System for efficiently recovering gold and silver from waste gold and silver smelting graphite crucible

Abstract

The utility model relates to a system for efficiently recovering gold and silver from a waste gold and silver smelting graphite crucible. The system comprises a sanding machine, and a discharge port of the sanding machine is connected with a feed port of a ball mill; a discharge hole of the ball mill is connected with an inlet of the material distribution box through a slurry mixing barrel A and a slurry pump A; a rotational flow outlet of the material distribution box is connected with the feeding end of the spiral chute, a concentrate outlet and a middling outlet of the spiral chute are connected with the first-stage shaking table feeding groove through a size mixing barrel B and a slurry pump B, and a concentrate outlet and a middling outlet of the first-stage shaking table are connected with the second-stage shaking table feeding groove through a size mixing barrel C and a slurry pump C. The system is used for smelting a graphite crucible from waste gold and silver, and adopts a dressing-smelting combined process system to deeply remove impurities and continuously enrich gold and silver; the problems of refractory pyrometallurgy, insufficient oxidizing roasting, gold robbing of carbonaceous substances leached by a wet method, high unit energy consumption or high water consumption and the like caused by huge amount of carbonaceous substance gangue in the traditional process of the waste gold and silver smelting graphite crucible slag are solved, and the recovery of gold and silver dispersed in the waste gold and silver smelting graphite crucible is effectively realized.

Description

TECHNICAL FIELD

[0001] The utility model belongs to solid waste recycling technical field, concretely relates to a system for efficiently recovering gold and silver from waste gold and silver smelting graphite crucible. BACKGROUND

[0002] Gold and silver metallurgical industry generally adopts medium (high) frequency induction furnace to carry out gold and silver smelting, refining, smelting and other operations, and generally uses high-density graphite crucible, graphite clay crucible or graphite silicon carbide crucible as smelting furnace. These crucibles will be subjected to mechanical scouring of gold and silver liquid, internal pressure, flux corrosion, high-temperature oxidation and other effects during use, resulting in gradual peeling of the dense layer or glaze layer on the inner lining surface, and the gold and silver molten liquid disperses into the pores or gaps of the crucible wall in the form of small particles. In gold and silver metallurgy, graphite, graphite clay and graphite silicon carbide all belong to difficult-to-treat carbonaceous material gangue components. During fire smelting, carbonaceous material greatly increases the melting point of slag, affects the fluidity of slag, and reduces the metal recovery rate. During wet extraction, carbonaceous material has a strong "gold robbing" effect, and a small amount of carbon, especially organic carbon, can greatly reduce the gold and silver leaching rate. Therefore, in theory, gold and silver raw materials containing carbonaceous material are usually subjected to oxidation roasting to oxidize carbonaceous material, so as to eliminate the adverse effects of high melting point of carbonaceous material on fire smelting and the "gold robbing" effect on wet metallurgy.

[0003] At present, there are few researches or applications on recovering gold, silver or other valuable metals from metal smelting waste graphite crucible. CN108823416B discloses a method for extracting gold and silver from clay graphite crucible slag, which makes the crucible slag first react with a mixed solution of sulfuric acid and fluorosilicic acid, then calcines at 900-1000℃, and finally separates gold and silver by acid and aqua regia leaching methods respectively. CN109055767A discloses a method for extracting gold and silver from clay graphite crucible slag by alkali roasting, which is aimed at the same crucible slag as CN108823416B, and uses alkali roasting, water washing and acid washing, and finally separates gold and silver by acid and aqua regia leaching methods respectively. However, the above two methods are directly aimed at a large amount of graphite clay crucible slag, or first wet or first fire impurity removal, and the impurity removal effect is not good, with the highest impurity removal rate of only 42.69%, and a large amount of wastewater is generated by first wet impurity removal, and a huge energy consumption is required by first fire impurity removal. In addition, the amount of enriched slag after impurity removal is still large, and at this time, direct nitric acid silver separation and aqua regia gold separation exist on one hand the "gold robbing" of the carbonaceous material not fully oxidized, and on the other hand the gold and silver production practice shows that trace amounts of gold and silver (impurity composition as high as 99.95%) are difficult to be effectively recovered by aqua regia gold separation or nitric acid silver separation, and there is still a large amount of gold and silver residue in the gold separation residue and silver separation residue.

