Process for recovering multiple metals from complex and precious materials by full wet method

Abstract

The application discloses a process for recovering multiple metals from complex rare and precious materials by a full-wet method, which comprises the following steps: step 1: adding the complex rare and precious materials into a hydrochloric acid solution, adding an oxidizing agent to react, and then filtering to obtain a chlorination liquid and a chlorination residue; step 2: adopting two-stage countercurrent gold loading to obtain a gold-loaded liquid and a post-loading liquid, reducing the gold-loaded liquid, clarifying an organic phase, and filtering a precipitate to separate a post-reduction liquid and sponge gold; the post-reduction liquid is evaporated and concentrated to produce concentrated liquid 1 and a condensate; the concentrated liquid is cooled and crystallized, and the residual oxalic acid is filtered out to return to the original process, and the post-crystallization liquid is returned to gold loading; step 3: low-temperature distillation of the post-loading liquid to obtain concentrated liquid 2; step 4: high-temperature distillation of the concentrated liquid 2 to obtain concentrated liquid 3; step 5: directional crystallization and centrifugal filtration of the concentrated liquid 3 to obtain crystallization residue and selenous acid; and step 6: washing and filtering of the crystallization residue by using cold water or the low-acid condensate produced in step 3 to obtain tellurium residue and a palladium-platinum-rhodium-rich liquid. The process provided by the application has the advantages of no waste water generation, a short process flow and high recovery rate of precious metals.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of comprehensive recovery of rare and precious metals, and particularly relates to a process for recovering multiple metals from complex rare and precious materials by a full wet method. BACKGROUND

[0002] In the non-ferrous metal smelting process, non-ferrous metals are enriched in anode slime along with gold, platinum, palladium, rhodium, selenium and tellurium. After wet treatment of the anode slime, a product co-enriched with gold, platinum, palladium, rhodium, selenium and tellurium, such as crude gold powder or platinum-palladium concentrate, is often produced. These products are intermediate products containing rare and precious metals obtained by reduction of the solution after chlorination of the anode slime for gold extraction.

[0003] The complex rare and precious material containing gold, platinum, palladium, rhodium, selenium and tellurium is treated by the following conventional wet process: complex precious metal material-water solution chlorination dissolution-purification-reduction-gold powder (gold grade ≤ 99.9%), and the platinum, palladium and part of the rhodium in the reduced solution is precipitated by ammonium chloropalladate, and the tellurium and selenium are recovered from the reduced solution, respectively. The conventional process can well separate tellurium and bismuth from precious metals, but has the following problems:

[0004] Firstly, the low dissolution rate of platinum, palladium and rhodium in the chlorination gold separation process leads to dispersion and difficulty in enrichment, and the subsequent recovery rate is low.

[0005] Secondly, the chlorination slag is difficult to filter, and gold, platinum, palladium and rhodium are easily lost by being wrapped and carried.

[0006] Thirdly, the gold extraction wastewater is difficult to treat, a large amount of neutralizing agent needs to be added, and neutralization slag containing gold, platinum and palladium is produced, and the high-chlorine and salt-containing wastewater after neutralization cannot be recycled. SUMMARY

[0007] Therefore, to solve the problem, the application provides a process for recovering multiple metals from complex rare and precious materials by a full wet method, i.e. there is no sodium salt, no cyanide, no nitrogen oxide and no sulfide in the water phase system, conditions are created for the cooperation of ion exchange technology and distillation concentration, the regeneration and recycling of hydrochloric acid and water are realized, gold powder with gold content greater than 99.99% is produced, and high enrichment ratio (greater than 30) of precious metals, no wastewater generation in the whole process, short process and high recovery rate of precious metals are achieved.

[0008] To achieve the above purpose, the application adopts the following technical scheme:

[0009] A process for recovering multiple metals from complex rare and precious materials by a full wet method, comprising the following steps:

[0010] Step 1: chlorination dissolution, adding hydrochloric acid aqueous solution, complex rare and precious materials into a reaction kettle, stirring and reacting, heating to 60-70℃, slowly adding oxidant, after the reaction is completed, adding a small amount of complex rare and precious materials to stir and remove chlorine, stopping stirring to clarify, then pumping the upper chlorination liquid into gold loading, and the precipitated chlorination residue is used as raw material for recovering silver; the technical conditions are controlled as follows: the concentration of hydrochloric acid aqueous solution is 5-7 mol / L, the liquid-solid ratio is 3-6:1, and the oxidation process temperature is 80-95℃;

[0011] Step 2: gold loading, using two-stage countercurrent gold loading, after the chlorination liquid is loaded, gold-loaded liquid and post-loading liquid are obtained, the gold-loaded liquid is reduced to the end point and then is separated statically, the organic phase is clarified, and the precipitate is filtered to separate the post-reduction liquid and sponge gold; the post-reduction liquid is evaporated and concentrated to produce concentrated liquid 1 and condensate;

[0012] Step 3: cooling the concentrated liquid 1 in step 2 to <30℃, stirring and crystallizing, and then filtering to obtain crystallized liquid and residual oxalic acid, wherein the crystallized liquid returns to the gold loading process in step 2, and the residual oxalic acid returns to the reduction process of the gold-loaded liquid in step 2;

[0013] Step 4: low-temperature distillation, performing low-temperature distillation on the post-loading liquid in step 2 to distill low-acid condensate and high-acid condensate, returning the high-acid condensate to step 1 as hydrochloric acid, and entering the low-acid condensate into step 6 for washing, and the post-distillation residue is concentrated liquid 2;

[0014] Step 5: high-temperature distillation, performing high-temperature distillation on the concentrated liquid 2 in step 4 to remove residual water to obtain concentrated liquid 3;

[0015] Step 6: directional crystallization and centrifugal filtration, performing directional crystallization and centrifugal filtration on the concentrated liquid 3 to obtain crystallization residue and selenous acid;

[0016] Step 7: washing, washing the crystallization residue with cold water or the low-acid condensate produced in step 4, and filtering to obtain tellurium residue and palladium-platinum-rhodium rich liquid.

