[0040] According to a preferred embodiment of the present invention, the precipitating agent is selected from one or more of carbon dioxide, sulfur dioxide and sulfur trioxide, and the method for recovering lead oxide from waste containing lead oxide preferably further includes the step ( 3) The gas obtained by the desalination and decomposition of the lead salt precipitation is recycled as the precipitating agent described in step (2), which can achieve the requirements of atomic economic reaction, thereby achieving zero consumption and zero emission, and has more industrial application prospects.
[0041] According to another preferred embodiment of the present invention, the precipitation agent is selected from one or more of ammonium sulfate, ammonium oxalate and ammonium carbonate, and the method for recovering lead oxide from waste containing lead oxide preferably further comprises: Step (2) The ammonia solution formed by the ammonia gas produced by the reaction is used in the desalination decomposition process of step (3), and the product obtained by the desalination decomposition is subjected to solid-liquid separation, and then the ammonium sulfate solution and ammonium oxalate solution obtained after the desalination decomposition One or more of the ammonium carbonate solution and the ammonium carbonate solution are used again in the precipitation process of step (2), which can also meet the requirements of atomic economic reaction, thereby achieving zero consumption and zero emission, and has more industrial application prospects.
[0042] When the precipitating agent is ammonium sulfate, ammonium oxalate or ammonium carbonate, the reaction principle of the precipitation process is different from using carbon dioxide as the precipitating agent. The following takes ammonium sulfate as an example to illustrate the difference between the principles of these two precipitants:
[0043] (1) The lead oxide-containing waste material is contacted with a complexing agent solution to complex and dissolve the PbO component in the lead oxide-containing waste material in the complexing agent, and the contact product is solid-liquid separated to obtain lead-containing The reaction formula of filtrate and filter residue is expressed as:
[0044] PbO+P/S+H 2 O=Pb(P/S) 2+ +2OH - (1)
[0045] (2) The lead-containing filtrate is reacted with the precipitating agent to obtain lead salt precipitation, while the complexing agent is regenerated, and the generated ammonia volatilizes to obtain ammonia water. Taking ammonium sulfate as the precipitating agent as an example, the reaction formula is expressed as:
[0046] Pb(P/S) 2+ +SO 4 2- =PbSO 4 +P/S (5)
[0047] 2NH 4 + +2OH - =2NH 3 +2H 2 O (6)
[0048] (3) Desalting and decomposing the lead salt precipitation to obtain PbO, while regenerating the precipitation agent:
[0049] PbSO 4 +2NH 3 +2H 2 O=PbO+H 2 O+(NH 4 ) 2 SO 4 (7)
[0050] Ammonium sulfate was added during the reaction, and the alkalinity generated during the complexing and dissolving process of PbO was used to make NH 3 Volatilize and make Pb(P/S) 2+ And SO 4 2- PbSO is obtained by precipitation reaction 4 At the same time, the complexing agent P/S is regenerated. The ammonia produced by volatilization can be hot and separated into PbSO 4 The desalination reaction is carried out to obtain PbO solid and ammonium sulfate solution, and the regenerated ammonium sulfate can be used as a precipitant again in the precipitation process of step (2). In addition, in the process, the use of ammonia for desalination and decomposition to obtain PbO sometimes entrains a small amount of Pb(OH) 2 , These carry a small amount of Pb(OH) 2 Desalination and decomposition products containing PbO can completely decompose lead hydroxide into PbO and H after drying at 60-300℃ for 10-60min 2 O, so as to obtain pure PbO.
[0051] The present invention does not specifically limit the conditions for contacting the lead oxide-containing waste with the complexing agent in step (1), but in order to facilitate the complexation and dissolution of the PbO, so that the resulting lead-containing filtrate has A higher concentration of lead-containing complex ion concentration, preferably, the conditions for contacting the lead oxide-containing waste with the complexing agent solution include: a temperature of 5-102°C, more preferably 25-95°C, more preferably 45°C -80°C; time is 1-150 min, more preferably 3-120 min, more preferably 20-60 min.
