Method for obtaining an iron-comprising solution of high concentration

Abstract

The current invention concerns a method for increasing an iron content of a solution by converting low iron containing solutions into highly concentrated ferric chloride solutions by adding iron containing substances. The invention concerns also methods for transporting and storage of said highly concentrated ferric chloride solutions.

Claims

1. A method for obtaining a solution comprising an increased ferric chloride concentration of between about 67 wt. % and about 75 wt. %, comprising the steps of: (a) providing a solution comprising ferric chloride and/or ferrous chloride, and having an initial ferric chloride concentration; (b) increasing an iron content of said solution from the iron content of less than about 10 wt. % to the iron content of more than about 23 wt. % by adding a substance comprising iron, ferric iron and/or ferrous iron, wherein the step after adding a substance comprising iron, ferric iron and/or ferrous ion further comprises at least one of the following steps: (1) adding hydrochloric acid to the solution, and/or (2) oxidizing ferrous ion in the solution; and (c) obtaining the solution comprising an increased ferric chloride concentration of between about 67 wt. % and about 75 wt. %.

2. The method according to claim 1, wherein the method is carried out without an evaporation step.

3. The method according to claim 1, further comprising the step of maintaining a temperature of about 8 C. or higher of the solution comprising an increased ferric chloride concentration of between about 67 wt. % and about 75 wt. %.

4. The method according to claim 1, wherein said solution obtained in step (b) comprises ferrous ion and said ferrous ion in said solution is oxidized in step (b)(2).

5. The method according to claim 1, wherein said increased ferric chloride concentration is higher than said initial ferric chloride concentration by at least about 1 wt. %.

6. The method according to claim 1, wherein the provided solution in step (a) comprises a ferric chloride concentration of at least about 12 wt. %.

7. The method according to claim 1, wherein said iron-comprising substance comprises iron, hematite, magnetite, iron oxide, ferrite, or any combination thereof.

8. The method according to claim 1, wherein step (b) comprises oxidation using ozone, oxygen gas, chlorine dioxide, sodium hypochlorite, peroxide, hydrogen peroxide, perchlorate, or sodium perchlorate, chlorination and/or oxychlorination.

9. The method according to claim 1, wherein the steps of adding the substance comprising iron, ferric iron and/or ferrous iron, increasing the iron content of said solution, adding hydrochloric acid to the solution, and oxidizing the ferrous ion in the solution are performed multiple times subsequently or simultaneously.

10. The method according to claim 1, wherein step (b)(1) is performed before, during and/or after adding the substance comprising iron, ferric iron and/or ferrous iron, and/or wherein step (b)(1) is performed before and/or during step (b)(2).

11. The method according to claim 1, wherein in step (b)(1) hydrochloric acid in a gaseous state is added to and absorbed by said solution in step (b).

12. The method according to claim 1, for increasing an iron content of a solution, wherein step (a) comprises providing a solution having an initial iron content of at least about 4 wt. %; and wherein step (b) comprises adding a substance comprising iron, to obtain a solution having an increased iron content of at least about 12 wt. % compared to the solution provided in step (a).

13. The method according to claim 1, further comprising diluting the solution obtained by the method of claim 1 to decrease its concentration of ferric chloride.

14. A method for storing, transporting and/or moving a ferric chloride solution with an iron content of at least about 23 wt. % or higher comprising placing the solution obtained by the method of claim 1 in an intermodal container or barge.

15. The method according to claim 1, whereby said solution is stored, transported and/or moved in an intermodal container or in a barge.

16. A method for storing, transporting and/or moving a ferric chloride solution with an iron content of between about 67 wt. % and about 75 wt. %, comprising placing the solution obtained by the method according to claim 1 in an intermodal container or barge adapted for long-time storage, long-distance transport without tracing, and/or long-distance transport with tracing.

17. The method according to claim 1, wherein step (b)(2) comprises oxidizing ferrous ion with an agent selected from chlorine gas, ozone, oxygen gas, chlorine dioxide, sodium hypochlorite, oxychlorination gas, peroxides, perchlorate or a combination of one or more thereof.

18. The method according to claim 17, wherein the oxychlorination gas comprises a combination of oxygen gas and hydrochloric acid gas.