[0004] For the recovery of gold and silver in waste graphite crucible smelting, if the broken graphite crucible slag is directly smelted, it is difficult to melt due to the high content of graphite (graphite melting point 3652℃); if the crucible slag is fully oxidized and roasted, there are problems of large roasting treatment, low ashing efficiency, insufficient oxidation, high unit energy consumption and the like; if the wet process is used, due to the 'gold robbing' effect of carbonaceous material, it is difficult to effectively recover the relatively low gold and silver from a large amount of graphite carbon powder; if the conventional fire-wet combined process is used, the common problems of the two methods exist. Therefore, under the existing process equipment conditions, there is almost no effective method for the gold and silver smelting enterprise to systematically recover the dispersed gold and silver in the waste graphite crucible for gold and silver smelting.

[0005] In order to recover part of the dispersed gold and silver in the waste graphite crucible for gold and silver smelting, only a small amount of gold and silver can be recovered by manually cleaning the inner wall surface of the crucible and then washing, and most of the dispersed gold and silver still remains in the crucible wall, with gold or silver content as high as 200-450g / t. These dispersed gold and silver in the crucible wall can only be sold to non-ferrous smelting plants together with the crucible at a low valuation coefficient of 10%-25% for gold and 5%-10% for silver, and used as a small amount of reduction smelting additive to gradually recover the dispersed loss of gold and silver. However, for the gold and silver smelting enterprise, the total recovery rate of gold or silver is only 5%-25%, and the gold and silver cannot be effectively recovered and utilized, resulting in the loss of valuable resources.

[0006] In order to solve the problem of the recovery of dispersed gold and silver in the waste graphite crucible for gold and silver smelting, the present application provides a method for efficiently recovering gold and silver from waste graphite crucible for gold and silver smelting, which is simple, economical, feasible, environmentally friendly and has strong adaptability. Content of the application

[0007] In view of the above problems, the present application provides a method for efficiently recovering gold and silver from waste graphite crucible for gold and silver smelting, which is simple, economical, feasible, environmentally friendly and has strong adaptability.

[0008] The specific technical scheme of the present application is: a system for efficiently recovering gold and silver from waste graphite crucible for gold and silver smelting, comprising a sanding machine, the discharge port of the sanding machine being connected with the feed inlet of a ball mill; the discharge port of the ball mill is connected with the inlet of a distribution box through a slurry tank A and a slag slurry pump A;

[0009] The spiral chute fine ore outlet and the spiral chute middling outlet are connected with the first-stage table feed tank through the thickener B and the slurry pump B, the first-stage table fine ore outlet and the first-stage table middling outlet are connected with the second-stage table feed tank through the thickener C and the slurry pump C, the second-stage table middling outlet is connected with the thickener B inlet, and the second-stage table fine ore outlet is connected with the filter tank B inlet.

[0010] The filter tank B filter residue outlet is connected with the muffle furnace feed port, the muffle furnace discharge port is connected with the autoclave feed port, the autoclave discharge port is connected with the filter tank C inlet, the filter tank C filter residue outlet is connected with the glass reaction kettle feed port, the glass reaction kettle discharge port is connected with the filter tank D inlet, and the filter tank D filter residue outlet is the coarse gold powder or the coarse silver powder.

[0011] Further, preferably, the spiral chute tailing pulp outlet and the second-stage table tailing pulp outlet are connected with the filter tank A inlet, the filter tank A filtrate outlet is connected with the sedimentation tank, and the filter tank A filter residue outlet is the tailing residue.

[0012] Further, preferably, the filter tank B filtrate outlet is connected with the sedimentation tank.

[0013] Further, preferably, the filter tank C filtrate outlet and the filter tank D filtrate outlet are connected with the waste water tank.

[0014] Further, preferably, the spiral chute is a single-head chute, the cross-sectional width of which is 25-30 cm, the transverse inclination angle of which is 9-12°, and the number of blade turns of which is 5-8.

[0015] Further, preferably, the first-stage table and the second-stage table are both small fine sand tables, the sieve surface of which is 60-88 slots, the transverse slope of which is 1.5-3.5°, and the longitudinal slope of which is 0.5-1.5°; the stroke of the first-stage table is 12-15 mm, and the stroke frequency is 250-280 times / min, the stroke of the second-stage table is 8-12 mm, and the stroke frequency is 300-340 times / min.

