Device and method for separating and recovering gold and silver from aqua regia gold residue

Abstract

The invention relates to a device and method for separating and recovering gold and silver from aqua regia gold residue, and the device comprises a recovery crucible which is formed by connecting an upper-layer crucible body, a middle-layer crucible body and a lower-layer crucible body which are sequentially arranged from top to bottom; a smooth dome-shaped condensation cover is formed at the top of the upper-layer crucible body, a bucket-shaped backflow bearing piece is fixedly mounted at the upper end of the middle-layer crucible body, and a through hole penetrating through the backflow bearing piece is formed in the middle-layer crucible body; the fixing mechanism is adjusted, and the upper-layer crucible body, the middle-layer crucible body and the lower-layer crucible body are sequentially connected in an abutting mode and connected in a sealed mode to form the recycling crucible; a vacuum unit; the heating mechanism comprises an upper-layer heating piece and a lower-layer heating piece which are arranged at an interval up and down and are fixed on the inner side wall of the heat preservation furnace box; the chlorine gas absorption mechanism is mounted in the gas guide pipe and is used for absorbing and recovering chlorine gas discharged outwards from the crucible in a grading manner. Separation and recovery of aqua regia and gold and silver in residues are achieved, the gold and silver separation and recovery efficiency is effectively improved, gold and silver separation is thorough, the metal direct recovery rate is high, and the process is short.

Description

Technical Field

[0001] The present invention relates to the technical field of non-ferrous metal vacuum metallurgy, specifically to a device and method for separating and recovering gold and silver from aqua regia gold parting slag, involving pyrometallurgy of precious metals, and particularly to a device and method for separating and recovering gold and silver from aqua regia gold parting slag by "low-temperature - high-temperature" two-stage vacuum distillation gasification. Background Art

[0002] Gold has extensive applications in the fields of electronics, aerospace, and medical due to its high electrical conductivity and excellent corrosion resistance. The main sources of gold include vein gold deposits, placer gold deposits, and associated minerals of heavy metals such as copper and lead. Crude gold mainly contains silver, copper, lead, iron, nickel, and platinum group metals, etc. Aqua regia leaching is a common process for refining crude gold. When the silver content in crude gold is higher than 5%, silver forms silver chloride precipitation during the aqua regia leaching process, which wraps around the surface of gold particles and prevents further dissolution, ultimately resulting in the generation of aqua regia gold parting slag with a gold content of 0.5 - 10%.

[0003] Currently, the treatment of aqua regia gold parting slag is mainly based on the idea of dissolving or converting silver chloride and selectively recovering gold. Common methods mainly include ammonia leaching - hydrazine hydrate reduction method, thiosulfate leaching - reduction method, thiourea reduction - zinc powder displacement method, zinc powder direct reduction method, etc. For example, Chinese Patent CN117431407A discloses a method for preparing silver chloride from silver slag in the pyrometallurgy of gold and recovering silver by reducing with hydrazine hydrate, obtaining silver powder with a silver content of 99.5%. The same method is used to recover silver from silver chloride in Chinese Patent CN116372157A. By thoroughly washing silver chloride with different cleaning agents, silver powder with a purity greater than 99.99% is finally obtained.

[0004] Existing processes generally have problems such as incomplete separation due to the mutual coating of silver and gold, resulting in a long process, low direct recovery rate of precious metals, high requirements for raw material composition, and inevitably large amounts of toxic wastewater and high consumption of chemical reagents in the all-wet process.

[0005] Therefore, the research objective of the present invention is to design a device and method for separating and recovering gold and silver from aqua regia gold parting slag that has strong applicability to raw materials, thorough separation of gold and silver, high direct recovery rate of metals, and a short process. Summary of the Invention

[0006] In view of the above technical problems existing in the prior art, the present invention provides a device and method for separating and recovering gold and silver from aqua regia gold parting slag, which can effectively solve the technical problems existing in the above prior art.

[0007] The technical solution of the present invention is as follows: A device for separating and recovering gold and silver from aqua regia gold parting slag includes: A heat preservation furnace box, with a corresponding closing door that can be opened and closed on its front side; A recovery crucible, detachably installed in the heat preservation furnace box, and is connected and formed by an upper crucible body, a middle crucible body, and a lower crucible body that are sequentially arranged from top to bottom; the top of the upper crucible body forms a smooth dome-shaped condensation cover, the upper end of the middle crucible body is fixedly installed with a funnel-shaped reflux receiving member, the upper end of the reflux receiving member is vertically fixedly installed with a plurality of partition plates arranged in an annular array, the lower ends of the partition plates are symmetrically and vertically fixedly connected with corresponding flow guiding plates, the end spacing between two relatively arranged flow guiding plates installed on adjacent two partition plates gradually decreases, a through hole penetrating up and down is arranged on the reflux receiving member between two flow guiding plates installed on the same partition plate, and a corresponding receiving groove is formed downward in the middle of the reflux receiving member; An adjusting and fixing mechanism, used for movably installing the lower crucible body up and down, and after the lower crucible body moves upward in place, it is used to fix the upper crucible body and the middle crucible body, and the upper crucible body, the middle crucible body, and the lower crucible body are sequentially abutted, tightened, and sealed to form the recovery crucible; A vacuum unit, a corresponding air duct is fixedly installed on the top of the heat preservation furnace box, one end of the air duct extends into the heat preservation furnace box and its end abuts and communicates with the middle of the dome of the upper crucible body, and the other end is respectively connected outward and connected to the vacuum unit through a corresponding three-way pipe and a valve; A heating mechanism, including an upper heating element and a lower heating element that are arranged at an upper and lower interval and fixed on the inner side wall of the heat preservation furnace box, the upper and lower parts of the reflux receiving member cooperate to form a high-temperature distillation area, the lower crucible body and the reflux receiving member cooperate to form a low-temperature distillation area, the upper heating element is used for high-temperature heating and distillation of substances in the high-temperature distillation area, and the lower heating element is used for low-temperature heating and distillation of substances in the low-temperature distillation area; A chlorine absorption mechanism, installed in the air duct for grading absorption of chlorine discharged outward from the recovery crucible or installed at the end of the air duct to collect chlorine discharged outward from the recovery crucible.

