FI20245342A1 - Method and apparatus for manufacturing manganese sulphate component, manganese sulphate component and its use and product - Google Patents

Abstract

The invention relates to a method for producing a manganese sulfate component from a material derived from a secondary manganese source. The method comprises dissolving (101, 201, 402) a material (11) in the presence of water (12), sulfuric acid (13) and at least one reducing agent (14) to form a suspension (25); forming a process solution (15) from the suspension by separating (102, 202, 403) a first precipitate (16) therefrom comprising at least lead (17) and silver (18); precipitating (103, 203, 408) at least one sulfide source (19) from the process solution using metals and/or metal compounds, including one or more of the following: zinc (20), copper (21); a precipitate (23) containing metal sulfides (22) is separated (104, 204, 409) from the process solution, after which the manganese sulfate component (24) formed is suitable for use as a fertilizer (24.1) in agriculture or as an industrial raw material (24.2). In addition, the invention also relates to a corresponding apparatus, a manganese sulfate component, its use and a product.

Description

METHOD AND APPARATUS FOR PREPARING A MANGANESE SULPHATE COMPONENT

WHY, THE MANGANESE SULPHATE COMPONENT AND ITS USE AND PRODUCT

The invention relates to a method for producing a manganese sulfate component. In addition, the invention also relates to a corresponding apparatus, a manganese sulfate component and its use, and a product.

In zinc electrolysis, the zinc contained in the calcined zinc concentrate is dissolved in sulfuric acid, and this zinc sulfate solution is then electrolyzed, causing the zinc to adhere to the surface of an aluminum cathode. Once the zinc layer has grown thick enough, the zinc is removed from the cathode and the cathode is returned to the process.

The anode material in electrolysis is lead, which has been alloyed with some silver to improve the properties of the cathode. The anode contains 0.6 — 1.0% silver by weight. The purpose of the silver is to make the lead anode stronger and it also catalyzes the evolution of oxygen.

Zinc concentrate contains some manganese, which dissolves but is not removed during solution purification. In electrolysis 3, this manganese is oxidized to manganese dioxide on the anode surface.

N This presence of manganese also protects the anode from excessive corrosion, and extends the life of the anode. The manganese formed

S 25 dioxide forms layers on the anode surface, which over time

E essa sinks to the bottom of the electrolysis tanks. For this reason, the electro-

N lysis tanks must be maintained and cleaned at certain intervals. 0

OF

< Manganese-rich anode sludge from the zinc industry is treated as landfilled waste. Disposal results in environmental problems if it is not carried out with appropriate protection,

which in turn incurs costs. Large quantities of anode sludge are generated annually as a result of continuous industrial operations. In this case, large areas of land must be reserved for its final disposal. This procedure is not appropriate, as manganese is currently classified as a critical raw material in several market areas, and its recycling should be significantly enhanced.

The purpose of this invention is to provide a method for producing a manganese sulfate component, in which a final product is produced from material originating from a secondary manganese source, which is a manganese sulfate solution, which is suitable as an agricultural fertilizer and/or as an industrial manganese-containing raw material. The characteristic features of the method according to the invention are presented in patent claim 1. In addition, the purpose of the invention is to provide a corresponding apparatus. The characteristic features of the apparatus according to the invention are presented in patent claim 13.

In the invention, metals and metal compounds present in the material originating from a secondary manganese source are removed by chemical methods, whereby the end result of the method is

As a result, an aqueous solution of manganese sulfate component is obtained, which is suitable for use as a fertilizer in agriculture.

N 25 in or as an industrial raw material. z

N According to a first embodiment, as a sub-step of the method, a secondary manganese source is

Aqueous acid leaching of the material in the presence of at least one reducing agent and separating the precipitate formed in the acid leaching from the resulting solution. The resulting manganese sulfate solution component is suitable for agricultural use.

According to another embodiment of the method, the process solution formed after the acid leaching and subsequent precipitation is subjected to sulfide precipitation using at least one sulfide source. A second precipitate is now formed in it, which is separated from the process solution. The manganese sulfate solution component formed after this precipitation is suitable for agricultural use and also as a raw material for industry.

According to one embodiment of the method, the method may include, in both of the above embodiments, reducing the iron content of the suspension and/or process solution. According to one embodiment, iron may be precipitated as part of the first precipitate. In this case, the iron precipitation step is after the acid leaching.

Even then, the method can be implemented, according to its first embodiment, with only one separation of the sags or, according to its second embodiment, with only two separations of the sags.

Another way to reduce the iron content of the process solution is sulfide precipitation itself. & 3 According to one embodiment of the method, the method may include,

N 25 again in both of the above-mentioned embodiments, at least

E one sub-step complex, in which the oxidation number of manganese is changed

N kua to ensure that the final product remains in solution form. 3 After the dissolution stage in suspension and subsequently formed from it

The process solution to be taken may still contain oxidation number forms of manganese that are undesirable in terms of oxidation number. These later result, for example, in the precipitation of the end product in the form of solid manganese dioxide. The presence of these undesirable oxidation number forms is detected by the color of the process solution. In the processing of the oxidation number of manganese, the oxidation number desired is manifested as a pink color of the process solution. If the color of the solution is something other than pink, it is possible to conclude that the process solution then contains unfavorable and thus precipitating oxidation number forms of manganese. As a result of the observation, the process solution is subjected to processing that changes the oxidation number of manganese in the process solution to a favorable, non-precipitating form. Another advantage of this embodiment is that, according to one embodiment, this same processing also reduces the cadmium content of the solution. With a suitable reagent used for pH adjustment, this occurs as a side effect of changing the oxidation number of manganese.

The oxidation number of manganese can be changed, for example, after acid leaching and also after the subsequent iron precipitation, if such is separately used in one embodiment. The oxidation number of manganese is changed by pH adjustment of the solution. In this case, the pH is first lowered by adding sulfuric acid and then raised by adding metallic zinc. 3 As already stated, according to one embodiment, the need for manganese

The oxidation number of N can be determined by visual inspection of the solution. It is a simple procedure and

N 25 fast and does not require special equipment. z

N According to one embodiment, the material to be treated by method 3 according to the invention is moist. This results in advantages such as:

Ok regarding the pretreatment of the material before its chemical treatment.

According to one embodiment, the separation of solids after the dissolution stage of the material can be divided into two parts, coarse filtration of the formed suspension and subsequent fine filtration. In coarse filtration, the coarse material that has not dissolved in the dissolution stage is first separated from the suspension-like process solution formed during dissolution.

This includes, for example, manganese-containing material that is insoluble in the solution, i.e. the starting material of the process, which is present in the coarsely filtered material as particles of different sizes. One can also speak of screening the process solution, through which a suspension formed by the liquid solution fraction and the fine-grained sulphate precipitate, which is mainly formed during the solution, passes through. The separated coarse manganese-containing material can be treated in a selected way and then directed back to the solution stage. After the coarse filtration, the suspension is fine-filtered. In this, the fine-grained sulphate precipitate formed during the solution is separated from the process solution in the form of a suspension, which is more homogeneous in particle composition.

According to one embodiment, in the separation of the sulfate precipitate from the process solution, washing of the separation means and the sulfate precipitate is performed. The sulfate precipitate contains manganese, which is washed from it.

N with hot water. The manganese-containing wash water can then be used as a base solution for the 3 leaching. In addition, this also improves the

S 25 further processing of the phatic precipitate component. Others with the invention

The additional benefits that can be achieved are evident from the explanatory part and the characteristic

N features of the accompanying claims.