[0016] Further, preferably, the muffle furnace controls the working temperature to be 600-900℃.

[0017] Further, preferably, the autoclave controls the total reaction pressure to be 2.0-5.0 Mpa, the oxygen partial pressure to be 0.1-0.5 Mpa, the reaction temperature to be 140-180℃, and the reaction time to be 1-2.5 h.

[0018] Further, preferably, the glass reaction kettle controls the reaction temperature to be 50-70℃, the stirring speed to be 200-300 r / min, and the reaction time to be 1-2 h.

[0019] The embodiment also provides a method for efficiently recovering gold and silver from a waste gold and silver smelting crucible by using the recovery system.

[0020] (1) Crucible classification, pretreatment, crushing and fine grinding: After cleaning the gold (silver) adhering to the inner wall of the gold (silver) smelting crucible with a shovel, add it to the sand crusher while watering (watering reduces graphite dust). The crushed slag is sent to the ball mill for fine grinding for 1.5 to 3 hours to obtain crucible slag with a particle size of -0.074 mm or more of 85%. After being thoroughly mixed several times, it is spread evenly to a slag layer thickness of about 3 cm and repeatedly sampled. The sample is analyzed for gold (silver) and main impurity components.

[0021] (2) Spiral chute pre-enrichment: Mix crucible slag and water at a weight ratio of 1:3 to 1:6 to make a slurry, and then introduce it into the top distribution box of the spiral chute. The stirring paddle in the box rotates at 300 r / min. Control the opening of the bottom valve of the box to make the slurry flow from top to bottom. The feed rate is 200-300 kg / h. The transverse inclination angle of the chute is 9-12° and the number of blades is 5. The interception valve at the end of the chute is adjusted according to the distribution of the concentrate and middlings. The mixture of spiral concentrate and middlings is the pre-enriched slag. The tailings are filtered and dried to obtain spiral tailings for sale. The filtrate and tailings are discharged into the settling tank for reuse.

[0022] (3) Two-stage fine sand shaking table beneficiation: The pre-enriched slag is fed into a first-stage shaking table for separation. The first-stage shaking table has 60-88 slots, a transverse slope of 1.5-3.5°, a longitudinal slope of 0.5-1.5°, a stroke of 12-15 mm, a stroke rate of 250-280 times / min, a feed rate of 100-200 kg / h, a feed concentration of 25%-35%, and a washing water rate of 15-35 L / min to obtain first-stage concentrate, middlings and tailings.

[0023] The primary concentrate and middlings are fed into a secondary shaking table for further separation. The secondary shaking table has a screen with 60-88 slots, a transverse slope of 1.5-3°, a longitudinal slope of 0.5-1.5°, a stroke of 8-12 mm, a stroke rate of 300-340 times / min, a feed rate of 100-150 kg / h, a feed concentration of 20%-30%, and a washing water rate of 15-20 L / min. This process yields secondary concentrate, middlings, and tailings. The secondary concentrate is filtered and dried to obtain gold (silver) rich slag. The secondary middlings are returned to the primary shaking table for further separation. The primary and secondary tailings are mixed, filtered, and dried to obtain shaking table tailings for sale. The filtrate and tailings are discharged into a settling tank for reuse.

[0024] (4) Oxidation roasting and ashing of gold (silver) slag: Add potassium nitrate at 2% to 5% of the weight of gold slag, mix evenly, spread evenly with a thickness of 0.5 to 2.0 cm, roast for 3 to 6 hours under the conditions of working temperature of 600 to 900℃ in muffle furnace and furnace door open 2 to 5 cm to obtain ashing slag.

[0025] (5) High temperature and high pressure strong alkali leaching: The ashing residue is mixed with a sodium hydroxide solution with a concentration of 2-5 mol / L at a liquid-solid ratio of 4:1-6:1. 1.0%-2.5% potassium nitrate by weight of the ashing residue is added as a catalyst. The mixture is introduced into a stainless steel high-pressure reactor. The total pressure in the reactor is controlled at 2.0-5.0 MPa, the oxygen partial pressure at 0.1-0.5 MPa, the reaction temperature at 140-180℃, and the reaction time at 1-2.5 h. The mixture is cooled, filtered, and washed to obtain alkali leaching residue. The filtrate is discharged into the wastewater tank.