[0008] The adjusting and fixing mechanism includes a sleeve member fixedly connected below the lower crucible body and a stud fixedly installed at the inner bottom of the heat preservation furnace box, and the inner side wall of the sleeve member is evenly distributed with internal threads adapted to the stud; the lower crucible body is fixedly installed in the heat preservation furnace box by screwing the sleeve member onto the stud, and the upper crucible body, the middle crucible body, and the lower crucible body are tightened, fixed, and sealed by rotating the sleeve member upward to form the recovery crucible.

[0009] Auxiliary tightening mechanisms for enhancing the installation stability of the recycled crucible are provided both above and below the recycled crucible. The auxiliary tightening mechanisms include a number of support columns that are spaced apart and fixed to the top or bottom of the heat preservation furnace box. The support columns are circumferentially distributed around the recycled crucible. One end of the support column that is not connected to the heat preservation furnace box is fixedly connected to a corresponding support ring through a corresponding elastic member. After the recycled crucible is installed in place, the elastic member has a tendency to push the support ring to tightly abut against the top or bottom of the recycled crucible.

[0010] The gas guide pipe is a water-cooled sleeve, and a corresponding chlorine absorption zone 1 and a chlorine absorption zone 2 are respectively arranged at the air inlet section and the air outlet section thereof. The chlorine absorption mechanism includes activated carbon loaded with CuCl2 filled in the chlorine absorption zone 1 and a mixture of Ca(OH)2 and Fe2O3 filled in the chlorine absorption zone 2 respectively.

[0011] Both the upper heating member and the lower heating member are heating elements spirally distributed upward. The heating element is made of high-purity graphite. The lower heating member is spirally installed on the outside of the lower crucible body, and the upper heating member is spirally installed on the outside of the middle crucible body at the position where the reflux receiving member is located.

[0012] A stepped exhaust hole is arranged in the middle of the dome of the upper crucible body. When the recycled crucible is installed in place, the bottom of the gas guide pipe is abutted and fixed to the stepped part of the guide through hole of the upper crucible body with a corresponding gasket and is communicated with the recycled crucible.

[0013] The inner side wall of the upper crucible body forms a downwardly inclined arc shape at the connection with the lower crucible body and forms a streamlined connection with the inner side wall of the reflux receiving member.

[0014] All side walls and the closing door of the heat preservation furnace box are of sandwich structures and filled with corresponding heat preservation materials. The heat preservation material is graphite hard felt. The middle crucible body and the lower crucible body have the same diameter, and the middle crucible body and the reflux receiving member are made of high-purity quartz, and the lower crucible body is made of high-purity graphite. The vacuum unit is composed of a mechanical pump and a molecular pump, and its vacuum degree is 10 -2 ~10 -6 Pa of high vacuum. It also includes a vacuum measuring device. The vacuum measuring device is a high-precision vacuum gauge. The recycled crucible is also provided with temperature measuring thermocouples for respectively detecting the middle crucible body and the lower crucible body.

[0015] A method for separating and recycling gold and silver from aqua regia gold slag uses the device for separating and recycling gold and silver from aqua regia gold slag described above, and includes the following steps: S1. Fix and install the lower crucible body in the heat preservation furnace box, place the aqua regia gold parting residue in the lower crucible body, stack and install the middle crucible body and the upper crucible body on the lower crucible body in sequence, and connect and install the air guide pipe in a butting manner above the upper crucible body; then move the lower crucible body upward and fix it through the adjustment and fixing mechanism, so that the upper crucible body, the middle crucible body and the lower crucible body are butted, tightened and hermetically connected in sequence. S2. Control certain system pressure and the temperature of the low-temperature distillation area respectively through the vacuum unit and the heating mechanism. Through low-temperature distillation, silver chloride is vaporized and volatilized upward, while gold remains at the inner bottom of the lower crucible body. S3. The vaporized silver chloride generated in step S2 volatilizes upward and enters the upper crucible body through the guide through-hole of the reflux receiving part. The silver chloride liquefies on the smooth dome-shaped condensing cover and then flows back along the condensing cover to the four peripheries and the inner side wall of the upper crucible body in sequence, and flows along the reflux receiving part and is guided and gathered into the receiving groove and the reflux receiving part. S4. After the reflux is completed, control the temperature of the high-temperature distillation area through the heating mechanism. Through high-temperature distillation, silver chloride is decomposed into silver and chlorine gas in the high-temperature distillation area. The chlorine gas volatilizes upward and is absorbed or collected by the chlorine gas absorption mechanism, and the silver remains in the reflux receiving part and the receiving groove.

[0016] Among them, the system pressure during the distillation process in step S2 is 10 -3 ~10 -5 Pa; the heating temperature of the low-temperature distillation area is 750-1000 °C, the time of the low-temperature distillation is 30-120 min, and during the low-temperature distillation, the heating temperature of the high-temperature distillation area is 600-750 °C; the heating temperature of the high-temperature distillation area in step S3 is 1100-1300 °C, and the time of the high-temperature distillation is 30-120 min.

