Method for recovering boron oxide from dust generated in ferroboron smelting process

Abstract

A method for recovering boron oxide from dust generated in the ferroboron smelting process belongs to the technical field of boron metallurgy and specifically comprises the following steps: in the ferroboron smelting process, high-temperature tail gas is introduced into a cyclone dust collection system and then is fed into a bag dust collection system to obtain boron-containing dust; the preparation method comprises the following steps: taking hexanediol, isooctanol, isoamyl alcohol and butanol as raw materials to prepare mixed polyol; the method comprises the following steps: mixing boron-containing dust with a composite solvent, and then transferring to a stirring reflux device for leaching under a constant-temperature condition; after the leaching is finished, separating by adopting a vacuum filtration mode to obtain a boron-containing solution and primary residues, washing the obtained primary residues by using butanol to obtain a washing solution and secondary residues, and returning the washing solution to the washing process of the primary residues for recycling; carrying out vacuum evaporation on the boron-containing solution to obtain solid-phase diboron trioxide and a solvent, and carrying out vacuum evaporation and condensation on the solvent to obtain a mixed solvent; the solid-phase diboron trioxide is used as a ferroboron smelting raw material, and the mixed solvent is returned to the selective leaching process for recycling.

Description

Technical Field

[0001] The invention belongs to the technical field of boron metallurgy, and in particular relates to a method for recovering boron oxide from dust generated in a ferroboron smelting process. Background Art

[0002] As a strong deoxidizer and boron element additive in steel production, ferroboron alloy can not only significantly improve the hardenability of steel, but also improve mechanical properties, cold deformation properties, welding properties and high temperature properties. Since boron can form high-hardness iron-boron compounds in steel, it can greatly improve the hardness and wear resistance of steel materials. It is mainly used in steel and cast iron, such as alloy structural steel, spring steel, low-alloy high-strength steel, heat-resistant steel, stainless steel, etc. At the same time, boron can improve the toughness and wear resistance in cast iron, and is widely used in the manufacture of automobiles, tractors, machine tools, etc.

[0003] There are two main production processes for ferroboron alloys: metallothermic method and electrocarbon thermal method. Currently, electrocarbon thermal method is the main production method for ferroboron alloys. This method usually uses magnesium or carbon furnace linings, and the raw materials used are boric anhydride, boron concentrate, steel scraps, charcoal, etc. Under the condition of a smelting temperature of more than 1700°C, the smelting time is controlled and the preparation is carried out by the mold ingot method. Although various types of ferroboron alloys can be prepared by the electrocarbon thermal method, there is a relatively low boron yield problem in the smelting process of ferroboron alloys. The main reason is that boron oxide is easy to sublimate at high temperatures, and part of the boron oxide phase enters the dust, which not only leads to a high production cost of ferroboron alloys, but also causes a waste of resources. Therefore, it is urgent to solve the problem of resource utilization of boron-containing dust in the production process of ferroboron alloys and its high-value utilization. However, there is no public report on the patent for the recycling of dust generated during the smelting process of ferroboron alloys. Summary of the invention

[0004] In view of the deficiencies in the prior art, the object of the present invention is to provide a method for recovering boron oxide from the dust generated during the preparation of ferroboron, which can return the recovered boron oxide to the ferroboron smelting process, thereby not only significantly improving the utilization rate of boron in the ferroboron smelting process, but also maximizing the resource utilization rate of boron.

[0005] A method for recovering boron oxide from dust generated in a ferroboron smelting process comprises the following steps:

[0006] (1) Dust capture and recovery: During the ferroboron smelting process, the high-temperature tail gas is introduced into the cyclone dust collection system through the induced draft system, and then sent to the bag dust collection system to obtain boron-containing dust;

[0007] (2) Preparation of composite solvent: using hexanediol, isooctyl alcohol, isopentanol and butanol as raw materials to prepare mixed polyol;

[0008] (3) Selective leaching of boron from dust: mixing the boron-containing dust with the composite solvent obtained in step (2), and then transferring to a stirring reflux device for leaching under constant temperature conditions;

[0009] (4) Separation of boron and solvent in the solution: After leaching, vacuum filtration is used to separate the boron-containing solution and the primary residue. The primary residue is washed with butanol to obtain a washing liquid and a secondary residue. The washing liquid is returned to the washing process of the primary residue for recycling;

[0010] (5) Recycling of solvent: The separated boron-containing solution is vacuum evaporated to obtain solid-phase diboron trioxide and solvent. The solvent is vacuum evaporated and condensed to obtain a mixed solvent. The obtained solid-phase diboron trioxide is returned to the ferroboron smelting process for use as a raw material, and the mixed solvent is returned to the selective leaching process of step (3) for recycling.