[0026] (6) Deep purification by dilute acid leaching: The alkali leaching residue is mixed with dilute hydrochloric acid with a molar mass of 3-5 mol / L at a liquid-solid ratio of 2:1-5:1. The temperature is controlled at 50-70℃, the stirring speed at 200-300 r / min, and the reaction time at 1-2 h. The mixture is then filtered and washed to obtain coarse gold powder or coarse silver powder. The filtrate is discharged into the wastewater tank.

[0027] The beneficial effects of this utility model are:

[0028] (1) This utility model adopts a combined beneficiation and smelting process system to deeply remove a large amount of graphite and other impurity components from the gold and silver smelting crucible slag, and obtains highly enriched gold and silver products that are easy to process by conventional refining and purification processes. This effectively solves the problem that gold and silver smelting enterprises were previously unable to efficiently recover dispersed gold and silver from waste gold and silver smelting graphite crucibles.

[0029] (2) This utility model utilizes the characteristic that the density of gold and silver is much greater than that of graphite powder to remove impurities by heavy separation. The impurity removal rate is as high as 95.29%, and the gold and silver enrichment ratio can reach 110 times. The separation effect is significant. It solves the problems of the huge amount of carbonaceous gangue in the waste gold and silver smelting graphite crucible slag in the traditional process, such as the difficulty in melting in pyrometallurgical process, insufficient oxidation roasting, "gold robbery" of carbonaceous matter in wet leaching, high unit energy consumption or large water consumption, and obtains gold and silver preliminary enrichment that is easy to process by metallurgical process.

[0030] (3) Based on the principle of continuous enrichment in precious metal extraction, this utility model adopts oxidation roasting and ashing, high temperature and high pressure alkali leaching and acid leaching to further remove impurities. The impurity removal rate is as high as 98.53%, gold is enriched 2560 times, silver is enriched 1897 times, the gold recovery rate is increased from 10% to 25% to 92.89%, and the silver recovery rate is increased from 5% to 10% to 88.62%, effectively realizing gold and silver recovery and achieving significant economic benefits.

[0031] (4) The process system of this utility model is efficient, simple, economical, environmentally friendly and adaptable. It has broad reference and promotion value for gold and silver recovery of carbonaceous resources in gold and silver smelting enterprises. Attached Figure Description

[0032] Figure 1This is an equipment diagram illustrating a system for efficiently recovering gold and silver from waste gold and silver smelting graphite crucibles, as described in Example 1.

[0033] Figure 2 Example 2 shows a process flow diagram of a system for efficiently recovering gold and silver from waste gold and silver smelting graphite crucibles;

[0034] In the diagram: 1-Sandblasting machine, 2-Ball mill, 3-Slurry mixing tank A, 4-Slurry pump A, 5-Distribution box, 6-Spiral chute, 7-Slurry mixing tank B, 8-Slurry pump B, 9-First-stage shaking table, 10-Slurry mixing tank C, 11-Slurry pump C, 12-Second-stage shaking table, 13-Filter tank B, 14-Muffle furnace, 15-High-pressure reactor, 16-Filter tank C, 17-Glass reactor, 18-Filter tank D, 19-Filter tank A, 20-Sedimentation tank, 21-Wastewater tank. Detailed Implementation

[0035] To make the technical problems and solutions solved by this utility model clearer, the present utility model will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present utility model and are not intended to limit the present utility model.

[0036] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0037] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Example 1

[0038] like Figure 1 As shown, this embodiment provides a system for efficiently recovering gold and silver from waste gold and silver smelting graphite crucibles, including a sandblasting machine 1, the discharge port of the sandblasting machine 1 being connected to the inlet of a ball mill 2; the discharge port of the ball mill 2 being connected to the inlet of a distribution box 5 via a slurry mixing tank A3 and a slurry pump A4;

[0039] The cyclone outlet of the feed box 5 is connected to the feed end of the spiral chute 6. The concentrate outlet and middlings outlet of the spiral chute 6 are connected to the feed trough of the first-stage shaking table 9 via the slurry mixing tank B7 and the slurry pump B8. The concentrate outlet and middlings outlet of the first-stage shaking table 9 are connected to the feed trough of the second-stage shaking table 12 via the slurry mixing tank C10 and the slurry pump C11. The middlings outlet of the second-stage shaking table 12 is connected to the inlet of the slurry mixing tank B7. The concentrate outlet of the second-stage shaking table 12 is connected to the inlet of the suction filter tank B13.