[0017] Advantages of the present invention: 1) During the process of dissolving gold in aqua regia residue, the present invention separates gold through low-temperature distillation in the lower layer. The vaporized silver chloride flows upward through the through-hole of the reflux receiving member, condenses into a liquid on the dome-shaped condensation cover, and then flows around the dome and downward along the inner wall of the recovery crucible to the reflux receiving member. On the funnel-shaped reflux receiving member, a plurality of partition plates are vertically and fixedly connected in an annular array. The lower ends of the partition plates are fixedly connected with oppositely arranged flow guide plates. The end portions of the flow guide plates extend to the receiving groove arranged in the middle of the reflux receiving member. The flow guide plates surround the through-hole, which can guide and protect the liquid silver chloride, effectively preventing it from flowing back to the bottom of the recovery crucible through the through-hole, thereby ensuring the effect of separating gold and silver from the gold slag. The non-standard reflux receiving member of the present invention cooperates with the heating mechanism arranged at different temperatures with an upper and lower interval for the recovery treatment of gold and silver in the gold slag. It can realize the recovery of gold and silver in the same device. It can not only ensure the smooth upward transmission of the separated gaseous silver chloride, but also guide and collect the condensed liquid silver chloride, and then decompose silver and chlorine through high-temperature distillation. The chlorine is completely absorbed or collected by the chlorine absorption mechanism, so as to realize the separation and recovery of gold and silver in aqua regia and its residue, and effectively improve the efficiency of separation and recovery.

[0018] 2) The present invention adds a non-standard reflux receiving member for synchronously separating and recovering silver in the gold slag. To facilitate the loading and unloading of materials, the present invention further divides the recovery crucible into an upper crucible body, a middle crucible body, and a lower crucible body arranged in sequence from top to bottom, and adds a corresponding adjustment and fixing mechanism for stably installing and conveniently disassembling the recovery crucible. By fixedly connecting a corresponding sleeve member below the lower crucible body and fixedly installing a corresponding stud at the inner bottom of the heat preservation furnace box, the lower crucible body is fixedly installed in the heat preservation furnace box by screwing the sleeve member onto the stud, and materials are filled in the lower crucible body; then, the middle crucible body and the upper crucible body are sequentially stacked and installed on the lower crucible body, and the sleeve member is rotated upward to move the upper crucible body, the middle crucible body, and the lower crucible body upward, so that the air guide pipe abuts and communicates with the step portion of the upper crucible body until the upper crucible body, the middle crucible body, and the lower crucible body are tightly abutted, fixed, and hermetically connected to each other. The adjustment and fixing mechanism of the present invention can not only fixedly and hermetically install the recovery crucible, but also quickly and conveniently disassemble the recovery crucible to facilitate the loading and unloading of materials, enabling the reflux receiving member to be actually used and realizing the synchronous recovery of silver, ensuring the practical effect of the present invention.

[0019] 3) In the present invention, the air duct and the adjustment and fixing mechanism, which are arranged above and below the middle of the recovery crucible, cooperate with each other to tightly hold and fix the installation of the recovery crucible. In order to further improve the support stability and reduce the operation lightness of personnel during the installation of the recovery crucible, the present invention respectively sets corresponding auxiliary tightening mechanisms at the upper and lower ends of the recovery crucible. When the lower crucible body is screwed to the bottom through the sleeve part and the stud, the elastic member of the lower auxiliary tightening mechanism is compressed; after the recovery crucible is installed, the support ring sets at the upper and lower ends are sleeved on the upper and lower ends of the recovery crucible, and both are pushed to assist in supporting the recovery crucible under the elastic force of the connected elastic members, enhancing the installation stability of the recovery crucible. And during installation, there is the support and limit of the lower auxiliary tightening mechanism, which can reduce the support force of personnel on the lower crucible body during installation, further ensuring the practical effect of the present invention.

[0020] 4) The chlorine absorption mechanism of the present invention is installed on the water-cooled sleeve, and includes activated carbon loaded with CuCl2 filled in the first chlorine absorption area and a mixture of Ca(OH)2 and Fe2O3 filled in the second chlorine absorption area. Through the activated carbon loaded with CuCl2 and the mixture of Ca(OH)2 and Fe2O3, it can ensure the comprehensive and timely absorption of the separated chlorine.

[0021] 5) The present invention synchronously recovers gold and silver from the gold residue through the optimized and improved device for separating and recovering gold and silver from aqua regia gold residue. Under the condition that the system pressure is 10 -3 ~10 -5 Pa, and heated to 750 - 1000 °C for low-temperature distillation for 30 - 120 min, so that gold is separated and remains in the lower crucible body, and silver is uploaded in the form of gaseous silver chloride, passes through the through-hole of the reflux receiving member, and condenses into a liquid on the dome of the upper crucible body, and then flows along the inner side wall of the upper crucible body to the reflux receiving member. And during the low-temperature distillation, the heating temperature of the high-temperature distillation area is 600 - 750 °C, which can effectively prevent the gaseous silver chloride from condensing and flowing back at the reflux receiving member to ensure the separation effect, and the liquid silver chloride has a low volatility at this temperature. On the basis of ensuring the smooth reflux of the liquid silver chloride, the high-temperature distillation area is preheated to accelerate the efficiency of subsequent high-temperature distillation; then the high-temperature distillation area is heated to 1100 - 1300 °C for high-temperature distillation for 30 - 120 min to separate silver, and the chlorine gas volatilizes and is comprehensively and timely absorbed by the activated carbon loaded with CuCl2 and the mixture of Ca(OH)2 and Fe2O3, thus ensuring the method for separating and recovering gold and silver from aqua regia gold residue has the advantages of short process flow, low cost, high efficiency, environmental friendliness, and high noble metal recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the present invention.