[0011] in:

[0012] In the step (1), the temperature of the exhaust gas entering the bag dust collection system is controlled to be ≤200°C.

[0013] In the step (2), hexanediol, isooctyl alcohol, isopentanol and butanol are all national standard first-grade products, and the mass fractions of the components in the mixed polyol are: hexanediol 15% to 30%, isooctyl alcohol 15% to 30%, isopentanol 10% to 30%, butanol 10% to 40%.

[0014] In the step (3), the mass ratio of the boron-containing dust to the composite solvent is 1:(6-12).

[0015] In the step (3), the constant temperature is 60°C to 100°C.

[0016] In the step (3), the stirring speed is 45 r / min to 90 r / min, and the leaching time is 60 min to 180 min.

[0017] In the step (5), the conditions for vacuum evaporation are: negative pressure 2000Pa-3000Pa, temperature 100°C-150°C.

[0018] In the step (5), the purity of the solid phase boron trioxide is ≥98%.

[0019] In the step (5), after the solid phase boron trioxide is returned to the smelting process for use, the total recovery rate of boron element in the ferroboron smelting process is ≥94%.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The method provided by the present invention can return the recovered boron oxide to the ferroboron smelting process, which not only significantly improves the utilization rate of boron in the ferroboron smelting process, but also maximizes the level of boron resource utilization. This technology can significantly reduce the production cost of ferroboron smelting, improve the technical level of ferroboron smelting in my country, save resources, and is in line with the resource recycling policy currently actively advocated by my country. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A process flow chart of recovering boron oxide from dust generated during the preparation of ferroboron according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In the examples of the present invention, the purities of the hexanediol, isooctyl alcohol, isopentanol and butanol used are all analytically pure.

[0024] Example 1

[0025] A method for recovering boron oxide from dust generated in the ferroboron smelting process, the process flow chart of which is as follows Figure 1 As shown, the specific steps include:

[0026] (1) Dust capture and recovery: During the ferroboron smelting process, the high-temperature exhaust gas is introduced into the cyclone dust collection system through the induced draft system, and then sent to the bag dust collection system. The exhaust gas temperature entering the bag dust collection system is controlled to ≤200°C to obtain boron-containing dust.

[0027] (2) Preparation of composite solvent: Hexylene glycol, isooctyl alcohol, isopentanol and butanol are used as raw materials to prepare a mixed polyol; the mass fractions of the components in the mixed polyol are: 15% hexylene glycol, 15% isooctyl alcohol, 30% isopentanol and 40% butanol.

[0028] (3) Selective leaching of boron from dust: The boron-containing dust was mixed with the composite solvent obtained in step (2) at a mass ratio of 1:6, and then transferred to a stirring reflux device for leaching at a constant temperature of 60° C., with a stirring speed of 45 r / min and a leaching time of 180 min.

[0029] (4) Separation of boron and solvent in the solution: After leaching, vacuum filtration is used to separate the boron-containing solution and the primary residue. The primary residue is washed with butanol to obtain a washing liquid and a secondary residue. The washing liquid is returned to the washing process of the primary residue for recycling;

[0030] (5) Recycling of solvent: The separated boron-containing solution is subjected to solid-liquid separation by vacuum evaporation. The vacuum evaporation conditions are: negative pressure 2000 Pa, temperature 100° C., to obtain solid-phase diboron trioxide and solvent. The solvent is vacuum evaporated and condensed to obtain a mixed solvent. The obtained solid-phase diboron trioxide has a purity of 98%. It is returned to the ferroboron smelting process and used as a raw material for boric anhydride. The total recovery rate of boron element in the ferroboron smelting process is 94.2%. The mixed solvent is returned to the selective leaching process of step (3) for recycling.