[0017] The chemical equation of step 1 reaction is as follows:

[0018] 8Au+3HClO4+29Cl - +21H + =8[AuCl4] -1 +12H2O

[0019] The beneficial effects are: the problems of long reaction time and poor on-site environment caused by the chlorine chasing operation in the chlorination dissolution process of other technologies can be avoided; the gold leaching effect in the chlorination dissolution process is improved by re-chlorination of the chlorination residue, the filtration frequency of the chlorination residue is reduced, and the gold loss in the filtration process is avoided.

[0020] Preferably, the complex rare and precious material components include, in mass percentage, selenium 3-20%, tellurium 3-40%, gold ≥1%, platinum ≥0.1%, palladium ≥0.1%, rhodium ≥0.005%, and other impurities <30%, wherein the selenium, tellurium, gold, platinum, palladium and rhodium are in the form of elemental phase.

[0021] Preferably, the gold uploading in step 2 is specifically performed by controlling the flow ratio of the uploading agent, i.e. the chlorination liquid, to be 1:0.8-8, and using the uploading counterflow column 1 and the uploading counterflow column 2 to perform two-stage uploading reaction kettle counterflow gold uploading. After the uploading, a gold-loaded liquid and an uploading post-liquid are obtained. The gold-loaded liquid is sent into a reduction reaction kettle for reduction. After reduction to the end point, static separation is performed, and the static state is maintained for more than 10 minutes. The organic phase is separated and clarified, and the precipitate is filtered and separated to obtain a reduction post-liquid and sponge gold. The reduction post-liquid is evaporated and concentrated to obtain a concentrated liquid 1 and a condensate. The concentrated liquid 1 is returned to the reduction process, and the condensate is returned to step 1 to supplement the hydrochloric acid aqueous solution.

[0022] Preferably, the two-stage uploading reaction kettle in step 2 includes a first-stage uploading reaction kettle and a second-stage uploading reaction kettle. A potentiometer is installed at the water phase outlet of the first-stage uploading reaction kettle to monitor the potential value of the water phase. When the potential value is reduced to <520 mV, the chlorination liquid is stopped. At this time, the first-stage gold-loaded liquid is pumped to the reduction reaction kettle for reduction, and the second-stage uploading reaction kettle is switched to the first-stage uploading reaction kettle.

[0023] The uploading reaction is as follows:

[0024] R + HAuCl4 = [RH + ][AuCl4 - ]

[0025] Preferably, in step 2, the gold-loaded liquid is sent into the reactor for reduction, and the temperature is controlled to be 90-95°C. The gold content in the gold-loaded liquid at the reduction end point is <0.1 g / L. The reducing agent is oxalic acid.

[0026] The reduction reaction is as follows:

[0027] 3H2C2O4 + 2[RH + ][AuCl4 - ] = 2Au + 6CO2 + 8H + + 8Cl - + 2R

[0028] Preferably, in step 4, the liquid temperature in the low-temperature distillation column is controlled to be 60-75°C, and the pressure in the distillation column is 55-65 kPa.

[0029] Preferably, in step 5, the high-temperature distillation temperature is 90-100°C, and the pressure in the evaporator is 60-80 kPa.

[0030] Preferably, the temperature of the directional crystallization in step 6 is 75-80℃.

[0031] The principle of the phase crystallization is that after high-temperature distillation, the free water and hydrochloric acid in the loaded liquid are distilled dry, and the remaining part is platinum chloride, palladium chloride, rhodium chloride, tellurium chloride and selenious acid. When the temperature is reduced to 75-80℃, except selenious acid, the others are precipitated in solid form, and directional crystallization separates the noble metals and tellurium from selenium.

[0032] Preferably, the crystalline slag is washed with cold water to dissolve the soluble noble metal salt into the palladium-platinum-rhodium rich liquid, and separate the tellurium. The obtained palladium-platinum-rhodium rich liquid has high noble metal concentration and impurity tellurium, and can be used as a liquid raw material for separation and purification of palladium, platinum and rhodium. The palladium extraction, platinum extraction and rhodium reduction precipitation process can be used to separate and purify palladium, platinum and rhodium to obtain corresponding products or high-grade concentrates.

[0033] Preferably, the oxidizing agent in step 1 is perchloric acid with a concentration of 26-30%, and the oxidizing agent is added in an amount of 2.5-4 times the total amount of gold, selenium and tellurium in the input material.

[0034] Preferably, the loading agent is a mixture of methyl isobutyl ketone MIBK and TBP, and the diluent is one of n-dodecane and sulfonated kerosene or a mixture of the two and chloroform.

[0035] Compared with the prior art, the present application has the following beneficial effects:

[0036] (1) The present application proposes a wastewater zero discharge technology, i.e. no sodium salt, no cyanide, no nitrogen oxide, no sulfide in the aqueous phase system, which creates conditions for the cooperation of ion exchange technology and distillation concentration, and realizes the regeneration and circulation of hydrochloric acid and water.

[0037] (2) The present application has strong adaptability to complex gold, platinum, palladium, rhodium, selenium and tellurium material composition, and is particularly suitable for high-selenium and tellurium low-noble metal material, can obtain higher direct recovery rate and recovery, and separate selenium and tellurium from the solution to obtain high-concentration platinum, palladium, rhodium and rhodium noble liquid, which is convenient for further extraction of these metals. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0039] Figure 1 It is a process flow chart for full-hydraulic recovery of multiple metals from complex rare and precious materials disclosed by the present application. DETAILED DESCRIPTION

[0040] Embodiments of the present application are described below, examples of which are shown in the accompanying drawings, the embodiments described with reference to the drawings are exemplary and are intended to explain the present application, and are not understood as limiting the present application.