O

S

< The invention, which is not limited to the embodiments presented below, is described in more detail with reference to the accompanying drawings, in which

Figure 1a shows, as a rough block diagram, the sub-steps of the method according to the invention in the case of a first embodiment,

Figure 1b shows a rough block diagram of the sub-steps of the method according to the invention in the case of another embodiment,

Figure 2a shows a first example of the method according to the invention as a rough flowchart,

Figure 2b shows another example of the method according to the invention as a rough flowchart,

Figure 3 shows a schematic diagram of the apparatus according to the invention in the case of the flow chart shown in Figure 2b,

Figure 4 shows an example of a flowchart of a slightly more advanced embodiment of the invention,

Figure 5 shows a schematic diagram of the apparatus according to the invention in the case of the flow chart shown in Figure 4,

Figure 6 shows an embodiment of the steps involved in acid leaching of material from a secondary manganese source,

Figure 7 shows an embodiment for precipitating iron 3 from a suspension into a first precipitate,

N Figure 8 shows an embodiment of the sub-steps for influencing the oxidation number of manganese 1 3 in the process solution and

S 25 for the accompanying cadmium removal,

E Figure 9 shows an embodiment of a partial sulfite

N for separating the disaccha from the process solution, 3 Figure 10 shows a rough block diagram of the invention

Another embodiment of the method comprising the precipitation of iron shown in Figure 7,

,

Figure 11 shows a rough block diagram of a third embodiment of the method according to the invention, comprising influencing the oxidation number of manganese shown in Figure 8,

Figure 12 shows a rough block diagram of a fourth embodiment of the method according to the invention, comprising the steps of the flowchart shown in Figure 4 and

Figure 13 shows a rough block diagram of a fifth embodiment of the method comprising (only) at least one sediment separation.

Figures 1a and 1b show, in rough block diagram form, some examples of an industrial process according to the invention for producing a manganese sulphate component from material originating from a secondary manganese source. Here, an industrial process, as distinguished from, for example, a laboratory scale operation, means an operation in which it is possible to process tons of starting material into a final product daily. In the process, step 101 involves leaching the material originating from a secondary manganese source.

The purpose is to form a manganese sulfate component from manganese-containing material by acid dissolution, which

N is then treated according to the method to obtain a pure MnSO4 solution 3 as the final product of the method. Manganese sulfate-

The N 25 component is formed in the method by precipitating at least one

In the previous sub-step 101, 103 of the method, the precipitate, which

N is also separated from the manganese sulfate component in the following, at least one sub-step 102, 104. The precipitate is removed

O metals and metal compounds other than manganese that were present in material 11 and thus also dissolved in the manganese sulfate component formed from it.

Figure 2a shows a first example of the method according to the invention as a flow chart, which corresponds to the block diagram of Figure 1a. Reference is also made to the hardware diagram of Figure 3.

In step 201 of the method, material 11 from a secondary manganese source is dissolved in the presence of water 12, sulfuric acid 13 and at least one reducing agent 14 to form a suspension 25. The dissolution takes place in a reactor 31. The water 12 forms an aqueous matrix for the sulfate formed during the acid dissolution of the manganese-containing material 11, into which dissolution takes place.

In the dissolution, sulfuric acid 13 and at least one reducing agent 14 react with the manganese dioxide in solid form in the material 11. In this case, they break down the structure of the manganese dioxide (MnO4) and convert the manganese released from it into manganese sulfate (MnSO4) in the aqueous solution.

Water 12 can be, for example, tap water. In addition to tap water, the water used can also be the wash water 43’ of the lead-silver precipitate to be separated from the suspension 25, i.e. the first precipitate 16 (Figure 3). It is produced from the filtration step 32 of the suspension 25. The wash water 43’ contains manganese remaining in the precipitate 16, which is recovered by recycling the wash water 43’. The wash water 43”

N can be recycled to the next dissolution batch as its base solution.

No. 25

E Sulfuric acid 13 is preferred as the acid in the process according to the invention.

N line dissolving chemical for use, for example, because 3 in the battery industry, which is an exemplary application

For the final product 24.2 obtained by the method according to the invention, the battery materials, including manganese, are prepared by precipitating the metals as solid hydroxides out of the sulfate solution, leaving a sodium sulfate solution. By using sulfuric acid 13 for the dissolution, manganese sulfate is specifically formed in solution form, from which manganese is subsequently precipitated as hydroxide.

It is known from industrial processes to dissolve solid manganese sulphate in water. The manganese sulphate is then powdery and dusty when poured into the water, creating occupational safety risks (manganism). However, in the case of the product according to the invention, the product is already liquid, which eliminates the dangerous dusty work step characteristic of the known method.

The reducing agent 14 used in the dissolution may be one or more selected from the following: peroxide 14', citric acid, one or more sugars. Of these examples, peroxide 14', such as hydrogen peroxide, is the most preferred because it is more effective than the other reducing agents 14 mentioned as examples. In addition, only water remains in the process from peroxide 14', and not, for example, organic carbon residues.

Peroxide 14” is added during the dissolution stage, more specifically, its 10- 3 sachets, so that the pH range of the suspension is reached at 25

N pH = 3 - 4. This is a preferred pH range for pipelines 3 and also for filter structures. In addition, the peroxide 14’ is useful

S 25 dyning for pH adjustment purposes is also advantageous because

E that, for example, in the suspension 25 that will be carried out later,

In N dation, the use of peroxide 14’ as a pH adjuster guarantees the functionality of the filtration medium 32, compared to, for example, sodium hydroxide

O roxide, which would be a logical choice as a pH adjustment chemical due to its affordability and availability. The applicant has observed in the pilot phase tests of the method that sodium hydroxide causes problems in the form of filter clogging because it forms a very fine precipitate in the process according to the invention.

In the illustrated embodiment, step 202 forms a process solution 15 by separating a first precipitate 16 from a suspension 25.

Thus, the first precipitate 16 already originates from the formation step 201 of the suspension 25, i.e. from the dissolution of the manganese-containing material 11 in the presence of water 12, sulfuric acid 13 and at least one reducing agent 14. In this way, two functions are thus achieved in the same single process step 201, dissolution and additionally the formation of the first precipitate 16 in the suspension 25 formed in the dissolution.

The first precipitate 16 contains at least lead 17, silver 18 and calcium 44 originating from the material 11 as corresponding sulphates. These substances removed with the solid dissolution residue are formed into sulphates at the latest in this dissolution stage, if they are not already so at the beginning. The first precipitate 16 is present at this point in the entire solution volume, which is thus a suspension 25. The separation of the first precipitate 16 can be carried out, for example, by means of a suitable filtration means 32. As an example,

Of these, the frame filter 32" can be mentioned. 3

S 25 In connection with the filtration medium 32, the precipitate 16 is additionally washed with a washing

E with water 43, for which a filter means 32 is arranged

N feed and recovery. Precipitate 16 is washed because in the further processing of the 3 precipitate components it forms, it is advantageous not to have manganese

O would be present in the precipitate 16 in small amounts, which would remain in the precipitate 16 as the manganese sulfate remaining in it dries. As previously stated, the manganese-containing wash water 43' from washing the precipitate 16 can be utilized by using it as a base solution in the dissolution process of step 201, instead of/in addition to the pure water 12.