19. The method according to claim 1, further comprising maintaining the solution comprising an increased ferric chloride content above its freezing point.

Description

DESCRIPTION OF FIGURES

(1) FIGS. 1-3 illustrate embodiments of methods for obtaining a ferric chloride comprising solution with increased concentration according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(2) The present invention concerns a method for obtaining a solution comprising a ferric chloride at an increased concentration. The present invention also concerns a method for increasing iron content of a solution.

(3) Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.

(4) As used herein, the following terms have the following meanings:

(5) A, an, and the as used herein refers to both singular and plural referents unless the context clearly dictates otherwise. By way of example, a compartment refers to one or more than one compartment.

(6) About as used herein referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of +/20% or less, preferably +/10% or less, more preferably +/5% or less, even more preferably +/1% or less, and still more preferably +/0.1% or less of and from the specified value, in so far such variations are appropriate to perform in the disclosed invention. However, it is to be understood that the value to which the modifier about refers is itself also specifically disclosed.

(7) Comprise, comprising, and comprises and comprised of as used herein are synonymous with include, including, includes or contain, containing, contains and are inclusive or open-ended terms that specifies the presence of what follows e.g. component and do not exclude or preclude the presence of additional, non-recited components, features, element, members, steps, known in the art or disclosed therein.

(8) The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within that range, as well as the recited endpoints.

(9) The expression % by weight or wt % (weight percent), here and throughout the description unless otherwise defined, refers to the relative weight of the respective component based on the overall weight of the formulation.

(10) The term iron content of a solution refers to the concentration of iron in said solution. The iron could be in the form of iron atoms, iron ions, ferric iron, ferrous iron, iron bound in molecules, etc. Note that e.g. iron-comprising solids are not part of the solution and therefore do not contribute to the solution's iron content.

(11) In an aspect, the invention provides a method for obtaining a solution comprising a ferric chloride at an increased concentration according to claims 13 and 14, i.e. a method for increasing iron content of a solution, comprising the steps of: (D1) providing a solution comprising an initial iron content, preferably of at least 6 wt %; and (D2) adding a substance comprising iron,
leading to a solution comprising an increased iron content, preferably of at least 12 wt %.

(12) Note that adding said substance is to result in an increase of the iron content of the solution, the iron content being a concentration of all iron dissolved in the solution. Said iron can be present in the form of atoms, ions, ferrous and/or ferric iron, bound in molecules or unbound, etc.

(13) Said solution of increased iron content can be obtained as an intermediate solution in a method for obtaining a solution of high ferric chloride concentration as described in this document. Also, said method for increasing iron content of a solution can be used in a a method for obtaining a solution of high ferric chloride concentration as described in this document, in particular in step (C3).

(14) In a preferred embodiment, the added substance comprises solid ferric and/or ferrous iron, and preferably the methods herein described comprise the step of dissolving said iron in said solution, more preferably before, during and/or after said iron is bound in ferric and/or ferrous chloride.

(15) In an embodiment, the iron content of the solution is increased from an iron content of less than 10 wt %, preferably between 4 wt % and 9 wt %, to an iron content of more than 15 wt %, e.g. 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 wt % or any value there between. Preferably the concentration is increased to more than 20 wt %, more preferably more than 21 wt %, yet more preferably more than 22 wt %, still more preferably more than 23 wt %, even more preferably more than 24 wt %. In a preferred embodiment, the concentration is increased to less than 30 wt %, more preferably less than 29 wt %, yet more preferably less than 28 wt %, still more preferably less than 27 wt %, even more preferably less than 26 wt %, yet even more preferably less than 25 wt %. Most preferably, the concentration is increased to about 24.5 wt %.

(16) The present invention provides a method for obtaining a solution comprising a ferric chloride at an increased concentration, preferably a concentration of at least 15 wt %, preferably at least 18 wt %, more preferably at least 20 wt %, still more preferably at least 23 wt %, yet more preferably at least 25 wt %, even more preferably at least 27 wt %, yet more preferably at least 30 wt %, still more preferably at least 32 wt %, even more preferably at least 35 wt %, yet still more preferably at least 38 wt %, yet even more preferably at least 40 wt %, still even more preferably at least 50 wt %, still more preferably at least 60 wt %, yet more preferably at least 65 wt %, e.g. 66 wt %, 67 wt %, 68 wt %, 69 wt %, 70 wt %, 71 wt %, 72 wt %, 73 wt %, 74 wt %, 75 wt % or higher, most preferably about 71 wt %.