[0041] Example 1

[0042] The precious and rare materials 100 kg of selenium 3.0%, tellurium 37.3%, gold 1.16%, platinum 0.107%, palladium 0.31%, rhodium 0.0052% were put in, and the operation steps of example 1 were as follows:

[0043] Step 1: chlorination dissolution, 36% hydrochloric acid 355 kg was added in the reaction kettle according to the liquid-solid ratio of 5:1, and water was supplemented to prepare 500 ml of 7 mol / L hydrochloric acid solution, then the stirrer was started, and the complex precious and rare materials were slowly added for stirring, and the temperature was raised to 60°C, 28% perchloric acid 47 kg was slowly added, the oxidation temperature was controlled at 82°C, after the reaction was completed, 3 kg of complex precious and rare materials were added for stirring to remove chlorine, after stopping stirring and clarifying, the upper chlorination liquid clarified liquid was extracted into gold upper loading, and the chlorination slag precipitated was left in the kettle for chlorination dissolution with the next batch of materials, and the cycle was repeated for two times, then the chlorination slag 3.2 kg was filtered as the raw material for recovering silver. The weight composition of the chlorination slag was: gold 0.188%, platinum 0.066%, palladium 0.0165%, rhodium 0.0012%, tellurium 11.73%, selenium 1.65%, silver 28.67%, lead 7.35%, and the chlorination liquid clarified liquid 461 L was obtained (containing gold 2.59 g / L, platinum 0.234 g / L, palladium 0.693 g / L, rhodium 0.0112 g / L, tellurium 82.7 g / L, selenium 6.61 g / L).

[0044] Step 2: Gold recovery: The loading agent was prepared by mixing MIBK, TBP, sulfonated kerosene and chloroform in the ratio of 30%, 10%, 50% and 10% respectively. The chlorination solution prepared in step 1 was loaded with gold in two stages (stage 1 and stage 2) by countercurrent loading. A potential meter was installed at the outlet of the water phase in the loading reactor to monitor the potential value of the water phase. When the potential value decreased to 508 mV, the chlorination solution was stopped. At this time, the first stage loaded gold solution was pumped into the reduction reactor for reduction, and the second stage loading was switched to the first stage loading. After loading, 58 L of loaded gold solution and 460.6 L of post-loading solution were obtained. The loaded gold solution contained 20.58 g / L of gold, <0.001 g / L of platinum, palladium and rhodium, which was sent to the reducer for reduction. The reducer was oxalic acid, which was prepared into a 80 g / L oxalic acid solution of 20 L. The reduction temperature was 90°C. The reduction endpoint of the loaded gold solution contained 0.01 g / L of gold. The reduction was stopped at the endpoint and static separation was carried out for more than 10 minutes. The organic phase and the mixed crude gold powder after reduction were separated by filtration to obtain 19.5 L of post-reduction solution and 1.192 kg of sponge gold with a gold grade of 99.996%. The post-reduction solution was evaporated in an evaporator to obtain concentrated solution 1 (3 L) and condensate (16 L). The concentrated solution 1 was returned to the reduction process, and the condensate was returned to step 1.

[0045] Step 3: The concentrated solution 1 was cooled to 26°C and stirred to crystallize. After filtration, the crystallized solution and residual oxalic acid were obtained. The crystallized solution was returned to the gold loading process of step 2, and the residual oxalic acid was returned to the reduction process of the loaded gold solution of step 2.

[0046] Step 4: Low-temperature distillation: The post-loading solution of step 2 was pumped into a low-temperature vacuum evaporator. The liquid temperature in the low-temperature distillation column was controlled at 65°C, and the pressure in the distillation column was 55 kPa. Low-acid condensate 143.2 L (containing 0.0001 g / L of gold, 0.0001 g / L of platinum, 0.0001 g / L of palladium, 0.0001 g / L of rhodium, 2.2 g / L of tellurium and 0.12 g / L of selenium) and high-acid condensate 113 L (containing <0.0001 g / L of gold, <0.0001 g / L of palladium, <0.0001 g / L of rhodium, 2.21 g / L of tellurium, 0.1 g / L of selenium, 2.6 g / L of H + 2.6 g / L) were distilled. The high-acid condensate was returned to step 1 as hydrochloric acid, and the low-acid condensate was used for washing in step 6. Concentrated solution 2 (204.4 L) containing 0.0026 g / L of gold, 0.527 g / L of platinum, 1.56 g / L of palladium, 0.0251 g / L of rhodium, 184.86 g / L of tellurium and 14.77 g / L of selenium was obtained.

[0047] Step 5: High-temperature distillation: The concentrated solution 2 of step 4 is transferred to a high-temperature evaporator, the temperature is further increased to 96°C, the pressure in the evaporator is controlled at 68 kPa, and the residual moisture is removed until crystals are produced, resulting in concentrated solution 3.

