Leaching agent and leaching method for platinum group elements in Fe-Si-P-PGMs alloy

Abstract

The invention relates to a leaching agent and a leaching method for platinum group elements in Fe-Si-P-PGMs alloy. The leaching agent comprises a solution containing ferric chloride, hydrogen peroxide and hydrochloric acid. According to the leaching agent provided by the invention, through the design of the components of the leaching agent, when the leaching agent is used for leaching the Fe-Si-P-PGMs alloy, the high-efficiency leaching of platinum group elements and iron elements in the Fe-Si-P-PGMs alloy can be realized, and the high-efficiency recovery of the platinum group elements is facilitated; the leaching rates of Pd, Pt and Rh in the Fe-Si-P-PGMs alloy can reach 99% or above, 97% or above and 96% or above correspondingly, and the total leaching rate of platinum group metal is 98% or above.

Description

Technical Field

[0001] The invention relates to the technical field of comprehensive utilization of secondary resources of platinum group metals, and in particular to a leaching agent and a leaching method for platinum group elements in a Fe-Si-P-PGMs alloy. Background Art

[0002] At present, the technology of plasma smelting iron to capture platinum group metals in waste automobile exhaust catalysts is a more efficient, more environmentally friendly and more potential pyrometallurgical enrichment technology. However, the alloy obtained by this technology is usually an iron alloy containing silicon, phosphorus and platinum group metals (Fe-Si-P-PGMs). This type of alloy has extremely strong chemical stability and strong resistance to acid and alkali corrosion. Even with aqua regia leaching, only partial dissolution can be achieved. In order to better recover platinum group metals, efficient leaching of platinum group metals in iron-silicon-phosphorus alloys is an important key link / process.

[0003] For example, CN111893313A discloses that the leaching of platinum group metals in iron silicon alloy is finally achieved by roasting, reducing water leaching, sulfuric acid leaching and aqua regia leaching. First, during the roasting process, the alloy is alkaline smelted with NaOH to convert Fe, Si and part of the platinum group metals into corresponding sodium salts. Then, during the reducing water leaching process, Na2O·nSiO2 is dissolved in water, and sodium ferrite is hydrolyzed and then reduced to elemental iron with hydrazine hydrate, and the platinum group metal salt is also reduced to a metallic state during the process. Subsequently, in the sulfuric acid leaching process, the iron is leached and the solid-liquid separation is performed to obtain a leached slag containing platinum group metals. Finally, the platinum group metals are leached with boiling aqua regia, and the leaching rates of Pt, Pd and Rh are 99%, 99% and 96% respectively.

[0004] CN113621869A discloses a two-step method for removing silicon and phosphorus from an iron-silicon-phosphorus alloy containing platinum group metals to obtain an iron-platinum group metal alloy. In the first step, a slag-forming agent and iron oxide are used to slag-form and refine the iron-silicon-phosphorus alloy containing platinum group metals, so that silicon enters the slag phase, and the iron-phosphorus alloy containing platinum group metals is obtained after slag-gold separation. In the second step, the iron-phosphorus platinum group metal alloy obtained in the first step is vacuum-refined to remove phosphorus from the alloy, and finally an iron-platinum group metal alloy is obtained.

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

[0006] CN112501439A discloses a method for pretreating a ferroalloy containing precious metals, which is carried out in sequence according to the following steps: A. powdering: processing the ferroalloy containing precious metals into a powder material with a particle size of 30-300 meshes; B. pressurized alkali leaching: adding alkali, heating, and pressurizing the ferroalloy powder material containing precious metals obtained in step A to leach silicon from the alloy; C. liquid-solid separation: cooling and filtering the feed liquid after the pressurized alkali leaching reaction in step B to obtain a silicon-containing leaching liquid and an alkaline leaching residue; D. acid dissolution and iron removal: adding hydrochloric acid to the alkaline leaching residue obtained in step C, and then adding water to make the liquid-solid ratio 10:1, and dissolving at room temperature for 4 hours; E. liquid-solid separation: filtering the feed liquid after the acid dissolution and iron removal reaction in step D to obtain an iron-containing leaching liquid and a precious metal-enriched material.

[0007] However, the existing PGE recovery process in Fe-Si-P-PGMs alloy still has the following problems: low PGE leaching rate, harsh leaching conditions of the leaching agent used, high operating risks and easy generation of toxic NO. x Problems such as large amounts of gas and wastewater. Summary of the invention

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

[0009] To achieve this object, the present invention adopts the following technical solutions:

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

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

[0012] The leaching agent provided by the present invention can play a role in reducing the amount of hydrochloric acid used and providing synergistic oxidation during the leaching process, hydrogen peroxide can play a role in oxidizing platinum group metals, and hydrochloric acid can play a role in providing favorable conditions for the existence of platinum group metal complexes, and then through the synergistic effect of ferric chloride, hydrogen peroxide and hydrochloric acid, the Fe3Si, Fe5Si3 and Fe2P phases in the alloy are effectively destroyed, and the effective release of platinum group elements in the Fe-Si-P-PGMs alloy is achieved, and the efficient recovery of platinum group elements in the Fe-Si-P-PGMs alloy is achieved. Using the leaching agent provided by the present invention, 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, it also has a good leaching effect on Fe in the Fe-Si-P-PGMs alloy, and the leaching rate can reach 100%.