[0052] In the present invention, the conditions for reacting the lead-containing filtrate with the precipitating agent in step (2) are not particularly limited, as long as the soluble lead salt can be used as lead carbonate, lead sulfite, lead sulfate and their corresponding alkali At least one precipitation substance in the lead salt of the formula may be precipitated. For example, the conditions for reacting the lead-containing filtrate with the precipitation agent include: the temperature may be -2°C to 80°C, preferably 5-80°C, more Preferably it is 50-80°C; the time can be 1-300min, preferably 2-80min, more preferably 10-60min.
[0053] In order to ensure the purity of PbO obtained by desalting and decomposition, when the precipitating agent is selected from one or more of carbon dioxide, sulfur dioxide and sulfur trioxide, the method of performing desalting and decomposition of the lead salt precipitation is to precipitate the lead salt Carry out thermal decomposition, which includes two stages in sequence; the conditions of the first stage include: the temperature is 60-290°C, and the time is 1-30min; the conditions of the second stage include: the temperature is 300-1350°C, The time is 2-90min. When the precipitating agent is selected from one or more of ammonium sulfate, ammonium oxalate and ammonium carbonate, the conditions for the precipitation of the lead salt for desalination and decomposition include: a temperature of 45-100°C, a time of 1-150 min, The concentration of the ammonia solution is 0.1-5.5mol/L.
[0054] In order to ensure the best dissolution effect, the concentration of the complexing agent solution is preferably controlled at 0.1-4.5 mol/L. In addition, the solvent in the complexing agent solution may be various liquid substances known in the art that can be used as a reaction medium and can dissolve the complexing agent, but do not dissolve PbO and insoluble impurities in the lead oxide-containing waste. For example, specific examples thereof include, but are not limited to, one or more of methanol, ethanol, n-propanol, isopropanol, and water, and water is particularly preferred. In the actual operation process, the temperature at which the lead oxide-containing waste is contacted with the complexing agent refers to the temperature of the complexing agent solution.
[0055] In the present invention, the solid-liquid separation can be carried out according to various methods known to those skilled in the art for separating solids and liquids, such as filter press or centrifugal separation, preferably filter press.
[0056] According to a specific embodiment of the present invention, such as figure 1 As shown, the method for recovering lead oxide from waste containing lead oxide includes adding the waste containing lead oxide to a complexing agent solution, and PbO in the waste containing lead oxide reacts with the complexing agent to form a soluble lead salt The reaction product is leached in the form of leaching, and the reaction product is pressure-filtered to obtain lead-containing filtrate and filter residue; then carbon dioxide is introduced into the lead-containing filtrate, so that the soluble lead salt in the filtrate generates lead carbonate and/or basic lead carbonate precipitation, The reaction product is filtered under pressure to obtain lead carbonate and/or basic lead carbonate and a complexing agent filtrate. The complexing agent filtrate is recycled to react with the PbO in the lead oxide-containing waste, and the lead carbonate and /Or the basic lead carbonate is thermally decomposed to obtain PbO and carbon dioxide, and the carbon dioxide is recycled to react with the lead-containing filtrate.
[0057] The method provided by the present invention is suitable for recovering lead oxide from various existing lead oxide-containing waste materials, as long as it contains PbO and insoluble impurities that need to be removed. For example, the lead oxide-containing waste material may be lead-containing flue ash, lead paste from waste lead-acid batteries, PbO waste material recovered from waste electrode plates, other lead oxide-containing waste materials in the production process of lead-acid batteries, and production in other fields. One or more of waste materials containing lead oxide. Studies have shown that the content of PbO in various lead oxide-containing wastes is very different. For example, the flue ash produced in the smelting process of some copper and iron ore generally contains only 2-7% of PbO by weight, and some zinc The flue ash and waste lead paste of lead mines generally contain 45-70% by weight of PbO, and some lead-acid battery ball milling process contains lead oxide wastes that contain PbO as high as 75-99% by weight. In addition, studies have shown that when the weight percentage content of PbO in a single or several mixed lead oxide waste materials reaches 3-99%, and the weight percentage content of insoluble impurities reaches 1-97%, the PbO can be contained in the The complexing agent solution is more effectively dissolved, and the precipitation agent is used for precipitation and recovery.