[0023] Figure 2For Figure 1 Schematic cross-sectional view of

[0024] Figure 3 Schematic structural view of the reflux receiving member.

[0025] Figure 4 Schematic diagram of the flow of gaseous silver chloride and liquid silver chloride in the second embodiment.

[0026] In the drawings: heat preservation furnace box 1, recovery crucible 2, upper crucible body 201, middle crucible body 202, lower crucible body 203, chlorine absorption mechanism 3, reflux receiving member 4, partition plate 5, diversion plate 6, guide through hole 7, receiving groove 8, adjustment and fixing mechanism 9, sleeve member 901, stud 902, vacuum unit 10, air guide pipe 11, chlorine absorption area 1101, chlorine absorption area 1102, heating mechanism 12, upper heating member 1201, lower heating member 1202, auxiliary pressing mechanism 13, support column 1301, elastic member 1302, support ring member 1303. Detailed implementation manners

[0027] For the convenience of those skilled in the art to understand, the structure of the present invention will be further described in detail below in conjunction with the accompanying drawings: Embodiment 1 Refer to Figures 1-3 , a device for separating and recovering gold and silver from aqua regia gold slag, comprising: Heat preservation furnace box 1, a corresponding closing door is arranged on the front side thereof in an openable and closable manner; Recovery crucible 2, detachably installed in the heat preservation furnace box 1, and is connected and formed by an upper crucible body 201, a middle crucible body 202 and a lower crucible body 203 which are distributed in sequence from top to bottom; the top of the upper crucible body 201 forms a smooth dome-shaped condensation cover, the upper end of the middle crucible body 202 is fixedly installed with a funnel-shaped reflux receiving member 4, the upper end of the reflux receiving member 4 is vertically fixedly installed with a plurality of partition plates 5 arranged in an annular array, the lower ends of the partition plates 5 are symmetrically and vertically fixedly connected with corresponding diversion plates 6, the distance between the end parts of two diversion plates 6 which are installed on two adjacent partition plates 5 and are oppositely arranged gradually decreases, a guide through hole 7 penetrating through the upper and lower parts is arranged on the reflux receiving member 4 between two diversion plates 6 which are located on the same partition plate 5, a corresponding receiving groove 8 is formed downward in the middle of the reflux receiving member 4, and two diversion plates 6 connected to one partition plate 5 can also be integrally formed into an annular structure; The adjusting and fixing mechanism 9 is used for movably mounting the lower crucible body 203 up and down, and after the lower crucible body 203 moves upward in place, it is used to fix the upper crucible body 201 and the middle crucible body 202, and the upper crucible body 201, the middle crucible body 202 and the lower crucible body 203 are sequentially abutted, tightened and sealed to form the recovery crucible 2; The vacuum unit 10, a corresponding air guide pipe 11 is fixedly installed on the top of the heat preservation furnace box 1, one end of the air guide pipe 11 extends into the heat preservation furnace box 1 and its end abuts and communicates with the middle part of the dome of the upper crucible body 201, and the other end is externally connected and connected to the vacuum unit 10 respectively through a corresponding three-way pipe and a valve; The heating mechanism 12 includes an upper heating element 1201 and a lower heating element 1202 which are arranged at an upper and lower interval and fixed on the inner side wall of the heat preservation furnace box 1. The upper and lower parts of the reflux receiving part 4 cooperate to form a high-temperature distillation area, and the lower crucible body 203 and the reflux receiving part 4 cooperate to form a low-temperature distillation area. The upper heating element 1201 is used for high-temperature heating and distillation of substances in the high-temperature distillation area, and the lower heating element 1202 is used for low-temperature heating and distillation of substances in the low-temperature distillation area; The chlorine absorption mechanism 3 is installed in the air guide pipe 11 for grading the chlorine discharged from the recovery crucible 2 or installed at the end of the air guide pipe 11 to collect the chlorine discharged from the recovery crucible 2.

[0028] In the process of separating gold from the aqua regia leaching residue of gold ore by the present invention, gold is separated by low-temperature distillation in the lower layer. The vaporized silver chloride flows upward through the through hole 7 of the reflux receiving part 4, condenses into a liquid on the dome-shaped condensation cover and then flows around along the dome, and then flows downward along the inner side wall of the recovery crucible 2 to the reflux receiving part 4. On the funnel-shaped reflux receiving part 4, a plurality of partition plates 5 are vertically fixed in an annular array. The lower ends of the partition plates 5 are fixedly connected with oppositely arranged diversion plates 6. The end parts of the diversion plates 6 extend to the receiving groove 8 arranged in the middle of the reflux receiving part 4. The diversion plates 6 surround the periphery of the through hole 7, and can divert and protect the liquid silver chloride, effectively preventing it from flowing back to the bottom of the recovery crucible 2 through the through hole 7, thereby ensuring the effect of separating gold and silver from the gold ore leaching residue. The non-standard reflux receiving part 4 of the present invention cooperates with the heating mechanism 12 which is arranged at different temperatures with an upper and lower interval for the recovery treatment of gold and silver in the gold ore leaching residue. The gold and silver can be recovered in the same device. It can not only ensure the smooth upward transmission of the separated gaseous silver chloride, but also divert and collect the condensed liquid silver chloride, and then decompose silver and chlorine through high-temperature distillation. The chlorine is completely absorbed or collected by the chlorine absorption mechanism 3, so as to realize the separation and recovery of gold and silver in the aqua regia and the residue, and effectively improve the separation and recovery efficiency.

