Method for resourceful treatment of tantalum hydrometallurgy by-products

Abstract

The invention discloses a method for resourceful treatment of a wet-process tantalum smelting byproduct, which comprises the following steps: 1) crushing the wet-process tantalum smelting byproduct to obtain powder with the particle size of less than 150 microns; 2) primary leaching; 3) washing the tantalum-containing sodium fluoride crude salt; 4) dissolving sodium fluoride to prepare tantalum; 5) preparing sodium fluoride by evaporative crystallization; (6) evaporating and crystallizing the primary leaching completion liquid; (7) secondary leaching; 8) evaporating and crystallizing to prepare sodium chloride; 9) refining sodium chloride; 10) cooling and crystallizing to prepare potassium chloride; according to the method disclosed by the invention, resource recycling can be carried out on a byproduct mixture containing fluorine, chlorine, potassium, sodium and a small amount of tantalum powder in a wet-process tantalum smelting process to obtain elemental tantalum, sodium fluoride, sodium chloride and potassium chloride products. According to the method, the production cost of an enterprise is reduced, and meanwhile pollution and harm to the environment caused by mixed salt are avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of resource recovery of nonferrous metal smelting by-products, and particularly relates to a method for resource treatment of hydrometallurgical tantalum smelting by-products. Background Art

[0002] Tantalum, a rare gray metal with high melting and boiling points, is resistant to high temperatures and corrosion. It is widely used in modern electronics, cemented carbide, low-temperature superconductors, high-temperature furnace components, the nuclear industry, and modern weaponry, making it an indispensable metal material in high-tech industries. Currently, my country primarily uses hydrometallurgical processes to extract tantalum from ores, which include concentrate preparation, acid leaching, precipitation, pH adjustment, and extraction. These steps produce potassium fluorotantalate solid. This solid is then added to a mixture of potassium fluoride, potassium chloride, sodium chloride, and tantalum pentoxide for high-temperature molten salt electrolysis, yielding tantalum powder with a purity of 99.8% to 99.9%.

[0003] After the tantalum powder is separated from the smelting system, the remaining molten salt cools to form a mixture containing fluorine, chlorine, potassium, sodium, and a small amount of tantalum powder (referred to as the byproduct of wet tantalum refining). The wet tantalum refining byproduct is usually produced by adding a large amount of water to dissolve the salt, filtering and recovering the small amount of tantalum in the solution, then adding lime to the salt solution to remove fluoride ions, forming a calcium fluoride precipitate, and finally evaporating the remaining salt solution to form mixed salts. This process is not only energy-intensive, but the calcium fluoride and mixed salts produced can only be treated as solid waste, wasting salt resources and incurring high solid waste disposal costs. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for resource recovery of tantalum by-products produced by wet tantalum smelting.

[0005] The technical solution of the present invention is summarized as follows:

[0006] A method for resource processing of tantalum by-products from wet smelting, comprising the following steps

[0007] 1) crushing the by-product of wet tantalum refining to obtain a powder with a particle size of less than 150 microns;

[0008] 2) One-time leaching:

[0009] Under stirring, the powder is mixed with water or the primary washing liquid obtained in step 3) and the crystallization mother liquor obtained in step 10) to carry out a primary leaching, so that most of the sodium chloride and potassium chloride in the powder are dissolved, and the solid-liquid is separated to obtain a primary leaching solution and crude sodium fluoride-containing tantalum salt;

[0010] 3) Washing of crude salt containing tantalum and sodium fluoride:

[0011] Under stirring, adding water to the crude sodium tantalum fluoride salt to perform a primary washing, and performing solid-liquid separation to obtain purified sodium tantalum fluoride and a primary washing liquid, and the primary washing liquid is returned to step 2);

[0012] 4) Tantalum production by dissolving sodium fluoride:

[0013] Under stirring, adding water to the purified sodium fluoride containing tantalum to dissolve the sodium fluoride, and performing solid-liquid separation to obtain elemental tantalum and a nearly saturated sodium fluoride solution;

[0014] 5) Evaporation crystallization to produce sodium fluoride:

[0015] The nearly saturated sodium fluoride solution is evaporated to precipitate sodium fluoride. After the evaporation is completed, the solid-liquid separation is performed, and the solid is dried to obtain high-purity sodium fluoride. The mother liquor is returned to this step to continue evaporation;

