Leaching agent and leaching method for platinum group elements in fe-si-p-pgm alloys

Abstract

The present application relates to a kind of Fe-Si-P-PGMs alloy in platinum group element leaching agent and leaching method, the leaching agent includes: the solution containing ferric chloride, hydrogen peroxide and hydrochloric acid.The leaching agent provided by the present application can realize the efficient leaching of platinum group element and iron element in Fe-Si-P-PGMs alloy when Fe-Si-P-PGMs alloy is leached by the design of leaching agent component, which is beneficial to the efficient recovery of platinum group element, using the leaching agent provided by the present application, the leaching rate of Pd, Pt and Rh in Fe-Si-P-PGMs alloy can reach more than 99%, more than 97% and more than 96% respectively, and the total leaching rate of platinum group metal is more than 98%.

Description

Technical Field

[0001] This invention relates to the field of comprehensive utilization technology of secondary resources of platinum group metals, specifically to a leaching agent and leaching method for platinum group elements in Fe-Si-P-PGMs alloys. Background Technology

[0002] Currently, plasma smelting for capturing platinum group metals (PGMs) from waste automotive exhaust catalysts is a more efficient, environmentally friendly, and promising pyrometallurgical enrichment technology. However, the alloys obtained by this technology are typically ferroalloys containing silicon, phosphorus, and PGMs (Fe-Si-P-PGMs). These alloys exhibit extremely high chemical stability and resistance to acid and alkali corrosion, and even aqua regia leaching only achieves partial dissolution. Therefore, efficient leaching of PGMs from iron-silicon-phosphorus alloys is a crucial step / process for better recovery.

[0003] CN111893313A discloses a method for leaching platinum group metals from iron-silicon alloys through roasting, reducing water leaching, sulfuric acid leaching, and aqua regia leaching. First, during roasting, the alloy is alkaline-melted with NaOH to convert Fe, Si, and some platinum group metals into their corresponding sodium salts. Next, during reducing water leaching, Na₂O·nSiO₂ dissolves in the water, while sodium ferrite hydrolyzes and is subsequently reduced to elemental iron with hydrazine hydrate; in this process, the platinum group metal salts are also reduced to their metallic state. Subsequently, in the sulfuric acid leaching process, the iron is leached, and solid-liquid separation is performed to obtain a leaching residue containing platinum group metals. Finally, boiling aqua regia is used to leach the platinum group metals, achieving leaching rates of 99% for Pt, 99% for Pd, and 96% for Rh.

[0004] CN113621869A discloses a two-step method for removing silicon and phosphorus from a platinum group metal-containing iron-silicon-phosphorus alloy to obtain an iron-platinum group metal alloy. The first step involves slag refining the platinum group metal-containing iron-silicon-phosphorus alloy using a slag-forming agent and iron oxides, causing silicon to enter the slag phase. After slag-metal separation, the platinum group metal-containing iron-phosphorus alloy is obtained. The second step involves vacuum refining the iron-phosphorus platinum group metal alloy obtained in the first step to remove phosphorus from the alloy, ultimately yielding the iron-platinum group metal alloy.

[0005] CN105603193A discloses a pretreatment method for recovering platinum group metals from plasma furnace enrichment material, including the following steps: (1) ball milling: ball milling the enrichment material to 100-200 mesh; (2) batching: mixing the finely ground enrichment material with NaOH and NaNO3; (3) melting: loading the mixed material into a stainless steel container and heating it in a muffle furnace to melt; (4) dissolving: transferring the melt into a glass beaker, adding 4-6 mol / L hydrochloric acid, heating to dissolve, with a platinum dissolution rate greater than 95%, a palladium dissolution rate greater than 95%, and a rhodium dissolution rate greater than 92%.