[0031] Example 2

[0032] A method for recovering boron oxide from dust generated in a ferroboron smelting process comprises the following steps:

[0033] (1) Dust capture and recovery: During the ferroboron smelting process, the high-temperature exhaust gas is introduced into the cyclone dust collection system through the induced draft system, and then sent to the bag dust collection system. The exhaust gas temperature entering the bag dust collection system is controlled to ≤200°C to obtain boron-containing dust.

[0034] (2) Preparation of composite solvent: Hexylene glycol, isooctyl alcohol, isopentanol and butanol are used as raw materials to prepare a mixed polyol; the mass fractions of the components in the mixed polyol are: 20% hexylene glycol, 20% isooctyl alcohol, 20% isopentanol and 40% butanol.

[0035] (3) Selective leaching of boron from dust: The boron-containing dust was mixed with the composite solvent obtained in step (2) at a mass ratio of 1:8, and then transferred to a stirring reflux device for leaching at a constant temperature of 80° C., with a stirring speed of 60 r / min and a leaching time of 90 min.

[0036] (4) Separation of boron and solvent in the solution: After leaching, vacuum filtration is used to separate the boron-containing solution and the primary residue. The primary residue is washed with butanol to obtain a washing liquid and a secondary residue. The washing liquid is returned to the washing process of the primary residue for recycling;

[0037] (5) Recycling of solvent: The separated boron-containing solution is subjected to solid-liquid separation by vacuum evaporation. The vacuum evaporation conditions are: negative pressure 2500 Pa, temperature 120° C., to obtain solid phase diboron trioxide and solvent. The solvent is vacuum evaporated and condensed to obtain a mixed solvent. The obtained solid phase diboron trioxide has a purity of 98.5%. It is returned to the ferroboron smelting process as a raw material for boric anhydride. The total recovery rate of boron element in the ferroboron smelting process is 94.8%. The mixed solvent is returned to the selective leaching process of step (3) for recycling.

[0038] Example 3

[0039] A method for recovering boron oxide from dust generated in a ferroboron smelting process comprises the following steps:

[0040] (1) Dust capture and recovery: During the ferroboron smelting process, the high-temperature exhaust gas is introduced into the cyclone dust collection system through the induced draft system, and then sent to the bag dust collection system. The exhaust gas temperature entering the bag dust collection system is controlled to ≤200°C to obtain boron-containing dust.

[0041] (2) Preparation of composite solvent: Hexylene glycol, isooctyl alcohol, isopentanol and butanol are used as raw materials to prepare a mixed polyol; the mass fractions of the components in the mixed polyol are: 30% hexylene glycol, 20% isooctyl alcohol, 30% isopentanol and 20% butanol.

[0042] (3) Selective leaching of boron from dust: The boron-containing dust was mixed with the composite solvent obtained in step (2) at a mass ratio of 1:10, and then transferred to a stirring reflux device for leaching at a constant temperature of 100° C., with a stirring speed of 90 r / min and a leaching time of 120 min.

[0043] (4) Separation of boron and solvent in the solution: After leaching, vacuum filtration is used to separate the boron-containing solution and the primary residue. The primary residue is washed with butanol to obtain a washing liquid and a secondary residue. The washing liquid is returned to the washing process of the primary residue for recycling;

[0044] (5) Recycling of solvent: The separated boron-containing solution is subjected to solid-liquid separation by vacuum evaporation. The vacuum evaporation conditions are: negative pressure 3000 Pa, temperature 150° C., to obtain solid-phase diboron trioxide and solvent. The solvent is vacuum evaporated and condensed to obtain a mixed solvent. The obtained solid-phase diboron trioxide has a purity of 99%. It is returned to the ferroboron smelting process as a raw material for boric anhydride. The total recovery rate of boron element in the ferroboron smelting process is 95%. The mixed solvent is returned to the selective leaching process of step (3) for recycling.

[0045] Example 4

[0046] A method for recovering boron oxide from dust generated in a ferroboron smelting process comprises the following steps:

[0047] (1) Dust capture and recovery: During the ferroboron smelting process, the high-temperature exhaust gas is introduced into the cyclone dust collection system through the induced draft system, and then sent to the bag dust collection system. The exhaust gas temperature entering the bag dust collection system is controlled to ≤200°C to obtain boron-containing dust.