In the case of the embodiment shown, the filtering means 32 is a frame filter 32' located in a horizontal plane. The washing of the precipitate 16 is carried out after the filter chambers of the frame filter 32' are filled, i.e. before the filter is emptied. In this case, the washing water flows through the precipitate cakes and rinses the manganese solution in the precipitate 16 with it. This manganese-containing washing water 43" is collected in a washing water tank located after the filter, from which it can then be returned as raw material for the next leaching process. When the washing step of the precipitate 16 has been completed, the filter chambers are opened and the precipitate cakes are dropped out of the filter, after which the chambers are closed and the filtration is continued with a new batch of pulp solution, i.e. suspension 25.

The amount of dry lead-silver precipitate 16 containing calcium crystals 44 is approximately 25-40% of the dry weight of the material 11 fed to the dissolution reactor 31. In other words, if 100 g of material 11 is fed, the moisture content of which is, for example, 30%, 70 g of dry material 11 enters the reactor 31, of which 25-40% is lead-silver precipitate 3 16 and calcium crystals 44. After filtration, the man-

N ganic sulfate solution 24 is suitable for use as a fertilizer 3 24.1 in agriculture. However, it can still be processed

S 25, for example, with the iron precipitates described later in the description

With E (before sedimentation 202) and/or manganese oxidation

N vun adjustment (after precipitation 202). Manganese sulfate 3 solution 24 for agricultural use, however, does not necessarily require

O fid precipitation (Figure 2b, reference numbers 203 and 204), which is subsequently carried out on the process solution 15 as a main step of the method.

Figure 2b shows another example of the method according to the invention as a flow chart and Figure 3 shows the corresponding equipment diagram at a slightly more detailed level. For steps 201 and 202, reference is made to the explanations of Figure 2a. The presented embodiment extends the applications of the manganese sulfate solution 24 to industrial use as well. Nevertheless, the implementation at the equipment level remains relatively simple, but still versatile.

In manufacturing, the transition from one product to another occurs quickly and, as a manufacturing process, does not require major modification of the equipment 10, either in terms of the existing equipment 10 or the equipment 10 to be acquired.

After the process solution 15 is completed, i.e. after the first precipitate separation 202, in step 203 at least one sulfide source 19 is precipitated using metals and/or metal compounds from the process solution 15. The apparatus 10 may have its own reactor 34 for this. In this case, the substances separated from the process solution 15 precipitate as metal sulfides 22. The metals or sulfide compounds comprising them that precipitate in the precipitate 23 include one or more metals present in the material 11. Some of these 3 may include, for example, zinc 20, copper 21, cadmium 30,

N 30.1 and iron 27, 27.1. 3

S 25 In step 204, metal sulfides are separated from the process solution 15

E 22 containing and now the second precipitate 23. This is

N mainly zinc sulfide, but other metals already mentioned above 3 are also present as precipitated metal sulfides 22. This

The manganese sulfate solution 24 formed after O is suitable for use, for example, as a fertilizer 24.1 in agriculture and also as an industrial raw material 24.2.

Figure 4 shows an example of an industrial scale method according to the invention as a flow chart and Figure 5 shows a corresponding equipment diagram as an even more detailed application example compared to the previously presented application examples. However, a person skilled in the art will understand that the more detailed implementation presented in the figures and in this application is only one point-by-point application example of the method.

The various subassemblies of the method and the implementation methods presented for them achieve different, even mutually independent, inventive advantages. Thus, all of the subassemblies and steps shown, for example, in Figures 4 and 5, and their more detailed substeps, shown in Figures 6-9, are not absolutely necessary for implementing the idea according to the invention and achieving the advantages.

In addition, all sub-steps (for example, reducing the iron content and/or changing the oxidation number of manganese in the process solution 15) can advantageously be combined arbitrarily and also utilized in the application of Figure 2a, which lacks, for example, sulfide precipitation. 3 The raw material of the method according to the invention, i.e. from the secondary

The material 11 originating from the manganese source N may be, for example, manganese sludge 11' from the zinc industry, which contains

S 25 manganese dioxide. Material 11 can also be referred to as manganese

As a waste fraction containing E. As described in the prior art

As already mentioned, manganese sludge 11’ is formed in the electrolysis process of zinc concentrate 3 at the bottom of the electrolysis tank. From there it

O is scraped off from time to time. According to one embodiment, instead of intermediate storage, the sludge 11' is collected directly from the tank, i.e. wet, into suitable transport containers, in which it is delivered to the treatment according to the invention and from which it is dumped directly into the treatment process according to the invention. This avoids contamination from the sorting step, such as stones and/or foreign chemicals ending up in the material 11. In addition, it has been observed that wet material 11 passes more efficiently through the vibrating screen 42 used in the pre-screening of the material 11 than dry material. This is because the material 11, for example in the case of manganese sludge 11 from the zinc industry, contains water-soluble sulphate, which tends to clump when it dries. When it dries, the soluble sulphate contained in the material 11 solidifies as the water evaporates. When it is drier, the material 11 also produces dust, which is a work safety risk. Of course, the use of piled material 11 could also be possible, but material 11 delivered wet directly from the bottom of the tank to the process achieves at least the above-mentioned advantages and also avoids the collection and treatment of leachate associated with piling. Thus, the moisture content of the material 11 used as raw material in the method can be, according to one embodiment, for example 30 - 55%, more particularly 35 - 50%.

In a processing plant, the material 11 can be transferred to the reactor 3 31, for example, by a conveyor. Feeding from a transport vessel to a

N for the jetter can happen so that before the conveyor, more generally, before the reactor 31, the step 401 is the pre-

N 25 screening 42. According to one embodiment, it can be implemented

E for example with a grate equipped with vibration motors and/or

N with a screening screen 42”. The purpose of the pre-screening 42 is to remove material 3 11, and in particular zinc concentrate, from the electrolysis process

O from the manganese slurry 11" contains particles that are undesirable for the process equipment 10, such as stones, concrete pieces and possible plastic debris accompanying the material 11.

If the material 11 is slightly damp, the vibration also breaks up the lumpy wet mass, which then flows easily down through the screen mesh. If the force of the vibration motors is also applied to the feed silo below the mesh, the mass flows easily along the sides of the feed silo onto the conveyor. For this purpose, a mechanical connection has also been arranged from the vibration motor to the feed silo.

In step 402, the material originating from the secondary manganese source is dissolved in water 12, acid 13 and at least one reducing agent 14. As already stated earlier in connection with figures 2a and 2b, this step can also be called the formation of a suspension 25. According to the partial step flow diagram shown in figure 6, according to one embodiment, step 402, i.e. the formation of a suspension 25, can be divided into several sub-steps 601 - 607, one possible combination of which is shown as an example below. According to one embodiment, the reactor 31 pre-charged with water 12 in step 601 is charged in step 602 according to the lowest assumed manganese concentration 3 of the material 11 to be dissolved. In other words, the reactor 31 is initially charged with a large amount of

N manganese slurry 11, and a little water 12. According to one embodiment 3, the default value of the manganese content of the material 11 can be

For example, N 25 uses a value of 25% by weight. It can of course

However, it may be lower or higher than that if processed-

In the N material 11, the concentration is typically even lower than this 3 or higher. When mixing in step 603 man-

O-ganic material 11 in water 12 is formed into a suspension 25.