[0029] The adjusting and fixing mechanism 9 comprises a sleeve member 901 fixedly connected to the lower crucible body 203 and a stud 902 fixedly installed at the inner bottom of the insulation furnace box 1, and the inner wall of the sleeve member 901 is evenly distributed with internal threads adapted to the stud 902; the lower crucible body 203 is fixedly installed in the insulation furnace box 1 by screwing the sleeve member 901 to the stud 902, and the upper crucible body 201, the middle crucible body 202 and the lower crucible body 203 are tightened and fixed and sealed by rotating the sleeve member 901 upwards to form the recovery crucible 2.

[0030] The present invention adds a non-standard reflux receiving part 4 for synchronously separating and recovering silver from gold slag. In order to facilitate the loading and taking out of materials, the present invention further divides the recovery crucible 2 into an upper crucible body 201, a middle crucible body 202 and a lower crucible body 203 which are sequentially arranged in the upper, middle and lower parts, and adds a corresponding adjustment and fixing mechanism 9 for firmly installing and conveniently disassembling the recovery crucible 2. By fixing a corresponding sleeve member 901 under the lower crucible body 203 and fixing a corresponding stud 902 on the inner bottom of the heat preservation furnace box, the sleeve member 901 is spirally connected to the screw. The column 902 fixes the lower crucible body 203 in the heat preservation furnace box, and fills the material on the lower crucible body 203; then, the middle crucible body 202 and the upper crucible body 201 are sequentially stacked and installed on the lower crucible body 203, and the sleeve 901 is rotated upward to move the upper crucible body 201, the middle crucible body 202 and the lower crucible body 203 upward, so that the air guide tube 11 abuts and connects with the step portion installed on the upper crucible body 201, until the upper crucible body 201, the middle crucible body 202 and the lower crucible body 203 are mutually tightened and fixed and sealed. The present invention utilizes the adjusting and fixing mechanism 9 to not only fix and seal the recovery crucible 2, but also quickly and conveniently disassemble the recovery crucible 2 to facilitate the taking and placing of materials, so that the reflux receiving member 4 can be actually used, and the synchronous recovery of silver can be achieved, ensuring the practical effect of the present invention.

[0031] Auxiliary tightening mechanisms 13 for enhancing the installation stability of the recovery crucible 2 are arranged above and below the recovery crucible 2. The auxiliary tightening mechanism 13 includes a plurality of support columns 1301 spaced apart and fixed on the top or bottom of the insulation furnace box 1. The support columns 1301 are distributed circumferentially with the recovery crucible 2 as the axis. The end of the support column 1301 that is not connected to the insulation furnace box 1 is fixedly connected to a corresponding support ring 1303 through a corresponding elastic member 1302. After the recovery crucible 2 is installed in place, the elastic member 1302 has a movement tendency to push the support ring 1303 to press against the top or bottom of the recovery crucible 2.

[0032] The present invention fixes and installs the recovery crucible 2 by the cooperation and tight pushing of the air duct 11 and the adjustment and fixing mechanism 9 arranged up and down in the middle of the recovery crucible 2. In order to further improve the support stability and reduce the operation lightness of personnel during the installation of the recovery crucible 2, the present invention respectively sets corresponding auxiliary tight pushing mechanisms 13 at the upper and lower ends of the recovery crucible 2. When the lower crucible body 203 is screwed to the bottom through the sleeve member 901 and the stud 902, the elastic member 1302 of the lower auxiliary tight pushing mechanism 13 is compressed; after the recovery crucible 2 is installed, the support ring members 1303 at the upper and lower ends are sleeved on the upper and lower ends of the recovery crucible 2, and both push and support the recovery crucible 2 under the elastic force of the connected elastic members 1302, enhancing the installation stability of the recovery crucible 2. And during installation, there is the support and limit of the lower auxiliary tight pushing mechanism 13, which can reduce the support force of personnel on the lower crucible body 203 during installation, further ensuring the practical effect of the present invention.

[0033] The air duct 11 is a water-cooled sleeve, and a corresponding chlorine absorption zone 1101 and a chlorine absorption zone 1102 are respectively arranged at the air inlet section and the air outlet section thereof. The chlorine absorption mechanism 3 includes activated carbon loaded with CuCl2 filled in the chlorine absorption zone 1101 and a mixture of Ca(OH)2 and Fe2O3 filled in the chlorine absorption zone 1102 respectively.

[0034] Both the upper heating element 1201 and the lower heating element 1202 are heating bodies spirally distributed upward, and the material of the heating body is high-purity graphite. The lower heating element 1202 is spirally installed on the outside of the lower crucible body 203, and the upper heating element 1201 is spirally installed on the outside of the middle crucible body 202 at the position where the reflux receiving member 4 is located.

[0035] A stepped exhaust hole is arranged in the middle of the dome of the upper crucible body 201. When the recovery crucible 2 is installed in place, the bottom of the air duct 11 is fixedly abutted against the stepped part of the guide through hole 7 of the upper crucible body 201 with a corresponding gasket, and is communicated with the recovery crucible 2.

[0036] The inner side wall of the upper crucible body 201 forms a downwardly inclined arc shape at the connection with the lower crucible body 203 and forms a streamlined connection with the inner side wall of the reflux receiving member 4.

