Device and method for treating acid wastewater containing ruthenium, rhodium and iridium

Abstract

The invention relates to the technical field of precious metal wastewater treatment, in particular to a device and method for treating ruthenium-rhodium-iridium-containing acid wastewater, and the device comprises a resin adsorption unit, a neutralization and precipitation unit, an evaporation and concentration unit, an aeration unit, an activated carbon adsorption unit and a pure water making machine unit which are connected in sequence; the resin adsorption unit comprises a resin A adsorption column and a resin B adsorption column; the evaporation and concentration unit comprises a compressor, an evaporation cylinder and a condenser which are connected in sequence; the aeration unit comprises an aeration cylinder and an air compressor; alkali is added into the neutralization and precipitation unit to keep the pH value; and the output end of the pure water making machine unit is connected with a production water end. The method has the advantages of being high in recovery rate, small in environmental pollution, high in resource utilization rate, capable of saving water resources, beneficial to sustainable development and good in application prospect.

Description

Technical Field

[0001] This invention relates to the field of precious metal wastewater treatment technology, and in particular to an apparatus and method for treating acidic wastewater containing ruthenium, rhodium, and iridium. Background Technology

[0003] CN 112811551 A discloses a method for treating wastewater from electroplating and precious metal smelting, comprising separating sludge containing complexed metals with a water content of 85% and a portion of wastewater through wastewater chelation precipitation; dewatering and drying the sludge to a water content between 30% and 50%, and pouring it into a sludge storage tank; heating the sludge in the sludge storage tank with a metal content exceeding 5%; incinerating the sludge with a metal content below 5%, and detecting whether the fly ash generated during the incineration process contains heavy metals and whether the heavy metals exceed the standard.

[0004] CN 105439316 A discloses a method for recovering valuable metals from precious metal smelting wastewater and for the environmentally friendly treatment of waste materials, including the following steps: adjusting the pH value of the solution, solid-liquid separation, pretreatment of filter residue, acid leaching treatment, and harmless treatment of wastewater. The method has a good precipitation effect on valuable metal ions such as Cu, As, Ni, Zn, Pb, Se, Au, Ag, Pt, and Pd in ​​the wastewater, and the effluent quality meets the "Emission Standard of Pollutants for Copper, Nickel, and Cobalt Industries" (GB25467-2010). Simultaneously, precious metals such as Au, Ag, Pt, and Pd are effectively enriched in the acid leaching residue, facilitating subsequent comprehensive recovery of precious metals.

[0005] The above methods have obvious advantages, but they are not effective for separating specific platinum group elements, and the water resources are not centrally recycled. CN 112811551 A incinerates the sludge, which produces a lot of smoke and dust, some platinum group metals are carried away by the flue gas and lost, and there are also problems such as high energy consumption.

[0006] Therefore, based on existing processes for treating acidic wastewater containing precious metals, it is of great significance to develop a method and apparatus for effectively separating ruthenium, rhodium, and iridium, recycling resources, and being environmentally friendly. Summary of the Invention

[0007] The features and advantages of the present invention are set forth in part in the description which follows, or may be apparent from the description, or may be learned by practicing the invention.

[0008] To overcome the problems of existing technologies, this invention provides a treatment device for acidic wastewater containing ruthenium, rhodium, and iridium, comprising a resin adsorption unit, a neutralization and precipitation unit, an evaporation and concentration unit, an aeration unit, an activated carbon adsorption unit, and a pure water production unit connected in sequence; the resin adsorption unit includes a resin A adsorption column and a resin B adsorption column; the evaporation and concentration unit includes a distillation kettle connected to the neutralization and precipitation unit, an evaporator connected to the top of the distillation kettle, a condenser connected at both ends to the evaporator and the distillation kettle respectively, and a compressor also connected at both ends to the evaporator and the distillation kettle respectively; the aeration unit includes an aeration cylinder and a compressed air compressor; alkali is added to the neutralization and precipitation unit to maintain the pH; the output end of the pure water production unit is connected to the production water end.

