according to claim 1, wherein the desired metal is recovered in metal form from the sulfate solution by electrolysis after extraction of iron. (7) A method according to claim 1, wherein the desired metal is recovered from the sulfate solution in the form of a metal salt after extraction of the iron.

(8) The raw material is a solid zinc-iron containing raw material produced by roasting zinc sulfide concentrate, and the complex formed is a complex of a part of zinc and a cation exchanger component. , a solid containing iron and the remaining zinc is separated from the organic liquid containing the complex, an aqueous iron-containing zinc sulfate solution is formed by leaching the solid with an aqueous sulfuric acid solution, and the sulfate solution and the zinc Iron is extracted by contacting the separated organic liquid containing the complex with the body phase, whereby the iron moves into the organic phase and forms a complex with the cation exchange component, and the zinc moves into the organic phase. 2. The method of claim 1, wherein the zinc is transferred from the aqueous sulfate solution to the sulfate phase and then the zinc is recovered from the aqueous sulfate solution.

(9) Following extraction, the iron-containing organic phase is contacted with a mineral acid, thereby precipitating the iron as a salt, and the regenerated organic phase is recycled for leaching the raw solid concentrate. 8th
The method described in section.

Following extraction, the Ql iron-containing organic phase is contacted with a gas selected from the group consisting of hydrogen chloride, carbon dioxide and sulfur dioxide, thereby precipitating the iron as a salt and converting the regenerated organic phase into the starting solid. 9. The method according to item 8 above, wherein the sacrificial ore is recycled for leaching.

(11) The method according to item 8, wherein zinc is recovered in metallic form by electrolysis after iron extraction.

(12) The method according to item 8, wherein zinc is recovered from the sulfate aqueous solution in the form of zinc salt after iron extraction.

t(13) Following extraction, the iron-containing organic phase is contacted with a mineral acid, whereby the iron is precipitated as a salt, and the regenerated organic phase is recycled for contacting the desired metal-containing material. The method according to claim 2. (10) for contacting the iron-containing organic phase, following extraction, with a gas selected from the group consisting of hydrogen chloride, carbon dioxide and sulfur dioxide, and for contacting the regenerated organic phase with the desired metal-containing material. 3. A method according to claim 2 of recycling.

(15) The method of claim 2, wherein the iron-containing raw material comprises a metal oxide selected from the group consisting of oxides of copper, zinc and iron, and mixtures thereof.

(16) Claim 2, wherein the iron-containing raw material is produced by roasting a concentrate selected from the group consisting of copper sulfide concentrate, zinc chloride concentrate, and mixtures thereof. the method of.

(17) Claim 2, wherein the iron-containing raw material is a metal oxide produced by oxidizing a metal material selected from the group consisting of waste metals and metals obtained from the purification of electrolytic solutions. The method described in.

(18) The method according to claim 2, wherein the desired metal is recovered in metal form from an aqueous sulfate solution by electrolysis after iron extraction.

(19) The method according to claim 2, wherein the method is recovered in the form of a desired metal salt.

(20) The raw material is a solid zinc-iron-containing raw material produced by roasting zinc sulfide concentrate, and an iron-containing zinc sulfate solution is formed by leaching, and an organic liquid phase and a zinc and cation exchanger component are formed. a complex formed by contacting said organic liquid layer with a zinc-containing material different from the starting iron-containing material to be leached, and the extraction removes zinc from the organic phase as a sulfate. 3. The method of claim 2, wherein the zinc is transferred to an aqueous solution and then recovered from the aqueous sulfate solution.

(21) said second step of contacting the iron-containing organic phase with a mineral acid following extraction, thereby precipitating the iron as a salt, and recycling the regenerated organic phase to contact a different zinc-containing material; Methods listed in order.

(22) Following extraction, the iron-containing organic phase is contacted with a gas selected from the group consisting of hydrogen chloride, carbon dioxide, and sulfur dioxide, thereby precipitating the iron as a salt, and the regenerated organic phase is The method according to the second paragraph, wherein the zinc-containing material is recycled for contact with the zinc-containing material.

(23) The method according to the second chapter, wherein zinc is recovered in metal form by electrolysis after iron extraction from the sulfate aqueous solution.

(20) The method according to the second order, wherein zinc is recovered from an aqueous sulfate solution in the form of a zinc salt after iron extraction.

[Brief explanation of the drawing]

Figure 1 is a flow sheet for the extraction and separation of metals illustrating the principles of the invention, Figure 2 is a flow sheet for the extraction and separation of iron from a zinc sulfate solution, and Figure 3 is a flow sheet for the extraction and separation of iron from a zinc sulfate solution. This is a flow sheet for the recovery and separation of copper, zinc and iron from salt solutions (mine water).

Claims (1)

[Claims] 1. Copper, nickel,
A method for recovering at least one metal selected from the group consisting of cobalt or zinc by a wet metallurgy method, wherein the solid concentrate of the raw material is treated with an anolyte selected from the group consisting of organic carboxylic acids and alkyl phosphoric acids. The ion exchanger component is leached in an organic liquid phase from a solution in an organic solvent, thereby forming a complex with said ion exchanger component with a portion of at least one desired metal, and iron and the remainder of the desired metal. The separated solid containing the metal from the organic liquid phase containing said complex is leached with a sulfuric acid solution, thereby forming an aqueous iron-containing metal sulfate solution, and the sulfate solution is separated from the organic liquid phase containing said complex. Iron is extracted by contacting with an organic liquid phase, thereby transferring the iron to the organic phase to form a complex with the cation exchanger component, and removing the desired metal of the complex from the organic phase with the sulfuric acid. A method for recovering metals from iron-containing raw materials comprising transferring to an aqueous salt solution and then recovering the desired metal from said aqueous sulfate solution. 2. At least one desired metal selected from the group consisting of copper, nickel, cobalt, or zinc is extracted from an iron-containing raw material selected from the group consisting of oxide ore, metal oxide waste, and roasted sulfide ore. A wet metallurgical recovery method, wherein the iron-containing raw material is leached with an aqueous sulfuric acid solution, thereby forming an aqueous iron-containing metal sulfate solution, and the aqueous solution is
Iron is extracted from the aqueous solution by contacting it with an organic liquid phase consisting of a cation exchanger component selected from the group consisting of organic carboxylic acids and alkyl phosphoric acids dissolved in an organic solvent; , a complex of at least one of the desired metals and the cation exchanger component;
comprising a complex formed by contacting said organic liquid phase with a material containing the desired metal different from the starting iron-containing feedstock to be leached, said extraction transferring iron to the organic phase; to form a complex with the cation exchanger component, the desired metal of the complex is transferred from an organic phase to an aqueous sulfate solution, and then the desired metal is recovered from the sulfate solution.