When forming a suspension 25 of material 11 and water 12, at least one sample 26 is taken from the reactor 31 in step 604 for the determination of the manganese content to be carried out in step 605.i. In this case, before the final formation of the suspension 25, i.e. the addition of other chemicals belonging to it, i.e. sulfuric acid 13 and at least one reducing agent 14, to the reactor 31, several samples 26 are taken from the suspension 25 formed by material 11 and water 12 in order to determine the exact manganese content of the solid component of material 11, i.e. the raw material. By taking one or more samples 26 from the suspension 25, a very precise concentration value of the combined material 11 fed to the reactor 31 can be determined compared to a point sample taken from the material 11 itself. If samples were taken directly from separate solids containers before feeding the material 11 into the reactor 31, their manganese content could vary very greatly due to the significant internal concentration variations of the manganese slurry 11.

By sampling 26 finished combinations of multiple mass batches, significantly more reliable concentration data is obtained.

When the suspension 25 formed by the material 11 and water 12 has been formed and samples 26 have been taken from it, the material is started

N 11 dissolution, i.e. formation of the final suspension 25 by dosing 3 in step 605.1 to the intended process and the reactor

S 25 to the suspension of material 11 and water 12 formed in the tube 31

E 25 sulfuric acid 13. At this stage, sulfuric acid 13 is dosed

N to the suspension 25 in reactor 31 of the manganese-containing material 11 at the calculated lowest assumed manganese concentration

O according to quantity.

In step 605.i, the exact manganese content of the solid component of the material 11 is determined from one or more samples 26 taken from the suspension 25. At the same time, however, the dissolution of the material 11 with water 12 and sulfuric acid 13 is already in full swing.

In the concentration determination carried out in step 605.1, one or more samples 26 previously taken from the reactor 31 are broken down for analysis in order to determine their exact manganese concentrations. Here, the solid and liquid in the suspension 25 are first suction filtered, leaving the solid on the paper. The suction filtered solid can be rinsed with clean hot water before taking the sample 26 to be analyzed. In this way, any manganese amounts contained in the manganese sample precipitate, which may be contained in the washing waters 43' fed to the reactor 31 and obtained from subsequent filtration steps 32, can be washed out of the solid concentration determination result, which is distorted by the solid manganese sample precipitate.

The water-washed solid is then dispensed into sample tubes, to which concentrated acids are also added. The tubes are then placed in the laboratory's microwave disintegration equipment for about an hour. As a result, the tubes contain liquid, which is diluted and then analyzed for manganese content.

N Once these have been determined, a calculation is made in step 606.ii of how much manganese the mass placed in the pipes originally contained.

S 25 An alternative method is to perform the determination as a solids analysis.

E The analysis device arrangement is referred to in Figure 5 by reference number

N 35. %

OF

< Once the manganese content of the solid has been determined, it is recorded in the batch report, as a result of which the report's counter 36 indicates how much sulfuric acid 13 and water 12 are still added to the reactor.

31. In addition, the final amount of reducing agent 14 to be added to the formation of suspension 25 is also determined here. However, the feeding of reducing agent 14 may already be in progress and started as step 605.2 during and/or after the initial sulfuric acid dosing, possibly before the result of the precise concentration determination is determined. During the concentration determination, i.e. step 606.1, the dissolution of material 11 in water 12, sulfuric acid 13 and reducing agent 14 may already be in progress.

The calculators 36 are based on the amount of manganese. The dissolution formula is:

Mn02 + H2S04 + H202 ——> MnS04 + 2 HO + O? (1)

It can be seen that at least one mole of acid and one mole of peroxide are required for each mole of manganese. When the amount of manganese itself has been precisely determined by the above-mentioned decomposition experiments, it is possible to say how much manganese the mass 11 fed into the reactor 31 contained and therefore how much chemicals its (optimal) dissolution will require. 3 After the manganese content of the material 11 has been ascertained as a step 607

N the suspension 25 is finished by dosing the necessary 3 additional amounts of water 12, sulfuric acid 13 and/or at least one

S 25 tensioner 14 to the material 11 specification specified in step 605.i

Based on the manganese content of the first. If 14 is used as the reducing agent,

For example, hydrogen peroxide 14’ is fed into the reactor 31 slowly/moderately, pumping according to the concentrations

O is the final calculated amount. After this, the amounts of substances 12 - 14 correspond to the higher and more actual manganese concentration measured in material sample 26.

The reactor 31 may include a possible antifoam. According to a first embodiment, it can be implemented by feeding at least one antifoam. The antifoam is resistant to acidic conditions and preferably biodegradable. Another possibility is to implement antifoam, for example, by spraying a mist formed by water 12, sulfuric acid 13 and hydrogen peroxide 14' into the foam. According to an embodiment, the supply of hydrogen peroxide 14' can be arranged below the surface of the suspension 25. This can prevent premature decomposition of hydrogen peroxide 14' when forming the suspension 25. In addition, by pumping below the surface, hydrogen peroxide 14' comes into better contact with the manganese particles of the suspension 25 and therefore works more efficiently.

The reactor 31 is provided with cooling 37 during the dissolution process, since the process is strongly exothermic. In addition, cooling the temperature of the reactor 31 to 40 degrees or preferably even below reduces the strong gas formation developed by the hydrogen peroxide 14". The cooler suspension 25 foams less, allowing for faster dissolution. In addition, the cooling 37 makes it easier to see into the reactor 31, because fog does not form as easily in the reactor 31. The reactor 31 may also have

N a breaking "whip" 38 or similar fitted to the top of the mixer shaft 3 39 to keep the rising foam layer down

N 25 in the castle. Another alternative for implementing anti-foaming can be

E be the use of ultrasound (not shown). ti 0 This embodiment, i.e. the sampling process and especially

The advantage of analyzing O before the final dosing of the process chemicals 12 - 14 is that the dissolution process of the material 11 with the chemicals, especially sulfuric acid 13, can be started immediately, i.e. even before the concentration analyses are completed.

If the lowest concentration of material 11 is assumed to be 25 wt% manganese (25-45 wt%), the initial chemical quantities are obtained from the calculator 36. However, since there is usually more manganese in material 11 (typically about 30-45 wt%, but more commonly 25-50 wt%), chemicals 13, 14 are added later, already while the dissolution is in progress, in more quantity than initially calculated, and this additional quantity is determined when a mass sample is obtained from the mass belonging to suspension 25, i.e. material 11, and analyzed. Thus, by using this 25 wt% assumption of the concentration of material 11, it is not necessary to wait for the final analysis result before starting the dissolution process, but the start of the process 606.1 and the analysis of sample 26 605.i, 606.ii can be run over each other.

In the formation step 402 of the suspension 25, its manganese content can be monitored by intermediate analyses. In addition, the color of the suspension 25 can possibly be monitored, for example by monitoring filtered intermediate samples to visually monitor the progress of the dissolution. 3 Returning to Figure 4, an embodiment of the method according to

The method may further include at least one step 403, 3 in which iron is removed from the manganese sulfate component 27.2.

N 25 This step can be implemented in several different ways. In addition

It can be implemented at different points in the overall process. In one case,

According to the N vellus form, iron 27.2 can be removed from the suspension 3 25 by precipitating it as part of the first precipitate 16, which forms

This is done in connection with the dissolution step 402 of the manganese-containing material 11. In this case, at the end of the dissolution step 402 of the manganese-containing material 11, the pH of the suspension 25 is adjusted in step 403 by adding iron.