[0058] In the implementation of the present invention, the insoluble impurities in the lead oxide-containing waste may contain Pb, PbCO 3 , Pb 3 O 4 , PbO 2 , PbSO 4 , Pb 3 (PO 4 ) 2 , Basic lead sulfate, basic lead carbonate, CuO, Al 2 O 3 , SnO 2 And Fe 2 O 3 One or more of. Among them, when the insoluble impurities contain Pb, PbCO 3 , Pb 3 O 4 , PbO 2 , PbSO 4 , Pb 3 (PO 4 ) 2 , Basic lead sulfate and basic lead carbonate one or more non-PbO components, the method for recovering lead oxide from lead oxide-containing waste material preferably further includes the step of combining the lead oxide-containing waste material with Before contact with the agent, the lead oxide-containing waste material is pretreated, so that the non-PbO components are converted into Pb(OH) 2 And/or PbO, thereby significantly increasing the overall yield of PbO.
[0059] The pretreatment can be performed by a conventional method in the art, for example, it can be selected from at least one of pre-desalination treatment, Pb addition for redox treatment, and pre-heat treatment in air.
[0060] Specifically, the pre-desalting treatment usually refers to contacting and reacting the lead oxide-containing waste with an alkaline substance (such as potassium hydroxide, sodium hydroxide, ammonium hydroxide, etc.), so that the alkaline substance can interact with the PbSO in waste containing lead oxide 3 , PbSO 4 , Pb 3 (PO 4 ) 2 , Basic lead sulfate and basic lead carbonate and other non-PbO components react to produce Pb(OH) that can be dissolved in the complexing agent solution 2 And/or PbO, filtered to obtain the lead-containing material after pre-desalination, and then Pb(OH) formed by pre-desalination 2 And/or PbO and the lead-containing material are contacted with a complexing agent to recover the lead oxide. When pre-desalting is used for treatment, in order to ensure the completion of the reaction, the reaction temperature should usually be controlled at 10-105°C, and the reaction time should be controlled at 1-30 min.
[0061] The oxidation-reduction treatment by adding Pb usually refers to the high-valence lead oxide (such as Pb) in the lead oxide-containing waste 3 O 4 , PbO 2 Etc.) Redox reaction with Pb (Pb+Pb 3 O 4 =4PbO, Pb+PbO 2 = 2PbO), so that the Pb and Pb in the lead oxide-containing waste 3 O 4 , PbO 2 Converted to PbO. The pre-heat treatment in the air means that under heating conditions, the easily decomposable lead-containing oxides (such as PbCO 3 , PbSO 4 , Basic lead sulfate and basic lead carbonate, etc.) decompose into PbO. For some containing Pb, PbO, PbCO 3 , Pb 3 O 4 , Pb(OH) 2 And PbO 2 The lead oxide-containing waste can be directly preheated in the air. At this time, the Pb and Pb in the waste 3 O 4 And PbO 2 PbO can be obtained by oxidation-reduction reaction in air atmosphere, and PbCO in waste 3 , Pb 3 O 4 , Pb(OH) 2 And PbO 2 During the preheating process, a decomposition reaction occurs to generate PbO, thereby obtaining a lead-containing material mainly PbO. In this process, in order to ensure the completion of the reaction, it is preferable to preheat the lead oxide-containing waste in two stages in the air. The conditions of the first stage preheat treatment include: the temperature is 60-290°C and the time is 1-30min; The conditions of the second stage of pre-heat treatment include: temperature is 300-1350℃, time is 2-90min.