[0016] 6) One-time leaching completes liquid evaporation and crystallization:

[0017] Evaporating the primary leaching solution to precipitate crude sodium chloride salt, and separating the solid and liquid after the evaporation to obtain crude sodium chloride salt and the primary evaporation solution;

[0018] 7) Secondary leaching:

[0019] Under stirring, adding water to the crude sodium chloride salt for secondary leaching to dissolve most of the sodium chloride in the crude salt, and separating the solid and liquid to obtain crude sodium fluoride salt and a saturated sodium chloride solution. The crude sodium fluoride salt is returned to step 3) for washing;

[0020] 8) Evaporation and crystallization of sodium chloride:

[0021] Evaporating the saturated sodium chloride solution to precipitate sodium chloride, and separating the solid and the liquid after the evaporation is completed to obtain sodium chloride and a secondary evaporation completed liquid;

[0022] 9) Sodium chloride refining:

[0023] Under stirring, water is added to the sodium chloride for secondary washing, solid-liquid separation is performed to obtain high-purity industrial wet salt and secondary washing liquid, and the secondary washing liquid is returned to step 6) for evaporation and crystallization;

[0024] 10) Cooling crystallization to produce potassium chloride:

[0025] Under stirring, the first evaporation completed liquid obtained in step 6) and the second evaporation completed liquid obtained in step 8) are mixed, cooled, potassium chloride crystallized, solid-liquid separation is performed, and the solid is dried to obtain potassium chloride, and the crystallization mother liquor is returned to step 2);

[0026] The water is deionized water.

[0027] Preferably, the stirring speed in step 2) is 300 to 500 rpm, and the leaching time is 90 to 120 min.

[0028] Preferably, in step 3), the mass ratio of crude sodium tantalum fluoride salt to water is 1:4; the stirring speed is 300 to 500 rpm, and the stirring time is 60 to 90 min.

[0029] Preferably, in step 4), the mass ratio of the purified sodium tantalum fluoride to water is 1:25; the stirring speed is 300 to 500 rpm, and the stirring time is 90 to 120 min.

[0030] Preferably, in step 5), the evaporation process temperature is maintained at 95-105°C.

[0031] Preferably, in step 6), the evaporation process temperature is maintained at 105-110°C.

[0032] Preferably, in step 7), the mass ratio of crude sodium chloride salt to water is 1:2; the stirring speed is 300 to 500 rpm, and the leaching time is 90 to 120 min.

[0033] Preferably, in step 8), the evaporation process temperature is maintained at 105-110°C.

[0034] Preferably, in step 9), the mass ratio of sodium chloride to water is 20-30:1, the stirring speed is 300-500 rpm, and the stirring time is 30-60 min.

[0035] Preferably, in step 10), the stirring speed is 100-300 rpm, and the crystallization endpoint temperature is 25-45°C.

[0036] Advantages of the present invention:

[0037] The method of the present invention can recycle a mixture of fluorine, chlorine, potassium, sodium, and a small amount of tantalum powder, a byproduct of the wet smelting process, to produce elemental tantalum, sodium fluoride, sodium chloride, and potassium chloride products. This method reduces production costs while avoiding the pollution and harm to the environment caused by the mixed salt. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The present invention is a process flow chart of a method for resource processing of tantalum by-products produced by wet smelting.

[0039] Figure 2 The solubility curves of tantalum, sodium fluoride, sodium chloride and potassium chloride in water at different temperatures are shown in the figure.

[0040] Figure 3This is the phase diagram of the sodium fluoride-sodium chloride-water ternary system at 25°C of the present invention. DETAILED DESCRIPTION

[0041] The water involved in each embodiment of the present invention is deionized water.

[0042] The technical solution of the present invention is further described below with reference to specific embodiments.

[0043] First, the components of the hydrometallurgical tantalum by-product (experimental sample) were tested, and the main components are shown in Table 1.

