A stable waste TBP / kerosene suspension and its preparation method

Abstract

The invention provides a stable waste TBP / kerosene suspension and a preparation method thereof. The waste TBP / kerosene suspension is composed of the following components in mass percentage: 50% to 80% TBP, 0.1% to 20% DBP calcium salt, 5% to 10% kerosene, 5% to 25% soluble calcium salt, and 2% to 5% water. The DBP calcium salt used as an emulsifier is prepared as follows: a flask, a Soxhlet extractor, an oil-water separator, and a condenser are connected in sequence, TBP and water are added to the flask, calcium hydroxide wrapped with filter paper is placed in the Soxhlet extractor, heated for reflux, and the upper layer of DBP calcium salt is collected after a certain period of time. Then, a waste TBP / kerosene suspension is prepared by the following method: TBP and DBP calcium salts are added into a beaker and mixed evenly to form an organic phase; calcium nitrate and calcium formate are dissolved in water and heated, and stirred until completely dissolved to form a solution; the obtained solution is slowly added into the organic phase while stirring; and the prepared waste TBP / kerosene suspension is stirred on an electric stirrer in the laboratory.

Description

Technical Field

[0001] The present invention relates to the preparation of a waste TBP / kerosene suspension, in particular to a stable waste TBP / kerosene suspension and a preparation method thereof. Background Art

[0002] At present, the pyrolysis incineration method is mainly used to treat radioactive TBP / kerosene organic waste liquid at home and abroad. In order to avoid the corrosion of corrosive substances such as P2O5 or H3PO4 produced by pyrolysis to the equipment, alkali metal oxides, hydroxides, basic carbonates and carbonates and other phosphorus-fixing agents are often added to the liquid to convert the highly corrosive phosphorus-containing compounds produced during the pyrolysis of TBP into stable phosphates or pyrophosphates. At the same time, appropriate emulsifiers or surfactants are added to make the TBP / kerosene organic waste liquid and the phosphorus-fixing agent such as calcium hydroxide form a stable and uniform mixed liquid, overcoming the difficulty of the liquid being easily settled due to the poor solubility of the phosphorus-fixing agent.

[0003] TBP and kerosene are non-polar substances with weak intermolecular interactions and a density lower than that of water. The measured density of TBP / kerosene organic waste liquid is about 0.84-0.98 g / cm 3 Calcium oxide, magnesium oxide, calcium hydroxide and magnesium hydroxide are highly polar substances with strong intermolecular interactions and tend to form crystals with a density exceeding 2.0 g / cm 3 (For example, the density of calcium hydroxide is 2.24 g / cm 3 ). Due to the above characteristics, the mixed system consisting of TBP / kerosene organic waste liquid and neutralizers such as calcium hydroxide is thermodynamically unstable and easily undergoes solid-liquid phase separation, resulting in the neutralizers such as calcium hydroxide being deposited at the bottom of the container and TBP / kerosene floating on top, which has an adverse effect on the pyrolysis and incineration of the organic waste liquid. Summary of the invention

[0004] The purpose of the present invention is to provide a waste TBP / kerosene suspension with simple formula, stable and uniform, controllable viscosity, good thermal stability and low cost and a preparation method thereof. The method uses a soluble calcium salt to prepare a saturated high-concentration aqueous solution to replace a neutralizing agent such as calcium hydroxide, so that the thermal decomposition rate of TBP and the phosphorus capture efficiency can be improved, and the sedimentation rate can be slowed down; and the DBP calcium salt obtained by rapid hydrolysis of TBP under alkaline washing conditions (pH of a saturated calcium hydroxide aqueous solution is ≈ 10-11) is used as an emulsifier to form an oil-in-water emulsion system to obtain a stable waste TBP / kerosene suspension.

[0005] The technical solution to achieve the purpose of the present invention is: a stable waste TBP / kerosene suspension, characterized in that it is composed of the following components expressed in mass percentage: TBP 50% to 80%, DBP calcium salt 0.1% to 20%, kerosene 5% to 10%, soluble calcium salt 5% to 25%, water 2% to 5%. The soluble calcium salt and water constitute the aqueous phase, TBP / kerosene and DBP calcium salt constitute the organic phase, and the two solutions are mixed and stirred to form a stable and uniform waste TBP / kerosene suspension.