[0037] All side walls and the closing door of the heat preservation furnace box 1 are of sandwich structures and filled with corresponding heat preservation materials. The material of the heat preservation material is graphite hard felt. The middle crucible body 202 and the lower crucible body 203 have the same diameter, and the materials of the middle crucible body 202 and the reflux receiving member 4 are high-purity quartz, and the material of the lower crucible body 203 is high-purity graphite; the vacuum unit 10 is composed of a mechanical pump and a molecular pump, and its vacuum degree is 10-2 ~10 -6 a high vacuum of -6 Pa, and also includes a vacuum measuring device, the vacuum measuring device being a high-precision vacuum gauge. The recovery crucible 2 is also provided with temperature-measuring thermocouples for respectively detecting the middle crucible body 202 and the lower crucible body 203. The top of the heat preservation furnace box 1 is also provided with a corresponding pressure relief valve and a pressure gauge. After distillation is completed, the pressure can be relieved through the pressure relief valve to facilitate the extraction of gold and silver.

[0038] Example 2 Reference Figure 4 , a method for separating and recovering gold and silver from aqua regia gold slag, using the device for separating and recovering gold and silver from aqua regia gold slag described above, includes the following steps: S1, fixedly install the lower crucible body 203 in the heat preservation furnace box 1, place the aqua regia gold slag in the lower crucible body 203, and sequentially stack and install the middle crucible body 202 and the upper crucible body 201 on the lower crucible body 203. The air guide pipe 11 is abutted and connected above the upper crucible body 201; then, move the lower crucible body 203 upward and fix it through the adjustment and fixing mechanism 9, so that the upper crucible body 201, the middle crucible body 202, and the lower crucible body 203 are sequentially abutted, tightened, and sealed. S2, respectively control a certain system pressure and the temperature of the low-temperature distillation zone through the vacuum unit 10 and the heating mechanism 12. Through low-temperature distillation, silver chloride is vaporized and volatilized upward, while gold remains at the inner bottom of the lower crucible body 203. S3, the vaporized silver chloride volatilized upward in step S2 enters the upper crucible body 201 through the guide hole 7 of the reflux receiving member 4. Silver chloride liquefies on the smooth dome-shaped condensation cover and sequentially flows back along the condensation cover to the four peripheries and the inner wall of the upper crucible body 201, and is guided and gathered into the receiving groove 8 and the reflux receiving member 4 along the reflux receiving member 4. S4, control the temperature of the high-temperature distillation zone through the heating mechanism 12. Through high-temperature distillation, silver chloride decomposes into silver and chlorine gas in the high-temperature distillation zone. The chlorine gas volatilizes upward and is absorbed or collected by the chlorine gas absorption mechanism 3, and silver remains in the reflux receiving member 4 and the receiving groove 8.

[0039] Among them, the system pressure during the distillation process in step S2 is 10 -3 ~10 -5 Pa; the heating temperature of the low-temperature distillation zone is 750 - 1000 °C, the time of low-temperature distillation is 30 - 120 min, and during low-temperature distillation, the heating temperature of the high-temperature distillation zone is 550 - 800 °C; the heating temperature of the high-temperature distillation zone in step S3 is 1100 - 1300 °C, and the time of high-temperature distillation is 30 - 120 min.

[0040] The present invention synchronously recovers gold and silver from gold slag through an optimized and improved device for separating and recovering gold and silver from aqua regia gold slag. Under the condition that the system pressure is 10 -3 ~10 -5 Pa, and heated to 750 - 1000 °C for low-temperature distillation for 30 - 120 min, gold is separated and remains in the lower crucible body 203, and silver is uploaded in the form of gaseous silver chloride, passes through the through-hole 7 of the reflux receiving member 4, and condenses into a liquid on the dome of the upper crucible body 201, and then flows along the inner side wall of the upper crucible body 201 to the reflux receiving member 4. During the low-temperature distillation, the heating temperature of the high-temperature distillation zone is 600 - 750 °C, which not only effectively prevents the gaseous silver chloride from condensing and flowing back at the reflux receiving member to ensure the separation effect, and the liquid silver chloride has low volatility at this temperature to ensure the smooth reflux of the liquid silver chloride, but also preheats the high-temperature distillation zone to accelerate the efficiency of subsequent high-temperature distillation; then the high-temperature distillation zone is heated to 1100 - 1300 °C for high-temperature distillation for 30 - 120 min to separate silver, and the chlorine gas volatilizes and is comprehensively and timely absorbed by the mixture of activated carbon loaded with CuCl2 and Ca(OH)2 and Fe2O3, so as to ensure that the method for separating and recovering gold and silver from aqua regia gold slag has a short process flow, low cost, high efficiency, environmental friendliness, and high precious metal recovery rate.

[0041] Example 3 The difference from Example 2 is that the aqua regia gold slag with a gold mass percentage of 0.5% and a silver content of 73.3% is placed in the lower crucible body 203. Under the conditions of a system pressure of 10 -4 Pa, a low-temperature distillation temperature of 900 °C, a distillation time of 45 min, and during the low-temperature distillation, the heating temperature of the high-temperature distillation zone is 650 °C, and the high-temperature distillation temperature is 1150 °C and the distillation time is 45 min, vacuum distillation separation is carried out; after treatment, gold is enriched in the bottom lower crucible body 203 with a purity of 99.7% and a direct recovery rate higher than 99.9%; silver is enriched in the reflux receiving member 4 of the middle crucible body 202 in the high-temperature distillation zone after being decomposed from silver chloride, with a purity of 99.3% and a direct recovery rate of 97.2%. A small amount of silver chloride vapor diffuses into the chlorine absorption device before decomposition, resulting in a decrease in the direct recovery rate of silver. This part of silver can be recovered after the absorption device fails.