[0040] The filter residue outlet of filter tank B13 is connected to the feed inlet of muffle furnace 14. The discharge outlet of muffle furnace 14 is connected to the feed inlet of autoclave 15. The discharge outlet of autoclave 15 is connected to the inlet of filter tank C16. The filter residue outlet of filter tank C16 is connected to the feed inlet of glass reactor 17. The discharge outlet of glass reactor 17 is connected to the inlet of filter tank D18. The filter residue outlet of filter tank D18 is coarse gold powder or coarse silver powder.

[0041] The tailings slurry outlet of spiral chute 6 and the tailings slurry outlet of secondary shaking table 12 are connected to the inlet of filter tank A 19. The filtrate outlet of filter tank A 19 is connected to settling tank 20. The filter residue outlet of filter tank A 19 is tailings residue. The filtrate outlet of filter tank B 13 is connected to settling tank 20. The filtrate outlets of filter tank C 16 and filter tank D 18 are connected to wastewater tank 21. Example 2

[0042] like Figure 2 As shown, this embodiment also provides a method for efficiently recovering gold and silver from waste gold and silver smelting crucibles using the system described in Embodiment 1. The specific steps include:

[0043] (1) Crucible classification, pretreatment, crushing and fine grinding: After cleaning the gold (silver) adhering to the inner wall of the gold (silver) smelting crucible with a shovel, add sand crusher 1 while watering (watering reduces graphite dust). The crushed slag is sent to ball mill 2 for fine grinding for 1.5 to 3 hours to obtain crucible slag with a particle size of -0.074 mm or more of 85%. After being thoroughly mixed several times, it is spread evenly to a slag layer thickness of about 3 cm and repeatedly sampled. The sample is analyzed for gold (silver) and main impurity components.

[0044] (2) Spiral chute pre-enrichment: The crucible slag is transferred into the slurry mixing tank A3 and mixed with water at a weight ratio of 1:3 to 1:6. After mixing, the slurry is introduced into the distribution box 5 through the slurry pump A4. The stirring paddle speed in the box is 300 r / min. The opening of the bottom valve of the box is controlled so that the slurry flows from top to bottom to the spiral chute 6. The transverse inclination angle of the spiral chute 6 is 9 to 12° and the number of blades is 5. During the swirling process, the feed rate is controlled at 200 to 300 kg / h. The interception valve at the end of the chute is adjusted according to the distribution of the concentrate and middlings. The mixture of spiral concentrate and middlings is the pre-enriched slag. The tailings enter the suction filter tank A19 for filtration and drying to obtain the spiral tailings for sale. The filtrate and tailings are discharged into the settling tank 20 for reuse.

[0045] (3) Two-stage fine sand shaking table selection: The pre-enriched slag is fed into the slurry mixing tank B7 for slurry mixing, and the concentration is adjusted to 25% to 35%. The slurry is then pumped by the slurry pump B8 to the first-stage shaking table 9 for separation. The first-stage shaking table 9 has 60 to 88 screens, a transverse slope of 1.5 to 3.5°, a longitudinal slope of 0.5 to 1.5°, a stroke of 12 to 15 mm, and a stroke rate of 250 to 280 times / min. The feed rate during the separation process is controlled at 100 to 200 kg / h and the washing water rate is 15 to 35 L / min to obtain first-stage concentrate, middlings and tailings.

[0046] The primary concentrate and middlings are fed into the slurry mixing tank C10 for slurry mixing, with the concentration adjusted to 20%–30%. The slurry is then pumped by the slurry pump C11 to the secondary shaking table 12. The secondary shaking table 12 has 60–88 screens, a transverse slope of 1.5–3°, a longitudinal slope of 0.5–1.5°, a stroke of 8–12 mm, and a stroke rate of 300–340 strokes / min. The feed rate during the separation process is controlled at 100–150 kg / h, and the washing water rate is 15–20 L / min. This process yields secondary concentrate, middlings, and tailings. The secondary concentrate is filtered in the suction filter tank B13 and dried to obtain gold (silver) rich slag. The secondary middlings are returned to the slurry mixing tank B7 for further mixing before being fed into the primary shaking table 9 for further separation. The primary and secondary tailings are filtered in the suction filter tank A19 and dried to obtain shaking table tailings for sale. The filtrate and tailings from the suction filters B13 and A19 are discharged into the settling tank 20 for reuse.