[0044] Table 1 Composition of by-products of tantalum hydrometallurgy

[0045] Test items Mass percentage (wt%) <![CDATA[Na + ]]> 38.21 <![CDATA[K + ]]> 12.97 <![CDATA[F - ]]> 25.42 <![CDATA[Cl - ]]> 23.10 Ta 0.3

[0046] Example 1

[0047] A method for resource processing of tantalum by-products from hydrometallurgy Figure 1 , including the following steps

[0048] 1) crushing the by-products of wet tantalum smelting using a jaw crusher to obtain a powder with a particle size of less than 150 microns;

[0049] 2) One-time leaching:

[0050] Under stirring (stirring speed of 400 rpm), 1 kg of powder is mixed with water (water used in the first operation) or the primary washing liquid obtained in step 3) and the crystallization mother liquor obtained in step 10) to carry out a primary leaching (leaching time of 100 min) to dissolve most of the sodium chloride and potassium chloride in the powder, and solid-liquid separation is carried out to obtain a primary leaching solution and crude sodium fluoride-containing tantalum salt.

[0051] The composition of the primary leaching solution was detected by chemical titration and ion chromatography, see Table 2.

[0052] Table 2 Composition of the first leaching solution

[0053] Test items Mass percentage (wt%) <![CDATA[Na + ]]> 5.76 <![CDATA[K + ]]> 8.5 <![CDATA[F - ]]> 0.62 <![CDATA[Cl - ]]> 15.44 water 69.68

[0054] That is, the method of the present invention is used to carry out a single leaching. By utilizing the difference in solubility of tantalum, sodium fluoride, sodium chloride and potassium chloride in water, tantalum and sodium fluoride in the system can be present in solid form, while most of the sodium chloride and potassium chloride in the tantalum by-product salts are present in the single leaching solution. The solubility curves of tantalum, sodium fluoride, sodium chloride and potassium chloride in water at different temperatures are shown in FIG. Figure 2 .

[0055] 3) Washing of crude salt containing tantalum and sodium fluoride:

[0056] Under stirring (stirring speed is 500 rpm, stirring time is 60 min), water is added to the crude sodium tantalum fluoride salt for washing (the mass ratio of the crude sodium tantalum fluoride salt to water is 1:4), and solid-liquid separation is performed to obtain purified sodium tantalum fluoride and a primary washing liquid, and the primary washing liquid is returned to step 2).

[0057] The composition of the obtained solid (purified sodium tantalum fluoride) was determined by chemical titration and ion chromatography, as shown in Table 3.

[0058] Table 3 Percentage of solid composition

[0059] Test items Mass percentage (wt%) NaF 89.52 Ta 0.6 NaCl 0.03 KCl 0.02 water 9.83

[0060] That is, the purity of sodium fluoride in the solid can be improved by washing using the method of the present invention.

[0061] 4) Tantalum production by dissolving sodium fluoride:

[0062] Under stirring (stirring speed of 500 rpm, stirring time of 90 min), water is added to the purified sodium fluoride containing tantalum to dissolve the sodium fluoride (the mass ratio of the purified sodium fluoride containing tantalum to water is 1:25), and solid-liquid separation is performed to obtain elemental tantalum and a nearly saturated sodium fluoride solution;

[0063] Taking advantage of the fact that tantalum is insoluble in water and sodium fluoride is soluble in water, sodium fluoride and tantalum can be separated to obtain elemental tantalum and nearly saturated sodium fluoride solution.

[0064] 5) Evaporation crystallization to produce sodium fluoride:

[0065] The nearly saturated sodium fluoride solution is evaporated (the temperature is maintained at 101° C. during the evaporation process) to precipitate sodium fluoride. After the evaporation is completed, the solid-liquid separation is performed, and the solid is dried to obtain high-purity sodium fluoride. The mother liquor is returned to this step for further evaporation.

[0066] Chemical titration and ion chromatography were used to detect the composition of the evaporated crystallized solid, see Table 4.

[0067] Table 4 Evaporation crystallization solid composition

[0068] Serial number Evaporation temperature (℃) NaF (wt%) Water (wt%) 1 95 95.58 4.42 2 97 95.49 4.51 3 101 95.62 4.38 4 103 95.53 4.47 5 105 95.35 4.65

[0069] 6) One-time leaching completes liquid evaporation and crystallization:

[0070] The primary leaching completed liquid is evaporated (the temperature is maintained at 108° C. during the evaporation process) to precipitate crude sodium chloride salt. After the evaporation is completed, solid-liquid separation is performed to obtain crude sodium chloride salt and the primary evaporation completed liquid.