[0006] CN112501439A discloses a pretreatment method for precious metal-containing ferroalloys, comprising the following steps: A. Powdering: processing the precious metal-containing ferroalloy into powder with a particle size of 30-300 mesh; B. Pressure alkaline leaching: adding alkali, heating, and pressurizing the precious metal-containing ferroalloy powder obtained in step A to leach silicon from the alloy; C. Liquid-solid separation: cooling and filtering the liquid after the pressure alkaline leaching reaction in step B to obtain a silicon-containing leachate and an alkaline leaching residue; D. Acid dissolution to remove iron: adding hydrochloric acid to the alkaline leaching residue obtained in step C, followed by adding water to make the liquid-solid ratio 10:1, and dissolving at room temperature for 4 hours; E. Liquid-solid separation: filtering the liquid after the acid dissolution to remove iron in step D to obtain an iron-containing leachate and a precious metal-enriched material.

[0007] However, existing platinum group element recovery processes in Fe-Si-P-PGMs alloys still suffer from low leaching rates of platinum group elements, demanding leaching conditions for the leaching agents used, high operational risks, and the potential generation of toxic NO. x Problems include large volumes of gas and wastewater. Summary of the Invention

[0008] In view of the problems existing in the prior art, the purpose of this invention is to provide a leaching agent and leaching method for platinum group elements in Fe-Si-P-PGMs alloys, so as to solve the problems of low leaching rate, complex leaching process, and NO generation during the leaching process of current Fe-Si-P-PGMs alloys. x The problems include toxic gases, long process flow, and large wastewater volume.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a leaching agent for platinum group elements in Fe-Si-P-PGMs alloys, the leaching agent comprising:

[0011] A solution containing ferric chloride, hydrogen peroxide, and hydrochloric acid.

[0012] The leaching agent provided by this invention utilizes ferric chloride to reduce the amount of hydrochloric acid required during the leaching process while providing synergistic oxidation. Hydrogen peroxide oxidizes platinum group metals, and hydrochloric acid provides favorable conditions for the formation of platinum group metal complexes. Through the synergistic effect of ferric chloride, hydrogen peroxide, and hydrochloric acid, the Fe3Si, Fe5Si3, and Fe2P phases in the alloy are effectively destroyed, achieving efficient release of platinum group elements from the Fe-Si-P-PGMs alloy and high-efficiency recovery of these elements. Using the leaching agent provided by this invention, the leaching rates of Pd, Pt, and Rh can reach over 99%, over 97%, and over 96%, respectively, with a total leaching rate of over 98% for the platinum group metals. Furthermore, it also exhibits good leaching effect on Fe in the Fe-Si-P-PGMs alloy, with a leaching rate reaching approximately 100%.

[0013] The Fe-Si-P-PGMs alloy described in this invention includes, but is not limited to, plasma-melted iron smelting material generated from plasma-melted iron smelting of waste automotive exhaust catalysts. The main phases of the plasma-melted iron smelting material generated from plasma-melted iron smelting of waste automotive exhaust catalysts include Fe3Si, Fe5Si3, and Fe2P. When treated with traditional thermochemical methods, the solubility of iron by H2SO4, HNO3, and HCl is relatively poor due to the inhibitory effect of silicon, especially for PGMs. Aqua regia has a better dissolving effect, but the harsh operating conditions are clearly unsuitable for sustainable metallurgy.

[0014] The leaching agent used in this invention is more environmentally friendly and effective, and under the action of mechanochemistry, it can more effectively destroy the Fe3Si, Fe5Si3 and Fe2P phases, which is beneficial to the leaching and recovery of Pd, Pt and Rh.

[0015] As a preferred embodiment of the present invention, the concentration of ferric chloride in the leaching agent is 0.7-1 mol / L, the concentration of hydrogen peroxide is 2.5-3 mol / L, and the concentration of hydrogen chloride is 2-3 mol / L.

[0016] In this invention, the concentration of each material in the leaching agent is the same as the concentration of the solute in the solution. For example, the concentration of ferric chloride is the same as the concentration of ferric chloride in the solution, and so on for other components.

[0017] In this invention, the concentration of ferric chloride in the leachate is 0.7-1 mol / L, for example, it can be 0.7 mol / L, 0.71 mol / L, 0.72 mol / L, 0.73 mol / L, 0.74 mol / L, 0.75 mol / L, 0.76 mol / L, 0.77 mol / L, 0.78 mol / L, 0.79 mol / L, 0.8 mol / L, 0.81 mol / L, 0.82 mol / L, 0.83 mol / L, 0.84 mol / L, 0... The values ​​are 0.85 mol / L, 0.86 mol / L, 0.87 mol / L, 0.88 mol / L, 0.89 mol / L, 0.9 mol / L, 0.91 mol / L, 0.92 mol / L, 0.93 mol / L, 0.94 mol / L, 0.95 mol / L, 0.96 mol / L, 0.97 mol / L, 0.98 mol / L, 0.99 mol / L, or 1 mol / L, but are not limited to the listed values. Other unlisted values ​​within this range also apply.