(17) Preferred embodiments of these methods are described in claims 1 to 12 and further in this document.

(18) In a preferred embodiment, the hydrochloric acid is added in step (C2) by absorption from a gaseous state by said solution.

(19) In a preferred embodiment, said substance added in step (C3) comprises solid iron and/or solid hematite. By using solid hematite, the ferric chloride concentration can be increased to more than 75 wt %. By using solid iron or a mixture of solid iron and hematite, the ferric chloride concentration can be increased even higher than with hematite.

(20) The previous embodiments of the method comprise the step of increasing an iron content of said solution by adding a substance comprising iron. This step seems necessary to allow an increase of the iron content of the solution without evaporation step and thus in a more energy efficient manner as in the prior art.

(21) The ferric chloride solution with a high iron content, preferably 23 wt %, 24 wt %, 25 wt %, 26 wt % or higher, can be stored, transported or moved as a solution by maintaining a solution temperature so the ferric chloride is stable in solution. In a preferred embodiment the temperature is 8 C. or higher. In other embodiments the temperature can be 30 C. or higher and in another embodiment the temperature can be 50 C., for example about 80 C. or about 100 C. In a preferred embodiment the temperature is 100 C. or lower. In other embodiments the temperature can be 75 C. or lower for example about 8 C. or about 50 C. For frozen ferric chloride solutions, heat can be applied to facilitate the solid to liquid phase change. Once transported to the desired location, the ferric chloride solution having the high iron content can then be reconstituted on-site to the desired iron concentration as desired.

(22) In an embodiment, the method comprises the step of ensuring that said solution, in particular said solution comprising an increased ferric chloride concentration, remains or becomes liquid, e.g. by altering or controlling climatic parameters of said solution such as temperature and/or pressure. More in particular, the method may comprise the step of keeping said solution comprising a ferric chloride concentration above the freezing temperature of said solution. Note hereby that the freezing temperature of the solution depends on the concentration and that this step may require heating of said solution, in particular for ferric chloride concentrations higher than 75 wt %.

(23) Therefore, the present invention also concerns a method for storing, transporting and/or moving a ferric chloride solution, preferably a ferric chloride solution obtained by a method according to the present invention, with an iron content of at least 23 wt %, preferably at least 24 wt %, such as 24 wt %, 25 wt %, 26 wt % or higher and any value there between. Preferably said method comprises storing, transporting and/or moving said ferric chloride solution at a temperature of about 8 C. or more. Preferably, said solution is stored for a duration which is longer than 1 day, more preferably longer than 2 days, still more preferably longer than 3 days, such as 4, 5, 6, 7, 8, 9, 10 days or longer, and/or preferably said solution is transported or moved over distances longer than 100 km, preferably longer than 500 km, more preferably longer than 1000 km, such as 2000 km, 3000 km, 4000 km, 5000 km, 6000 km, 7000 km, 8000 km, 9000 km, 10000 km or any value there between or even longer than 10000 km. In an embodiment, said ferric chloride solution is stored, transported and/or moved in an intermodal container or by barge.