[0042] Example 4 The difference from Example 2 is that the aqua regia gold slag with a gold mass percentage of 8% and a silver content of 68.2% is placed in the lower crucible body 203 in the low-temperature zone. Under the condition of a system pressure of 10 -4Under a pressure of Pa, the distillation temperature in the low-temperature zone is 950 °C, and the distillation time is 45 min. During the low-temperature distillation, the heating temperature in the high-temperature distillation zone is 750 °C. Vacuum distillation separation is carried out under the conditions that the distillation temperature in the high-temperature zone is 1200 °C and the distillation time is 45 min. After treatment, gold is enriched in the lower crucible body 203 at the bottom, with a purity of 99.6% and a direct recovery rate higher than 99.5%. Silver is decomposed from silver chloride and then enriched in the reflux receiving part 4 of the middle crucible body 202 in the high-temperature distillation zone, with a purity of 99.1% and a direct recovery rate of 96.4%.

[0043] Comparative Example 1: A distillation separation experiment was carried out on the same gold-bearing aqua regia residue with a gold mass percentage of 0.5% and a silver content of 70.3% in a single-temperature zone vacuum distillation furnace. The system pressure was 10 -4 Pa, the distillation temperature was 900 °C, and the distillation time was 90 min. After treatment, gold was enriched at the bottom of the high-purity graphite crucible, with a purity of 98.4% and a direct recovery rate higher than 99.9%. Silver was enriched in the upper condensation zone in the form of silver chloride, and elemental silver could not be directly obtained.

[0044] Comparative Example 2: A distillation separation experiment was carried out on the same gold-bearing aqua regia residue with a gold mass percentage of 0.5% and a silver content of 70.3% in a single-temperature zone vacuum distillation furnace. The system pressure was 10 -4 Pa, the distillation temperature was 1200 °C, and the distillation time was 90 min. After treatment, gold was enriched at the bottom of the high-purity graphite crucible, with a purity of 98.4% and a direct recovery rate of 92.6%. A small amount of gold volatilized together with silver chloride to the upper condensation zone, and the crude silver in the condensation zone contained 8.4% chlorine. The decomposition of silver chloride was incomplete, and the complete separation of gold and silver and the one-step production of elemental metals could not be achieved either.

[0045] It can be seen that using the device and method of the present invention to treat gold slag can obtain crude gold and crude silver with gold and silver contents higher than 99%, a direct recovery rate of gold higher than 99.5%, and a direct recovery rate of silver higher than 96.7%. There is no generation of three wastes throughout the process, and the process is short, the cost is low, and the efficiency is high.

[0046] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An apparatus for separating and recovering gold and silver from aqua regia gold separation residue, characterized in that, Comprising: A heat preservation furnace box (1), with a corresponding closing door that can be opened and closed on its front side; A recovery crucible (2), detachably installed inside the heat preservation furnace box (1), and is connected and formed by an upper crucible body (201), a middle crucible body (202), and a lower crucible body (203) that are sequentially arranged from top to bottom; the top of the upper crucible body (201) forms a smooth dome-shaped condensation cover, the upper end of the middle crucible body (202) is fixedly installed with a funnel-shaped reflux receiving member (4), the upper end of the reflux receiving member (4) is vertically fixedly installed with a plurality of partition plates (5) arranged in an annular array, the lower ends of the partition plates (5) are symmetrically and vertically fixedly connected with corresponding flow guide plates (6), the end spacing between two relatively arranged flow guide plates (6) installed on adjacent two partition plates (5) gradually decreases, a through hole (7) penetrating up and down is provided on the reflux receiving member (4) between two flow guide plates (6) installed on the same partition plate (5), and a corresponding receiving groove (8) is formed downward in the middle of the reflux receiving member (4); An adjusting and fixing mechanism (9), used for movably installing the lower crucible body (203) up and down, and after the lower crucible body (203) moves upward in place, it is used to fix the upper crucible body (201) and the middle crucible body (202), and the upper crucible body (201), the middle crucible body (202), and the lower crucible body (203) are sequentially abutted, tightened, and hermetically connected to form the recovery crucible (2); A vacuum unit (10), a corresponding air guide pipe (11) is fixedly installed on the top of the heat preservation furnace box (1), one end of the air guide pipe (11) extends into the heat preservation furnace box (1) and its end abuts and communicates with the middle of the dome of the upper crucible body (201), and the other end is externally connected and connected to the vacuum unit (10) respectively through a corresponding three-way pipe and a valve; A heating mechanism (12), comprising an upper heating element (1201) and a lower heating element (1202) that are arranged at an upper and lower interval and fixed on the inner side wall of the heat preservation furnace box (1), the upper heating element (1201) is used for high-temperature heating and distillation of substances in the high-temperature distillation area, and the lower heating element (1202) is used for low-temperature heating and distillation of substances in the low-temperature distillation area; A chlorine absorption mechanism (3), installed in the air guide pipe (11) for grading absorption of chlorine discharged outward from the recovery crucible (2) or installed at the end of the air guide pipe (11) to collect chlorine discharged outward from the recovery crucible (2).

2. The device for separating and recovering gold and silver from aqua regia gold slime according to claim 1, characterized in that, The adjusting and fixing mechanism (9) comprises a sleeve member (901) fixedly connected to the bottom of the lower crucible body (203) and a stud (902) fixedly installed on the inner bottom of the heat-insulating furnace box (1), and the inner wall of the sleeve member (901) is evenly distributed with internal threads that match the stud (902); the lower crucible body (203) is fixedly installed in the heat-insulating furnace box (1) by screwing the sleeve member (901) to the stud (902), and the upper crucible body (201), the middle crucible body (202) and the lower crucible body (203) are tightly fixed and sealed by rotating the sleeve member (901) upwards to form the recovery crucible (2).