[0018] In this invention, the concentration of hydrogen peroxide in the leaching agent is 2.5-3 mol / L, for example, it can be 2.5 mol / L, 2.52 mol / L, 2.54 mol / L, 2.56 mol / L, 2.58 mol / L, 2.6 mol / L, 2.62 mol / L, 2.64 mol / L, 2.66 mol / L, 2.78 mol / L, 2.7 mol / L, 2.72 mol / L, 2.74 mol / L, 2.76 mol / L, 2.78 mol / L, 2.8 mol / L, 2.82 mol / L, 2.84 mol / L, 2.86 mol / L, 2.88 mol / L, 2.9 mol / L, 2.92 mol / L, 2.94 mol / L, 2.96 mol / L, 2.98 mol / L, or 3 mol / L, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0019] In this invention, the concentration of hydrogen chloride in the leaching agent is 2-3 mol / L, for example, it can be 2 mol / L, 2.05 mol / L, 2.1 mol / L, 2.15 mol / L, 2.2 mol / L, 2.25 mol / L, 2.3 mol / L, 2.35 mol / L, 2.4 mol / L, 2.45 mol / L, 2.5 mol / L, 2.55 mol / L, 2.6 mol / L, 2.65 mol / L, 2.7 mol / L, 2.75 mol / L, 2.8 mol / L, 2.85 mol / L, 2.9 mol / L, 2.95 mol / L, or 3 mol / L, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0020] For example, the leaching agent is prepared by mixing ferric chloride, hydrogen peroxide, and hydrochloric acid with a solvent according to a formula.

[0021] In this invention, the solvent can be water or other solvents commonly used in the art that do not affect the leaching process.

[0022] In a second aspect, the present invention provides a method for leaching platinum group elements in Fe-Si-P-PGMs alloys, the leaching method comprising mixing the leaching agent described in the first aspect with the Fe-Si-P-PGMs alloy for mechanical activation leaching.

[0023] As a preferred technical solution of the present invention, the liquid-to-solid ratio of the leaching agent and the Fe-Si-P-PGMs alloy during mixing is (25-40):1, for example, it can be 25:1, 26:1, 27:1, 28:1, 29:1, 30:1, 31:1, 32:1, 33:1, 34:1, 35:1, 36:1, 37:1, 38:1, 39:1 or 40:1, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable. The unit of liquid-to-solid ratio is mL / g.

[0024] As a preferred technical solution of the present invention, the mass ratio of Fe-Si-P-PGMs alloy to grinding balls in the mechanical activation leaching is 1:(40-60), for example, it can be 1:40, 1:41, 1:42, 1:43, 1:44, 1:45, 1:46, 1:47, 1:48, 1:49, 1:50, 1:51, 1:52, 1:53, 1:54, 1:55, 1:56, 1:57, 1:58, 1:59 or 1:60, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0025] As a preferred technical solution of the present invention, the rotation speed in the mechanical activation leaching is ≥500 r / min, for example, it can be 500 r / min, 550 r / min, 600 r / min, 650 r / min, 700 r / min, 750 r / min, 800 r / min, 850 r / min, 900 r / min, 950 r / min or 1000 r / min, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0026] In this invention, when the rotation speed is too low during the leaching process, the reaction effect between the alloy and the leaching agent will be significantly reduced, resulting in a significant decrease in the leaching of platinum group elements in the alloy. For example, when the rotation speed is reduced to 300 r / min during the leaching process, the leaching rates of Pd, Pt, and Rh all decrease to below 60%. However, a higher rotation speed is not necessarily better during the leaching process. When the rotation speed is too high, energy consumption will increase, and the requirements for the equipment will also increase significantly. Therefore, in this invention, the rotation speed in mechanical activation is preferably 500-800 r / min. The rotation speed in the mechanical activation leaching is 500-800 r / min, for example, it can be 500 r / min, 510 r / min, 520 r / min, 530 r / min, 540 r / min, or 550 r / min. The speeds are n, 560 r / min, 570 r / min, 580 r / min, 590 r / min, 600 r / min, 610 r / min, 620 r / min, 630 r / min, 640 r / min, 650 r / min, 660 r / min, 670 r / min, 680 r / min, 690 r / min, 700 r / min, 710 r / min, 720 r / min, 730 r / min, 740 r / min, 750 r / min, 760 r / min, 770 r / min, 780 r / min, 790 r / min, or 800 r / min, etc., but are not limited to the listed values. Other unlisted values ​​within this range also apply.