[0048] Step 6: Directional crystallization and centrifugal filtration: The concentrated solution 3 (63 L) released in step 5 contains 0.0017 g / L of gold, 1.705 g / L of platinum, 4.93 g / L of palladium, 0.079 g / L of rhodium, 585.93 g / L of tellurium, and 45.0 g / L of selenium. The temperature is lowered to 76°C, directional crystallization is performed, and centrifugal filtration is used to obtain 58.45 kg of crystalline residue (containing 0.0002% of gold, 0.184% of platinum, 0.53% of palladium, 0.0084% of rhodium, 62.78% of tellurium, and 0.39% of selenium) and 4.3 L of selenous acid (containing 0.0004 g / L of gold, 0.04 g / L of platinum, 0.159 g / L of palladium, 0.0067 g / L of rhodium, 50.64 g / L of tellurium, and 606.25 g / L of selenium);

[0049] Step 7: The crystalline residue in step 6 is washed with cold water or the low-acid condensate produced in step 4, and the pH during the washing process is controlled at 2-3. After washing, filtration is performed to obtain 63.4 kg of tellurium residue (containing <0.0001% of gold, <0.0001% of platinum, 0.001% of palladium, <0.0001% of rhodium, 56.55% of tellurium, and 0.19% of selenium) and a palladium-platinum-rhodium-rich liquid (containing 0.004 g / L of gold, 4.52 g / L of platinum, 13.11 g / L of palladium, 0.209 g / L of rhodium, 35.76 g / L of tellurium, and 4.491 g / L of selenium).

[0050] Comparative Example 1: Implementation method:

[0051] For the composition of the waste acid treated in Example 1, the water-solution chlorination method is used to dissolve the chlorinated liquid containing noble metals—neutralize and adjust the pH—reduce and precipitate gold—ammonium chloropalladate precipitates platinum-palladium, and the specific operation steps are as follows:

[0052] (1) According to the liquid-solid ratio of 5:1, 60 g / L of hydrochloric acid, and 15 kg of sodium chlorate, the temperature is controlled at 95°C, and the solution is dissolved for 4 hours to obtain 452 L of chlorinated liquid (containing 2.46 g / L of gold, 0.65 g / L of palladium, 0.33 g / L of platinum, 0.01 g / L of rhodium, 5.37 g / L of selenium, and 79.72 g / L of tellurium), and 18.6 kg of chlorinated residue (containing 0.477% of gold, 0.14% of palladium, 0.0037% of rhodium, 0.033% of platinum, 13.24% of tellurium, and 3.51% of selenium).

[0053] (2) The chlorination solution obtained in step (1) is neutralized to pH = 3 by adding sodium hydroxide, and a neutralized solution 449 L (containing gold 2.2 g / L, platinum 0.22 g / L, palladium 0.63 g / L, rhodium 0.01 g / L, tellurium 75.84 g / L, selenium 5.38 g / L) and a neutralized residue 3.4 kg (containing gold 2.05%, platinum 0.153%, palladium 0.322%, rhodium 0.0009%, tellurium 58.3%, selenium 0.34%) are obtained by filtration.

[0054] (3) The neutralized solution obtained in step (2) is heated to 86-90°C, and oxalic acid 0.3 kg is added to obtain about 0.988 kg of gold powder with a gold grade of 99.9% by reduction, and a post-reduction solution 445 L is obtained.

[0055] (4) The post-reduction solution obtained in step (3) is controlled at a temperature of 57°C, and sodium chlorate 8 kg is slowly added to obtain 1.0 kg of ammonium chloropalladate containing gold 0.28%, platinum 7.78%, palladium 24.72%, rhodium 0.169%, tellurium 3.4%, and selenium 1.1%. A post-palladium precipitation solution 445 L is obtained, containing gold 0.519 g / L, platinum 0.061 g / L, palladium 0.08 g / L, rhodium 0.0063 g / L, tellurium 76.45 / L, and selenium 5.1 g / L.

[0056] Example 1 Effect Comparison:

[0057] In Example 1, gold powder with a purity of 99.99% is obtained from rare and valuable materials containing selenium 3.0%, tellurium 37.3%, gold 1.16%, platinum 0.107%, palladium 0.31%, and rhodium 0.0052%, and a palladium, platinum, and rhodium-rich solution is recovered. The direct recovery rate of metals is shown in Table 1, and the direct recovery rate and recovery rate of each metal in Example 1 are superior to those in Comparative Example 1. In addition, by using the method of Example 1, no nitric acid, cyanide, sulfur dioxide, alkali, or other reagents are used, and the acid is truly regenerated and used, achieving zero emission. The specific implementation technical and economic indicators are shown in Table 1.

[0058] Table 1 Effect Comparison of Example 1 and Comparative Example 1

[0059]

[0060] Example 2

[0061] For rare and valuable materials 100 kg containing selenium 11.9%, tellurium 17.8%, gold 15.0%, platinum 0.146%, palladium 11.93%, and rhodium 0.0064%, the operation steps of Example 2 are as follows:

[0062] Step 1: Chlorination dissolution: according to the liquid-solid ratio 3:1, 36% hydrochloric acid 182.5 kg is added, water is added in the reaction kettle to prepare 300 L of hydrochloric acid solution containing 6 mol / L hydrochloric acid, the stirring is started, the complex rare and precious materials are slowly added and stirred, the temperature is raised to 65°C, 26% perchloric acid 43 kg is slowly added, the temperature of the oxidation process is controlled at 88°C, after the reaction is completed, 3 kg of complex rare and precious materials are added for stirring and chlorine removal, after the stirring is stopped and clarification, the upper chlorination liquid clarification liquid is extracted into the gold loading, the chlorination residue precipitated is left in the kettle and continues to chlorinate with the next batch of materials, and the process is recycled for three times, then filtration is performed to obtain 2.7 kg of chlorination residue, which is used as a raw material for recovering silver. The composition of the chlorination residue obtained by filtration is: 0.41% gold, 0.0011% platinum, 0.0957% palladium, 0.0041% rhodium, 11.65% tellurium, 1.82% selenium, 29.2% silver, and 3.51% lead, and the chlorination liquid clarification liquid 296 L is produced (containing 41.52 g / L gold, 0.51 g / L platinum, 4.147 g / L palladium, 0.0065 g / L rhodium, 60.76 g / L tellurium, and 41.39 g / L selenium).