3. The device for separating and recovering gold and silver from aqua regia gold dregs according to claim 1, characterized in that, Auxiliary tightening mechanisms (13) for enhancing the installation stability of the recovery crucible (2) are arranged above and below the recovery crucible (2); the auxiliary tightening mechanisms (13) comprise a plurality of support columns (1301) spaced apart and fixed to the top or bottom of the insulation furnace box (1); the support columns (1301) are distributed around the circumference with the recovery crucible (2) as the axis; one end of the support column (1301) not connected to the insulation furnace box (1) is fixedly connected to a corresponding support ring (1303) via a corresponding elastic member (1302); after the recovery crucible (2) is installed in place, the elastic member (1302) has a movement tendency to push the support ring (1303) to press against the top or bottom of the recovery crucible (2).

4. The device for separating and recovering gold and silver from aqua regia gold slag according to claim 1, characterized in that, The air guide pipe (11) is a water-cooled sleeve, and its air inlet section and air outlet section are respectively provided with a corresponding chlorine absorption zone 1 (1101) and chlorine absorption zone 2 (1102), and the chlorine absorption mechanism (3) comprises activated carbon loaded with CuCl2 filled in the chlorine absorption zone 1 (1101) and a mixture of Ca(OH)2 and Fe2O3 filled in the chlorine absorption zone 2 (1102), respectively.

5. The device for separating and recovering gold and silver from aqua regia gold leaching residue according to claim 1, characterized in that, The upper heating element (1201) and the lower heating element (1202) are both heating elements that are spirally distributed upward, and the heating element is made of high-purity graphite. The lower heating element (1202) is spirally installed on the outside of the lower crucible body (203), and the upper heating element (1201) is spirally installed on the outside of the middle crucible body (202) located at the position of the reflux receiving element (4).

6. The device for separating and recovering gold and silver from aqua regia gold slags according to claim 1, characterized in that, A stepped exhaust hole is provided in the middle of the dome of the upper crucible body (201); when the recovery crucible (2) is installed in place, the bottom of the air guide tube (11) cooperates with a corresponding gasket to abut and fix against the stepped portion of the conduction hole (7) of the upper crucible body (201), and is connected to the recovery crucible (2).

7. The device for separating and recovering gold and silver from aqua regia gold leaching residues according to claim 1, characterized in that, The inner side wall of the upper crucible body (201) is located at the connection with the lower crucible body (203) to form a downwardly inclined arc surface, and forms a streamlined connection with the inner side wall of the reflux receiving member (4).

8. The device for separating and recovering gold and silver from aqua regia gold slag according to claim 1, wherein, All side walls and closing doors of the heat-insulating furnace chamber (1) are of sandwich structure and filled with corresponding heat-insulating materials. The heat-insulating material is graphite hard felt. The middle crucible body (202) and the lower crucible body (203) have the same diameter, and the middle crucible body (202) and the reflux receiving member (4) are made of high-purity quartz, while the lower crucible body (203) is made of high-purity graphite. The vacuum unit (10) consists of a mechanical pump and a molecular pump, and its vacuum degree is 10 -2 ~10 -6 Pa of high vacuum. It also includes a vacuum measuring device, and the vacuum measuring device is a high-precision vacuum gauge. The recovery crucible (2) is also provided with temperature-measuring thermocouples for detecting the middle crucible body (202) and the lower crucible body (203) respectively.

9. A method for separating and recovering gold and silver from aqua regia gold separation residue, characterized in that: The device for separating and recovering gold and silver from aqua regia gold slag according to any one of claims 1 to 8 comprises the following steps: S1. Fix and install the lower crucible body (203) inside the heat preservation furnace box (1), place the aqua regia gold parting slag in the lower crucible body (203), and stack and install the middle crucible body (202) and the upper crucible body (201) on the lower crucible body (203) in sequence. The air duct (11) is butted and connected above the upper crucible body (201); then, move the lower crucible body (203) upward and fix it through the adjusting and fixing mechanism (9) so that the upper crucible body (201), the middle crucible body (202), and the lower crucible body (203) are butted, tightened, and hermetically connected in sequence. S2. Control a certain system pressure and the temperature of the low-temperature distillation area respectively through the vacuum unit (10) and the heating mechanism (12). Through low-temperature distillation, silver chloride is vaporized and volatilized upward, while gold remains at the inner bottom of the lower crucible body (203). S3. The vaporized silver chloride generated in step S2 volatilizes upward and enters the upper crucible body (201) through the through hole (7) of the reflux receiving part (4). The silver chloride liquefies on the smooth dome-shaped condensation cover and then flows back along the condensation cover to the four peripheries and the inner wall of the upper crucible body (201) in sequence, and flows along the reflux receiving part (4) to be guided and gathered in the receiving groove (8) and the reflux receiving part (4). S4. After the reflux is completed, control the temperature of the high-temperature distillation area through the heating mechanism (12). Through high-temperature distillation, the silver chloride in the reflux receiving part (4) is decomposed into silver and chlorine gas in the high-temperature distillation area. The chlorine gas volatilizes upward and is absorbed or collected by the chlorine gas absorption mechanism (3), and the silver remains in the reflux receiving part (4) and the receiving groove (8).

10. A method for separating and recovering gold and silver from aqua regia gold leaching residues according to claim 9, characterized in that: Among them, the system pressure in the distillation process in step S2 is 10 -3 ~10 -5 Pa; the heating temperature in the low-temperature distillation zone is 750-1000 °C, the time of the low-temperature distillation is 30-120 min, and during the low-temperature distillation, the heating temperature in the high-temperature distillation zone is 600-750 °C. In step S3, the heating temperature in the high-temperature distillation zone is 1100-1300 °C, and the time of the high-temperature distillation is 30-120 min.

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