[0027] In this invention, the mechanical activation leaching can be carried out using a planetary ball mill or other commonly used mechanical activation ball milling equipment in the art, such as a drum mill, a stirred ball mill, or a vibratory mill. When a planetary ball mill is used, the specified rotational speed is its own rotation speed.

[0028] As a preferred technical solution of the present invention, the mechanical activation leaching time is ≥4h, for example, it can be 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h or 10h, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0029] In this invention, a good leaching rate for Pd, Pt and Rh can be guaranteed when the mechanical activation leaching time reaches 4 hours, with leaching rates of over 99%, over 97% and over 96% respectively. Excessively extending the mechanical activation leaching time will lead to increased energy consumption of the equipment. Therefore, this invention further selects the mechanical activation leaching time as 4-5 hours.

[0030] As a preferred technical solution of the present invention, the mechanical activation leaching time is 4-5 hours, for example, it can be 4 hours, 4.1 hours, 4.2 hours, 4.3 hours, 4.4 hours, 4.5 hours, 4.6 hours, 4.7 hours, 4.8 hours, 4.9 hours or 5 hours, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0031] As a preferred technical solution of the present invention, the leaching method includes mechanically activating leaching by mixing the leaching agent and the Fe-Si-P-PGMs alloy;

[0032] The liquid-to-solid ratio of the leaching agent and the Fe-Si-P-PGMs alloy during mixing is (25-40):1, with the unit of liquid-to-solid ratio being mL / g; the mass ratio of the Fe-Si-P-PGMs alloy and the grinding balls in the mechanical activation leaching is 1:(40-60); the rotation speed in the mechanical activation leaching is 500-800 r / min; and the mechanical activation leaching time is 4-5 h.

[0033] Compared with existing technical solutions, the present invention has the following beneficial effects:

[0034] (1) The leaching agent provided by the present invention is a ternary leaching system composed of HCl, H2O2 and FeCl3, which is significantly different from the typical aqua regia leaching system. It does not produce nitrogen oxides that are harmful to the environment, and the leaching only involves one step, making the process simple and easy to implement.

[0035] (2) The leaching method provided by the present invention has a high leaching rate for platinum group metals in Fe-Si-P-PGMs alloy. The leaching rates of Pd, Pt and Rh can reach more than 99%, more than 97% and more than 96%, respectively, and the total leaching rate of platinum group metals is more than 98%. Furthermore, Fe in Fe-Si-P-PGMs alloy also has a high leaching rate, which can reach 100%. Attached Figure Description

[0036] Figure 1 This is the XRD pattern of the plasma-melted iron catcher material in the embodiments of the present invention;

[0037] Figure 2 This is an electron probe microanalysis diagram of Fe element in plasma-melted iron catcher material in an embodiment of the present invention;

[0038] Figure 3 This is an electron probe microanalysis diagram of Si element in plasma-melted iron catcher material in an embodiment of the present invention;

[0039] Figure 4 This is an electron probe microanalysis diagram of the phosphorus element in the plasma-melted iron collecting material in an embodiment of the present invention;

[0040] Figure 5 This is an electron probe microanalysis diagram of Pd element in plasma-melted iron catcher material in an embodiment of the present invention;

[0041] Figure 6 This is an electron probe microanalysis diagram of the Rh element in the plasma-melted iron catcher material in an embodiment of the present invention;

[0042] Figure 7 This is an electron probe microanalysis diagram of Pt element distribution in plasma-melted iron catcher material in an embodiment of the present invention.