[0062] According to a specific embodiment of the present invention, the lead oxide-containing waste material is derived from the lead-containing flue ash of the Huitong smelter, which mainly contains 60-70% by weight of lead oxide, and the rest is a small amount of SnO 2 , CaSiO 3 , Al 2 O 3 And SiO 2 Such as insoluble impurities, the lead oxide-containing material can be directly put into step (1) for complexation and dissolution.
[0063] According to another embodiment of the present invention, the lead oxide-containing waste is derived from lead-containing flue ash from a gold-lead smelter, and it mainly contains 60-65% by weight of PbO and 5-10% by weight of PbSO 4 , The rest is a small amount of Al 2 O 3 And SiO 2 For insoluble impurities, the lead oxide-containing material can be pre-desalted with an alkaline substance, and the pre-desalted lead-containing material can be obtained by filtering, and then the lead-containing material can be put into step (1) for complexation and dissolution.
[0064] According to another specific embodiment of the present invention, the lead oxide-containing waste material is derived from the lead-containing waste material of Henan Haoda Company, which mainly contains 60-65% by weight of PbO and 5-10% by weight of PbSO. 4 , 3-5% by weight PbCO 3 And 2-4% by weight of Pb 3 O 4 , The rest is a small amount of Al 2 O 3 And SiO 2 And other insoluble impurities, the lead oxide-containing material can be pre-desalted with an alkaline substance, and the pre-desalted lead-containing material can be obtained by filtration, and then the lead-containing material obtained by chemical analysis of the lead paste is Pb 3 O 4 The actual content, according to Pb 3 O 4 Carry out redox reaction (Pb+Pb 3 O 4 =4PbO) The theoretical amount of metal Pb needed to supplement the corresponding Pb powder (Pb 3 O 4 The molar ratio with Pb powder is 1.02-3.0:1), which promotes the Pb 3 O 4 Basically converted to PbO.
[0065] According to another specific embodiment of the present invention, the lead oxide-containing waste material is derived from the lead paste of the blue sky 12V, 12Ah waste electric vehicle battery, which contains Pb and PbSO in addition to PbO 4 , PbO 2 And basic lead sulfate, the lead oxide-containing material can be pre-desalted with alkaline substances, and filtered to obtain the desalted lead paste, and then the Pb and PbO in the desalted lead paste obtained from the chemical analysis of the lead paste 2 The actual content, according to PbO 2 Carry out redox reaction (Pb+PbO 2 =2PbO) The theoretical amount of metal Pb needed to supplement the corresponding Pb powder (PbO 2 The molar ratio with Pb powder is 1.02-3.0:1), which promotes the PbO 2 Basically converted to PbO. Or use the high temperature of the second stage of preheating (temperature is 300-1350℃) to make excess PbO 2 Direct decomposition into PbO (2PbO 2 =2PbO+O 2 ).
[0066] According to another specific embodiment of the present invention, the lead oxide-containing waste is derived from lead-containing materials in the laboratory of a lead-acid battery factory, and it mainly contains 70-72% by weight of PbO and 10-15% by weight of basic sulfuric acid Lead, 3-5% by weight lead carbonate, and the balance is water and clay, then the lead-containing material can be pre-desalted with an alkaline substance, and filtered to obtain a desalted lead paste, and then the desalted lead paste is placed in the air The heating is carried out in two stages in the atmosphere. The heat treatment temperature of the two stages is controlled to 60-290℃ and 300-650℃ respectively, and the heat treatment time is 1-30min and 2-90min respectively, so that the PbCO 3 After heat treatment, it is decomposed into PbO, and finally lead oxide-based lead-containing materials are obtained, which are put into step (1) for complexation and dissolution.
[0067] The present invention will be described in detail below through examples.
