Recovery device for precious metal rhodium in rhodium-containing working solution

Abstract

In order to solve the problems of substandard flue gas emission and large rhodium loss in the recovery process of precious metal rhodium in a rhodium-containing working solution, the utility model provides the recovery device for precious metal rhodium in the rhodium-containing working solution, which comprises an incinerator, a heat exchanger, a cyclone separator, a bag-type dust collector, an alkaline washing tower, a water washing tower and an induced draft fan which are connected in sequence, the water scrubber comprises at least two groups which are connected in series, a flue gas outlet of the incinerator is connected with an inlet of the heat exchanger through a flue gas pipe, the flue gas pipe is connected with a blowback pipe, one end of a gas inlet of the blowback pipe is connected with a gas outlet of the blowback device, solid components in flue gas are recovered through the separator, the bag-type dust collector and the water scrubber, and the loss of rhodium in the recovery process is reduced; phosphorus oxide in the flue gas is neutralized through the alkaline washing tower, and then secondary water washing treatment is carried out, so that the flue gas is discharged after reaching the standard; the reverse blowing device can blow the pipe wall of the heat exchanger, and the recovery amount of rhodium is further increased.

Description

Technical Field

[0001] The utility model relates to the technical field of precious metal recovery, in particular to a device for recovering precious metal rhodium from rhodium-containing working fluid. Background Art

[0002] Butyl octanol is an important raw material for the synthesis of fine chemical products. It is mainly used in the production of plasticizers, solvents, dehydrating agents, defoaming agents, dispersants, flotation agents, petroleum additives (such as: etc.) and synthetic fragrances. The carbonyl synthesis process of butyl octanol uses propylene, synthesis gas and hydrogen as raw materials. Mixed butyraldehyde is generated under the action of a catalyst. The catalyst is separated and recycled. The separated n- / isobutyraldehyde is hydrogenated to generate n-butanol and isobutanol, and the n-butanol and isobutanol products are obtained through distillation separation: n-butyraldehyde is condensed and dehydrated under the catalytic action of sodium hydroxide to generate octenal, and octenal is hydrogenated to produce crude octanol, which is then distilled to obtain the product octanol.

[0003] The industrial unit for producing 1,2-butanol mainly adopts a low-pressure carbonyl synthesis process for propylene using an oil-soluble rhodium-phosphine complex as a catalyst. The catalyst is deactivated due to the presence of various by-products produced during the reaction and impurities in the raw materials. The waste liquid containing the rhodium catalyst needs to be discharged, the rhodium therein needs to be recovered, and the rhodium needs to be reprocessed into a rhodium catalyst for reuse. Since rhodium catalysts are expensive, the recovery of rhodium catalysts is of great value to the environment and benefits.

[0004] The residual liquid of butanol containing waste rhodium catalyst is relatively viscous. Its main components are: butyraldehyde and its polymers, high-boiling point by-products, triphenylphosphine, triphenylphosphine oxide, rhodium, impurities (mainly a small amount of iron, nickel, chromium, copper and other metal ions). Among them, the rhodium content is between 100-600ppm. Due to the low rhodium content, it is often concentrated and enriched before treatment. After concentration, the rhodium content is about 1500-3000ppm.

[0005] At present, the main methods for recovering rhodium from rhodium catalyst waste liquid include incineration, extraction, adsorption, etc. Among them, the incineration method has a simple process and a short recovery cycle, and is a method suitable for factory application. However, during the incineration process, problems such as material splashing as the temperature rises, rhodium entrained in the flue gas, and easy ignition of organic matter may occur. Utility Model Content

[0006] The utility model provides a device for recovering precious metal rhodium in rhodium-containing working fluid, which can effectively recover tail gas of rhodium catalyst waste liquid after incineration, reduce rhodium loss in the recovery process and increase the recovery amount of rhodium.

[0007] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0008] A device for recovering precious metal rhodium in a rhodium-containing working fluid, characterized in that it comprises an incinerator, a heat exchanger, a cyclone separator, a bag dust collector, an alkali washing tower, a water washing tower and an induced draft fan connected in sequence, the water washing tower comprises at least two groups arranged in series, the flue gas outlet of the incinerator is connected to the inlet of the heat exchanger through a flue gas pipe, the flue gas pipe is connected to a backflush pipe, and one end of the air inlet of the backflush pipe is connected to the air outlet of the backflush device.

[0009] Preferably, the flue gas pipe is provided with a first switch valve and a second switch valve, which are respectively located in front of and behind the connection point between the backblowing pipe and the flue gas pipe in the flue gas flow direction, and the backblowing pipe is provided with a third switch valve.

[0010] Preferably, the backflush device is an air compressor.

[0011] Preferably, a fourth switch valve and a temperature sensor are provided on the connecting pipe between the heat exchanger and the cyclone separator.

[0012] Preferably, the alkali washing tower and the water washing tower connected to the air inlet of the induced draft fan are both provided with a pH meter.

[0013] Preferably, the water washing tower comprises a primary water washing tower and a secondary water washing tower connected in series.