[0009] Preferably, the resin in the resin A adsorption column is CH40 type resin; and the resin in the resin B adsorption column is CPs-HP50 type resin.

[0010] Preferably, the activated carbon adsorption unit includes a tank connected to the output end of the aeration unit, a liquid inlet at the top of the tank, a flushing water outlet parallel to the liquid inlet, a rectifier plate at the top of the tank, two parallel and opposite isolation nets in the middle of the tank, activated carbon between the two isolation nets, a flushing water pipe between the isolation nets and the rectifier plate and connected to the outside, a saturated carbon recovery pipe above the lower isolation net, sand and gravel at the bottom of the tank and below the lower isolation net, and a liquid outlet at the bottom of the tank; a flushing water inlet is provided next to the liquid outlet.

[0011] Preferably, the alkali is a soluble alkali, including sodium hydroxide and potassium hydroxide.

[0012] Preferably, the evaporation cylinder includes at least three cylinders connected in parallel; the volume of the cylinder is ≥10m3; the material of the cylinder is pure titanium, and the connecting pipes between the cylinders are all made of pure titanium.

[0013] Preferably, the present invention also provides a method for treating acidic wastewater containing ruthenium, rhodium, and iridium, wherein the method uses the aforementioned treatment device for acidic wastewater containing ruthenium, rhodium, and iridium to treat the wastewater.

[0014] The beneficial effects of this invention: The device of this invention for recovering ruthenium, rhodium, and iridium from acidic wastewater has the following advantages: (1) The device and method can efficiently recover platinum group metals ruthenium, rhodium and iridium from wastewater, with the recovery rates of ruthenium and rhodium ≥99.9% and the recovery rate of iridium ≥99.7%; (2) The device and method can achieve a water recycling rate of ≥90.0%, and concentrated salt and other substances can be used in an environmentally friendly manner, effectively reducing the possibility of resource waste and environmental pollution.

[0015] This invention has the advantages of high recovery rate, low environmental pollution, high resource utilization rate, water conservation, and good prospects for sustainable development when treating acidic wastewater containing ruthenium, rhodium, and iridium. Attached Figure Description

[0016] The present invention will be described in detail below with reference to the accompanying drawings and examples. The advantages and implementation methods of the present invention will become more apparent from this description. The accompanying drawings are for illustrative purposes only and do not constitute any limitation on the present invention. In the accompanying drawings: Figure 1 This is a process flow diagram of a treatment device for acidic wastewater containing ruthenium, rhodium, and iridium according to a specific embodiment of the present invention; Figure 2 This is a schematic diagram of the activated carbon adsorption unit of a treatment device for acidic wastewater containing ruthenium, rhodium, and iridium in a specific embodiment of the present invention; Figure 3 This is a suggested process flow diagram of the pure water production unit of a treatment device for acidic wastewater containing ruthenium, rhodium, and iridium in a specific embodiment of the present invention. Detailed Implementation

[0017] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" 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. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. Specific Implementation Example 1

