Refining method of high-purity silicon iron

Abstract

The invention relates to a refining method of high-purity ferrosilicon, and relates to the technical field of refining of high-purity ferrosilicon, the refining method of high-purity ferrosilicon comprises the following steps: preparing a refining agent; when one third of iron is tapped, the refining agent is put into a ladle at a time for oxygen blowing, stirring and refining; after the refining agent is added, the heat preservation agent is added into the ladle at a time, and oxygen blowing, stirring and refining are continued; according to oxygen blowing stirring refining, bottom blowing oxygen serves as oxidizing stirring gas, discharged molten iron is directly poured into a ladle containing a refining agent, and refining is conducted while iron is discharged. The whole refining process is carried out in the tap hole gas collecting hood, refining is carried out while tapping is carried out, the operation time from tapping to refining is greatly shortened, and the method has the advantages of being convenient and fast in refining operation, safe, environmentally friendly and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of high-purity ferrosilicon refining, and in particular to a refining method of high-purity ferrosilicon. Background Art

[0002] High-purity ferrosilicon (HSI) is a crucial material in the metallurgical industry, and the refining process is crucial in its production. The aluminum content of molten HSI from the hot furnace is typically maintained at approximately 0.18%, while the calcium content is roughly 0.08%. However, to meet market demand for high-quality products, both aluminum and calcium levels must be strictly controlled below 0.03%. This stringent quality requirement makes the refining process an essential step in producing qualified HSI.

[0003] Currently, the high-purity ferrosilicon industry generally uses chlorine-blowing refining to remove impurities, particularly aluminum and calcium, from molten iron. This method has been widely adopted within the industry due to its effective impurity removal capabilities. However, with increasing production practice, the numerous drawbacks of this refining method have gradually become apparent.

[0004] First, the refining process is time-consuming. Chloride refining can only begin after the molten iron has been completely tapped and transported to the fume hood. The entire refining process, from tapping to completion, takes approximately 60 minutes, significantly increasing production cycle time and costs.

[0005] Secondly, as a toxic substance, chlorine poses potential safety hazards during its transportation, storage, vaporization, and use. This not only requires manufacturers to have strict safety management measures, but also places higher demands on the professional skills of operators.

[0006] Furthermore, the chlorides produced during the chlorination refining process are highly polluting, placing significant pressure on the company's environmental protection efforts. Although these chlorides are captured and purified by fume hoods, their highly corrosive nature still causes severe corrosion to the fume capture and purification equipment, increasing equipment maintenance costs and replacement frequency.

[0007] In summary, finding a convenient, safe, and environmentally friendly high-purity ferrosilicon refining method has become a pressing challenge for high-purity ferrosilicon producers. This not only impacts production efficiency and cost control, but also their sustainable development and environmental responsibility. Therefore, the industry should increase its technological research and development efforts and actively explore new refining processes to promote the green and efficient development of the high-purity ferrosilicon industry. Summary of the Invention

[0008] In order to solve the above problems, the present invention provides a method for refining high-purity ferrosilicon.

[0009] The present invention provides a method for refining high-purity ferrosilicon, which comprises the following steps:

[0010] Preparation of refining agents;

[0011] When one third of the iron is tapped, the refining agent is added into the molten iron ladle at one time for oxygen blowing and stirring refining;

[0012] After the refining agent is added, the heat preservation agent is added into the molten iron ladle at one time to continue the oxygen blowing and stirring refining;

[0013] The oxygen blowing and stirring refining uses bottom blowing oxygen as the oxidizing and stirring gas, and the molten iron discharged from the furnace is directly injected into the ladle containing the refining agent, and the refining is carried out while the iron is being discharged.

[0014] Furthermore, the refining agent comprises quartz sand, calcite and limestone in a weight ratio of (50-55):(30-35):(13-18).

[0015] Furthermore, the refining agent includes quartz sand, calcite and limestone in a weight ratio of 52:32:16.