[0047] (4) Oxidation, roasting and ashing of gold (silver) slag: The gold (silver) slag filtered out by the suction filter tank B13 is transferred into the muffle furnace 14, and potassium nitrate is added at 2% to 5% of the weight of the gold (silver) slag and mixed evenly. The mixture is spread evenly with a thickness of 0.5 to 2.0 cm. The working temperature of the muffle furnace 14 is 600 to 900℃ and the furnace door is open by 2 to 5 cm for roasting for 3 to 6 hours to obtain ashing slag.

[0048] (5) High-temperature and high-pressure strong alkali leaching: The ashing slag is transferred into the high-pressure reactor 15 and a sodium hydroxide solution with a concentration of 2-5 mol / L (liquid-solid ratio 4:1-6:1) is added and mixed. 1.0%-2.5% of potassium nitrate by weight of the ashing slag is added as a catalyst. The total pressure in the high-pressure reactor 15 is controlled at 2.0-5.0 MPa, the oxygen partial pressure at 0.1-0.5 MPa, the reaction temperature at 140-180℃, and the reaction time at 1-2.5 h. After the reaction is completed, the mixture is cooled and transferred to the suction filter tank C16 for filtration and washing to obtain the alkali leaching slag. The filtrate is discharged into the wastewater tank 21.

[0049] (6) Deep purification by dilute acid leaching: Transfer the alkali leaching residue into the glass reactor 17, add 3-5 mol / L of dilute hydrochloric acid (liquid-solid ratio 2:1-5:1) and mix. Control the reaction temperature at 50-70℃, the stirring speed at 200-300 r / min and the reaction time at 1-2 h. After the reaction is completed, transfer it to the vacuum filter tank D18 for filtration and washing to obtain coarse gold powder or coarse silver powder. The filtrate is discharged into the wastewater tank 21.

[0050] Example 2.1

[0051] The main components of the gold smelting crucible slag used in this embodiment are: Au 248.41 g / t, C 76.46%, SiO2 7.62%, Al2O3 2.06%, CaO 5.56%, Fe2O3 0.74%, MgO 1.69%, K2O 0.42%, H2O 4.33%, and others <1.12%.

[0052] The method described in Example 2 was applied to the slag sample. The results were as follows: 200.00 kg of crucible slag was combined with a spiral chute and a two-stage fine sand shaking table to obtain 1770.52 g of gold-rich slag with a gold content of 2.61%. The impurity removal rate reached 93.85%, the gold enrichment was 105 times, and the direct gold recovery rate was 92.91%, demonstrating significant separation effects. The gold-rich slag underwent enhanced impurity removal, achieving an impurity removal rate of 98.25% and yielding 76.34 g of coarse gold powder with a gold content of 60.45%. The cumulative gold enrichment throughout the process was 2434 times, and the comprehensive gold recovery rate was 92.89%. This effectively achieved deep removal of impurities such as graphite from the waste crucibles in gold smelting and high enrichment and efficient recovery of gold.

[0053] Example 2.2

[0054] The main components of the gold smelting crucible slag used in this embodiment are the same as those in Example 2.1.

[0055] The method described in Example 2 was applied to the slag sample. The results were as follows: 200.00 kg of crucible slag was combined with a spiral chute and a two-stage fine sand shaking table to obtain 1562.74 g of gold-rich slag with a gold content of 2.75%. The impurity removal rate reached 95.29%, the gold enrichment was 110 times, and the direct gold recovery rate was 86.49%, demonstrating significant separation effects. The gold-rich slag underwent enhanced impurity removal, achieving an impurity removal rate of 95.39% and yielding 72.09 g of coarse gold powder with a gold content of 59.19%. The cumulative gold enrichment throughout the process was 2383 times, and the comprehensive gold recovery rate was 85.89%. This effectively achieved deep removal of impurities such as graphite from the waste crucibles in gold smelting and high enrichment and efficient recovery of gold.