[0043] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims. Detailed Implementation

[0044] To better illustrate the present invention and facilitate understanding of its technical solutions, typical but non-limiting embodiments of the present invention are as follows:

[0045] In a specific embodiment of the present invention, the Fe-Si-P-PGMs alloy is sourced from plasma-melted iron ore. This source is only for clearly illustrating the technical solution of the present invention and is not considered as a further limitation of the present invention.

[0046] In this specific embodiment of the invention, plasma-melted iron ore aggregate is used as the leaching raw material to evaluate the leaching performance of the leaching agent in this invention, and to illustrate the technical effects of the leaching method of this invention. The chemical composition of the plasma-melted iron ore aggregate used is shown in Table 1 below:

[0047] Table 1

[0048]

[0049] Table 1 shows that the Fe-Si-P-PGMs alloy mainly contains Fe (75 wt.%), Si (15 wt.%), P (4 wt.%), and PGMs (2 wt.% Pd, 0.1 wt.% Pt, and 0.06 wt.% Rh). This indicates that Fe is a PGMs-attracting agent and also the most important element in the alloy. Si mainly comes from cordierite (Mg2Al4Si5O3), a catalyst carrier from waste automotive exhaust. 18 Its presence makes alloys difficult to smelt. P, mainly derived from lubricating oil and gasoline, is one of the culprits behind the deterioration of catalyst performance.

[0050] Depend on Figures 1 to 7 It is known that the Fe-Si-P-PGMs alloy used in the specific embodiments of the present invention has the following properties: it readily generates substances such as Fe5Si3, Fe3Si and Fe2P during the high-temperature collection process;

[0051] Furthermore, based on the elemental distribution diagram of plasma-melted iron ore aggregate ( Figures 2-7 As can be seen, Fe and Si are the most widely and evenly distributed elements because they have the highest content and form Fe3Si and Fe5Si3 compounds. P does not combine with Fe and Si simultaneously, but only forms Fe2P with Fe and segregates at the grain boundaries of the alloy. Pd is mainly concentrated at the grain boundaries of the alloy, while Pt and Rh are more evenly distributed in the matrix.

[0052] Specific examples are as follows, all of which use the aforementioned plasma melting iron ore collecting material.

[0053] Example 1

[0054] This embodiment provides a leaching agent for platinum group elements in smelted iron catcher, its preparation process, and leaching method, specifically including:

[0055] The leaching agent comprises: 1 mol / L ferric chloride, 2.5 mol / L hydrogen peroxide, and 2 mol / L hydrogen chloride; specifically, it is obtained by mixing ferric chloride, hydrogen peroxide, and hydrochloric acid with a solvent according to the formula, ensuring that the concentration of ferric chloride in the obtained solution is 1 mol / L, the concentration of hydrogen peroxide is 2.5 mol / L, and the concentration of hydrogen chloride is 2 mol / L, and the solvent used is deionized water.

[0056] The specific leaching method involves mixing the leaching agent with plasma-melted iron ore and then mechanically activating and leaching it.

[0057] The liquid-to-solid ratio in the mixture is 30:1 (mL / g); the mechanical activation leaching is carried out using a planetary ball mill; the mass ratio of plasma-melted iron ore collector to grinding balls in the mechanical activation leaching is 1:50; the rotation speed in the mechanical activation leaching is 700 r / min; and the mechanical activation leaching time is 4.5 h.

[0058] After leaching, solid-liquid separation was performed, and the elemental content of the resulting leachate was analyzed by ICP. The leaching rates of platinum group elements and iron were calculated and are detailed in Table 1.

[0059] Example 2

[0060] This embodiment provides a leaching agent for platinum group elements in smelted iron catcher, its preparation process, and leaching method, specifically including:

[0061] The leaching agent comprises: 0.7 mol / L ferric chloride, 3 mol / L hydrogen peroxide, and 3 mol / L hydrogen chloride; specifically, it is obtained by mixing ferric chloride, hydrogen peroxide, and hydrochloric acid with a solvent according to the formula, ensuring that the concentration of ferric chloride in the obtained solution is 0.7 mol / L, the concentration of hydrogen peroxide is 3 mol / L, and the concentration of hydrogen chloride is 3 mol / L, and the solvent used is deionized water.