[0019] like Figure 1As shown, this invention provides a treatment device for acidic wastewater containing ruthenium, rhodium, and iridium, comprising a resin adsorption unit 1, a neutralization and sedimentation unit 2, an evaporation and concentration unit 3, an aeration unit 4, an activated carbon adsorption unit 5, and a pure water purification unit 6 connected in sequence. The resin adsorption unit 1 includes a resin A adsorption column 101 and a resin B adsorption column 102. The neutralization and sedimentation unit 2 consists of a three-stage tank with a volume of 50 cubic meters, comprising an alkali addition tank, a sedimentation tank, and a clear water tank. The alkali addition tank, sedimentation tank, and clear water tank can be configured as tanks or simple pool-like containers according to actual needs, and are not specifically limited here. The pH is adjusted to neutral by adding caustic soda flakes, and the neutral solution enters the evaporation and concentration unit 3. The evaporation and concentration unit 3 includes a distillation vessel connected to the neutralization and precipitation unit 2, an evaporator connected to the top of the distillation vessel, a condenser connected at both ends to the evaporator and the distillation vessel respectively, and a compressor also connected at both ends to the evaporator and the distillation vessel respectively. The evaporation temperature is set to 30-40℃. The preferred model of the evaporation and concentration unit is HG-DDZ-DR-15T. The maximum concentration ratio of the evaporation and concentration unit 3 is 70%~90%. The salt obtained from the evaporation and concentration unit 3 can be recycled and reused. The aeration unit 4 includes an aeration cylinder and a compressed air compressor. In the neutralization and precipitation unit 2, alkali is added to maintain the pH, i.e., caustic soda flakes (i.e., sodium hydroxide) or other alkali to adjust the pH to neutral, and the mixture is allowed to stand for 24-48 hours. The type of alkali is not specifically limited here. The upper liquid obtained from the neutralization and precipitation unit 2 enters the evaporation and concentration unit 3, and the lower precipitate containing precious metal solids is subjected to precious metal roasting and enrichment recovery, thereby realizing the recovery of precious metals from wastewater and reducing precious metal loss. The aeration unit 4 is a 50 cubic meter water tank with an aeration disc at the bottom, through which air is introduced for aeration. Figure 2 As shown, the activated carbon adsorption unit 5 includes a tank 110 connected to the output end of the aeration unit 4, a liquid inlet 120 at the top of the tank 110, a flushing water outlet 130 parallel to the liquid inlet 120, a rectifier plate 140 at the top of the tank 110, two parallel and opposite isolation nets 150 in the middle of the tank, activated carbon 160 between the two isolation nets 150, a flushing water pipe 170 between the isolation nets 150 and the rectifier plate 140 and connected to the outside, a saturated carbon recovery pipe 180 above the lower isolation net 150, sand and gravel 190 at the bottom of the tank 110 and below the lower isolation net 150, and a liquid outlet 200 at the bottom of the tank 110; a flushing water inlet 210 is provided next to the liquid outlet 200. Both the flushing water inlet 210 and the flushing water outlet 130 are equipped with control valves, and the tank 110 has support legs at the bottom. The output of the pure water purification unit 6 is connected to the production water supply. The pure water purification unit 6 is a 0.5T / H+EDI model. Figure 3As shown, the pure water purification unit 6 includes, in sequence, a raw water tank 610, a booster pump 620, a sand filter 630, a carbon filter 640, a water softener 650, a brine tank 660, a filter 670, a high-pressure pump 680, a reverse osmosis sludge mechanism 690, and a pure water tank 700. This invention can achieve a primary recovery rate of over 99.7% for iridium in wastewater and over 99.9% for ruthenium and rhodium (excluding data from metals recovered through smelting and enrichment). It achieves efficient recovery of ruthenium, rhodium, and iridium from acidic wastewater, with a total water recycling rate of over 90%. It is environmentally friendly, conserves water resources, promotes sustainable development, and has promising application prospects.

[0020] Furthermore, the resin in the resin A adsorption column 101 is CH40 type resin; the resin in the resin B adsorption column 102 is CPs-HP50 type resin.

[0021] Furthermore, the alkali is a soluble alkali, including sodium hydroxide and potassium hydroxide. The pH value is maintained between 6 and 8.

[0022] Furthermore, the evaporation tank comprises at least three tank bodies connected in parallel; the volume of each tank body is ≥10m³. 3 The cylinder body is made of pure titanium, and the connecting pipes between the cylinder bodies are also made of pure titanium. In this embodiment, the evaporation cylinder comprises three cylinder bodies connected in parallel.