[0063] Step 2: Gold recovery: the loading agent is prepared according to MIBK:TBP:sulfonated kerosene:chloroform = 35%:5%:55%:5%. The chlorination liquid in step 1 is loaded according to the flow ratio of the loading agent:chlorination liquid:1:6, and the gold is loaded in two stages (first stage and second stage) countercurrently. A potential meter is installed at the water phase outlet of the first stage loading reactor to monitor the potential value of the water phase. When the potential value decreases to 512 mV, the chlorination liquid is stopped. At this time, the first stage loaded gold liquid is pumped into the reduction reactor for reduction, and the second stage loading is switched to the first stage loading. After loading, 164 L of loaded gold liquid and 295 L of loaded liquid are obtained. The loaded gold liquid contains 74.87 g / L gold, <0.001 g / L platinum, <0.001 g / L palladium, and <0.001 g / L rhodium, which is sent to the reducer for reduction. The reducing agent is oxalic acid, which is prepared into 85 g / L oxalic acid solution 50 L. The reduction temperature is 92°C. The loaded gold liquid contains 0.007 g / L gold at the end of reduction. After reduction to the end point, static separation is performed for more than 10 minutes. The organic phase and the mixed crude gold powder after reduction are separated by filtration to obtain 49.6 L of reduced liquid and 12.28 kg of sponge gold with a gold grade of 99.996%. The reduced liquid is evaporated in an evaporator to produce concentrated liquid 1 (8 L) and condensed liquid (41 L). The concentrated liquid 1 is returned to the reduction process, and the condensed liquid is returned to step 1.

[0064] Step 3: The concentrated liquid 1 is cooled to 25°C and crystallized by stirring. After filtration, the crystallized liquid and residual oxalic acid are obtained. The crystallized liquid is returned to the gold loading process of step 2, and the residual oxalic acid is returned to the reduction process of the loaded gold liquid of step 2.

[0065] Step 4: Low temperature distillation: The liquid after loading in step 2 was pumped into a low temperature vacuum evaporator, the temperature in the low temperature distillation column was controlled at 70°C, the pressure in the distillation column was controlled at 61 kPa, low acid condensate 124 L (containing gold 0.0001 g / L, platinum 0.0001 g / L, palladium 0.0001 g / L, rhodium 0.0001 g / L, tellurium 0.876 g / L, selenium 0.877 g / L) and high acid condensate 104 L (containing gold <0.0001 g / L, palladium <0.0001 g / L, rhodium <0.0001 g / L, tellurium 1.34 g / L, selenium 1.41 g / L) were distilled out, the high acid condensate was returned to step 1 as hydrochloric acid, the low acid condensate was used in step 6 for washing, concentrated liquid 2 (67 L) was produced, containing gold 0.0147 g / L, platinum 2.227 g / L, palladium 18.31 g / L, rhodium 0.096 g / L, tellurium 263.67 g / L, selenium 178.67 g / L. + 2.6 g / L), high acid condensate was returned to step 1 as hydrochloric acid, low acid condensate was used in step 6 for washing, concentrated liquid 2 (67 L) was produced, containing gold 0.0147 g / L, platinum 2.227 g / L, palladium 18.31 g / L, rhodium 0.096 g / L, tellurium 263.67 g / L, selenium 178.67 g / L.

[0066] Step 5: High temperature distillation: The concentrated liquid 2 in step 4 was transferred to a high temperature evaporator, the temperature was further increased to 96°C, the pressure in the evaporator was controlled at 68 kPa, residual moisture was removed until crystalline material was produced, concentrated liquid 3 was produced.

[0067] Step 6: Directional crystallization and centrifugal filtration: The concentrated liquid 3 (32 L) produced in step 5, containing gold 0.306 g / L, platinum 4.66 g / L, palladium 38.245 g / L, rhodium 0.200 g / L, tellurium 545.35 g / L, selenium 372.67 g / L, was cooled to 73°C, directional crystallization was carried out, and crystalline residue 27.36 kg (containing gold 0.035%, platinum 0.544%, palladium 4.467%, rhodium 0.023%, tellurium 63.407%, selenium 3.504%) and selenous acid 16.83 L (containing gold 0.0004 g / L, platinum 0.04 g / L, palladium 0.159 g / L, rhodium 0.0067 g / L, tellurium 50.64 g / L, selenium 606.25 g / L) were obtained by centrifugal filtration.

[0068] Step 7: The crystalline residue in step 6 was washed by cold water or the low acid condensate produced in step 4, the pH during the washing process was controlled at 2-3, after washing, filtration was carried out to obtain tellurium residue 63.4 kg (containing gold <0.0001%, platinum <0.0001, palladium 0.001%, rhodium <0.0001%, tellurium 56.55%, selenium 0.19%) and palladium platinum rhodium rich liquid (containing gold 0.004 g / L, platinum 4.52 g / L, palladium 13.11 g / L, rhodium 0.209 g / L, tellurium 35.76 g / L, selenium 4.491 g / L).

[0069] Comparative Example 2: Method for implementation:

[0070] For the composition of the waste acid treated in Example 2, the water solution chlorination method is used to dissolve to obtain a chlorination solution containing noble metals - neutralize and adjust pH - reduce and precipitate gold - precipitate platinum palladium by ammonium chloropalladate, and the specific operation steps are as follows:

[0071] (1) According to the liquid-solid ratio of 3:1, 80 g / L hydrochloric acid, sodium chlorate 15 kg, control the temperature 95℃, stirring for 4 hours after dissolution, obtain chlorination solution 297L (containing gold 48.9g / L, palladium 3.84g / L, platinum 0.463g / L, rhodium 0.0197g / L, selenium 32.14g / L, tellurium 56.87g / L), chlorination residue 16.3kg (gold 5.99%, palladium 0.551%, rhodium 0.0046%, platinum 0.076%, tellurium 8.64%, selenium 16.9%).