[0048] (2) Preparation of composite solvent: Hexylene glycol, isooctyl alcohol, isopentanol and butanol are used as raw materials to prepare a mixed polyol; the mass fractions of the components in the mixed polyol are: 30% hexylene glycol, 30% isooctyl alcohol, 30% isopentanol and 10% butanol.

[0049] (3) Selective leaching of boron from dust: The boron-containing dust was mixed with the composite solvent obtained in step (2) at a mass ratio of 1:12, and then transferred to a stirring reflux device for leaching at a constant temperature of 100° C., with a stirring speed of 90 r / min and a leaching time of 180 min.

[0050] (4) Separation of boron and solvent in the solution: After leaching, vacuum filtration is used to separate the boron-containing solution and the primary residue. The primary residue is washed with butanol to obtain a washing liquid and a secondary residue. The washing liquid is returned to the washing process of the primary residue for recycling;

[0051] (5) Recycling of solvent: The separated boron-containing solution is subjected to solid-liquid separation by vacuum evaporation. The vacuum evaporation conditions are: negative pressure 3000 Pa, temperature 150° C., to obtain solid-phase diboron trioxide and solvent. The solvent is vacuum evaporated and condensed to obtain a mixed solvent. The obtained solid-phase diboron trioxide has a purity of 99.5%. It is returned to the ferroboron smelting process as a raw material for boric anhydride. The total recovery rate of boron element in the ferroboron smelting process is 94.6%. The mixed solvent is returned to the selective leaching process of step (3) for recycling.

[0052] Example 5

[0053] A method for recovering boron oxide from dust generated in a ferroboron smelting process comprises the following steps:

[0054] (1) Dust capture and recovery: During the ferroboron smelting process, the high-temperature exhaust gas is introduced into the cyclone dust collection system through the induced draft system, and then sent to the bag dust collection system. The exhaust gas temperature entering the bag dust collection system is controlled to ≤180°C to obtain boron-containing dust.

[0055] (2) Preparation of composite solvent: Hexylene glycol, isooctyl alcohol, isopentanol and butanol are used as raw materials to prepare a mixed polyol; the mass fractions of the components in the mixed polyol are: 20% hexylene glycol, 15% isooctyl alcohol, 30% isopentanol and 35% butanol.

[0056] (3) Selective leaching of boron from dust: The boron-containing dust was mixed with the composite solvent obtained in step (2) at a mass ratio of 1:10, and then transferred to a stirring reflux device for leaching at a constant temperature of 100° C., with a stirring speed of 50 r / min and a leaching time of 180 min.

[0057] (4) Separation of boron and solvent in the solution: After leaching, vacuum filtration is used to separate the boron-containing solution and the primary residue. The primary residue is washed with butanol to obtain a washing liquid and a secondary residue. The washing liquid is returned to the washing process of the primary residue for recycling;

[0058] (5) Recycling of solvent: The separated boron-containing solution is subjected to solid-liquid separation by vacuum evaporation. The vacuum evaporation conditions are: negative pressure 2500 Pa, temperature 120° C., to obtain solid-phase diboron trioxide and solvent. The solvent is vacuum evaporated and condensed to obtain a mixed solvent. The obtained solid-phase diboron trioxide has a purity of 98.2%. It is returned to the ferroboron smelting process and used as a raw material for boric anhydride. The total recovery rate of boron element in the ferroboron smelting process is 96%. The mixed solvent is returned to the selective leaching process of step (3) for recycling.

[0059] Example 6

[0060] A method for recovering boron oxide from dust generated in a ferroboron smelting process comprises the following steps:

[0061] (1) Dust capture and recovery: During the ferroboron smelting process, the high-temperature exhaust gas is introduced into the cyclone dust collection system through the induced draft system, and then sent to the bag dust collection system. The exhaust gas temperature entering the bag dust collection system is controlled to ≤190°C to obtain boron-containing dust.

[0062] (2) Preparation of composite solvent: Hexylene glycol, isooctyl alcohol, isopentanol and butanol are used as raw materials to prepare a mixed polyol; the mass fractions of the components in the mixed polyol are: 15% hexylene glycol, 15% isooctyl alcohol, 30% isopentanol and 40% butanol.