[0023] pH=2, volume 1m 3 The acidic wastewater containing ruthenium, rhodium, and iridium was pumped into resin A adsorption column 101 using an acid-resistant pump. The index data of the acidic wastewater before treatment are shown in Table 1 below: Table 1. Various indicators of wastewater before treatment in Example 1

[0024] After being treated by adsorption, neutralization, low-temperature evaporation, aeration, and activated carbon adsorption, the wastewater enters the pure water purification unit 6, producing 934L of water with a reuse rate of 93.4%. Relevant data for various indicators of the treated wastewater are shown in Table 2 below: Table 2. Various indicators of wastewater treated in Example 1

[0025] The recovery rates for iridium, rhodium, and ruthenium were 99.7%, 99.9%, and 99.9%, respectively. Example 2

[0026] The ruthenium-rhodium-iridium acidic wastewater was treated using the same treatment device as in Example 1, with a pH of 2 and a volume of 2m³. 3The acidic wastewater containing ruthenium, rhodium, and iridium was pumped into the resin A adsorption column 101 using an acid-resistant pump. The index data of the acidic wastewater before treatment are shown in Table 3 below: Table 3. Various indicators of wastewater before treatment in Example 2

[0027] After being treated by adsorption, neutralization, low-temperature evaporation, aeration, and activated carbon adsorption, the wastewater enters the pure water purification unit 6, producing 1912L of water with a reuse rate of 95.6%. Relevant data for various indicators of the treated wastewater are shown in Table 4 below: Table 4. Various indicators of the wastewater after treatment in Example 2

[0028] The recovery rates for iridium, rhodium, and ruthenium were 99.93% and 99.93%, respectively. Example 3

[0029] The same treatment device as in Example 1 was used to treat the ruthenium-rhodium-iridium acidic wastewater. A volume of 2 cubic meters of ruthenium-rhodium-iridium acidic wastewater with pH=3 was pumped into resin A adsorption column 101 using an acid-resistant pump. The index data of the acidic wastewater before treatment are shown in Table 5, as follows: Table 5. Various indicators of wastewater before treatment in Example 3

[0030] After being treated by adsorption, neutralization, low-temperature evaporation, aeration, and activated carbon adsorption, the wastewater enters the pure water purification unit 6, producing 1954L of water with a reuse rate of 97.7%. Relevant data for various indicators of the treated wastewater are shown in Table 6 below: Table 6. Various indicators of the wastewater after treatment in Example 3

[0031] The recovery rates for iridium were 99.91%, rhodium 99.93%, and ruthenium 99.95%.

[0032] Example 4 The same treatment device as in Example 1 was used to treat the ruthenium-rhodium-iridium acidic wastewater. A volume of 3 cubic meters of ruthenium-rhodium-iridium acidic wastewater with pH=3 was pumped into resin A adsorption column 101 using an acid-resistant pump. The index data of the acidic wastewater before treatment are shown in Table 7, as follows: Table 7. Various indicators of wastewater before treatment in Example 4

[0033] After being treated by adsorption, neutralization, low-temperature evaporation, aeration, and activated carbon adsorption, the wastewater enters the pure water purification unit 6, producing 2836L of water with a reuse rate of 94.5%. Relevant data for various indicators of the treated wastewater are shown in Table 8 below: Table 8. Various indicators of the wastewater after treatment in Example 4

[0034] The recovery rates for iridium were 99.93%, rhodium 99.92%, and ruthenium 99.91%. Example 5 The ruthenium-rhodium-iridium acidic wastewater was treated using the same treatment device as in Example 1, with a pH of 2 and a volume of 3m³. 3 The acidic wastewater containing ruthenium, rhodium, and iridium was pumped into resin A adsorption column 101 using an acid-resistant pump. The index data of the acidic wastewater before treatment are shown in Table 9 below: Table 9. Various indicators of wastewater before treatment in Example 5

[0035] After being treated by adsorption, neutralization, low-temperature evaporation, aeration, and activated carbon adsorption, the wastewater enters the pure water purification unit 6, producing 2811L of water with a reuse rate of 93.7%. Relevant data for various indicators of the treated wastewater are shown in Table 10 below: Table 10. Various indicators of the wastewater after treatment in Example 5

[0036] The recovery rates for iridium were 99.91%, rhodium 99.92%, and ruthenium 99.93%.