[0071] The composition of crude sodium chloride salt was determined by chemical titration and ion chromatography, see Table 5.

[0072] Table 5 Sodium chloride crude salt composition

[0073] Serial number Evaporation temperature (℃) Sodium chloride (wt%) Sodium fluoride (wt%) Potassium chloride (wt%) Water (wt%) 1 105 85.8 8.86 0.06 5.28 2 107 86.2 8.39 0.05 5.39 3 108 85.6 8.78 0.07 5.55 4 109 86.5 8.34 0.1 5.06 5 110 86.2 8.30 0.09 5.41

[0074] 7) Secondary leaching:

[0075] Under stirring (stirring speed is 400 rpm, leaching time is 100 min), the sodium chloride crude salt (sequence number 1) is added with water for secondary leaching (mass ratio of sodium chloride crude salt to water is 1:2), so that most of the sodium chloride in the crude salt is dissolved, and solid-liquid separation is performed to obtain sodium fluoride crude salt and a saturated sodium chloride solution. The sodium fluoride crude salt is returned to step 3) for washing.

[0076] The composition of the saturated sodium chloride solution was determined by chemical titration and ion chromatography, see Table 6.

[0077] Table 6 Composition of sodium chloride saturated solution

[0078] Test items Mass percentage (wt%) <![CDATA[Na + ]]> 11.25 <![CDATA[K + ]]> 0.01 <![CDATA[F - ]]> 0.59 <![CDATA[Cl - ]]> 17.36 water 70.80

[0079] The sodium chloride in the crude salt will gradually dissolve with the addition of deionized water, and the solid and liquid will separate to obtain a small amount of sodium fluoride crude salt and a saturated sodium chloride solution. The dissolution process is shown in Figure 3 Phase diagram of the sodium fluoride-sodium chloride-water ternary system.

[0080] 8) Evaporation and crystallization of sodium chloride:

[0081] The saturated sodium chloride solution is evaporated (the temperature is maintained at 108° C. during the evaporation process) to precipitate sodium chloride. After the evaporation is completed, the solid and liquid are separated to obtain sodium chloride and a secondary evaporation completed liquid.

[0082] The composition of the evaporated crystallized solid (sodium chloride) was determined by chemical titration and ion chromatography, as shown in Table 7.

[0083] Table 7 Evaporated crystallized solid (sodium chloride) composition

[0084] Test items Mass percentage (wt%) NaF 2.52 NaCl 92.9 KCl — water 4.58

[0085] 9) Sodium chloride refining:

[0086] Under stirring (stirring speed is 300 rpm, stirring time is 30 min), water is added to the sodium chloride obtained in step 8) for secondary washing (the mass ratio of sodium chloride to water is 25:1), and solid-liquid separation is performed to obtain high-purity industrial wet salt and secondary washing liquid, and the secondary washing liquid is returned to step 6) for evaporation and crystallization.

[0087] The purity of industrial wet salt was tested by chemical titration and ion chromatography, see Table 8.

[0088] Table 8 Composition of high-purity industrial wet salt

[0089] Test items Mass percentage (wt%) NaF 0.01 NaCl 96.97 water 3.02

[0090] 10) Cooling crystallization to produce potassium chloride:

[0091] The first evaporation solution obtained in step 6) and the second evaporation solution obtained in step 8) were mixed under stirring (stirring speed was 150 rpm), cooled to 30° C. (crystallization end temperature), potassium chloride crystallized, solid-liquid separation was performed, and the solid (potassium chloride) was dried to obtain potassium chloride. The crystallization mother liquor was returned to step 2).

[0092] The composition of the solid (potassium chloride) was detected by chemical titration and ion chromatography, see Table 9.

[0093] Table 9 Solid (potassium chloride) composition percentage

[0094] Test items Mass percentage (wt%) NaCl 0.58 KCl 95.9 water 3.52

[0095] The water described in this embodiment is deionized water.