[0062] The specific leaching method involves mixing the leaching agent with plasma-melted iron ore and then mechanically activating and leaching it.

[0063] The liquid-to-solid ratio in the mixture is 25:1 (mL / g); the mechanical activation leaching is carried out using a planetary ball mill; the mass ratio of plasma-melted iron ore collector to grinding balls in the mechanical activation leaching is 1:60; the rotation speed in the mechanical activation leaching is 500 r / min; and the mechanical activation leaching time is 4 h.

[0064] After leaching, solid-liquid separation was performed, and the elemental content of the resulting leachate was analyzed by ICP. The leaching rates of platinum group elements and iron were calculated and are detailed in Table 1.

[0065] Example 3

[0066] This embodiment provides a leaching agent for platinum group elements in smelted iron catcher, its preparation process, and leaching method, specifically including:

[0067] The leaching agent comprises: 0.8 mol / L ferric chloride, 2.8 mol / L hydrogen peroxide, and 2.5 mol / L hydrogen chloride; specifically, it is obtained by mixing ferric chloride, hydrogen peroxide, and hydrochloric acid with a solvent according to the formula, ensuring that the concentration of ferric chloride in the obtained solution is 0.8 mol / L, the concentration of hydrogen peroxide is 2.8 mol / L, and the concentration of hydrogen chloride is 2.5 mol / L, and the solvent used is deionized water.

[0068] The specific leaching method involves mixing the leaching agent with plasma-melted iron ore and then mechanically activating and leaching it.

[0069] The liquid-to-solid ratio in the mixture is 40:1 (mL / g); the mechanical activation leaching is carried out using a planetary ball mill; the mass ratio of plasma-melted iron ore collector to grinding balls in the mechanical activation leaching is 1:40; the rotation speed in the mechanical activation leaching is 800 r / min; and the mechanical activation leaching time is 5 h.

[0070] After leaching, solid-liquid separation was performed, and the elemental content of the resulting leachate was analyzed by ICP. The leaching rates of platinum group elements and iron were calculated and are detailed in Table 1.

[0071] Example 4

[0072] The only difference from Example 1 is that the concentration of ferric chloride is 1.5 mol / L.

[0073] After leaching, solid-liquid separation was performed, and the elemental content of the resulting leachate was analyzed by ICP. The leaching rates of platinum group elements and iron were calculated and are detailed in Table 1.

[0074] Example 5

[0075] The only difference from Example 1 is that the concentration of ferric chloride is 3 mol / L.

[0076] After leaching, solid-liquid separation was performed, and the elemental content of the resulting leachate was analyzed by ICP. The leaching rates of platinum group elements and iron were calculated and are detailed in Table 1.

[0077] Example 6

[0078] The only difference from Example 1 is that the concentration of hydrogen chloride is 5 mol / L.

[0079] After leaching, solid-liquid separation was performed, and the elemental content of the resulting leachate was analyzed by ICP. The leaching rates of platinum group elements and iron were calculated and are detailed in Table 1.

[0080] Example 7

[0081] The only difference from Example 1 is that the concentration of hydrogen peroxide is 4 mol / L.

[0082] After leaching, solid-liquid separation was performed, and the elemental content of the resulting leachate was analyzed by ICP. The leaching rates of platinum group elements and iron were calculated and are detailed in Table 1.

[0083] Example 8

[0084] The only difference from Example 1 is that the leaching agent also contains 1 mol / L of sodium chloride.

[0085] After leaching, solid-liquid separation was performed, and the elemental content of the resulting leachate was analyzed by ICP. The leaching rates of platinum group elements and iron were calculated and are detailed in Table 1.

[0086] Example 9

[0087] The only difference from Example 1 is that the leaching process is conventional heating and stirring leaching, the leaching temperature is 90°C, the time is 4 hours, the stirring speed during the leaching process is 800 r / min, and the liquid-solid ratio remains unchanged during leaching, that is, the liquid-solid ratio mL / g is 30:1.