27.2 to precipitate as part of the first precipitate 16. At the end of the dissolution stage, the pH of the suspension 25 is then in the range pH = 3 - 4.

As shown in Figure 7, according to one embodiment, step 403, i.e. precipitation of iron 27.2 as a separate sub-step from suspension 25 after its formation/finally, can be divided into several sub-steps 701 — 703, one possible combination of which is presented as an example below. Some reasons for reducing iron are, for example, the possible formation of iron precipitate in the final product. Iron-containing solids are staining and can clog farmers' sprayers. According to one embodiment, the pH of suspension 25 is adjusted such that at the end of the dissolution of manganese-containing material 11, in step 701, at least one reducing agent 14, such as hydrogen peroxide 14', is added to suspension 25 so that the pH of suspension 25 increases, for example, to approximately pH = 3.5. More generally, at the end of the dissolution of the material 11, the pH of the suspension 25 is adjusted in step 701 to a value range of pH = 3 to 5, more particularly, to a value range of pH = 3 to 4.

In this way, iron 27.2 is removed from the suspension 25 into the same first precipitate 16 that was already formed in the suspension 25 during the dissolution step 402 of the manganese-containing material 11 in the presence of water 12, 3 sulfuric acid 13 and at least one reducing agent 14.

N This also has the advantage that iron 27.2 can be removed with the chemical used in the dissolution of manganese-3 containing material 11

N 25, i.e. at least one reducing agent 14, such as hydrogen,

E with peroxide 14’ and no additional steps are required to remove iron 27.2

N substances. In addition, another additional advantage is that the precipitate 16 formed here is relatively easy to separate due to its fineness.

Can be taken from suspension 25 without, for example, the risk of filter clogging, which has been found to be a problem when, for example, sodium hydroxide is used for the same purpose. Also, the development of hydrogen sulfide in such a pH range in the sulfide precipitation carried out later in step 408 is less. In addition to the removal of iron 27.2, increasing the pH of suspension 25 also improves the quality of the final product 24, especially in fertilizer use. A pH of the final product 24 closer to neutral is healthier for plants than a solution that is too acidic.

If at least one reducing agent 14, such as hydrogen peroxide 147" is not sufficient to raise the pH of the suspension 25 (for example, to precipitate iron), a small amount of manganese sludge 11', i.e. the raw material of the method according to the invention, can also be added to the suspension 25 in step 703. The need for this addition is seen in step 702 by visual inspection of the sample 702.2 filtered from the suspension 25 in step 702.1. If in step 702.3 it is determined that the dissolution has gone too far, so to speak, i.e. there is a lot of excess peroxide 14' in the suspension 25, the process solution 15 filtered from the suspension 25 bubbles and is yellowish and the pH practically no longer rises sensibly. In this case, by adding manganese sludge 11' and possibly a small amount of acid to the suspension 25 in step 703 13, the reaction for the precipitation of iron 27.2 into the first precipitate 16 3 can be reversed if necessary. In this case, the suspension

The excess peroxide 14’ that ended up in No. 25 decomposes, which is what the steps 702, 703 in question can also be called. This

S 25 step 703 is only performed when necessary. In this case, the manganese slurry

E 11, the included small additional acid and manganese dioxide help

N to raise the pH of the suspension 25 when the acid, hydrogen peroxide 14” and 3 manganese dioxide react with each other. Thus, the suspension 25

The pH is adjusted when precipitating iron 27.2 using one or more of the following: at least one reducing agent 14, such as hydrogen peroxide 14', manganese-containing material 11 and/or acid 13. The procedures of step 403 can be carried out in the same reactor 31 as the actual dissolution, i.e. the formation of the suspension 25, was carried out.

Before separating the first precipitate 16 from the suspension 25 in step 405, the suspension 25 can, according to one embodiment, be pumped through a screen 45 in step 404 (Figure 3). This can be used to separate coarser material from the suspension 25, i.e., for example, any insoluble manganese granules and also anode chips.

In the pilot phase tests, it has been observed that not all manganese contained in the material 11 is necessarily completely dissolved in the dissolution stage 402 without a significant excess of chemicals. Coarse manganese-containing material granules remain at the bottom of the reactor 31, the size of which varies from millimeters to ten millimeters and even more. These cause process-technical disadvantages in pipelines and pumps. For example, a wet screen 45 can be used as the screen 45.

Thus, according to one embodiment, the manganese sulfate component in suspension form can be passed from the reactor 31 through a wet screen 45” in step 404, whereby the coarse fraction insoluble in the dissolution step 402 3 is collected as the overflow from the screen 45 and the fine fraction is

The N-part lead-silver precipitate 16, in turn, continues its journey through the sieve 45, suspended in the process solution 15, to the fine filter element 3.

N 25 to 32 for frame filter 32'. According to one embodiment

The boundary between coarse and fine filtration can be, for example,

N in the range of 0.5 — 2.5 mm. The complete insolubility of material 11 may be related, for example, to the fact that the material

O 11 is possibly manganese in two or more oxidation number forms, some of which dissolve more easily and some more difficultly.

Here, more soluble oxidation number forms are understood to mean oxidation number forms that are soluble mainly with calculated chemical amounts (for example, 5-10% excesses are allowed). Here, less soluble oxidation number forms are understood to mean oxidation number forms that are also soluble, but they nevertheless require significant chemical excesses that weaken the profitability of the process. This means chemical excesses of up to several tens of percent. Thus, the material 11 to be processed according to the invention can be characterized according to one embodiment as containing manganese in two or more oxidation number forms. In addition, there are solubility differences between its different oxidation number forms. This is precisely what is assumed to be the case in the manganese sludge 11 of zinc electrolysis. More generally, this feature can also be characterized from the perspective of the method according to the invention as comprising the optimization of the reducing acid treatment step with respect to the amount of one or more chemicals used therein. In this optimization, the chemicals are used in accordance with a calculated amount based on the manganese content of the material 11. In this case, it is possible that at the end of the dissolution step, undissolved starting material 11 still remains in the reactor 31, for example due to the above-mentioned reason. It does not dissolve 3 based on the manganese content of the material 11 calculated

N to the reactor and with the amount of chemicals dosed into it 31. In addition, 3 without an overdose of chemicals for insoluble material

S 25 is characterized by being separated from the suspension 25

E before its filtration 32. ti 0 After screening, the suspension 25 can be transferred, for example

O by pumping, for example, through an intermediate tank to the separation stage of the first precipitate 16, which takes place by filtration 32. According to one embodiment, this can be done, for example, with a frame filter 32". In this case, the lead-silver precipitate formed during the dissolution, i.e. the first precipitate 16 formed during the dissolution, is recovered, also containing iron 27.2 according to the embodiment now presented. However, the first precipitate 16 is mostly lead sulfate and calcium sulfate.

The first precipitate 16 can be supplied as a product component as an industrial raw material, for example to a lead smelter, or it can be subjected to further processing and further utilization of the fractions separated from it. Before the separation of the first precipitate 16, the screened manganese granules can be ground and subsequently dissolved (not shown).

Returning again to Figure 4, according to one embodiment of the method, the method may further include a sub-step 406 for adjusting the oxidation number of manganese. According to one embodiment, after the separation of the first precipitate 16, i.e. step 405, but nevertheless before the precipitation step 408 of the second sulfide precipitate 23 using at least one sulfide source 19, the oxidation number of manganese in the process solution 15 is changed/influenced, more generally, processed or even optimized if necessary by adjusting the pH of the process solution 15, which is carried out as step 406 to change the color of the yellowish/orange-tinged solution back to the surface.