[0096] Example 2

[0097] A method for resource processing of tantalum by-products from wet smelting, comprising the following steps

[0098] 1) crushing the by-products of wet tantalum smelting using a jaw crusher to obtain a powder with a particle size of less than 150 microns;

[0099] 2) One-time leaching:

[0100] Under stirring (stirring speed of 300 rpm), 1 kg of the powder is mixed with water (water for the first operation) or the primary washing liquid obtained in step 3) and the crystallization mother liquor obtained in step 10) to carry out a primary leaching (leaching time of 120 min) to dissolve most of the sodium chloride and potassium chloride in the powder, and solid-liquid separation is carried out to obtain a primary leaching solution and crude sodium fluoride-containing tantalum salt;

[0101] 3) Washing of crude salt containing tantalum and sodium fluoride:

[0102] Under stirring (stirring speed is 300 rpm, stirring time is 90 min), water is added to the crude sodium tantalum fluoride salt for primary washing (mass ratio of crude sodium tantalum fluoride salt to water is 1:4), solid-liquid separation is performed to obtain purified sodium tantalum fluoride and a primary washing liquid, and the primary washing liquid is returned to step 2);

[0103] 4) Tantalum production by dissolving sodium fluoride:

[0104] Under stirring (stirring speed is 300 rpm, stirring time is 120 min), water is added to the purified sodium fluoride containing tantalum to dissolve the sodium fluoride (the mass ratio of the purified sodium fluoride containing tantalum to water is 1:25), and solid-liquid separation is performed to obtain elemental tantalum and a nearly saturated sodium fluoride solution;

[0105] 5) Evaporation crystallization to produce sodium fluoride:

[0106] The nearly saturated sodium fluoride solution was evaporated (the temperature was maintained at 95°C during the evaporation process) to precipitate sodium fluoride. After evaporation, the solid and liquid were separated, and the solid was dried to obtain high-purity sodium fluoride. The mother liquor was returned to the current step for further evaporation. The composition of the evaporated crystallized solid was determined by chemical titration and ion chromatography, as shown in Table 4.

[0107] 6) One-time leaching completes liquid evaporation and crystallization:

[0108] The primary leaching solution was evaporated (the temperature was maintained at 105°C during the evaporation process) to precipitate crude sodium chloride salt. After evaporation, solid-liquid separation was performed to obtain crude sodium chloride salt and the primary evaporation solution. The composition of the crude sodium chloride salt was determined by chemical titration and ion chromatography, as shown in Table 5.

[0109] 7) Secondary leaching:

[0110] Under stirring (stirring speed is 300 rpm, leaching time is 120 min), adding water to the sodium chloride crude salt for secondary leaching (mass ratio of sodium chloride crude salt to water is 1:2), so that most of the sodium chloride in the crude salt is dissolved, and solid-liquid separation is performed to obtain sodium fluoride crude salt and a saturated sodium chloride solution, and the sodium fluoride crude salt is returned to step 3) for washing;

[0111] 8) Evaporation and crystallization of sodium chloride:

[0112] The saturated sodium chloride solution is evaporated (the temperature is maintained at 105°C during the evaporation process) to precipitate sodium chloride. After the evaporation is completed, the solid and liquid are separated to obtain sodium chloride and a secondary evaporation completed liquid;

[0113] 9) Sodium chloride refining:

[0114] Under stirring (stirring speed is 400 rpm, stirring time is 60 min), water is added to the sodium chloride obtained in step 8) for secondary washing (mass ratio of sodium chloride to water is 20:1), solid-liquid separation is performed to obtain high-purity industrial wet salt and secondary washing liquid, and the secondary washing liquid is returned to step 6) for evaporation and crystallization;

[0115] 10) Cooling crystallization to produce potassium chloride:

[0116] Under stirring (100 rpm), the first evaporation completed liquid obtained in step 6) and the second evaporation completed liquid obtained in step 8) are mixed and cooled to 25° C. (crystallization end temperature) to allow potassium chloride to crystallize. The solid-liquid separation is carried out, and the solid (potassium chloride) is dried to obtain potassium chloride. The crystallization mother liquor is returned to step 2).

[0117] The water described in this embodiment is deionized water.