[0088] Example 10

[0089] The only difference from Example 1 is that the leaching process is conventional heating and stirring leaching (the leaching agent used in the leaching is a mixed acid-aqua regia, the concentration of hydrochloric acid in the mixed acid is 9 mol / L, and the concentration of nitric acid is 3.5 mol / L), the leaching temperature is 90℃, the time is 4h, the stirring speed during the leaching process is 800r / min, and the liquid-solid ratio remains unchanged during the leaching, that is, the liquid-solid ratio mL / g is 30:1.

[0090] Example 11

[0091] The only difference from Example 1 is that the leaching process is conventional heating and stirring leaching (the leaching agent used in the leaching is 18 mol / L sulfuric acid), the leaching temperature is 90°C, the time is 4 hours, the stirring speed during the leaching process is 800 r / min, and the liquid-solid ratio remains unchanged during the leaching, that is, the liquid-solid ratio mL / g is 30:1.

[0092] Example 12

[0093] The only difference from Example 1 is that the leaching process is conventional heating and stirring leaching (the leaching agent used in the leaching is 14 mol / L nitric acid), the leaching temperature is 90°C, the time is 4 hours, the stirring speed during the leaching process is 800 r / min, and the liquid-solid ratio remains unchanged during the leaching, that is, the liquid-solid ratio mL / g is 30:1.

[0094] Example 13

[0095] The only difference from Example 1 is that the leaching process is conventional heating and stirring leaching (the leaching agent used in the leaching is 12 mol / L hydrochloric acid), the leaching temperature is 90°C, the time is 4 hours, the stirring speed during the leaching process is 800 r / min, and the liquid-solid ratio remains unchanged during the leaching, that is, the liquid-solid ratio mL / g is 30:1.

[0096] After leaching, solid-liquid separation was performed, and the elemental content of the resulting leachate was analyzed by ICP. The leaching rates of platinum group elements and iron were calculated and detailed in Table 2.

[0097] Table 2

[0098]

[0099]

[0100] The results of the above embodiments show that when the leaching agent provided by the present invention is not used, changing the concentration of ferric chloride, increasing the concentration of hydrogen chloride, increasing the concentration of hydrogen peroxide, or introducing the auxiliary agent sodium chloride will significantly reduce the leaching effect of the leaching agent of the present invention on platinum group elements. Furthermore, when the leaching agent of the present invention is used, conventional stirring and heating leaching in the art cannot achieve the leaching effect of the present invention. It can be seen that the leaching agent provided by the present invention, through the design of the leaching agent components and the combination with a specific mechanical activation leaching process, can ensure the efficient leaching of platinum group elements and iron elements in Fe-Si-P-PGMs alloys, which is beneficial to the efficient recovery of platinum group elements.

[0101] The present invention is described in detail through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the components used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0102] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0103] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0104] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for leaching platinum group elements in Fe-Si-P-PGMs alloys, characterized in that, The leaching agent used is a platinum group element leaching agent for Fe-Si-P-PGMs alloys, wherein the leaching agent comprises: A solution containing ferric chloride, hydrogen peroxide, and hydrochloric acid; wherein the concentration of ferric chloride in the leaching agent is 0.7-1 mol / L, the concentration of hydrogen peroxide is 2.5-3 mol / L, and the concentration of hydrogen chloride is 2-3 mol / L; The leaching method using a leaching agent for platinum group elements in the Fe-Si-P-PGMs alloy includes the following steps: The leaching agent and Fe-Si-P-PGMs alloy are mixed and mechanically activated for leaching. The liquid-to-solid ratio of the leaching agent and the Fe-Si-P-PGMs alloy during mixing is (25-40):1, with the unit of liquid-to-solid ratio being mL / g; The mass ratio of Fe-Si-P-PGMs alloy to grinding balls in the mechanically activated leaching process is 1:(40-60); The rotation speed during the mechanical activation leaching is ≥500 r / min.

2. The leaching method as described in claim 1, characterized in that, The rotation speed during the mechanical activation leaching is 500-800 r / min.

3. The leaching method as described in claim 1, characterized in that, The mechanical activation leaching time is ≥4 h.

4. The leaching method as described in claim 3, characterized in that, The mechanical activation leaching time is 4-5 hours.

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