[0063] (3) Selective leaching of boron from dust: The boron-containing dust was mixed with the composite solvent obtained in step (2) at a mass ratio of 1:8, and then transferred to a stirring reflux device for leaching at a constant temperature of 100° C., with a stirring speed of 60 r / min and a leaching time of 100 min.

[0064] (4) Separation of boron and solvent in the solution: After leaching, vacuum filtration is used to separate the boron-containing solution and the primary residue. The primary residue is washed with butanol to obtain a washing liquid and a secondary residue. The washing liquid is returned to the washing process of the primary residue for recycling;

[0065] (5) Recycling of solvent: The separated boron-containing solution is subjected to solid-liquid separation by vacuum evaporation. The vacuum evaporation conditions are: negative pressure 2500 Pa, temperature 120° C., to obtain solid-phase diboron trioxide and solvent. The solvent is vacuum evaporated and condensed to obtain a mixed solvent. The obtained solid-phase diboron trioxide has a purity of 99%. It is returned to the ferroboron smelting process as a raw material for boric anhydride. The total recovery rate of boron element in the ferroboron smelting process is 95%. The mixed solvent is returned to the selective leaching process of step (3) for recycling.

Claims

1. A method for recovering boron oxide from dust generated in a ferroboron smelting process, characterized in that: The specific steps include: (1) Dust capture and recovery: During the ferroboron smelting process, the high-temperature tail gas is introduced into the cyclone dust collection system through the induced draft system, and then sent to the bag dust collection system to obtain boron-containing dust; (2) Preparation of composite solvent: using hexanediol, isooctyl alcohol, isopentanol and butanol as raw materials to prepare mixed polyol; (3) Selective leaching of boron from dust: mixing the boron-containing dust with the composite solvent obtained in step (2), and then transferring to a stirring reflux device for leaching under constant temperature conditions; (4) Separation of boron and solvent in the solution: After leaching, vacuum filtration is used to separate the boron-containing solution and the primary residue. The primary residue is washed with butanol to obtain a washing liquid and a secondary residue. The washing liquid is returned to the washing process of the primary residue for recycling; (5) Recycling of solvent: The separated boron-containing solution is vacuum evaporated to obtain solid-phase diboron trioxide and solvent. The solvent is vacuum evaporated and condensed to obtain a mixed solvent. The obtained solid-phase diboron trioxide is returned to the ferroboron smelting process for use as a raw material, and the mixed solvent is returned to the selective leaching process of step (3) for recycling.

2. A method for recovering boron oxide from dust generated in a ferroboron smelting process according to claim 1, characterized in that: In the step (1), the temperature of the exhaust gas entering the bag dust collection system is controlled to be ≤200°C.

3. A method for recovering boron oxide from dust generated in a ferroboron smelting process according to claim 1, characterized in that: In the step (2), hexanediol, isooctyl alcohol, isopentanol and butanol are all national standard first-grade products, and the mass fractions of the components in the mixed polyol are: hexanediol 15% to 30%, isooctyl alcohol 15% to 30%, isopentanol 10% to 30%, butanol 10% to 40%.

4. A method for recovering boron oxide from dust generated in a ferroboron smelting process according to claim 1, characterized in that: In the step (3), the mass ratio of the boron-containing dust to the composite solvent is 1:(6-12).

5. A method for recovering boron oxide from dust generated in a ferroboron smelting process according to claim 1, characterized in that: In the step (3), the constant temperature is 60°C to 100°C.

6. A method for recovering boron oxide from dust generated in a ferroboron smelting process according to claim 1, characterized in that: In the step (3), the stirring speed is 45 r / min to 90 r / min, and the leaching time is 60 min to 180 min.

7. A method for recovering boron oxide from dust generated in a ferroboron smelting process according to claim 1, characterized in that: In the step (5), the conditions for vacuum evaporation are: negative pressure 2000Pa-3000Pa, temperature 100°C-150°C.

8. A method for recovering boron oxide from dust generated in a ferroboron smelting process according to claim 1, characterized in that: In the step (5), the purity of the solid phase boron trioxide is ≥98%.

9. A method for recovering boron oxide from dust generated in a ferroboron smelting process according to claim 1, characterized in that: In the step (5), after the solid phase boron trioxide is returned to the smelting process for use, the total recovery rate of boron element in the ferroboron smelting process is ≥94%.

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