[0006] A method for preparing the above waste TBP / kerosene suspension formulation comprises the following steps:

[0007] (1) Preparation of DBP calcium salt: connect a flask, a Soxhlet extractor, an oil-water separator and a condenser in sequence, then add TBP and water to the flask, and put calcium hydroxide wrapped in filter paper into the Soxhlet extractor; heat to 120°C for reflux, separate butanol from the oil-water separator, and collect water in the Soxhlet extractor, gradually dissolving calcium hydroxide to form a saturated solution, which returns to the flask after reaching a certain volume, thereby maintaining an alkaline environment for TBP hydrolysis. After collecting a certain amount of n-butanol, terminate the reaction, and let stand for stratification, the upper liquid is DBP calcium salt.

[0008] (2) Preparation of waste TBP / kerosene suspension: Step 1, add TBP and DBP calcium salts into a beaker and mix well to form an organic phase; Step 2, dissolve the soluble calcium salt in water and heat to 50°C to 70°C, stirring until completely dissolved to form a solution; Step 3, slowly add the solution obtained in Step 2 to the organic phase obtained in Step 1, stirring at the same time, to form a viscous emulsion; Step 4, mix kerosene with the emulsion obtained in Step 3; Step 5, stir the waste TBP / kerosene suspension obtained in Step 4 on an electric stirrer in the laboratory.

[0009] The soluble calcium salts of the waste TBP / kerosene suspension of the present invention are calcium nitrate and calcium formate.

[0010] The soluble calcium salt of the waste TBP / kerosene suspension of the present invention is a mixture of calcium nitrate and calcium formate in a mass ratio of 1:1.

[0011] Compared with the prior art, the present invention has the following significant advantages: 1. Soluble calcium salt is used as a calcium source to neutralize phosphoric acid produced by TBP degradation, which can improve the phosphorus capture efficiency and slow down the sedimentation rate. The density of the saturated solution of calcium nitrate and calcium formate is about 1.2 g / cm 3 , lower than 2.2g / cm of calcium hydroxide 3); 2. Formate ions are reducing and nitrate ions are weakly oxidizing. The combination of the two will react with each other to generate nitrogen and carbon dioxide to escape the reaction system, and will not form new anions to compete with phosphate for calcium ions; 3. DBP produced by TBP degradation can bind a large amount of calcium ions, so that calcium salts and TBP / kerosene waste organic liquid are evenly mixed at the molecular level to achieve an emulsification effect; 4. The thermal stability of TBP / kerosene organic waste liquid is significantly improved; 5. The formula is simple and the flexibility of selection is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Attached Figure 1 The flowchart of the preparation process of the waste TBP / kerosene suspension of the present invention is shown in FIG. Specific implementation plan

[0013] The present invention is further described in detail below with reference to the accompanying drawings.

[0014] First, DBP calcium salt is prepared by hydrolysis of TBP under alkaline conditions. The specific operation is as follows: 250g TBP and 120g water are added to a flask, and the flask port is connected to a Soxhlet extractor, an oil-water separator and a condenser in sequence. 20g of calcium hydroxide wrapped in filter paper is placed in the Soxhlet extractor, heated to 120°C for reflux, and butanol is separated from water and the produced butanol oil-water separator. Water gathers in the Soxhlet extractor, gradually dissolves calcium hydroxide to form a saturated solution, and returns to the flask after reaching a certain volume, thereby maintaining an alkaline environment for TBP hydrolysis. After collecting 60g of n-butanol, the reaction is terminated. In this way, the TBP in the flask is mainly transformed to obtain DBP. By standing and stratifying, the upper liquid is the calcium salt of DBP, and water is in the lower layer. Collect DBP calcium salt for standby use.

[0015] Example 1 Taking the preparation of 200g waste TBP / kerosene suspension as an example, the mass percentages of the components of the waste TBP / kerosene suspension are selected as follows: TBP 80%, DBP calcium salt 6%, kerosene 5%, calcium nitrate 2.5%, calcium formate 2.5%, and water 4%. According to the above ratio, accurately weigh TBP 160g, DBP calcium salt 12g, kerosene 10g, calcium nitrate 5g, calcium formate 5g, and water 8g.

[0016] Operation steps: Step 1, add TBP and DBP calcium salts into a beaker and mix them evenly to form an organic phase; Step 2, dissolve calcium nitrate and calcium formate in water and heat to 50°C, stirring until completely dissolved to form a solution; Step 3, slowly add the solution obtained in Step 2 to the organic phase obtained in Step 1, stirring at the same time to form a viscous emulsion; Step 4, mix kerosene with the emulsion obtained in Step 3; Step 5, stir the waste TBP / kerosene suspension obtained in Step 4 on an electric stirrer in the laboratory. The stable suspension time of the suspension was measured to be 18 hours, the viscosity of the suspension was 20mPa / s, and after heating and decomposing at 350°C for 15 minutes, the pyrolysis rate was 88.1%, and the phosphorus fixation rate was 87.5%.