[0013] The Fe-Si-P-PGMs alloy of the present invention includes but is not limited to the plasma-melted iron capture material produced in the plasma-melted iron capture waste automobile exhaust catalyst. The main phases of the plasma-melted iron capture material produced in the plasma-melted iron capture waste automobile exhaust catalyst include Fe3Si, Fe5Si3 and Fe2P, etc. When it is treated by traditional thermochemistry, due to the inhibitory effect of silicon, the solubility of H2SO4, HNO3 and HCl to iron is relatively poor, especially for the dissolution of PGMs, the dissolution effect of aqua regia is better, but the harsh operating conditions are obviously not suitable for sustainable metallurgy.

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

[0015] As a preferred technical solution 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 the present invention, the concentration of each material in the leaching agent is the concentration corresponding to the solute in the solution. Specifically, the concentration of ferric chloride is the concentration of ferric chloride in the solution, and the same applies to other components.

[0017] In the present invention, the concentration of ferric chloride in the leaching agent is 0.7-1 mol / L, for example, 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, 0.85 mol / L, 0.86 mol / L, 0.87 mol / L, 0.88 mol / L, 0.89 mol / L, 0.90 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, 0.10 0.85mol / L, 0.86mol / L, 0.87mol / L, 0.88mol / L, 0.89mol / L, 0.9mol / L, 0.91mol / L, 0.92mol / L, 0.93mol / L, 0.94mol / L, 0.95mol / L, 0.96mol / L, 0.97mol / L, 0.98mol / L, 0.99mol / L or 1mol / L, but not limited to the listed values, other values ​​not listed in the range are also applicable.

[0018] In the present 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, 2.82 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, and other values ​​not listed within the range are equally applicable.

[0019] In the present 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, and other values ​​not listed within the range are equally applicable.

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

[0021] In the present invention, the solvent may 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 a Fe-Si-P-PGMs alloy, 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, but is not limited to the listed values, and other unlisted values ​​within the 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, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

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

[0026] In the present invention, when the rotation speed is too low during the leaching process, the reaction effect of the alloy and the leaching agent will be significantly reduced, resulting in a significant reduction in the leaching of platinum group elements in the alloy. For example, when the rotation speed is reduced to 300r / min during the leaching process, the leaching rates of Pd, Pt and Rh are all reduced to below 60%. However, the higher the rotation speed during the leaching process, the better. When the rotation speed is too high, the energy consumption will increase and the requirements for the equipment will also be significantly increased. Therefore, in the present invention, the rotation speed in the mechanical activation is further preferably 500-800r / min. The rotation speed in the mechanical activation leaching is 500-800r / min, for example, it can be 500r / min, 510r / min, 520r / min, 530r / min, 540r / min, 550r / min r / min, but not limited to the listed values, other values ​​not listed in the range are equally applicable.

[0027] In the present invention, the mechanical activation leaching can be carried out by a planetary ball mill, or other commonly used mechanical activation ball milling equipment in the art, such as a drum mill, a stirring ball mill, a vibration mill, etc. When a planetary ball mill is used, the limited rotation speed is the rotation speed.

[0028] As a preferred technical solution of the present invention, the time of mechanical activation leaching 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, and other unlisted values ​​within the range are also applicable.

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

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

[0031] As a preferred technical solution of the present invention, the leaching method comprises mixing a leaching agent and a Fe-Si-P-PGMs alloy to perform mechanical activation leaching;

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

[0033] Compared with the prior art 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 and does not produce nitrogen oxides that are harmful to the environment. Moreover, the leaching process only includes one step, and the process is 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 alloys. The leaching rates of Pd, Pt and Rh can reach more than 99%, more than 97% and more than 96%, respectively. The total leaching rate of platinum group metals is more than 98%. Furthermore, the leaching rate of Fe in Fe-Si-P-PGMs alloy is also relatively high, which can reach 100%. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is the XRD diagram of the plasma smelting iron collection material in the embodiment of the present invention;

[0037] Figure 2 It is an electron probe distribution diagram of the Fe element in the plasma smelting iron collection material in an embodiment of the present invention;

[0038] Figure 3 This is an electron probe distribution diagram of Si element in the plasma smelting iron capture material in an embodiment of the present invention;

[0039] Figure 4 is an electron probe distribution diagram of the P element in the plasma smelting iron collection material in an embodiment of the present invention;

[0040] Figure 5 is an electron probe distribution diagram of the Pd element in the plasma smelting iron capture material in an embodiment of the present invention;

[0041] Figure 6 is an electron probe distribution diagram of the Rh element in the plasma smelting iron capture material in an embodiment of the present invention;

[0042] Figure 7 It is an electron probe distribution diagram of the Pt element in the plasma smelting iron capture material in the embodiment of the present invention.