[0016] Furthermore, the weight of the refining agent added is 45 to 55 kilograms per ton of molten iron.

[0017] Furthermore, the added weight of the refining agent is 50 kg per ton of molten iron.

[0018] Furthermore, the heat preservation agent is carbonized rice husk.

[0019] Furthermore, the added weight of the heat preservation agent is 25 to 35 kilograms per ton of molten iron.

[0020] Furthermore, the added weight of the heat preservation agent is 30 kg per ton of molten iron.

[0021] Furthermore, the particle sizes of the quartz sand, calcite and limestone are all 1 to 6 mm.

[0022] The above technical solution provided by the embodiment of the present invention has at least the following advantages compared with the prior art:

[0023] The embodiment of the present invention provides a method for refining high-purity ferrosilicon. The entire refining process of the present invention is carried out in the gas collecting hood of the iron outlet. The iron is tapped and refined at the same time, which greatly shortens the operation time from the completion of iron tapping to the completion of refining. The refining operation is convenient, safe, and environmentally friendly. Specifically:

[0024] The refining agent is a mixture of quartz sand, calcite, and limestone in a ratio of 52:32:16, which has the advantages of low melting point and low density. Bottom-blown oxygen is used as the oxidizing and stirring gas, which has the advantages of strong oxidizing and stirring capabilities. The molten iron is directly poured into the ladle containing the refining agent, and the refining is carried out while the iron is being tapped, which ensures sufficient contact and a short operation time of about 20 minutes from the completion of the tapping to the completion of the refining. Carbonized rice husks are used as the thermal insulation agent, which has the advantages of low density, strong thermal insulation performance, and good environmental protection. The mechanism is as follows:

[0025] Convenience: Since the entire refining process is carried out in the tapping hole gas collecting hood, the iron is tapped and refined at the same time, which greatly shortens the operation time from tapping to refining completion and makes the refining operation convenient.

[0026] Environmental protection: Since the entire refining process is carried out in the taphole gas collection hood, the environmental protection of high-purity ferrosilicon refining operations can be guaranteed.

[0027] Safety: Since the refining agents, gases and heat preservation agents used in refining are all non-toxic materials, the refining operation is safe, reliable and safe. DETAILED DESCRIPTION

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0029] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0030] The present invention provides a method for refining high-purity ferrosilicon, which comprises the following steps:

[0031] Preparation of refining agents;

[0032] When one third of the iron is tapped, the refining agent is added into the molten iron ladle at one time for oxygen blowing and stirring refining;

[0033] After the refining agent is added, the heat preservation agent is added into the molten iron ladle at one time to continue the oxygen blowing and stirring refining;

[0034] The oxygen blowing and stirring refining uses bottom blowing oxygen as the oxidizing and stirring gas, and the molten iron discharged from the furnace is directly injected into the ladle containing the refining agent, and the refining is carried out while the iron is being discharged.

[0035] The embodiment of the present invention provides a method for refining high-purity ferrosilicon. The entire refining process of the present invention is carried out in the gas collecting hood of the iron outlet. The iron is tapped and refined at the same time, which greatly shortens the operation time from the completion of iron tapping to the completion of refining. The refining operation is convenient, safe, and environmentally friendly. Specifically:

[0036] The refining agent is a mixture of quartz sand, calcite, and limestone in a ratio of 52:32:16, which has the advantages of low melting point and low density. Bottom-blown oxygen is used as the oxidizing and stirring gas, which has the advantages of strong oxidizing and stirring capabilities. The molten iron is directly poured into the ladle containing the refining agent, and the refining is carried out while the iron is being tapped, which ensures sufficient contact and a short operation time of about 20 minutes from the completion of the tapping to the completion of the refining. Carbonized rice husks are used as the thermal insulation agent, which has the advantages of low density, strong thermal insulation performance, and good environmental protection. The mechanism is as follows:

[0037] Convenience: Since the entire refining process is carried out in the tapping hole gas collecting hood, the iron is tapped and refined at the same time, which greatly shortens the operation time from tapping to refining completion and makes the refining operation convenient.

