A device for recovering valuable metals from slag

Abstract

This invention provides a device for recovering valuable metals from molten slag, comprising a vacuum distillation furnace. The vacuum distillation furnace contains graphite discs for condensation and a heating coil for temperature control. A discharge pipe is located at the bottom of the vacuum distillation furnace. The vacuum distillation furnace includes multiple vertically arranged temperature control zones. Multiple sets of graphite discs are arranged vertically, with a condensation zone formed between adjacent discs. Through holes are formed on the surface of each graphite disc to connect adjacent condensation zones. This invention enables molten slag to undergo multiple condensation separations with a single heating process, significantly shortening the metal separation cycle.

Description

Technical Field

[0001] This invention relates to the field of metal recycling technology, and in particular to a device for recycling valuable metals from slag. Background Technology

[0002] The anode mud in the copper smelting electrolysis process contains a large amount of valuable metals. One of the main ways to recover them is to put them into a Kaldor furnace for reduction smelting. However, this process is effective in recovering metals such as Au, Ag, Pt, Pd, Te, Se, and Cu from the anode mud, but valuable metals such as Sn, Pb, Sb, and Bi are not effectively recovered.

[0003] Kaldor furnace smelting slag is a product of the pyrochemical reduction smelting of copper smelting anode mud in a Kaldor furnace, containing a large amount of valuable metals such as Sn, Pb, Sb, and Bi. Therefore, how to effectively recover valuable metals from Kaldor furnace smelting slag is of great significance.

[0004] Condensation separation can separate metals with different boiling points to obtain the desired elemental metal. Most existing condensation separation methods use graphite discs for condensation separation. Traditional condensation designs are mostly single-stage designs, resulting in poor separation accuracy. When multiple metals need to be separated from anode mud, multiple heating and condensation processes are required, increasing the metal separation cycle and making equipment cleaning more difficult. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a device for recovering valuable metals from molten slag. This invention enables molten slag to undergo multiple condensation and separation processes with a single heating, significantly shortening the metal separation cycle.

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0007] A device for recovering valuable metals from molten slag includes a vacuum distillation furnace. The furnace contains graphite discs for condensation and heating coils for temperature control. A discharge pipe is located at the bottom of the furnace. The furnace includes multiple vertically arranged temperature control zones. Multiple sets of graphite discs are arranged vertically, with a condensation zone formed between adjacent discs. Through holes are formed on the surface of each disc to connect adjacent condensation zones. The heating temperature in each temperature control zone gradually decreases, controlling the condensation of metals with different boiling points in different condensation zones.

[0008] Specifically, gaseous metals with different boiling points are condensed in condensation zones at different heights. The slag can be heated in one go through a vacuum distillation furnace. As the gaseous slag flows upward, metals with higher boiling points condense and liquefy at the bottom, while metals with lower boiling points condense and liquefy at the top, thus achieving the condensation and recovery of metals with different boiling points at different heights.

[0009] The heating temperature in the multi-stage temperature control zone gradually decreases as the height increases, and the temperature in different temperature control zones is determined based on the metal in the molten slag.

[0010] Compared with traditional methods, the above-mentioned slag treatment method allows for centralized heating of the slag using a single device, and enables segmented temperature control and condensation. The height and number of temperature control and condensation zones can be combined according to the requirements of metal separation, achieving precise and efficient separation of metals with different boiling points, shortening the metal separation cycle, and reducing the difficulty of equipment cleaning and maintenance.

[0011] Preferably, the sidewall of the condensation area has an overflow port.

[0012] Once a certain amount of condensed liquid metal accumulates in the condensation zone, it can be discharged from the overflow port, ultimately achieving the separation of different metals.

[0013] Preferably, adjacent temperature control zones are relatively enclosed by partitions, a discharge pipe is installed at the bottom of the temperature control zone, and the overflow port is connected to the corresponding temperature control zone.

[0014] With the above setup, multiple overflow ports can correspond to a single temperature control zone, further improving the accuracy of metal separation control. Furthermore, the height of the temperature control zone and the condensation zone can be adjusted according to the amount of metal condensed at that temperature, ensuring that the amount of metal condensed in each condensation zone is relatively consistent, and ensuring that all areas of the overall equipment can perform efficient metal condensation and separation.

[0015] Preferably, the condensation region includes a first condensation side and a second condensation side, and two adjacent through holes are alternately located on different condensation sides.

[0016] With the above setup, the gaseous metal flows alternately in different condensation sides, which prolongs the flow path of the gaseous metal, increases the condensation time of the gaseous metal, and further improves the efficiency of gaseous metal condensation.

[0017] Furthermore, a columnar dividing device can be installed in the middle of the condensation zone to further increase the length of the gaseous metal flow path, making the gaseous metal flow in an arc shape, which further improves the efficiency of gaseous metal condensation. A control device can be installed inside the dividing device to divide the condensation zone, reduce the condensation zone, and improve the accuracy of temperature control within the condensation zone.