[0043] The present invention is further described in detail below. However, the following examples are only 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 shall be subject to the claims. DETAILED DESCRIPTION

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

[0045] In a specific embodiment of the present invention, the source of the Fe-Si-P-PGMs alloy is plasma smelting iron capture material, which is only for the purpose of clearly illustrating the technical solution of the present invention and is not regarded as a further limitation of the present invention.

[0046] Specific implementation methods of the present invention specifically use plasma smelting iron capture material as the leaching raw material to evaluate the leaching performance of the leaching agent in the present invention, and illustrate the technical effect of the leaching method of the present invention. The chemical composition of the plasma smelting iron capture material used is as shown in Table 1 below:

[0047] Table 1

[0048]

[0049] As shown in Table 1, the Fe-Si-P-PGMs alloy mainly contains Fe (75wt.%), Si (15wt.%), P (4wt.%) and PGMs (2wt.% Pd, 0.1wt.% Pt and 0.06wt.% Rh). It can be seen that Fe is a collector of PGMs and is also the main element of the alloy. Si mainly comes from cordierite (Mg2Al4Si5O 18 ), its appearance makes the alloy difficult to smelt. P mainly comes from lubricating oil and gasoline, and is one of the culprits for the deterioration of catalyst performance.

[0050] Depend on Figures 1 to 7 It can be seen that the Fe-Si-P-PGMs alloy used in the specific embodiment of the present invention has the following properties: substances such as Fe5Si3, Fe3Si and Fe2P are easily generated during the high-temperature capture process;

[0051] Further, according to the element distribution diagram of plasma smelting iron capture material ( Figure 2-Figure 7 ) It can be seen that the distribution of Fe and Si elements is the most extensive and uniform, because they have the highest content and form Fe3Si and Fe5Si3 compounds between them. The P element does not combine with Fe and Si at the same time, 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] The specific examples are as follows, all of which are carried out using the plasma smelting iron capture material of the aforementioned composition.

[0053] Example 1

[0054] This embodiment provides a leaching agent for platinum group elements in smelting iron capture material, a preparation process and a leaching method thereof, which specifically include:

[0055] The leaching agent comprises: 1 mol / L ferric chloride, 2.5 mol / L hydrogen peroxide, and 2 mol / L hydrogen chloride; specifically, the ferric chloride, hydrogen peroxide, and hydrochloric acid are mixed with a solvent according to a formula, and the concentration of ferric chloride in the obtained solution is ensured to be 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 is to mix the leaching agent and the plasma smelted iron capture material for mechanical activation leaching;

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

[0058] After leaching, the solid-liquid separation was performed and the obtained leaching solution was analyzed for element content by ICP. The calculated leaching rates of platinum group elements and iron elements are shown in Table 1.

[0059] Example 2

[0060] This embodiment provides a leaching agent for platinum group elements in smelting iron capture material, a preparation process and a leaching method thereof, which specifically include:

[0061] The leaching agent includes: 0.7 mol / L ferric chloride, 3 mol / L hydrogen peroxide, and 3 mol / L hydrogen chloride; specifically, the ferric chloride, hydrogen peroxide, and hydrochloric acid are mixed with a solvent according to a 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 is to mix the leaching agent and the plasma smelted iron capture material for mechanical activation leaching;

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

[0064] After leaching, the solid-liquid separation was performed and the obtained leaching solution was analyzed for element content by ICP. The calculated leaching rates of platinum group elements and iron elements are shown in Table 1.

[0065] Example 3

[0066] This embodiment provides a leaching agent for platinum group elements in smelting iron capture material, a preparation process and a leaching method thereof, which specifically include:

[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, the ferric chloride, hydrogen peroxide, and hydrochloric acid are mixed with a solvent according to a 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 is to mix the leaching agent and the plasma smelted iron capture material for mechanical activation leaching;

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

[0070] After leaching, the solid-liquid separation was performed and the obtained leaching solution was analyzed for element content by ICP. The calculated leaching rates of platinum group elements and iron elements are shown 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, the solid-liquid separation was performed and the obtained leaching solution was analyzed for element content by ICP. The calculated leaching rates of platinum group elements and iron elements are shown 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, the solid-liquid separation was performed and the obtained leaching solution was analyzed for element content by ICP. The calculated leaching rates of platinum group elements and iron elements are shown 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, the solid-liquid separation was performed and the obtained leaching solution was analyzed for element content by ICP. The calculated leaching rates of platinum group elements and iron elements are shown 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, the solid-liquid separation was performed and the obtained leaching solution was analyzed for element content by ICP. The calculated leaching rates of platinum group elements and iron elements are shown 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, the solid-liquid separation was performed and the obtained leaching solution was analyzed for element content by ICP. The calculated leaching rates of platinum group elements and iron elements are shown in Table 1.