(24) Note hereby that storage, transport or moving of ferric chloride solutions over a long period or over long distances, preferably in intermodal containers or a barge, do not seem to have been done or contemplated previously. The present invention allows to produce highly concentrated ferric chloride solutions in a fast, cheap and reliable manner, but requires the presence of iron containing substances. Due to its high concentration, it becomes possible to produce the ferric chloride solution at a site where iron containing substances are present, are produced or are collected, and store the solution over a longer time period or transport or move the solution over long distance, where it can be diluted to a required concentration, for a given use or application. In case the melting point or freezing point of the solution is high, in particular higher than ambient temperature, extra measures need to be taken to keep the product in a liquid state. Such measures could comprise e.g. isolation or tracing, to avoid the product from crystalizing or solidifying. In this respect, a solution with an increased concentration of between 67 wt % and 75 wt %, more preferably about 71 wt %, is preferred as it crystalizes only around 8 C., which simplifies transport and storage of the solution. For storage, e.g. a limited isolation and/or tracing could suffice. The melting or freezing temperature of the solution determines the type of tracing which can be used. If a product melts/freezes about 8 C., electrical tracing usually suffices. A product with metling/freezing temperature above 100 C. requires e.g. steam tracing. The type of tracing also determines at least partly the material which can be used in storage or transport vessels or pipes, as well as their lifetime. Intermodal containers can hereby be adapted for such long-time storage and/or long-distance transport. Barges can be adapted for long-distance transport. Note that, due to the corrosive nature of ferric chloride solutions, it is not evident to use barges for transporting ferric chloride solutions.

(25) Intermodal containers, also called container, freight container, ISO container, shipping container, hi-cube container, box, conex box or sea can, preferably are a standardized reusable steel box used for the safe, efficient and secure storage and movement of materials and products within a global containerized intermodal freight transport system. Intermodal indicates that the container can be moved from one mode of transport to another (e.g. from ship, to rail, to truck) without unloading and reloading the contents of the container.

(26) Barges refer to boats or ships, adapted for transporting goods and products over water ways, preferably over rivers, canals and lakes.

(27) In view of the above, the present invention also concerns an intermodal container or barge comprising a ferric chloride solution with a concentration of at least 15 wt %, preferably at least 18 wt %, more preferably at least 20 wt %, still more preferably at least 23 wt %, yet more preferably at least 25 wt %, even more preferably at least 27 wt %, yet more preferably at least 30 wt %, still more preferably at least 32 wt %, even more preferably at least 35 wt %, yet still more preferably at least 38 wt %, yet even more preferably at least 40 wt %, still even more preferably at least 50 wt %, still more preferably at least 60 wt %, yet more preferably at least 65 wt %, e.g. 66 wt %, 67 wt %, 68 wt %, 69 wt %, 70 wt %, 71 wt %, 72 wt %, 73 wt %, 74 wt %, 75 wt % or higher, most preferably about 71 wt %. The present invention also concerns the use of an intermodal container or barge for for storing, transporting and/or moving a ferric chloride solution, preferably a ferric chloride solution obtained by a method according to the present invention, and preferably said ferric chloride solution comprising a concentration of at least 15 wt %, preferably at least 18 wt %, more preferably at least 20 wt %, still more preferably at least 23 wt %, yet more preferably at least 25 wt %, even more preferably at least 27 wt %, yet more preferably at least 30 wt %, still more preferably at least 32 wt %, even more preferably at least 35 wt %, yet still more preferably at least 38 wt %, yet even more preferably at least 40 wt %, still even more preferably at least 50 wt %, still more preferably at least 60 wt %, yet more preferably at least 65 wt %, e.g. 66 wt %, 67 wt %, 68 wt %, 69 wt %, 70 wt %, 71 wt %, 72 wt %, 73 wt %, 74 wt %, 75 wt % or higher, most preferably about 71 wt %.

(28) The agent used in the oxidation step can be chosen out of the list of chlorine gas (Cl.sub.2), ozone (O.sub.3), oxygen gas (O.sub.2), chlorine dioxide (CIO.sub.2), sodium hypochlorite (NaOCl), oxychlorination gas (which could be a combination of oxygen gas (H.sub.2O.sub.2) and hydrochloric acid (HCl)), peroxides, especially hydrogen peroxide (H.sub.2O.sub.2), perchlorate, especially sodium perchlorate (NaClO.sub.3). Chlorine gas (Cl.sub.2), oxygen gas (O.sub.2), a mixture of oxygen gas and hydrochloric acid gas (O.sub.2+HCl), or a mixture thereof is used in a preferred embodiment.

(29) The present invention will be now described in more details, referring to examples that are not limitative.