N kixi. If the precipitation of iron 27.2 is done before this in step 403, 3 it can then be called the first pH adjustment and if

The oxidation state of N 25 manganese is affected in the same way.

In the first form, it can then be called a second pH adjustment.

N Step 406 may have its own reactor 40 after filtration 32.

OF

&

According to the flow chart shown in Figure 8, according to one embodiment, step 406, i.e. influencing the oxidation number of manganese after the separation step 405 of the first precipitate 16, can also be divided into several sub-steps 801 - 805, one possible combination of which is presented as an example below. According to one embodiment, the need to change the oxidation number of manganese is determined based on the visual inspection of the process solution 15 performed in step 801. The oxidation number of manganese is then the desired one, i.e. Mn?*, when the process solution 15 is determined in step 802 to be pink in color. On the other hand, if the process solution 15 is found in step 802 to be, for example, yellowish, orange or another color different from pink (shades of green or purple), the oxidation number of manganese in the process solution 15 is incorrect (too high) and can then be changed (reduced) by pH adjustment in step 803. If the oxidation number of manganese in the process solution 15 is not as desired, then solid manganese dioxide will begin to form at the bottom of the solution volume in the final product, i.e. manganese sulfate solution 24, over time. In addition, some manganese hydroxides may also precipitate out of the solution 24, which will subsequently oxidize.

Step 801: Determination of the oxidation number of manganese in the process solution 15 by visual inspection and possible

In addition, by changing N in a direction more favorable for the end product 24 3 , this same sub-process 406 can also

N 25 affects the cadmium concentration of the process solution 15 by lowering it.

E vsti. The steps are performed in an ATEX-classified cleaning tank.

At 40, because hydrogen is evolved in the process. 0

N o According to one embodiment, the oxidation number of manganese in the process solution 15 is changed in step 803 by reducing the pH of the process solution 15 from the value pH = 3.5 to the value range pH = 1.5 -

2.5 using sulfuric acid 13’. When the color of the process solution 15 changes from orange/yellowish to pink, it can be concluded from the color change observed in step 804 that the oxidation number of manganese in the process solution 15 has changed as desired. Sulfuric acid 13’ is a preferred chemical to use in this context, since the entire process is already based on it. Sulfuric acid 137” can be the same as that used in the acid dissolution of material 11.

Thereafter, in step 805, the pH of the process solution 15 is raised back to the range of pH = 2.5 to 4.5, more specifically, pH = 2.5 to 4.5 using metallic zinc 28 in powder or granules. Thus, the solid metallic zinc 28 restores the pH of the process solution 15 back to or near its original value.

The consumption of zinc 28 here may be, for example, about 1 to 5 grams, more particularly, 2 to 4 grams per liter of solution.

The partial dissolution of the solid metallic zinc 28 then consumes the acid and as a result the pH of the process solution 15 rises again. As mentioned above, cadmium is also removed from the process solution 15 in this sub-step and it is based on the presence of metallic zinc 28 in the process solution 15, which is used in one application.

According to the N formula, it is used to increase the pH of the process solution. In this case, cadmium binds to the surface of metallic zinc 28.

N 25 As an alternative to metallic zinc 28, you can use this at this point

E may be, for example, metallic manganese. ti 0 As with other concentrations, the method can be used if necessary

O also determines the cadmium content of the process solution 15. It can be done, for example, in connection with step 406, where a reduction in the amount of cadmium in the process solution 15 also occurs as a by-product. An example of a criterion value set for the cadmium content can be 200 mg / 1 kg of micronutrient (in fertilizer), i.e. approximately 30 mg / l in a solution containing 150 g / l manganese. The determination of the cadmium content of the process solution 15, as well as all other metal concentration measurements in the process, can be done, for example, with ICP-0ES analysis equipment.

Returning to Figure 4 again, the next step 407 after the pH adjustment steps 803 and 805 is the filtration of the pulp solution 41, i.e. the second precipitate 29 is separated from the process solution 15 in sequence (Figure 5). This can take place, for example, with a separate frame filter 417. The filtration is carried out approximately 15 to 60 minutes after the start of step 805, depending, for example, on how quickly the desired pH (> 3) (or cadmium content) was reached.

The metallic zinc precipitate 29 obtained from the filtration in step 407, also containing the cadmium 30.2 bound to zinc 28' from solution 15 by the same pH adjustment process, can be further used, for example, as a raw material for the zinc industry. Now, the processing of the oxidation state of manganese 3 is proposed to take place before the precipitate

N tus 103, 203, 408 using at least one sulfide source 19. 3 On the other hand, it could also happen only after that, i.e. when

N 25 sulfide precipitate 23 has been separated from solution 15. z

N Next, in step 408, sulfide precipitation is carried out. In this step, at least one sulfide precipitate is added as a reagent to the process solution 15.

O another substance 19 for precipitating metals and/or metal compounds from the process solution 15 as sulfide precipitation. The sulfide source 19 may be one or more of the following: sodium sulfide 19”,

barium sulfide or hydrogen sulfide. Preferably, the sulfide source 19 is sodium sulfide 197. Sodium sulfide 197 is an easy chemical in this context in terms of solubility and also in terms of feedability to the reactor 34. In step 408, the sulfide anion reacts with soluble metal cations in the solution to form solid metal sulfides, which can then be separated from the solution 15 as a precipitate. At least zinc 20, copper 21, possible cadmium residues 30.1 and possible iron residues 27.1 precipitate from the process solution 15 in the precipitate 23 formed as a result of the precipitation in step 408. Sodium sulfide 19' can be added to the process solution 15 as a solution. A gas scrubber is arranged in the reactor 34 for the treatment of the gaseous hydrogen sulfide formed (not shown).

In step 409, a precipitate 23 containing metal sulfides 22 and now, in the embodiment shown, the third in the order is separated from the process solution 15. The solid sulfide precipitate 23 contains mostly zinc sulfide, but as mentioned above, possibly also other aforementioned metals as metal sulfides.

This precipitate 23 can also be further utilized as an industrial raw material, i.e., forming its own product component.

N In addition to sulfide precipitation, precipitation of iron 27.2 from the process solution 3 15 into a second precipitate 23 can be carried out by sulfide precipitation

N 25 by the change in pH caused by the purchase itself. In this process

The pH of the pre-solution 15 changes naturally for the precipitation of iron 27.

Essentially without additional chemicals, because the sulfide precipitation itself 3 neutralizes the process solution 15 to some extent.

S

According to the flow chart shown in Figure 9, according to one embodiment, step 409, i.e. separation of sulfide precipitate 23 from process solution 15, may also be divided into several sub-steps 901 - 903, one possible combination of which is presented as an example below.

In step 901, the solution 15 is clarified. In this step, the solution 15 is settled by gravity so that the fine, heavy sulfide precipitate 23 settles at least in the lower part of the solution volume and most preferably on its bottom. The settling is preferably carried out in a conical container/thickener, whereby the precipitate 23 accumulates in the bottom cone and is more easily separated.