[0072] (2) The chlorination solution obtained in step (1) is neutralized to pH=2 by adding sodium hydroxide, and the neutralized solution 278L (containing gold 51.96g / L, palladium 4.212g / L, platinum 0.514g / L, rhodium 0.0236g / L, tellurium 61.746g / L, selenium 5.38g / L) is obtained by filtration, and the neutralization residue 4.8kg contains gold 21.95%, palladium 4.7%, platinum 0.15%, rhodium 0.0011%, tellurium 23.64%, selenium 0.34%.

[0073] (3) The neutralized solution produced in step (2) is heated to 90℃, and 5kg of oxalic acid is added to reduce to obtain about 14.446kg of gold powder with gold grade of 99.9%, and the reduced solution 273L is produced

[0074] (4) The reduced solution produced in step (3) is controlled at a temperature of 59℃, and sodium chlorate 6kg is slowly added to produce ammonium chloropalladate 4.2kg, containing gold 0.281%, palladium 24.73%, platinum 3.0%, rhodium 0.083%, tellurium 0.41%, selenium 0.22%. The palladium precipitation solution contains gold 1.86g / L, platinum 0.06g / L, palladium 0.49g / L, rhodium 0.011g / L, tellurium 63.517g / L, selenium 34.7g / L.

[0075] Effect comparison of Example 2:

[0076] From the rare and precious material containing selenium 11.9%, tellurium 17.8%, gold 15.0%, platinum 0.146%, palladium 11.93%, rhodium 0.0064, gold powder 99.99% is recovered, and palladium platinum rhodium rich solution is recovered, and the metal direct recovery rate is shown in Table 2. The direct recovery rate and recovery rate of each metal in Example 2 are better than those in Comparative Example 2. In addition, by using the method of Example 2, no nitric acid, cyanide, sulfur dioxide, alkali and other reagents are used, and the acid is truly regenerated and used, achieving the purpose of zero emission. The specific implementation technical and economic indicators are shown in Table 2.

[0077] Table 2 Effect comparison of Example 2 and Comparative Example 2

[0078]

[0079] Example 3

[0080] For 100 kg of rare and precious material containing 19.2% selenium, 3.2% tellurium, 51.1% gold, 0.35% platinum, 2.17% palladium, and 0.0071% rhodium, the operation steps of Example 3 are as follows:

[0081] Step 1: Chlorination dissolution, 365 kg of 36% hydrochloric acid is added according to the liquid-solid ratio of 6:1, water is added in the reaction kettle to prepare 600 L of hydrochloric acid solution containing 6 mol / L hydrochloric acid, stirring is started, and the complex rare and precious material is slowly added for stirring. The complex rare and precious material and the hydrochloric acid aqueous solution are stirred and reacted in the reaction kettle, the temperature is raised to 70°C, 48 kg of 30% perchloric acid is slowly added, the temperature of the oxidation process is controlled at 95°C, and after the reaction is completed, 3 kg of complex rare and precious material is added for stirring to remove chlorine. After stopping stirring and clarifying, the upper chlorination liquid clarified liquid is extracted into the gold upper load, and the chlorination residue precipitated is left in the kettle for chlorination dissolution with the next batch of material. After four cycles in turn, 2.4 kg of chlorination residue is obtained by filtration, which is used as the raw material for recovering silver. The composition of the chlorination residue obtained by filtration is: 1.98% gold, 0.003% platinum, 0.196% palladium, 0.005% rhodium, 2.37% tellurium, 3.3% selenium, 34.1% silver, and 2.92% lead. The chlorination liquid clarified liquid 597 L is obtained (containing 88.20 g / L gold, 0.60 g / L platinum, 3.74 g / L palladium, 0.012 g / L rhodium, 5.43 g / L tellurium, and 33.03 g / L selenium).

[0082] Step 2: Gold recovery: The loading agent was prepared by mixing MIBK, TBP, sulfonated kerosene and chloroform in the ratio of 40%, 5%, 50% and 5% respectively. The chlorination solution prepared in step 1 was loaded with gold by countercurrent loading in two stages (stage 1 and stage 2) at a flow ratio of loading agent to chlorination solution of 1:0.8. A potentiometer was installed at the outlet of the water phase in the loading reactor to monitor the potential value of the water phase. When the potential value decreased to 503 mV, the chlorination solution was stopped. At this time, the gold-loaded solution in stage 1 was pumped into the reduction reactor for reduction, and stage 2 loading was switched to stage 1 loading. After loading, 745 L of gold-loaded solution and 596 L of post-loading solution were obtained. The gold-loaded solution contained 70.55 g / L of gold and <0.001 g / L of platinum, palladium and rhodium, which was sent to the reducer for reduction. The reducer was oxalic acid, which was prepared into an oxalic acid solution of 85 g / L, 62 L. The reduction temperature was 93°C. The gold-loaded solution at the end of reduction contained 0.014 g / L of gold. The reduction was stopped at the end point and static separation was carried out for more than 10 minutes. The organic phase and the mixed crude gold powder after reduction were separated by filtration to obtain 61 L of post-reduction solution and 52.647 kg of sponge gold with a gold grade of 99.996%. The post-reduction solution was evaporated in an evaporator to obtain concentrated solution 1 (37 L) and condensate (706 L). The concentrated solution 1 was returned to the reduction process, and the condensate was returned to step 1.

[0083] Step 3: The concentrated solution 1 was cooled to 24°C and stirred to crystallize. After filtration, the crystallized solution was obtained and residual oxalic acid was obtained. The crystallized solution was returned to the gold loading process of step 2, and the residual oxalic acid was returned to the reduction process of the gold-loaded solution of step 2.