[0017] Example 2 Taking the preparation of 200g waste TBP / kerosene suspension as an example, the mass percentages of the components of the waste TBP / kerosene suspension are selected as follows: TBP 75%, DBP calcium salt 11%, kerosene 4%, calcium nitrate 4%, calcium formate 4%, and water 2%.According to the above ratio, accurately weigh TBP 150g, DBP calcium salt 22g, kerosene 8g, calcium nitrate 8g, calcium formate 8g, and water 4g.

[0018] Operation steps: Step 1, add TBP and DBP calcium salts into a beaker and mix evenly to form an organic phase; Step 2, dissolve calcium nitrate and calcium formate in water and heat to 65°C, stirring until completely dissolved to form a solution; Step 3, slowly add the solution obtained in Step 2 to the organic phase obtained in Step 1, stirring at the same time, to form a viscous emulsion; Step 4, mix kerosene with the emulsion obtained in Step 3; Step 5, stir the waste TBP / kerosene suspension obtained in Step 4 on an electric stirrer in the laboratory. The stable suspension time of the suspension was measured to be 24 hours, the viscosity of the suspension was 25 mPa / s, and after heating and decomposing at 350°C for 15 minutes, the pyrolysis rate was 88.7%, and the phosphorus fixation rate was 87.9%.

[0019] Example 3 Taking the preparation of 200g waste TBP / kerosene suspension as an example, the mass percentages of the components of the waste TBP / kerosene suspension are selected as follows: TBP 70%, DBP calcium salt 8%, kerosene 8%, calcium nitrate 6%, calcium formate 6%, and water 2%. According to the above ratio, accurately weigh TBP 140g, DBP calcium salt 16g, kerosene 16g, calcium nitrate 12g, calcium formate 12g, and water 4g.

[0020] Operation steps: Step 1, add TBP and DBP calcium salts into a beaker and mix them evenly to form an organic phase; Step 2, dissolve calcium nitrate and calcium formate in water and heat to 70°C, stirring until completely dissolved to form a solution; Step 3, slowly add the solution obtained in Step 2 to the organic phase obtained in Step 1, stirring at the same time, to form a viscous emulsion; Step 4, mix kerosene with the emulsion obtained in Step 3; Step 5, stir the waste TBP / kerosene suspension obtained in Step 4 on an electric stirrer in the laboratory. The stable suspension time of the suspension was measured to be 20 hours, the viscosity of the suspension was 15 mPa / s, and after heating and decomposing at 350°C for 15 minutes, the pyrolysis rate was 90.9%, and the phosphorus fixation rate was 91.9%.

[0021] Example 4 Taking the preparation of 200g waste TBP / kerosene suspension as an example, the mass percentages of the components of the waste TBP / kerosene suspension are selected as follows: TBP 65%, DBP calcium salt 13%, kerosene 6%, calcium nitrate 7%, calcium formate 7%, and water 2%. According to the above ratio, 130g TBP, 26g DBP calcium salt, 12g kerosene, 14g calcium nitrate, 14g calcium formate, and 4g water are accurately weighed.

[0022] Operation steps: Step 1, add TBP and DBP calcium salts into a beaker and mix them evenly to form an organic phase; Step 2, dissolve calcium nitrate and calcium formate in water and heat to 65°C, stirring until completely dissolved to form a solution; Step 3, slowly add the solution obtained in Step 2 to the organic phase obtained in Step 1, stirring at the same time, to form a viscous emulsion; Step 4, mix kerosene with the emulsion obtained in Step 3; Step 5, stir the waste TBP / kerosene suspension obtained in Step 4 on an electric stirrer in the laboratory. The stable suspension time of the suspension was measured to be 30 hours, the viscosity of the suspension was 25 mPa / s, and after heating and decomposing at 350°C for 15 minutes, the pyrolysis rate was 95.9%, and the phosphorus fixation rate was 96.2%.

[0023] Example 5 Taking the preparation of 200g waste TBP / kerosene suspension as an example, the mass percentages of the components of the waste TBP / kerosene suspension are selected as follows: TBP 60%, DBP calcium salt 20%, kerosene 10%, calcium nitrate 3.5%, calcium formate 3.5%, and water 3%. According to the above ratio, accurately weigh TBP 120g, DBP calcium salt 40g, kerosene 20g, calcium nitrate 7g, calcium formate 7g, and water 6g.