In step 902, the sulfide precipitate 23 is separated from the settling/thickening tank. In one embodiment, filtration can be used here, for example. The separated sulfide precipitate 23 is sent, for example, as a raw material for the zinc industry. In step 903, the solution layer in the upper part of the tank is filtered with a suitable filtration apparatus 33. In one embodiment, it can be, for example, a frame filter 33”.

In step 409, the manganese sulfate solution 24 separated from the sulfide precipitate 23 can be further diluted with water in step 410, for example to improve its frost resistance.

N and/or possible pH adjustment. This can be done, for example, with 3 sulfuric acid. The finished solution 24 can be used as fertilizer 24.1

S 25 in agriculture and/or industry as a manganese-containing raw material

E neena 24.2. The manganese content of solution 24 can be, for example,

N 150 — 200 g/liter. The pH of the finished solution 24 for further processing/use can be in the range pH = 3 - 4. In this case

O it is suitable for both agriculture and as an industrial raw material. In this case, as an industrial raw material 24.2, for example, chemical consumption in the hydroxide precipitation of the solution is lower.

Figures 10 - 12 show some further embodiments of the invention as rough block diagrams. The figures show that it is possible to vary different embodiments in many different ways, within the limits of the same inventive idea. Figure 10 shows a single embodiment of the method comprising the precipitation of iron A shown in Figure 7, Figure 11 shows a single embodiment of the method comprising the processing of the oxidation number of manganese B shown in Figure 8, and Figure 12 shows a single embodiment of the method comprising the steps of the flow chart shown in Figure 4, i.e. the precipitation of iron A and also the influencing of the oxidation number of manganese B.

Figure 13 shows another, simplified embodiment of an implementation of the method according to the invention.

In the above method, there have been two sediment separations 102 and 104, first for the sulfate precipitate 16 after the dissolution step 101 and thus for the sulfide precipitate 23 after the sulfide precipitation step 103. According to another embodiment, however, it could be operated in such a way that the method has only one sediment separation 102, 104. According to Figure 13, it would be only after the sulfide precipitation 103 or according to Figures 1a and 2a, only after the dissolution of the material 11.

After the note 101. Thus, the method 3 according to the invention can be said to include in its basic form at least one difference

N 25 tus. With the two above-described separations 102, 104, the

After the deposition of E fid 103 and in addition also the material 11

After the N dissolution 101, at least the advantage is achieved that after the first 3-stage sedimentation 102, the dissolution of the material 11 is

After the extraction 101, but before the sulfide precipitation 103, a precipitate 16 containing lead and silver is obtained from the process, which can be directed as a separate component for further use. This precipitate 16 is simpler in composition than if the precipitate 23 formed in the sulfide precipitation 103 were also mixed with it.

In addition to the method, the invention also relates to an apparatus 10 for producing a manganese sulfate component 24 from a material 11 originating from a secondary manganese source by reductive acid leaching. The apparatus 10 includes leaching means 31" for forming a suspension 25 from the material 11 in the presence of water 12, sulfuric acid 13 and at least one reducing agent 14. In addition, the apparatus 10 includes first separation means 32* for separating at least one first precipitate 16 from the suspension 25. Furthermore, the apparatus 10 includes precipitation means 34" for precipitating metals and/or metal compounds from the process solution 15 using at least one sulfide source 19. The apparatus 10 also includes second separation means 33* for separating a second precipitate 23 containing metal sulfides 22 from the process solution 15, after which the manganese sulfate component 24 formed is suitable for use as a fertilizer 24.1 in agriculture or as an industrial raw material 24.2. The apparatus 10 can be operated in all its parts and operations at normal pressure 3 and room temperature (no heating required), which

N make it simple in terms of implementation. Since the 3 dissolution process is strongly exothermic, and the solution heats up

N 25 all the time, the dissolution reactor 31 is equipped as mentioned above

E with cooling 37. Cooling 37, more generally, temperature control

N optimizes the consumption of hydrogen peroxide 14’. Thus, the method according to the invention may, in one embodiment thereof, comprise a dissolution

O process temperature optimization so that the temperature is below 40 °C in the dissolution, and even below that, such as below 38% to optimize the consumption of hydrogen peroxide 14'. When added to a reactor 31 that is too hot, some of the hydrogen peroxide 14' can spontaneously decompose into water and oxygen. This causes excessive gas formation in the reactor 31 and significantly increases the consumption of hydrogen peroxide 14'. By optimizing the temperature, the reaction of hydrogen peroxide 14' can be directed entirely to its actual purpose, i.e. the decomposition of manganese dioxide. In addition, the reactor 31 does not vaporize too much when the gas evolution is more moderate. The consumption of hydrogen peroxide 14' in side reactions would also have an unfavorable effect on other chemical consumption.

According to one embodiment, the apparatus 10 includes a pre-screening 42 of the material 11 arranged before the reactor 31, i.e. the dissolution step. According to one embodiment, the pre-screening 42 can be implemented, for example, with a grate equipped with vibration motors and/or a screen mesh 42'. The pre-screening 42 is adapted to remove particles that are undesirable for the process apparatus 10 from the material 11, and in particular from the manganese slurry 11° originating from the electrolysis process of zinc concentrate, such as, for example, stones, concrete and/or possible plastic debris accompanying the material 11. ä

As is clear from the description of the method above, the apparatus 10 3 can also be implemented, for example, without the equipment for sulphide

N 25 to form a disaccha 23 and remove it from the process solution

From E 15, whereby the dissolution process, including the accompanying steps, obtained

The final product 24 is suitable as a fertilizer for agriculture. However, a more preferred embodiment of the apparatus 10 is that which is

O is shown in the figures. In this case, with the same equipment configuration and also the same method, it is possible, with very minor changes, to produce an end product in the same process plant for agricultural use, for example as fertilizer (for example without sulfide precipitation) as well as for industrial needs (with sulfide precipitation).

In addition to the method and apparatus 10, the invention also provides a manganese sulfate component 24 formed from a material 11 originating from a secondary manganese source by means of a reducing acid treatment. In the reducing acid treatment, the material 11 is dissolved 101, 201, 402 in the presence of water 12, sulfuric acid 13 and at least one reducing agent 14 to form a suspension 25 of the material 11. A first precipitate 16 containing at least lead 17 and silver 18 is separated from the suspension 25. At least one sulfide source 19 is precipitated 103, 203, 408 from the process solution 15 using metals and/or metal compounds, including one or more of the following: zinc 20, copper 21. A precipitate 23 containing metal sulfides 22 is separated 104, 204, 409 from the process solution 15, after which the formed manganese sulfate component 24 is suitable for use as a fertilizer 24.1 in agriculture or as an industrial raw material 24.2. As stated, the process solution 15 obtained from the dissolution step as it is, i.e. without sulfide precipitation, would be 3 already suitable for use as fertilizer 24.1 for land-

In the N. 3

S 25 In addition, the invention also relates to manganese sulfate compounds

The use of the component 24 achieved by the invention

N method. Manganese sulfate component 24 is used as a component in the manufacture of the final product 24.1, 24.2, which is

O selected from fertilizer and, for example, battery chemicals.

Another application still related to the invention is also the use of the solid leaching residue of the material 11, i.e. the lead-silver precipitate 16, as a component in the manufacture of the final product. The final product may comprise one or more of the metals present in the sulphate precipitate 16, i.e. lead and/or silver. In particular, the sulphate precipitate 16 in question has been washed after the leaching in which it was formed. In this case, its manganese content is non-existent, so that it does not hinder the further processing of the precipitate 16 in question.