[0037] Example 6 The same treatment apparatus used in Example 1 was employed to treat the ruthenium-rhodium-iridium-containing acidic wastewater, with a pH of 3 and a volume of 2.5 m³. 3 The acidic wastewater containing ruthenium, rhodium, and iridium was pumped into the resin A adsorption column 101 using an acid-resistant pump. The index data of the acidic wastewater before treatment are shown in Table 11 below: Table 11. Various indicators of wastewater before treatment in Example 6

[0038] After being treated by adsorption, neutralization, low-temperature evaporation, aeration, and activated carbon adsorption, the wastewater enters the pure water purification unit 6, producing 2356L of water with a reuse rate of 94.24%. Relevant data for various indicators of the treated wastewater are shown in Table 12 below: Table 12 Various indicators of the wastewater after treatment in Example 6

[0039] The recovery rates for iridium were 99.90%, rhodium 99.94%, and ruthenium 99.92%.

[0040] The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. Those skilled in the art can implement the present invention in various modifications without departing from its scope and spirit. For example, a feature shown or described in one embodiment can be used in another embodiment to obtain yet another embodiment. The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. All equivalent changes made based on the description and drawings of the present invention are included within the scope of the present invention.

Claims

1. A treatment device for acidic wastewater containing ruthenium, rhodium, and iridium, characterized in that, The system comprises, in sequence, a resin adsorption unit, a neutralization and precipitation unit, an evaporation and concentration unit, an aeration unit, an activated carbon adsorption unit, and a pure water purifier unit. The resin adsorption unit includes a resin A adsorption column and a resin B adsorption column. The evaporation and concentration unit includes a distillation vessel connected to the neutralization and precipitation unit, an evaporator connected to the top of the distillation vessel, a condenser connected at both ends to the evaporator and the distillation vessel respectively, and a compressor also connected at both ends to the evaporator and the distillation vessel respectively. The aeration unit includes an aeration cylinder and a compressed air compressor. Alkali is added to the neutralization and precipitation unit to maintain the pH. The output of the pure water purifier unit is connected to the production water supply.

2. The treatment device for acidic wastewater containing ruthenium, rhodium, and iridium according to claim 1, characterized in that, The resin in the resin A adsorption column is CH40 type resin; the resin in the resin B adsorption column is CPs-HP50 type resin.

3. The treatment device for acidic wastewater containing ruthenium, rhodium, and iridium according to claim 1, characterized in that, The activated carbon adsorption unit includes a tank connected to the output end of the aeration unit, a liquid inlet at the top of the tank, a flushing water outlet parallel to the liquid inlet, a rectifier plate at the top of the tank, two parallel and opposite isolation nets in the middle of the tank, activated carbon between the two isolation nets, a flushing water pipe between the isolation nets and the rectifier plate and connected to the outside, a saturated carbon recovery pipe above the lower isolation net, sand and gravel at the bottom of the tank and below the lower isolation net, and a liquid outlet at the bottom of the tank; a flushing water inlet is provided next to the liquid outlet.

4. The treatment device for acidic wastewater containing ruthenium, rhodium, and iridium according to claim 1, characterized in that, The alkali is a soluble alkali, including sodium hydroxide and potassium hydroxide.

5. The treatment device for acidic wastewater containing ruthenium, rhodium, and iridium according to claim 1, characterized in that, The evaporation tank comprises at least three tank bodies connected in parallel; the volume of each tank body is ≥10m³. 3 The cylinder body is made of pure titanium, and the connecting pipes between the cylinder bodies are also made of pure titanium.

6. A method for treating acidic wastewater containing ruthenium, rhodium, and iridium, characterized in that, A method for treating acidic wastewater containing ruthenium, rhodium, and iridium using a treatment device as described in any one of claims 1-5.

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