[0086] Example 9

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

[0088] Example 10

[0089] The only difference from Example 1 is that the leaching process adopts conventional heated stirring leaching (the leaching agent used in the leaching is 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°C, the time is 4h, the stirring speed during the leaching process is 800r / min, and the liquid-to-solid ratio remains unchanged during the leaching, that is, the liquid-to-solid ratio mL / g is 30:1.

[0090] Embodiment 11

[0091] The only difference from Example 1 is that the leaching process adopts 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 4h, the stirring speed during the leaching process is 800r / min, and the liquid-to-solid ratio remains unchanged during the leaching, that is, the liquid-to-solid ratio mL / g is 30:1.

[0092] Example 12

[0093] The only difference from Example 1 is that the leaching process adopts 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 4h, the stirring speed during the leaching process is 800r / min, and the liquid-to-solid ratio remains unchanged during the leaching, that is, the liquid-to-solid ratio mL / g is 30:1.

[0094] Example 13

[0095] The only difference from Example 1 is that the leaching process adopts 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 4h, the stirring speed during the leaching process is 800r / min, and the liquid-to-solid ratio remains unchanged during the leaching, that is, the liquid-to-solid ratio mL / g is 30:1.

[0096] After leaching, the solid-liquid separation was performed and the obtained leaching solution was analyzed for element content by ICP. The calculated leaching rates of platinum group elements and iron elements are shown in Table 2.

[0097] Table 2

[0098]

[0099]

[0100] It can be seen from the results of the above embodiments that when the leaching agent provided by the present invention is not used, such as changing the concentration of ferric chloride, increasing the concentration of hydrogen chloride, or increasing the concentration of hydrogen peroxide, or introducing the auxiliary agent sodium chloride, the leaching effect of the leaching agent of the present invention on platinum group elements will be significantly reduced. Furthermore, when the leaching agent of the present invention is used, the conventional stirring and heating leaching in the field 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 combined with a specific mechanical activation leaching process, can ensure the efficient leaching of platinum group elements and iron elements in the Fe-Si-P-PGMs alloy when the leaching agent is used for leaching the Fe-Si-P-PGMs alloy, which is beneficial to the efficient recovery of platinum group elements.

[0101] It is stated that the present invention illustrates the detailed structural features of the present invention 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 improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, 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 are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to 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 further describe various possible combinations.

[0104] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A leaching agent for platinum group elements in Fe-Si-P-PGMs alloy, characterized in that: The leaching agent comprises: A solution containing ferric chloride, hydrogen peroxide and hydrochloric acid.

2. The leaching agent according to claim 1, characterized in that 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.

3. A method for leaching platinum group elements from Fe-Si-P-PGMs alloy, characterized in that: The leaching method comprises mixing the leaching agent as claimed in claim 1 or 2 with the Fe-Si-P-PGMs alloy for mechanical activation leaching.

4. The leaching method according to claim 3, characterized in that: During the mixing, the liquid-to-solid ratio of the leaching agent to the Fe-Si-P-PGMs alloy is (25-40):1, and the unit of the liquid-to-solid ratio is mL / g.

5. The leaching method according to claim 3 or 4, characterized in that: The mass ratio of the Fe-Si-P-PGMs alloy to the grinding balls in the mechanical activation leaching is 1:(40-60).

6. The leaching method according to any one of claims 4 to 5, characterized in that: The rotation speed in the mechanical activation leaching is ≥500r / min.

7. The leaching method according to claim 6, characterized in that: The rotation speed in the mechanical activation leaching is 500-800r / min.

8. The leaching method according to any one of claims 4 to 7, characterized in that: The mechanical activation leaching time is ≥4h.

9. The leaching method according to claim 8, characterized in that: The mechanical activation leaching time is 4-5h.

10. The leaching method according to any one of claims 4 to 9, characterized in that: The leaching method comprises mixing a leaching agent and a Fe-Si-P-PGMs alloy to perform mechanical activation leaching; The liquid-to-solid ratio of the leaching agent and the Fe-Si-P-PGMs alloy during mixing is (25-40):

1. mL / g; the mass ratio of Fe-Si-P-PGMs alloy to grinding ball in the mechanical activation leaching is 1:(40-60); The rotation speed in the mechanical activation leaching is 500-800 r / min; the time of the mechanical activation leaching is 4-5 hours.

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