EXAMPLES

Example 1: See FIG. 1

(30) A ferric chloride solution (11) is provided with a concentration of 12 wt %. Hydrochloric acid in gaseous state (12) is absorbed (13) in said solution (11), resulting in a solution comprising ferric chloride and hydrochloric acid (14). Note that this may decrease the concentration of ferric chloride in the solution (14). Ferric oxide (15), e.g. in the form of hematite or ferrite, is added to the solution (14). The ferric oxide reacts at least partially with the hydrochloric acid (16) to form ferric chloride in the solution. Note that the ferric oxide can be added as a solid, but that the reaction (16) results in ferric iron which is dissolved in the solution. Note also that adding the ferric oxide increases the iron content of the solution (14), even though water is formed in the reaction (16). This is due to the heavy molecular mass of ferric chloride compared to water, theoretically allowing up to about 85.7 wt % of ferric chloride solution with this reaction.

(31) The resulting ferric chloride solution (17) comprises a concentration, which is higher than 12 wt %, e.g. 16 wt %. The resulting solution may also comprise hydrochloric acid, e.g. which did not participate in reaction (16). In order to increase the concentration further, steps (13) and (16) could be repeated using the resulting solution (17) as input (19). This repetition of steps could be performed multiple times to increase the concentration of ferric chloride, resulting in a final solution (18) comprising at least 38 wt %, preferably 40 wt %, more preferably between 60 wt % and 80 wt %, most preferably about 71 wt % of ferric chloride.

(32) In case hydrochloric acid is present in the resulting solution (17), step (16) can be repeated using the resulting solution (17) as input (20).

(33) In a similar example, the initial ferric chloride concentration can be about 40 wt %: a. f.ex. A 40 wt % ferric chloride (FeCl.sub.3) solution, with an iron content of about 14 wt %, is saturated with wet hydrochloric acid gas (HCl.sub.(g)) b. Increasing iron content by adding magnetite (Fe.sub.3O.sub.4) yielding in a solution comprising ferric chloride (FeCl.sub.3) and ferrous chloride (FeCl.sub.2), with an increased iron content of about 16.5 wt %. c. Followed with chlorination of ferrous chloride to obtain a solution with a ferric chloride concentration of 47 wt %.

(34) TABLE-US-00001 X Fe.sub.3O.sub.4+ 8HCl+ FeCl.sub.3.fwdarw. FeCl.sub.2+ 3FeCl.sub.3+ 4H.sub.2O g X 231.5 291.7 162.2 126.8 486.6 g H.sub.2O 424.4 243.3 739.7 wt % X 41% 40% X FeCl.sub.2+ FeCl.sub.3+ Cl.sub.2-> FeCl.sub.3 g X 126.8 486.6 35.5 648.8 g H2O 739.7 739.7 wt % X 47%

(35) With these steps, the increased ferric chloride concentration is higher than said initial ferric chloride concentration by 7 wt %.

Example 2: See FIG. 2

(36) A ferric chloride solution (21) is provided with a concentration of about 12 wt %. The solution may also comprise ferrous chloride. Solid iron (22) is added to the solution (21). The solid iron (22) reacts with ferric chloride in the solution (21), to form ferrous chloride according to reaction (23). Note that this results in an increase of the iron content of the solution, and that a solution (24) is obtained comprising ferrous chloride and possibly ferric chloride which did not react in reaction (24). Chlorine gas (25) is added to the solution (24), resulting in the oxidation of the ferrous iron according to an oxychlorination reaction (26).

(37) The resulting ferric chloride solution (27) comprises a concentration, which is higher than 12 wt %, e.g. 38 wt %. The resulting solution may also comprise ferrous chloride, e.g. which did not participate in reaction (26).

(38) In order to increase the concentration further, steps (23) and (26) could be repeated using the resulting solution (27) as input (29). This repetition of steps could be performed multiple times to increase the concentration of ferric chloride, resulting in a final solution (28) comprising at least 40 wt %, preferably between 60 wt % and 80 wt %, most preferably about 71 wt % of ferric chloride.

(39) In case ferrous chloride is present in the resulting solution (27), step (26) can be repeated using the resulting solution (27) as input (30).