[0084] Step 4: Low-temperature distillation: The post-loading solution of step 2 was pumped into a low-temperature vacuum evaporator. The liquid temperature in the low-temperature distillation column was controlled at 62°C, and the pressure in the distillation column was 58 kPa. Low-acid condensate 325 L (containing 0.0001 g / L of gold, 0.0001 g / L of platinum, 0.0001 g / L of palladium, 0.0001 g / L of rhodium, 0.08 g / L of tellurium and 0.539 g / L of selenium) and high-acid condensate 184 L (containing <0.0001 g / L of gold, <0.0001 g / L of palladium, <0.0001 g / L of rhodium, 0.211 g / L of tellurium, 1.50 g / L of selenium and 2.2 g / L of H + 2.2 g / L) were distilled. The high-acid condensate was returned to step 1 as hydrochloric acid, and the low-acid condensate was used for washing in step 6. Concentrated solution 2 (87 L) containing 0.042 g / L of gold, 4.116 g / L of platinum, 25.68 g / L of palladium, 0.082 g / L of rhodium, 36.39 g / L of tellurium and 221.04 g / L of selenium was obtained.

[0085] Step 5: High temperature distillation: The concentrated solution 2 of step 4 was transferred to a high temperature evaporator, the temperature was further increased to 98°C, the pressure in the evaporator was controlled to 71 kPa, and the residual water was removed until crystals were produced, resulting in concentrated solution 3.

[0086] Step 6: Directional crystallization and centrifugal filtration: The concentrated solution 3 (62 L) released in step 5 contained 0.058 g / L of gold, 5.78 g / L of platinum, 36.01 g / L of palladium, 0.114 g / L of rhodium, 48.62 g / L of tellurium, and 309.66 g / L of selenium. The temperature was lowered to 71°C, directional crystallization was performed, and centrifugal filtration was used to obtain 27.36 kg of crystalline residue (containing 0.035% of gold, 0.544% of platinum, 4.467% of palladium, 0.023% of rhodium, 63.407% of tellurium, and 3.504% of selenium) and 16.83 L of selenous acid (containing 0.0004 g / L of gold, 0.04 g / L of platinum, 0.159 g / L of palladium, 0.0067 g / L of rhodium, 50.64 g / L of tellurium, and 606.25 g / L of selenium).

[0087] Step 7: The crystalline residue in step 6 was washed with cold water or the low-acid condensate produced in step 4, and the pH during the washing process was controlled to be 2-3. After washing, filtration was performed to obtain 5.8 kg of tellurium residue (containing <0.0001% of gold, <0.0001% of platinum, 0.001% of palladium, <0.0001% of rhodium, 50.48% of tellurium, and 14.24% of selenium) and a palladium-platinum-rhodium-rich liquid (containing 0.117 g / L of gold, 13.70 g / L of platinum, 85.52 g / L of palladium, 0.269 g / L of rhodium, 2.65 g / L of tellurium, and 27.61 g / L of selenium).

[0088] Comparative Example 3: Implementation method:

[0089] For the composition of the waste acid treated in Example 3, a water solution chlorination method was used to dissolve the chlorinated liquid containing noble metals - neutralize and adjust pH - reduce and precipitate gold - precipitate platinum palladium with ammonium chloropalladate. The specific operation steps are as follows:

[0090] (1) According to the liquid-solid ratio of 6:1, 60 g / L hydrochloric acid, and sodium chlorate 22 kg, the temperature was controlled at 90°C, and after stirring for 4 hours, 596 L of chlorinated liquid was obtained (containing 82.85 g / L of gold, 0.554 g / L of platinum, 3.84 g / L of palladium, 0.011 g / L of rhodium, 5.11 g / L of tellurium, and 25.78 g / L of selenium), and 14.2 kg of chlorinated residue (containing 23.38% of gold, 0.21% of platinum, 1.15% of palladium, 0.0059% of rhodium, 1.79% of tellurium, and 31.23% of selenium).

[0091] (2) The chlorination solution obtained in step (1) is neutralized to pH = 2 by adding sodium hydroxide, and a neutralized solution 278 L (containing gold 51.96 g / L, platinum 0.514 g / L, palladium 4.212 g / L, rhodium 0.0236 g / L, tellurium 61.746 g / L, selenium 5.38 g / L) and a neutralized residue 9.2 kg (containing gold 36.50%, platinum 0.136%, palladium 0.835%, rhodium 0.0006%, tellurium 1.72%, selenium 2.51%) are obtained by filtration.

[0092] (3) The neutralized solution obtained in step (2) is heated to 90°C, and oxalic acid 15 kg is added to reduce the gold powder with a gold grade of 99.9% to about 46.02 kg (after washing), and a reduced solution 593 L is obtained.

[0093] (4) The reduced solution obtained in step (3) is controlled at a temperature of 59°C, and sodium chlorate 6 kg is slowly added to obtain ammonium chloropalladate 7.2 kg (containing gold 0.015%, palladium 24.62%, platinum 3.90%, rhodium 0.0476%, tellurium 0.04%, selenium 0.21%), and a palladium precipitation solution 591 L (containing gold 0.126 g / L, platinum 0.061 g / L, palladium 0.38 g / L, rhodium 0.005 g / L, tellurium 4.48 g / L, selenium 25.60 g / L) is obtained.

[0094] Effect comparison of Example 3:

[0095] From the rare and precious material containing selenium 19.2%, tellurium 3.2%, gold 51.1%, platinum 0.35%, palladium 2.17%, and rhodium 0.0071%, gold powder 99.99% is recovered, and palladium platinum rhodium rich solution is recovered, and the direct recovery rate of each metal is shown in Table 3. The direct recovery rate and recovery rate of each metal in Example 3 are better than those in Comparative Example 3. In addition, by using the method of Example 3, no nitric acid, cyanide, sulfur dioxide, alkali and other reagents are used, and the acid is truly regenerated and used, achieving the purpose of zero emission. The specific implementation technical and economic indicators are shown in Table 3.