[0056] Example 2.3

[0057] The main components of the gold smelting crucible slag used in this embodiment are the same as those in Example 2.1.

[0058] The method described in Example 2 was applied to the slag sample. The results were as follows: 316.52 kg of crucible slag was combined with a spiral chute and a two-stage fine sand shaking table to obtain 2809.68 g of gold-rich slag with a gold content of 2.52%. The impurity removal rate reached 93.75%, the gold enrichment was 101 times, and the direct gold recovery rate was 89.69%, demonstrating significant separation effects. The gold-rich slag underwent enhanced impurity removal, achieving an impurity removal rate of 98.53% and yielding 110.89 g of coarse gold powder with a gold content of 63.59%. The cumulative gold enrichment throughout the process was 2560 times, and the overall gold recovery rate was 89.69%. This effectively achieved deep removal of impurities such as graphite from the waste crucibles in gold smelting and high enrichment and efficient recovery of gold.

[0059] Example 2.4

[0060] The main components of the silver smelting crucible slag used in this embodiment are: Ag 373.84 g / t, C 75.03%, SiO2 9.41%, Al2O3 2.49%, CaO 5.89%, Fe2O3 0.53%, MgO 1.75%, K2O 0.23%, H2O 3.86%, and others <0.81%.

[0061] The method described in Example 2 was applied to the slag sample. The results were as follows: 300.00 kg of crucible slag was combined with a spiral chute and a two-stage fine sand shaking table to obtain 2994.73 g of silver-rich slag, containing 3.21% silver. The impurity removal rate reached 95.17%, the silver enrichment was 88 times, and the direct silver recovery rate was 91.58%, demonstrating significant separation effects. The silver-rich slag underwent enhanced impurity removal, achieving an impurity removal rate of 95.50%, yielding 134.71 g of coarse silver powder, containing 70.93% silver. The total silver enrichment throughout the process was 1897 times, and the comprehensive silver recovery rate was 88.62%. This effectively achieved deep removal of impurities such as graphite from the waste crucibles in silver smelting and high enrichment and efficient recovery of silver.

[0062] Example 2.5

[0063] The main components of the silver smelting crucible slag used in this embodiment are the same as those in Example 2.4.

[0064] The method described in Example 2 was applied to the slag sample. The results were as follows: 400.00 kg of crucible slag was combined with a spiral chute and a two-stage fine sand shaking table to obtain 3714.64 g of silver-rich slag, containing 3.43% silver. The impurity removal rate reached 94.64%, the silver enrichment was 95 times, and the direct silver recovery rate was 91.58%, demonstrating significant separation effects. The silver-rich slag underwent enhanced impurity removal, achieving an impurity removal rate of 95.03%, yielding 184.61 g of coarse silver powder, containing 68.42% silver. The total silver enrichment was 1830 times, and the comprehensive silver recovery rate was 87.86%, effectively achieving deep removal of impurities such as graphite in the waste crucible from silver smelting and high enrichment and efficient recovery of silver.

[0065] The experimental results from Examples 2.1 to 2.5 show that using this method to treat waste gold and silver smelting graphite crucibles can effectively recover the gold and silver lost due to inclusions in the inner wall of the crucibles. The gold recovery rate has increased from 10%–25% (originally sold at a price) to 92.89%, and the resulting crude gold powder contains 63.59% gold, with a gold enrichment of 2560 times. The gold can then be efficiently purified and recovered using the aqua regia method. The silver recovery rate has increased from 5%–10% (originally sold at a price) to 88.62%, and the resulting crude silver powder contains 70.93% silver, with a silver enrichment of 1897 times. The silver can be directly recovered by electrolytically smelting and casting the anode plate.