Example 3: See FIG. 3

(40) A solution comprising ferrous and/or ferric chloride (31) is provided, comprising an iron content of about 6 wt %, e.g. waste pickling liquor from a steel pickling plant. Hydrochloric acid in gaseous state (32) is absorbed (33) in said solution (31). Note that this may decrease the iron content in the solution (34). Iron-comprising substances (35) are added to the solution (34). A number of reactions (36) may take place, resulting in an increase of the iron content. A solution (37) comprising ferrous chloride is obtained. This solution (37) may further comprise ferric chloride already formed in reactions (36) and/or hydrochloric acid which did not participate in reactions (36). An oxidizing agent (38) is added to the solution (37), resulting in the oxidation (43) of the ferrous iron in the ferrous chloride. The oxidizing agent (38) may be chlorine gas and/or oxygen gas, and the ferrous iron can be at least partially oxychlorinated. In case the amount of hydrochloric acid in the solution (37) is deemed too low to allow oxychlorination with oxygen gas, extra hydrochloric acid gas can be added in this step.

(41) The resulting ferric chloride solution (39) may comprise an iron content which is higher than about 10 wt % concentration, and a ferric chloride concentration which is higher than 16 wt %, e.g. 38 wt %. The resulting solution (39) may also comprise ferrous chloride and/or hydrochloric acid, e.g. which did not participate in reactions (36).

(42) In order to increase the concentration further, steps (33), (36) and (43) could be repeated using the resulting solution (39) as input (41). This repetition of steps could be performed multiple times to increase the concentration of ferric chloride, resulting in a final solution (40) comprising at least 38 wt %, preferably 40 wt %, more preferably between 60 wt % and 80 wt %, most preferably about 71 wt % of ferric chloride.

(43) In case hydrochloric acid and/or ferrous chloride is present in the resulting solution (39), steps (36) and (43) can be repeated using the resulting solution (39) as input (42). Note that if ferrous chloride is present in the resulting solution (39), step (43) can be repeated using the resulting solution (39) as input (44) in order to increase the ferric chloride concentration.

Example 4

(44) Reaction between iron (Fe), ferric chloride (FeCl.sub.3) and chlorine gas (Cl.sub.2) to obtain a 69 wt % ferric chloride (FeCl.sub.3) solution starting from a 40 wt % ferric chloride FeCl.sub.3 solution. See also example 2 and FIG. 2.

(45) In this example iron is added to a ferric chloride solution yielding to a solution comprising ferrous chloride. The ferrous chloride is oxidised into ferric chloride by reacting with chlorine gas. By repeating this process 3 times the ferric chloride content of the solution is raised from 40 wt %, over 50 wt % and 60 wt % to 69 wt %. With these steps, the increased ferric chloride concentration is higher than said initial ferric chloride concentration by 10 wt %, 20 wt % to even 29 wt %.

Multistage Increasing Iron Content by Adding Fe in FeCl3 Solution Followed by Oxidizing Ferrous into Ferric Chloride

(46) TABLE-US-00002 X Fe+ 2FeCl.sub.3.fwdarw. 3FeCl.sub.2 FeCl.sub.2+ Cl.sub.2.fwdarw. FeCl.sub.3 g X 55.8 324.4 380.3 380.3 106.4 486.6 g H.sub.2O 486.6 486.6 486.6 486.6 wt % X 40% 44% 44% 50% X Fe+ 2FeCl.sub.3.fwdarw. 3FeCl.sub.2 FeCl.sub.2+ Cl.sub.2.fwdarw. FeCl.sub.3 g X 83.8 486.6 570.4 570.4 159.5 729.9 g H.sub.2O 486.6 486.6 486.6 486.6 wt % X 50% 54% 54% 60% X Fe+ 2FeCl.sub.3.fwdarw. 3FeCl.sub.2 FeCl.sub.2+ Cl.sub.2.fwdarw. FeCl.sub.3 g X 125.7 729.9 855.6 855.6 239.3 1094.9 g H.sub.2O 486.6 486.6 486.6 486.6 wt % X 60% 64% 64% 69%

(47) Note that in this example 4, step (C2) is not performed, while step (C4) is performed as a large amount of ferrous ion is present in the ferrous chloride solution obtained after adding the iron (Fe) to the solution.