[0018] Preferably, the horizontal projection planes of the plurality of condensation regions overlap.

[0019] The horizontal projection surfaces of multiple condensation areas overlap, and the above-mentioned arrangement allows multiple graphite disks to overlap with each other, improving the stability of the overall device assembly.

[0020] The graphite discs here are cylindrical, with one side closed and the other side open. The closed side has a through hole, and the outer circumferential position of the closed side has an annular mounting groove. The annular end of the open side is consistent with the mounting groove. Multiple graphite discs can be detachably installed, and the connection points form a U-shaped sealed channel. Through the above structural design, it is easy to install as a whole while ensuring the sealing between the graphite discs, and ensuring the stability and accuracy of gaseous metal separation.

[0021] Preferably, the heating coils of the distillation furnace are arranged in multiple groups along the vertical direction.

[0022] Multiple distillation furnace heating coils are individually controlled, with different temperatures at different vertical heights, meeting the needs of segmented condensation of metals with different boiling points and satisfying the requirements for precise temperature control.

[0023] Preferably, it also includes a reduction smelting furnace, the bottom of which is connected to a discharge pipe, and a discharge valve is provided inside the discharge pipe.

[0024] Through the above structural design, the reduction smelting furnace and the vacuum distillation furnace are integrated into one unit. The reduction smelting furnace melts and reduces the slag, ensuring that different metals are in their corresponding elemental states. This facilitates the subsequent reduction smelting furnace to perform segmented condensation and separation of gaseous metals with different boiling points.

[0025] Preferably, the side wall of the reduction smelting furnace is provided with a smelting furnace heating coil and a slag discharge port, the interior of the reduction smelting furnace is provided with a graphite stirring paddle, and the top of the reduction smelting furnace is provided with a stirring motor for controlling the rotation of the graphite stirring paddle.

[0026] The beneficial effects of this invention are as follows:

[0027] Compared with traditional methods, the above-mentioned slag treatment method allows for centralized heating of the slag using a single device, and enables segmented temperature control and condensation. The height and number of temperature control and condensation zones can be combined according to the requirements of metal separation, achieving precise and efficient separation of metals with different boiling points, shortening the metal separation cycle, and reducing the difficulty of equipment cleaning and maintenance. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the present invention.

[0029] Figure 2 This is a schematic diagram of the vertical cross-sectional structure of the reduction melting furnace of the present invention.

[0030] Figure 3 This is a schematic diagram of the vertical cross-sectional structure of the vacuum distillation furnace of the present invention.

[0031] Figure 4This is a schematic diagram of the horizontal cross-sectional structure of the vacuum distillation furnace of the present invention. (The through hole on the left is a virtual circle, located on the surface of the adjacent graphite disk.)

[0032] In the diagram: 1. Rising flue; 2. Stirring motor; 3. Material feed port; 4. Smelting furnace top cover; 5. Reduction smelting furnace; 6. Smelting furnace heating coil; 7. Slag discharge port; 8. Graphite stirring paddle; 9. Distillation furnace top cover; 10. Vacuum tube; 11. Air inlet pipe; 12. Discharge pipe; 13. Discharge valve; 14. Fastening nut; 15. Upper section of distillation furnace; 16. Through hole; 17. Vacuum distillation furnace; 18. Graphite disc; 19. Middle section of distillation furnace; 20. Discharge pipe; 21. Lower section of distillation furnace; 22. Overflow port; 23. Distillation furnace heating coil. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] like Figure 1 As shown, after assembling the equipment and covering the top cover 4 of the reduction melting furnace, the materials are prepared and added to the reduction melting furnace 5 through the material feeding port 3. The heating program is started. After the materials melt, the stirring motor 2 is turned on to stir at low speed. The flue gas is discharged into the flue gas recovery system through the rising flue 1. After the material reaction is completed, the slag discharge port 7 is opened to discharge the upper slag and then the slag discharge port 7 is closed. The vacuum unit is started to evacuate the vacuum distillation furnace 17. The discharge valve 13 is opened to put the reduced alloy melt into the vacuum distillation furnace 17. After the discharge is completed, the discharge valve 13 is closed. Materials are continued to be added to the reduction melting furnace 5 through the material feeding port 3 for reduction melting.

[0035] The reduced alloy melt enters the graphite disk 18 in the lower section 21 of the vacuum distillation furnace through the discharge pipe 12. After the vacuum degree inside the vacuum distillation furnace 17 is lower than 5 Pa, the vacuum distillation furnace heating program is started. The distilled metal vapor gradually escapes upward through the through hole 16 on the graphite disk 18. After the various metal components condense at different heights, they are collected in the discharge pipe 20 through the overflow port 22. Then the valve is opened to release them.