[0014] The beneficial effects of the utility model are:

[0015] 1. By setting up an alkali washing tower and a water washing tower connected in sequence, the content of phosphorus oxides in the tail gas can be effectively removed, reducing pollution to the environment;

[0016] 2. The tail gas after the incineration of the rhodium-containing working fluid is treated by a cyclone separator, a bag filter and a multi-stage water scrubber to recover the solid components in the flue gas and reduce the loss of rhodium during the recovery process;

[0017] 3. The heat exchanger inlet is connected with a back-flush device, which can be used to purge the accumulated material on the heat exchanger tube wall to avoid accumulation of material inside the heat exchanger, thereby further increasing the recovery of rhodium. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of the utility model

[0019] Among them, 1-incinerator, 2-heat exchanger, 3-cyclone separator, 4-bag dust collector, 5-alkali washing tower, 6-primary water washing tower, 7-secondary water washing tower, 8-induced draft fan, 9-flue gas pipe, 10-backflush pipe, 11-first switch valve, 12-second switch valve, 13-third switch valve, 14-fourth switch valve, 15-air compressor, 16-temperature sensor, 17-first pH meter, 18-second pH meter. DETAILED DESCRIPTION

[0020] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0021] In the description of the utility model, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the viewing direction or position relationship, and are only for the convenience of describing the utility model, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0022] like Figure 1 As shown, a device for recovering precious metal rhodium in a rhodium-containing working fluid comprises an incinerator 1, a heat exchanger 2, a cyclone separator 3, a bag filter 4, an alkali washing tower 5, a primary water washing tower 6, a secondary water washing tower 7 and an induced draft fan 8 which are connected in sequence.

[0023] Specifically, the flue gas outlet of the incinerator 1 is connected to the inlet of the heat exchanger 2 through a flue gas pipe 9, a blowback pipe 10 is connected to the flue gas pipe 9, one end of the air inlet of the blowback pipe 10 is connected to the air outlet of the air compressor 15, and one end of the air outlet is connected to the flue gas pipe 9 through a three-way pipe joint, and a first switch valve 11 and a second switch valve 12 are respectively arranged in front and rear of the connection point between the blowback pipe 10 and the flue gas pipe 9, the front and rear are the flue gas flow directions inside the flue gas pipe 9, and a third switch valve 13 is arranged on the blowback pipe 10; the heat exchanger 2 The outlet is connected to the inlet of the cyclone separator through a first connecting pipe, and a fourth switch valve 14 and a temperature sensor 16 are sequentially arranged on the first connecting pipe near the outlet of the heat exchanger 2; in addition, a first pH meter 17 is arranged at the bottom of the alkali washing tower 5, and the first pH meter 17 is located below the liquid level of the alkali washing tower 5, and is used to detect the pH value of the internal dilute alkali solution; a second pH meter 18 is arranged at the bottom of the secondary water washing tower 7, and the second pH meter 18 is arranged below the liquid level of the second water washing tower 7, and is used to detect the pH value of the liquid inside the secondary water washing tower 7.

[0024] The working principle of this device is as follows:

[0025] The flue gas discharged from the incinerator 1 enters the heat exchanger 2 through the flue gas pipe 9 for cooling treatment, and is detected by the temperature sensor 16 to ensure that the flue gas temperature drops below 300°C to protect the filter bags of the bag filter 4; the heat exchanger 2 inlet is connected to a backflush device. When the heat exchanger 2 is closed and the accumulated material is closed, the first switch valve 11 is closed, the second switch valve 12 and the third switch valve 13 are opened, and the air compressor 15 passes high-pressure gas into the heat exchanger 2 through the backflush pipe 10, so as to purge the accumulated material on the wall of the heat exchanger 2. , avoiding material accumulation inside the heat exchanger 2, and at the same time effectively recovering the flue gas, thereby increasing the recovery of rhodium; the flue gas after cooling is collected by the cyclone separator 3 and the bag dust collector 4, the discharge valve of the cyclone separator 3 is opened regularly to discharge the material, and the recovered dust is combined with the incineration residue for treatment; the alkali washing tower 5 is provided with 5% dilute alkali solution, and the flue gas passes through the alkali washing tower 5, the first-level water washing tower 6 and the second-level water washing tower 7 in turn to remove the content of phosphorus oxides in the flue gas and reduce pollution to the environment. Finally, the flue gas is discharged through the induced draft fan 8.

[0026] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. A device for recovering precious metal rhodium from rhodium-containing working fluid, It is characterized in that It includes an incinerator, a heat exchanger, a cyclone separator, a bag dust collector, an alkali washing tower, a water washing tower and an induced draft fan which are connected in sequence. The water washing tower includes at least two groups which are arranged in series. The smoke outlet of the incinerator is connected to the inlet of the heat exchanger through a smoke pipe. The smoke pipe is connected to a back-blowing pipe. One end of the air inlet of the back-blowing pipe is connected to the air outlet of the back-blowing device.

2. The recovery device of the noble metal rhodium of the rhodium-containing working solution according to claim 1, It is characterized in that The flue gas pipe is provided with a first switch valve and a second switch valve, which are respectively located in front of and behind the connection point between the back-blowing pipe and the flue gas pipe in the flue gas flow direction, and the back-blowing pipe is provided with a third switch valve.

3. The recovery device of the noble metal rhodium of the rhodium-containing working solution according to claim 2, It is characterized in that The back-blowing device is an air compressor.

4. A recovery device for the precious metal rhodium of the rhodium-containing working solution according to any one of claims 1 to 3, It is characterized in that A fourth switch valve and a temperature sensor are arranged on the connecting pipeline between the heat exchanger and the cyclone separator.

5. The recovery device of the noble metal rhodium of the rhodium-containing working solution according to claim 4, It is characterized in that The alkali washing tower and the water washing tower connected to the air inlet of the induced draft fan are both provided with a pH meter.

6. The recovery device of the noble metal rhodium of the rhodium-containing working solution according to claim 1, It is characterized in that The water washing tower comprises a primary water washing tower and a secondary water washing tower connected in series.

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