(48) Note: once the reactor is filled with FeCl3 69% this reaction can take place in 1 step in the reactor by simultaneously adding Fe, FeCl.sub.3 40% and Cl.sub.2. i.e. after performing the steps (C3) and (C4) three times subsequently, they can now be performed simultaneously to increase the ferric chloride concentration of a solution of 40 wt % ferric chloride to 69 wt %, i.e. an increase of 29 wt %, in a single process combining steps (C3) and (C4) in a simultaneous manner. In an alternative view, one could also note that the amount of solution with a ferric chloride concentration of 69 wt % is increased. This is illustrated in the table below.

(49) TABLE-US-00003 X Fe+ 2FeCl.sub.3+ 3/2Cl.sub.2+ FeCl.sub.3-> FeCl3 g X 55.8 324.4 106.4 69.4 556.0 g H.sub.2O 145.7 104.0 249.8 wt % X 69% 40% 69%

Example 5

(50) Reaction between Iron (Fe), Hydrochloric Acid (HCl.sub.(g)) and Chlorine Gas (Cl.sub.2) to Obtain a 57 wt % Ferric Chloride (FeCl.sub.3) Solution starting from a 19 wt % Ferric Chloride (FeCl.sub.3) Solution. a. A 19 wt % ferric chloride (FeCl.sub.3) solution is saturated with hydrochloric acid (HCl.sub.(g)) b. Increasing iron content by adding iron (Fe) yielding in a solution comprising ferrous chloride (FeCl.sub.2) at a concentration of 51 wt %.

(51) TABLE-US-00004 X 2Fe+ 2HCl+ 2FeCl.sub.3.fwdarw. 4FeCl2+ H2.sub.(g) g X 62.8 72.9 40.2 173.9 2.0 g H.sub.2O 166.9 166.9 wt % X 19% 51% c. Oxidizing ferrous chloride (FeCl.sub.2) into ferric chloride (FeCl.sub.3) using chlorine gas (Cl.sub.2).

(52) TABLE-US-00005 X FeCl.sub.2+ Cl.sub.2.fwdarw. FeCl.sub.3 g X 173.9 48.6 222.5 g H.sub.2O 166.9 166.9 wt % X 51% 57%

(53) Hereby, performing steps (C2), (C3) and (C4) result in an increase of the ferric chloride concentration by 38 wt %.

Example 6

(54) Reaction between Magnetite (Fe.sub.3O.sub.4), Iron (Fe), Hydrochloric Acid (HCl.sub.(g)) and Chlorine Gas (Cl.sub.2) to obtain a 55 wt % Ferric Chloride (FeCl.sub.3) Solution starting from a 40 wt % Ferric Chloride (FeCl.sub.3) Solution. a. A 40 wt % ferric chloride (FeCl.sub.3) solution is saturated with hydrochloric acid (HCl.sub.(g)) b. Increasing iron content by adding magnetite (Fe.sub.3O.sub.4) yielding in a solution comprising ferric chloride and ferrous chloride (FeCl.sub.2) with an increased iron content.

(55) TABLE-US-00006 X Fe.sub.3O.sub.4+ 8HCl+ FeCl.sub.3.fwdarw. FeCl.sub.2+ 2FeCl.sub.3+ 4H.sub.2O g X 231.5 291.7 162.2 126.8 486.6 g H.sub.2O 424.3 241.4 739.7 wt % X 41% 40% c. Further increasing of iron content by adding iron (Fe) yielding in a solution comprising ferrous chloride (FeCl.sub.2)

(56) TABLE-US-00007 X Fe+ 2FeCl.sub.3+ FeCl.sub.2.fwdarw. 3FeCl.sub.2 g X 83.8 486.6 126.8 697.2 g H.sub.2O 739.7 739.7 wt % X 49% d. Oxidizing ferrous chloride into ferric chloride using chlorine gas (Cl.sub.2)

(57) TABLE-US-00008 X FeCl.sub.2+ Cl.sub.2.fwdarw. FeCl.sub.3 g X 697.2 195.0 892.2 g H.sub.2O 739.7 739.7 wt % X 49% 55%

(58) Hereby, an increase of 15 wt % of the ferric chloride concentration is achieved by performing steps (C2), (C3) and (C4).