[0036] The reduction smelting furnace is equipped with a graphite stirring paddle to agitate the melt and ensure that the smelting slag is fully reduced.

[0037] The top cover of the reduction smelting furnace is equipped with an upward flue and a feeding port for discharging flue gas and continuously feeding. A chute is opened on the side for discharging the slag after reduction. A discharge pipe is opened at the bottom of the reduction smelting furnace for discharging the reduction products.

[0038] The vacuum distillation furnace contains multiple layers of graphite trays for condensation and reflux of materials, ensuring the separation of various metals.

[0039] Furthermore, the graphite stirring paddle operates at a low speed, with a rotation speed of 10~60 r / min, to agitate the melt and ensure that the smelting slag is fully reduced.

[0040] Furthermore, the temperature of the reduction smelting furnace is set to 1300~1400℃ to ensure that the smelting slag in the Kaldo furnace is fully reduced.

[0041] Furthermore, the charging port of the reduction smelting furnace is equipped with a valve that is only opened during charging. The rising flue is the only normally open opening. Sufficient coke particles are added during reduction smelting to ensure a reducing atmosphere inside the furnace and to protect the graphite agitator, reducing its burn-out and extending its service life.

[0042] Furthermore, the distillation furnace body is detachable, facilitating furnace body replacement, maintenance, and furnace cleaning.

[0043] Furthermore, the distillation furnace employs multi-stage temperature control heating, and can be built at different heights according to the material composition to ensure the separation of each component.

[0044] Furthermore, the multi-layer graphite trays placed inside the distillation furnace have small holes on their sides to facilitate the discharge of high-boiling-point metals from inside the trays, and large vertical holes at the bottom to facilitate the evaporation and ascent of low-boiling-point metals.

[0045] Furthermore, the vacuum level inside the distillation furnace needs to be below 5 Pa to facilitate the volatilization of various metal components, thereby reducing energy consumption.

[0046] Furthermore, the temperature at the bottom of the distillation furnace is the highest, set at 1100~1200℃, the middle part at 900~1050℃, and the top part at 650~850℃, to ensure the separation of each metal component.

[0047] The beneficial effects of this invention are as follows:

[0048] This invention enables the separation of various valuable metals from the smelting slag of a Kaldor furnace, shortening the production cycle. Furthermore, the equipment can be combined in multiple stages, resulting in lower replacement and maintenance costs and easier furnace cleaning. This invention is simple, reasonable, economical, practical, and easy to use.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for recovering valuable metals from molten slag, comprising a vacuum distillation furnace (17), wherein the vacuum distillation furnace (17) is provided with a graphite disc (18) for condensation and a distillation furnace heating coil (23) for temperature control, and a discharge pipe (12) is provided at the bottom of the vacuum distillation furnace (17), characterized in that: The vacuum distillation furnace (17) includes multiple vertically arranged temperature control zones; multiple sets of graphite disks (18) are arranged along the vertical direction, and a condensation zone is formed between two adjacent graphite disks (18). The surface of the graphite disk (18) has through holes (16) for connecting two adjacent condensation zones; wherein, the heating temperature of the multiple temperature control zones gradually decreases, and metals with different boiling points are controlled to condense in different condensation zones. The condensation zone includes a first condensation side and a second condensation side. Two adjacent through holes (16) are alternately located on different condensation sides, and gaseous metal flows alternately in different condensation sides, extending the path of gaseous metal flow. A columnar divider is installed in the middle of the condensation zone to control the flow path of gaseous metal to be arc-shaped, thereby further increasing the length of the gaseous metal flow path.

2. The device for recovering valuable metals from molten slag according to claim 1, characterized in that, An overflow port (22) is provided on the side wall of the condensation area.

3. The device for recovering valuable metals from molten slag according to claim 2, characterized in that, The adjacent temperature control zones are relatively enclosed by partitions, and a discharge pipe (20) is installed at the bottom of the temperature control zone. The overflow port (22) is connected to the corresponding temperature control zone.

4. The device for recovering valuable metals from molten slag according to claim 1, characterized in that, The horizontal projection planes of the multiple condensation regions overlap.

5. The device for recovering valuable metals from molten slag according to claim 1, characterized in that, The heating coils (23) of the distillation furnace are arranged in multiple groups along the vertical direction.

6. The device for recovering valuable metals from molten slag according to claim 1, characterized in that, It also includes a reduction smelting furnace (5), the bottom of which is connected to a discharge pipe (12), and a discharge valve (13) is provided inside the discharge pipe (12).

7. A valuable metal recovery device for molten slag according to claim 6, characterized in that, The side wall of the reduction smelting furnace (5) is provided with a smelting furnace heating coil (6) and a slag discharge port (7). The inside of the reduction smelting furnace (5) is provided with a graphite stirring paddle (8). The top of the reduction smelting furnace (5) is provided with a stirring motor (2) to control the rotation of the graphite stirring paddle (8).

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