[0096] Table 3 Effect comparison of Example 3 and Comparative Example 3 is shown in the following table:

[0097]

[0098] In order to further prove the beneficial effects of the present application and better understand the present application, the technical features disclosed in the present application are further illustrated by the following comparative examples, but it should not be understood as a limitation of the present application. Other improvements without creative work made by those skilled in the art according to the above invention content are also considered to fall within the protection scope of the present application.

[0099] The foregoing description of the disclosed embodiments enables one skilled in the art to make or use the application. Numerous modifications of those embodiments can be apparent to those of skill in the art, and the general principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not to be limited to the implementations described herein but is to be accorded the broadest scope permissible by the principles and novel features set forth herein.

[0100] The above embodiments are only used to illustrate the technical solutions of the present application, rather than limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A process for the hydrometallurgical recovery of a plurality of metals from complex precious material, characterized in that, It comprises the following steps: Step 1: chlorination dissolution, adding hydrochloric acid aqueous solution, complex rare and precious materials into a reaction kettle, stirring and reacting, heating to 60-70℃, slowly adding oxidant, after the reaction is completed, adding a small amount of complex rare and precious materials to stir and remove chlorine, stopping stirring to clarify, then pumping the upper chlorination liquid into gold loading, the chlorination residue precipitated is used as raw material for recovering silver; the technical conditions are controlled as follows: the concentration of hydrochloric acid aqueous solution is 5-7 mol / L, the liquid-solid ratio is 3-6:1, and the oxidation process temperature is 80-95℃; Step 2: gold loading, using two-stage countercurrent gold loading, after the chlorination liquid is loaded, loaded gold liquid and post-loading liquid are obtained, the loaded gold liquid is reduced to the end point, static separation is carried out, the organic phase is clarified, and the precipitate is filtered to separate the post-reduction liquid and sponge gold; the post-reduction liquid is evaporated and concentrated to produce concentrated liquid 1 and condensate; Step 3: cooling the concentrated liquid 1 in step 2 to <30℃, stirring and crystallizing, and then filtering to obtain crystallized liquid and residual oxalic acid, wherein the crystallized liquid returns to the gold loading process in step 2, and the residual oxalic acid returns to the reduction process of the loaded gold liquid in step 2; Step 4: low-temperature distillation, the post-loading liquid in step 2 is subjected to low-temperature distillation, the liquid temperature in the low-temperature distillation tower is controlled to be 60-75℃, and the pressure in the distillation tower is 55-65 kPa; low-acid condensate and high-acid condensate are distilled out, the high-acid condensate returns to step 1 as hydrochloric acid, the low-acid condensate enters step 6 for washing, and the post-distillation residue is concentrated liquid 2; Step 5: high-temperature distillation, the concentrated liquid 2 in step 4 is subjected to high-temperature distillation, the high-temperature distillation temperature is 90-100℃, and the pressure in the evaporator is 60-80 kPa; residual water is removed to obtain concentrated liquid 3; Step 6: directional crystallization and centrifugal filtration, the concentrated liquid 3 is subjected to directional crystallization and centrifugal filtration to obtain crystalline residue and selenous acid; Step 7: washing, the crystalline residue is washed by cold water or the low-acid condensate produced in step 4, and filtered to obtain tellurium residue and palladium-platinum-rhodium rich liquid.

2. The process for recovering multiple metals in a complex precious material by a full wet method according to claim 1, characterized in that, The complex rare and precious material comprises, in mass percentage, selenium 3-20%, tellurium 3-40%, gold ≥1%, platinum ≥0.1%, palladium ≥0.1%, rhodium ≥0.005%, and other impurities <30%, and the selenium, tellurium, gold, platinum, palladium and rhodium are in the form of elementary phase.

3. The process as claimed in claim 1, wherein the process is characterized by, The specific operation of the gold loading in step 2 is as follows: the flow ratio of the chlorination liquid to the loading agent is 1:0.8-8, two-stage countercurrent gold loading is adopted by using the loading counter-tower 1 and the loading tower 2, and after loading, loaded gold liquid and post-loading liquid are obtained, the loaded gold liquid is sent to a reduction reaction kettle for reduction, static separation is carried out after reduction to the end point, the liquid is static for more than 10 minutes, the organic phase is clarified, and the precipitate is filtered to separate the post-reduction liquid and sponge gold; the post-reduction liquid is evaporated and concentrated to produce concentrated liquid 1 and condensate; the concentrated liquid 1 returns to the reduction process, and the condensate returns to step 1 to supplement hydrochloric acid aqueous solution.

4. The process as claimed in claim 1, wherein the process is a process for recovering multiple metals from complex precious material in a full wet process. The step 2 in 2-stage uploading reaction kettle includes the first stage uploading reaction kettle and the second stage uploading reaction kettle, a potentiometer is installed at the water phase outlet of the first stage uploading reaction kettle to monitor the potential value of the water phase, when the potential value is reduced to <520 mV, the input of the chlorination liquid is stopped, at this time, the first stage gold-loaded liquid pump is pumped to the reduction reaction kettle for reduction, and the second stage uploading reaction kettle is switched to the first stage uploading reaction kettle.

5. The process as claimed in claim 1, wherein the process is a process for recovering multiple metals from complex precious material in a full wet process. The gold-loaded liquid in step 2 is sent into the reactor for reduction, the temperature is controlled to be 90-95 DEG C, and the reduction end point gold-loaded liquid contains <0.1 g / L of gold; the reducing agent used in step 2 reduction is oxalic acid.

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