Example 7

(59) Reaction between Hematite (Fe.sub.2O.sub.3) and Hydrochloric Acid (HCl.sub.(g)) to obtain a 71 wt % Ferric Chloride (FeCl.sub.3) Solution starting from a 40 wt % Ferric Chloride (FeCl.sub.3) solution by simultaneously adding Hematite (Fe.sub.2O.sub.3) and Hydrochloric acid (HCl.sub.(g)) in a reactor

(60) TABLE-US-00009 X Fe.sub.2O.sub.3+ 6HCl+ FeCl.sub.3-> 2FeCl.sub.3+ 3H.sub.2O g X 159.7 218.8 73.0 324.4 54.0 g H.sub.2O 109.5 73.0 109.5 wt % X 40% 71%

(61) Hereby, an increase of 31 wt % of the ferric chloride concentration is achieved by performing steps (C2) and (C3) simultaneously.

Example 8

(62) Producing a ferric chloride (FeCl.sub.3) concentrate higher than 71 wt % FeCl.sub.3 starting from 40 wt % ferric chloride (FeCl.sub.3) solution.

(63) A 76.1 wt % FeCl.sub.3 solution has been prepared, starting from a 40 wt % ferric chloride solution, by 4 times repeating the following procedure: saturating the ferric chloride (FeCl.sub.3) solution with hydrochloric acid (HCl.sub.(g)), addition of magnetite (Fe.sub.3O.sub.4) and oxidation with chlorine gas (Cl.sub.2). The concentration FeCl.sub.3 raised from 40 wt % over 53.6 wt %, 62.3 wt %, 68.8 wt % to 76.1 wt % FeCl.sub.3.

(64) Analysis starting solution: 0.55 g/l Fe(II), 199.4 g/l Fe(III), 11.4 g/l HCl and d=1.434 g/ml=40.3 wt % FeCl.sub.3

(65) Step 1 1) HCl.sub.(g)-addition to a 40 wt % FeCl.sub.3-solution until saturation 2) Fe.sub.3O.sub.4-addition to the saturated HCl/FeCl.sub.3-solution 3) Cl.sub.2-addition to the FeCl.sub.2/FeCl.sub.3-solution. Yielding to <0.5 g/l Fe(II), 302.4 g/l Fe(III), 17.5 g/l HCl and d=1.638 g/ml=53.6 wt % FeCl.sub.3

(66) Step 2 4) HCl.sub.(g)-addition to a 53.6 wt % FeCl.sub.3-solution until saturation 5) Fe.sub.3O.sub.4-addition to the saturated HCl/FeCl.sub.3-solution 6) Cl.sub.2-addition to the FeCl.sub.2/FeCl.sub.3-solution. Yielding to 1.0 g/l Fe(II), 364.2 g/l Fe(III), 13.4 g/l HCl and d=1.696 g/ml=_62.3 wt % FeCl.sub.3.

(67) Step 3 7) HCl.sub.(g)-addition to a 62.3 wt % FeCl.sub.3-solution until saturation 8) Fe.sub.3O.sub.4-addition to the saturated HCl/FeCl.sub.3-solution 9) Cl.sub.2-addition to the FeCl.sub.2/FeCl.sub.3-solution. Yielding to <0.5 g/l Fe(II), 410.5 g/l Fe(III), 20.4 g/l HCl and d=1.734 g/ml=68.8 wt % FeCl.sub.3.

(68) Step 4 10) HCl.sub.(g)) addition to a 68.8 wt % FeCl.sub.3-solution until saturation 11) Fe.sub.3O.sub.4-addition to the saturated HCl/FeCl.sub.3-solution 12)Cl.sub.2-addition to 0.95 liter of the FeCl.sub.2/FeCl.sub.3-solution at 85 C. during 2 hours. Yielding to <0.5 g/l Fe(II), 476.4 g/l Fe(III), 8.1 g/l HCl and d=1.818 g/ml=_76.1 wt % FeCl.sub.3.

(69) It is supposed that the present invention is not restricted to any form of realization described previously and that some modifications can be added to the presented examples without reappraisal of the appended claims.