[0118] Example 3

[0119] A method for resource processing of tantalum by-products from wet smelting, comprising the following steps

[0120] 1) crushing the by-products of wet tantalum smelting using a jaw crusher to obtain a powder with a particle size of less than 150 microns;

[0121] 2) One-time leaching:

[0122] Under stirring (stirring speed of 500 rpm), 1 kg of the powder is mixed with water (water for the first operation) or the primary washing liquid obtained in step 3) and the crystallization mother liquor obtained in step 10) to carry out a primary leaching (leaching time of 90 minutes) to dissolve most of the sodium chloride and potassium chloride in the powder, and solid-liquid separation is carried out to obtain a primary leaching solution and crude sodium fluoride-containing tantalum salt;

[0123] 3) Washing of crude salt containing tantalum and sodium fluoride:

[0124] Under stirring (stirring speed is 400 rpm, stirring time is 80 min), water is added to the crude sodium tantalum fluoride salt for primary washing (mass ratio of crude sodium tantalum fluoride salt to water is 1:4), solid-liquid separation is performed to obtain purified sodium tantalum fluoride and a primary washing liquid, and the primary washing liquid is returned to step 2);

[0125] 4) Tantalum production by dissolving sodium fluoride:

[0126] Under stirring (stirring speed is 400 rpm, stirring time is 100 min), water is added to the purified sodium fluoride containing tantalum to dissolve the sodium fluoride (the mass ratio of the purified sodium fluoride containing tantalum to water is 1:25), and solid-liquid separation is performed to obtain elemental tantalum and a nearly saturated sodium fluoride solution;

[0127] 5) Evaporation crystallization to produce sodium fluoride:

[0128] The nearly saturated sodium fluoride solution was evaporated (the temperature was maintained at 105°C during the evaporation process) to precipitate sodium fluoride. After evaporation, the solid and liquid were separated, and the solid was dried to obtain high-purity sodium fluoride. The mother liquor was returned to the current step for further evaporation. The composition of the evaporated crystallized solid was determined by chemical titration and ion chromatography, as shown in Table 4.

[0129] 6) One-time leaching completes liquid evaporation and crystallization:

[0130] The primary leaching solution was evaporated (the evaporation temperature was maintained at 110°C) to precipitate crude sodium chloride salt. After evaporation, solid-liquid separation was performed to obtain crude sodium chloride salt and the primary evaporation solution. The composition of the crude sodium chloride salt was determined by chemical titration and ion chromatography, as shown in Table 5.

[0131] 7) Secondary leaching:

[0132] Under stirring (stirring speed is 500 rpm, leaching time is 90 min), adding water to the sodium chloride crude salt for secondary leaching (mass ratio of sodium chloride crude salt to water is 1:2), so that most of the sodium chloride in the crude salt is dissolved, and solid-liquid separation is performed to obtain sodium fluoride crude salt and a saturated sodium chloride solution, and the sodium fluoride crude salt is returned to step 3) for washing;

[0133] 8) Evaporation and crystallization of sodium chloride:

[0134] The saturated sodium chloride solution is evaporated (the temperature is maintained at 110°C during the evaporation process), sodium chloride is precipitated, and after the evaporation is completed, the solid and liquid are separated to obtain sodium chloride and a secondary evaporation completed liquid;

[0135] 9) Sodium chloride refining:

[0136] Under stirring (stirring speed is 500 rpm, stirring time is 40 min), water is added to the sodium chloride obtained in step 8) for secondary washing (the mass ratio of sodium chloride to water is 30:1), solid-liquid separation is performed to obtain high-purity industrial wet salt and secondary washing liquid, and the secondary washing liquid is returned to step 6) for evaporation and crystallization;

[0137] 10) Cooling crystallization to produce potassium chloride:

[0138] The first evaporation solution obtained in step 6) and the second evaporation solution obtained in step 8) were mixed under stirring (300 rpm), cooled to 45° C. (crystallization endpoint temperature), potassium chloride crystallized, solid-liquid separation was performed, and the solid (potassium chloride) was dried to obtain potassium chloride. The crystallization mother liquor was returned to step 2).

[0139] The water described in this embodiment is deionized water.

[0140] Experiments have shown that the quality of elemental tantalum, sodium fluoride, sodium chloride, and potassium chloride obtained by the methods of Examples 2 and 3 is similar to that of Example 1.

[0141] By adjusting the process parameters according to the present invention, resource recovery of tantalum hydrometallurgy byproducts can be achieved. The above description of the present invention is illustrative. It should be noted that any simple variation, modification, or equivalent substitution that can be made by those skilled in the art without inventive effort, without departing from the core of the present invention, falls within the scope of protection of the present invention.