[0066] The present invention has been described in detail above through specific and preferred embodiments. However, those skilled in the art should understand that the present invention is not limited to the embodiments described above. Any modifications or equivalent substitutions made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A system for efficient recovery of gold and silver from spent gold-silver smelting graphite crucibles, characterized by: The sanding machine (1) is connected with the ball mill (2) through the discharge port of the sanding machine (1) and the inlet of the ball mill (2); the ball mill (2) is connected with the distribution box (5) through the discharge port of the ball mill (2), the slurry tank A (3) and the slurry pump A (4); The spiral chute (6) is connected with the distribution box (5) through the cyclone outlet of the distribution box (5) and the feeding end of the spiral chute (6); the spiral chute (6) is connected with the first shaking table (9) through the concentrate outlet and the middling outlet of the spiral chute (6), the slurry tank B (7) and the slurry pump B (8); the first shaking table (9) is connected with the second shaking table (12) through the concentrate outlet and the middling outlet of the first shaking table (9), the slurry tank C (10) and the slurry pump C (11); the second shaking table (12) is connected with the slurry tank B (7) through the middling outlet of the second shaking table (12); the second shaking table (12) is connected with the filter tank B (13) through the concentrate outlet of the second shaking table (12). The filter tank B (13) is connected with the muffle furnace (14) through the filter residue outlet of the filter tank B (13) and the inlet of the muffle furnace (14); the muffle furnace (14) is connected with the autoclave (15) through the discharge port of the muffle furnace (14) and the inlet of the autoclave (15); the autoclave (15) is connected with the filter tank C (16) through the discharge port of the autoclave (15) and the inlet of the filter tank C (16); the filter tank C (16) is connected with the glass reaction kettle (17) through the filter residue outlet of the filter tank C (16) and the inlet of the glass reaction kettle (17); the glass reaction kettle (17) is connected with the filter tank D (18) through the discharge port of the glass reaction kettle (17) and the inlet of the filter tank D (18); the filter residue outlet of the filter tank D (18) is the coarse gold powder or the coarse silver powder.

2. The system for efficiently recovering gold and silver from waste gold-silver smelting graphite crucibles according to claim 1, characterized in that: The spiral chute (6) is connected with the filter tank A (19) through the tailing slurry outlet of the spiral chute (6) and the tailing slurry outlet of the second shaking table (12); the filter tank A (19) is connected with the sedimentation tank (20) through the filtrate outlet of the filter tank A (19); the filter residue outlet of the filter tank A (19) is the tailing residue.

3. The system for efficiently recovering gold and silver from waste gold-silver smelting graphite crucibles according to claim 1, characterized in that: The filter tank B (13) is connected with the sedimentation tank (20) through the filtrate outlet of the filter tank B (13).

4. The system for efficiently recovering gold and silver from waste gold-silver smelting graphite crucibles according to claim 1, characterized in that: The filter tank C (16) and the filter tank D (18) are connected with the wastewater tank (21) through the filtrate outlet of the filter tank C (16) and the filtrate outlet of the filter tank D (18).

5. The system for efficiently recovering gold and silver from waste gold-silver smelting graphite crucibles according to any one of claims 1-4, characterized in that: The spiral chute (6) is a single-head chute, the cross-sectional width of which is 25-30 cm, the transverse inclination angle of which is 9-12°, and the number of blade turns of which is 5-8.

6. The system for efficiently recovering gold and silver from waste gold-silver smelting graphite crucibles according to any one of claims 1-4, characterized in that: The first shaking table (9) and the second shaking table (12) are small fine sand shaking tables, the sieve surface of which is 60-88 slots, the transverse slope of which is 1.5-3.5°, and the longitudinal slope of which is 0.5-1.5°; the stroke of the first shaking table (9) is 12-15 mm, and the stroke frequency is 250-280 times / min; the stroke of the second shaking table (12) is 8-12 mm, and the stroke frequency is 300-340 times / min.

7. The system for efficiently recovering gold and silver from waste gold-silver smelting graphite crucibles according to any one of claims 1-4, characterized in that: The working temperature of the muffle furnace (14) is controlled to be 600-900℃.

8. The system for efficiently recovering gold and silver from waste gold-silver smelting graphite crucible according to any one of claims 1-4, characterized in that, The total pressure of the autoclave (15) is controlled to be 2.0-5.0 Mpa, the oxygen partial pressure is controlled to be 0.1-0.5 Mpa, the reaction temperature is controlled to be 140-180℃, and the reaction time is controlled to be 1-2.5 h.

9. The system for efficiently recovering gold and silver from waste gold-silver smelting graphite crucibles according to any one of claims 1-4, characterized in that, The reaction temperature of the glass reaction kettle (17) is controlled to be 50-70℃, the stirring speed is controlled to be 200-300 r / min, and the reaction time is controlled to be 1-2 h.

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