[0024] Operation steps: Step 1, add TBP and DBP calcium salts into a beaker and mix evenly to form an organic phase; Step 2, dissolve calcium nitrate and calcium formate in water and heat to 70°C, stirring until completely dissolved to form a solution; Step 3, slowly add the solution obtained in Step 2 to the organic phase obtained in Step 1, stirring at the same time, to form a viscous emulsion; Step 4, mix kerosene with the emulsion obtained in Step 3; Step 5, stir the waste TBP / kerosene suspension obtained in Step 4 on an electric stirrer in the laboratory. The stable suspension time of the suspension was measured to be 48 hours, the viscosity of the suspension was 30mPa / s, and after heating and decomposing at 350°C for 15 minutes, the pyrolysis rate was 99.9%, and the phosphorus fixation rate was 99.9%.

[0025] Example 6 Taking the preparation of 200g waste TBP / kerosene suspension as an example, the mass percentages of the components of the waste TBP / kerosene suspension are selected as follows: TBP 55%, DBP calcium salt 18%, kerosene 5%, calcium nitrate 10%, calcium formate 10%, and water 2%. According to the above ratio, accurately weigh TBP 110g, DBP calcium salt 36g, kerosene 10g, calcium nitrate 20g, calcium formate 20g, and water 4g.

[0026] Operation steps: Step 1, add TBP and DBP calcium salts into a beaker and mix evenly to form an organic phase; Step 2, dissolve calcium nitrate and calcium formate in water and heat to 55°C, stirring until completely dissolved to form a solution; Step 3, slowly add the solution obtained in Step 2 to the organic phase obtained in Step 1, stirring at the same time, to form a viscous emulsion; Step 4, mix kerosene with the emulsion obtained in Step 3; Step 5, stir the waste TBP / kerosene suspension obtained in Step 4 on an electric stirrer in the laboratory. The stable suspension time of the suspension was measured to be 72 hours, the viscosity of the suspension was 35mPa / s, and after heating and decomposing at 350°C for 15 minutes, the pyrolysis rate was 99.8%, and the phosphorus fixation rate was 99.7%.

[0027] Example 7 Taking the preparation of 200g of waste TBP / kerosene suspension as an example, the mass percentages of the components of the waste TBP / kerosene suspension are selected as follows: TBP 50%, DBP calcium salt 17%, kerosene 10%, calcium nitrate 9%, calcium formate 9%, and water 5%. According to the above ratio, accurately weigh TBP 100g, DBP calcium salt 34g, kerosene 20g, calcium nitrate 18g, calcium formate 18g, and water 10g.

[0028] Operation steps: Step 1, add TBP and DBP calcium salts into a beaker and mix them evenly to form an organic phase; Step 2, dissolve calcium nitrate and calcium formate in water and heat to 55°C, stirring until completely dissolved to form a dissolving solution; Step 3, slowly add the dissolving solution obtained in Step 2 to the organic phase obtained in Step 1, stirring at the same time, to form a viscous emulsion; Step 4, mix kerosene with the emulsion obtained in Step 3; Step 5, stir the waste TBP / kerosene suspension obtained in Step 4 on an electric stirrer in the laboratory. The stable suspension time of the suspension was measured to be 60 hours, the viscosity of the suspension was 30mPa / s, and after heating and decomposing at 350°C for 15 minutes, the pyrolysis rate was 99.7%, and the phosphorus fixation rate was 99.5%.

[0029] Example 8 Taking the preparation of 200g waste TBP / kerosene suspension as an example, the mass percentages of the components of the waste TBP / kerosene suspension are selected as follows: TBP 65%, DBP calcium salt 10%, kerosene 5%, calcium nitrate 9%, calcium formate 9%, and water 2%. According to the above ratio, accurately weigh TBP 130g, DBP calcium salt 20g, kerosene 10g, calcium nitrate 18g, calcium formate 18g, and water 4g.

[0030] Operation steps: Step 1, add TBP and DBP calcium salts into a beaker and mix evenly to form an organic phase; Step 2, dissolve calcium nitrate and calcium formate in water and heat to 65°C, stirring until completely dissolved to form a solution; Step 3, slowly add the solution obtained in Step 2 to the organic phase obtained in Step 1, stirring at the same time, to form a viscous emulsion; Step 4, mix kerosene with the emulsion obtained in Step 3; Step 5, stir the waste TBP / kerosene suspension obtained in Step 4 on an electric stirrer in the laboratory. The stable suspension time of the suspension was measured to be 24 hours, the viscosity of the suspension was 20mPa / s, and after heating and decomposing at 350°C for 15 minutes, the pyrolysis rate was 99.5%, and the phosphorus fixation rate was 99.5%.