Furthermore, the invention also relates to a product containing a manganese sulfate component obtained by the method according to the invention.

The raw material of the method according to the invention, i.e. the material 11 originating from the secondary = manganese source, can be, for example, manganese precipitate from zinc electrolysis. It consists mainly of oxidized manganese, i.e. solid manganese dioxide. Its manganese content can be, for example, 25-55% by weight, more particularly 30-50% by weight, even more particularly 35-%. The concentrations of metals to be removed as impurities by the method in the manganese precipitate can in turn be, for example, in the value ranges: zinc 20, for example 1-15% by weight, copper

N 21 for example 0.01 - 5 wt-%, cadmium 30, 30.1, 30.2 for example 0.01 - 5 wt-%, lead 17 for example 4 - 12 wt-%

S 25%, more particularly 4 - 8% by weight, silver 18 for example 0.01 - 5

E wt% and iron 27, 27.1, 27.2 for example 0.01 - 5 wt%

N (dry matter). Yet another example of material 11 3 can also be manganese dioxide separated from batteries.

S

The process according to the invention produces no wastewater at all.

The process water cycle is closed. All process wash water and residues from previous solvents can be returned to the process.

It should be understood that the above description and the accompanying drawings are intended to illustrate the present invention only. The invention is therefore not limited to the embodiments set forth above, but many different variations and modifications of the invention will be apparent to those skilled in the art, which are possible within the scope of the inventive concept defined by the appended claims. <t

OF

O

OF

O

<Q ©

OF

I a a

OF

<t

O

LÖ

+

OF

O

OF

Claims (15)

PATENT CLAIMS 1. A method for producing a manganese sulfate component from a material derived from a secondary manganese source, comprising — dissolving (101, 201, 402) the material (11) in the presence of water (12), sulfuric acid (13) and at least one reducing agent (14) to form a suspension (25), — forming a process solution (15) from the suspension (25) by separating (102, 202, 403) therefrom a first precipitate (16) comprising at least lead (17) and silver (18), — precipitating (103, 203, 408) metals and/or metal compounds comprising one or more of the following from the process solution (15) using at least one sulfide source (19), — separating (104, 204, 409) a precipitate (23) containing metal sulfides (22) from the process solution (15), after which the manganese sulfate component (24) formed is suitable for use as a fertilizer (24.1) in agriculture or as an industrial raw material (24.2). 3 2. The method according to claim 1, characterized in that the method is carried out without precipitation (103, 203, 408) of the process solution (15) using at least one sulfide source (19) and subsequent separation (104, 204, 409) of the precipitate E (23) containing metal sulfides (22) from the process solution (15), whereby the manganese sulfate component (24) formed is suitable for use as a fertilizer (24.1) in agriculture. & 3. A method according to claim 1 or 2, characterized in that the method further comprises at least one step (403), in which iron (27.2) is precipitated from the suspension (25) and/or the process solution (15) as part of the first and/or second precipitate (16, 23) by adjusting the pH of the suspension (25) and/or the process solution (15), and in which the pH of the suspension (25) and/or the process solution (15) is adjusted (403, 701, 703) preferably using one or more of the following: at least one reducing agent (14), such as hydrogen peroxide (147) and/or material from a secondary manganese source (11). 4. A method according to any one of claims 1 to 3, characterized in that the method comprises changing (406) the oxidation number of manganese in the process solution (15) if necessary by means of pH adjustment (803) of the process solution (15). 5. The method according to claim 4, characterized in that the oxidation number of manganese in the process solution (15) is changed (406) by - lowering (803) the pH of the process solution (15) to the value range pH = 1.5 - 2.5 using sulfuric acid (13), - raising (805) the pH of the process solution (15) to the value range pH = 2.5 - 4.5 using zinc (28). ä 6. A method according to claim 4 or 5, characterized in that in addition to changing the oxidation number of manganese, the cadmium content of the process solution (15) is reduced by pH adjustment (406) using said zinc (28) used to raise the pH of the process solution (15). 0 N < 7. A method according to any one of claims 1 to 6, characterized in that the sulfide source (19) is one or more of the following: sodium sulfide (197), barium sulfide or hydrogen sulfide. 8. A method according to claim 7, characterized in that the sulfide source (19) is sodium sulfide (197). 9. A method according to any one of claims 1 to 8, characterized in that the reducing agent (14) is one or more selected from the following: peroxide (147), citric acid, one or more sugars. 10. A method according to any one of claims 1 to 9, characterized in that the dissolution (101, 201, 402) of the material (11) is carried out by — forming (603) a suspension (25) by mixing the material (11) with water (12), — adding (605.1, 605.2) sulfuric acid (13) and at least one reducing agent (14) to the formed suspension (25). 11. A method according to any one of claims 1 to 10, characterized in that when starting the formation of the suspension (15), sulfuric acid (13) is dosed (605.1) according to the calculated amount of the lowest assumed manganese content of the material (11). ä N 12. A method according to any one of claims 1 to 11, characterized in that when starting the formation of the suspension (25) N 25 - a sample (26) is taken (604) from the suspension (25) formed by the material (11) and water (12) for the determination (605.i) of the manganese content N, 3 - the dissolution is started by dosing (605.1) sulfuric acid (13) into the suspension (25) intended for processing according to the calculated amount of the lowest assumed manganese content of the material (11), — determining (605.i) the exact manganese content of the dry component of the material (11) from a sample (26) taken from the suspension (25), — finalizing the suspension (25) by dosing (607) water (12), sulfuric acid (13) and at least one reducing agent (14) thereto based on the determined exact manganese content of the dry component of the material (11). 13. Apparatus for producing a manganese sulphate component from a material originating from a secondary manganese source by reductive acid leaching, the apparatus (10) comprising — leaching means (31) for forming a suspension (25) from the material (11) in the presence of water (12), sulphuric acid (13) and at least one reducing agent (14), — first separation means (32*) for separating a first precipitate (16) and forming a process solution (15), — precipitation means (347) for precipitating metals and/or metal compounds from the process solution (15) using at least one sulphide source (19), — second separation means (33*) for separating a second precipitate (23) containing metal sulphides (22) from the process solution N (15), after which the formed manganese sulphate component (24) is suitable for use as a fertiliser (24.1) N 25 in agriculture or as a raw material for industry (24.2). z N 14. A manganese sulfate component formed from material derived from a secondary manganese source by a reducing acid treatment, wherein — the material (11) is dissolved (101, 201, 402) in the presence of water (12), sulfuric acid (13) and at least one reducing agent (14) to form a suspension (25), — a process solution (15) is formed from the suspension (25) by separating therefrom a first precipitate (16) containing at least lead (17) and silver (18), — at least one sulfide source (19) is precipitated (103, 203, 408) from the process solution (15) using metals and/or metal compounds, including one or more of the following: zinc (20), copper (21), — a precipitate (23) containing metal sulfides (22) is separated (104, 204, 409) from the process solution (15), after which the manganese sulfate component (24) formed in the form of an aqueous solution is suitable for use as a fertilizer (24.1) in agriculture or as a raw material for industry (24.2). 15. Use of a manganese sulfate component, which manganese sulfate component (24.1, 24.2) in aqueous solution form has been obtained by the method according to any one of claims 1 to 12, as a component (24.1, 24.2) in the manufacture of a final product selected from a fertilizer and a battery chemical. O N O <Q © N I a a N <t O O + N O N