Claims

1. A method for resource processing of tantalum by-products from wet smelting, characterized in that Includes the following steps 1) crushing the by-product of wet tantalum refining to obtain a powder with a particle size of less than 150 microns; 2) One-time leaching: Under stirring, the powder is mixed with water or the primary washing liquid obtained in step 3) and the crystallization mother liquor obtained in step 10) to carry out a primary leaching, so that most of the sodium chloride and potassium chloride in the powder are dissolved, and the solid-liquid is separated to obtain a primary leaching solution and crude sodium fluoride-containing tantalum salt; 3) Washing of crude salt containing tantalum and sodium fluoride: Under stirring, adding water to the crude sodium tantalum fluoride salt to perform a primary washing, and performing solid-liquid separation to obtain purified sodium tantalum fluoride and a primary washing liquid, and the primary washing liquid is returned to step 2); 4) Tantalum production by dissolving sodium fluoride: Under stirring, adding water to the purified sodium fluoride containing tantalum to dissolve the sodium fluoride, and performing solid-liquid separation to obtain elemental tantalum and a nearly saturated sodium fluoride solution; 5) Evaporation crystallization to produce sodium fluoride: The nearly saturated sodium fluoride solution is evaporated to precipitate sodium fluoride. After the evaporation is completed, the solid-liquid separation is performed, and the solid is dried to obtain high-purity sodium fluoride. The mother liquor is returned to this step to continue evaporation; 6) One-time leaching completes liquid evaporation and crystallization: Evaporating the primary leaching solution to precipitate crude sodium chloride salt, and separating the solid and liquid after the evaporation to obtain crude sodium chloride salt and the primary evaporation solution; 7) Secondary leaching: Under stirring, adding water to the crude sodium chloride salt for secondary leaching to dissolve most of the sodium chloride in the crude salt, and separating the solid and liquid to obtain crude sodium fluoride salt and a saturated sodium chloride solution. The crude sodium fluoride salt is returned to step 3) for washing; 8) Evaporation and crystallization of sodium chloride: Evaporating the saturated sodium chloride solution to precipitate sodium chloride, and separating the solid and the liquid after the evaporation is completed to obtain sodium chloride and a secondary evaporation completed liquid; 9) Sodium chloride refining: Under stirring, water is added to the sodium chloride for secondary washing, solid-liquid separation is performed to obtain high-purity industrial wet salt and secondary washing liquid, and the secondary washing liquid is returned to step 6) for evaporation and crystallization; 10) Cooling crystallization to produce potassium chloride: Under stirring, the first evaporation completed liquid obtained in step 6) and the second evaporation completed liquid obtained in step 8) are mixed, cooled, potassium chloride crystallized, solid-liquid separation is performed, and the solid is dried to obtain potassium chloride, and the crystallization mother liquor is returned to step 2); The water is deionized water.

2. The method according to claim 1, characterized in that The stirring speed in step 2) is 300 to 500 revolutions per minute, and the leaching time is 90 to 120 minutes.

3. The method according to claim 1, characterized in that In step 3), the mass ratio of crude sodium tantalum fluoride salt to water is 1:4; the stirring speed is 300 to 500 rpm, and the stirring time is 60 to 90 min.

4. The method according to claim 1, wherein In step 4), the mass ratio of the purified sodium tantalum fluoride to water is 1:25; the stirring speed is 300 to 500 rpm, and the stirring time is 90 to 120 min.

5. The method according to claim 1, wherein In step 5), the temperature of the evaporation process is maintained at 95-105°C.

6. The method according to claim 1, characterized in that In step 6), the evaporation process temperature is maintained at 105-110°C.

7. The method according to claim 1, characterized in that In step 7), the mass ratio of sodium chloride crude salt to water is 1:2; the stirring speed is 300-500 rpm, and the leaching time is 90-120 min.

8. The method according to claim 1, characterized in that In step 8), the evaporation process temperature is maintained at 105-110°C.

9. The method according to claim 1, characterized in that In step 9), the mass ratio of sodium chloride to water is 20-30:1, the stirring speed is 300-500 rpm, and the stirring time is 30-60 min.

10. The method according to claim 1, characterized in that In step 10), the stirring speed is 100-300 rpm, and the crystallization endpoint temperature is 25-45°C.

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