[0031] Example 9 Taking the preparation of 200g waste TBP / kerosene suspension as an example, the mass percentages of the components of the waste TBP / kerosene suspension are selected as follows: TBP 58%, DBP calcium salt 12%, kerosene 6%, calcium nitrate 10%, calcium formate 10%, and water 4%. According to the above ratio, accurately weigh TBP 116g, DBP calcium salt 24g, kerosene 12g, calcium nitrate 20g, calcium formate 20g, and water 8g.

[0032] Operation steps: Step 1, add TBP and DBP calcium salts into a beaker and mix evenly to form an organic phase; Step 2, dissolve calcium nitrate and calcium formate in water and heat to 70°C, stirring until completely dissolved to form a solution; Step 3, slowly add the solution obtained in Step 2 to the organic phase obtained in Step 1, stirring at the same time, to form a viscous emulsion; Step 4, mix kerosene with the emulsion obtained in Step 3; Step 5, stir the waste TBP / kerosene suspension obtained in Step 4 on an electric stirrer in the laboratory. The stable suspension time of the suspension was measured to be 36 hours, the viscosity of the suspension was 25mPa / s, and after heating and decomposing at 350°C for 15 minutes, the pyrolysis rate was 99.7%, and the phosphorus fixation rate was 99.7%.

[0033] Example 10 Taking the preparation of 200g waste TBP / kerosene suspension as an example, the mass percentages of the components of the waste TBP / kerosene suspension are selected as follows: TBP 66%, DBP calcium salt 0.1%, kerosene 5%, calcium nitrate 12.5%, calcium formate 12.5%, and water 3.9%. According to the above ratio, accurately weigh TBP 132g, DBP calcium salt 0.2g, kerosene 10g, calcium nitrate 25g, calcium formate 25g, and water 7.8g.

[0034] Operation steps: Step 1, add TBP and DBP calcium salts into a beaker and mix them evenly to form an organic phase; Step 2, dissolve calcium nitrate and calcium formate in water and heat to 60°C, stirring until completely dissolved to form a solution; Step 3, slowly add the solution obtained in Step 2 to the organic phase obtained in Step 1, stirring at the same time, to form a viscous emulsion; Step 4, mix kerosene with the emulsion obtained in Step 3; Step 5, stir the waste TBP / kerosene suspension obtained in Step 4 on an electric stirrer in the laboratory. The stable suspension time of the suspension was measured to be 6 hours, the viscosity of the suspension was 10mPa / s, and after heating and decomposing at 350°C for 15 minutes, the pyrolysis rate was 85.7%, and the phosphorus fixation rate was 86.9%.

Claims

1. A stable waste TBP / kerosene suspension, characterized in that: It is composed of the following components expressed in mass percentage: TBP 50% to 80%, DBP calcium salt 0.1% to 20%, kerosene 5% to 10%, soluble calcium salt 5% to 25%, water 2% to 5%, wherein the soluble calcium salt and water constitute the aqueous phase, TBP / kerosene and DBP calcium salt constitute the organic phase, and the two solutions are mixed and stirred to form a stable and uniform waste TBP / kerosene suspension; The preparation method of DBP calcium salt comprises the following steps: connecting a flask, a Soxhlet extractor, an oil-water separator and a condenser in sequence, then adding TBP and water into the flask, and placing calcium hydroxide wrapped in filter paper into the Soxhlet extractor; heating the temperature to 120°C for reflux, separating butanol from the oil-water separator, and collecting water in the Soxhlet extractor to gradually dissolve calcium hydroxide to form a saturated solution, which is returned to the flask after reaching a certain volume, thereby maintaining an alkaline environment for TBP hydrolysis, collecting a certain amount of n-butanol and terminating the reaction, and separating the layers by standing to obtain the upper liquid, which is the DBP calcium salt.

2. The method for preparing the waste TBP / kerosene suspension according to claim 1, characterized in that The method comprises the following steps: in the first step, soluble calcium salt and water form an aqueous phase; In the second step, TBP / kerosene and DBP calcium salt constituted the organic phase; In the third step, the two solutions are mixed and stirred to form a stable and uniform waste TBP / kerosene suspension.

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