[0038] Environmental protection: Since the entire refining process is carried out in the taphole gas collection hood, the environmental protection of high-purity ferrosilicon refining operations can be guaranteed.

[0039] Safety: Since the refining agents, gases and heat preservation agents used in refining are all non-toxic materials, the refining operation is safe, reliable and safe.

[0040] In some specific embodiments, the refining agent includes quartz sand, calcite and limestone in a weight ratio of (50-55):(30-35):(13-18).

[0041] In some specific embodiments, the refining agent includes quartz sand, calcite, and limestone in a weight ratio of 52:32:16.

[0042] In some specific embodiments, the weight of the refining agent added is 45-55 kg per ton of molten iron.

[0043] In some specific embodiments, the weight of the refining agent added is 50 kg per ton of molten iron.

[0044] In some specific embodiments, the heat preservation agent is carbonized rice husk.

[0045] In some specific embodiments, the weight of the thermal insulation agent added is 25-35 kg per ton of molten iron.

[0046] In some specific embodiments, the weight of the thermal insulation agent added is 30 kg per ton of molten iron.

[0047] In some specific embodiments, the particle sizes of the quartz sand, calcite and limestone are all 1 to 6 mm.

[0048] In some specific embodiments, the above-mentioned high-purity ferrosilicon refining method includes the following process:

[0049] (1) Prepare the refining agent. The ingredients are as follows: quartz sand: 1-6 mm, accounting for 52%; calcite: 1-6 mm, accounting for 32%; limestone: 1-6 mm, accounting for 16%; mix the materials evenly and store them for later use.

[0050] (2) Prepare the heat preservation agent - carbonized rice husk and store it for later use.

[0051] (3) Install the air bricks and vent pipe on the ladle.

[0052] (4) The ladle with the air bricks and vent pipe installed is hoisted to the ladle baking area for baking.

[0053] (5) Before tapping, transport the baked molten iron ladle to the tapping place by the molten iron ladle car, connect and adjust the vent pipe valve, and open the compressed air valve to let in compressed air.

[0054] (6) When tapping iron, switch the compressed air pressure to oxygen.

[0055] (7) When one third of the iron has been tapped, add the refining agent into the ladle at one time (calculated at about 50 kg of refining agent per ton of molten iron).

[0056] (8) After adding the refining agent, add the insulation agent into the molten iron ladle at one time (calculated at about 30 kg insulation agent per ton of molten iron), and continue blowing oxygen and stirring to refine.

[0057] (9) After the iron is tapped, continue oxygen blowing refining for about 20 minutes to end the oxidation stirring refining (turn off the oxygen).

[0058] (10) Take a sample of refined iron water for analysis.

[0059] (11) Conduct statistics, evaluation and next cycle.

[0060] In some specific embodiments, the carbonized rice husk can be directly obtained from a commercial product, or can be prepared in-house according to existing processes:

[0061] 1. Collection and pretreatment of rice husks

[0062] Collection: Rice husks can be obtained from the processing of rice or from returning farmland straw to the fields.

[0063] Pretreatment: The collected rice husks need to be cleaned of impurities and dust to ensure the quality of the rice husks. In addition, the rice husk raw materials need to be dried before entering the carbonization furnace to ensure the uniformity of the raw materials and their suitability for the carbonization process.

[0064] 2. Crushing and Grinding

[0065] The pre-treated rice husks are ground into granular materials. This can increase the reaction speed during the carbonization process, and the ground particles are easier to heat evenly, which is conducive to the production of high-quality biochar.

[0066] 3. Carbonization reaction

[0067] Equipment: The ground rice husk particles are placed in a carbonization furnace for high-temperature carbonization. The carbonization furnace can be a traditional carbonization furnace or a modern continuous or batch carbonization furnace.

[0068] Temperature control: Carbonization temperature is between 500℃-900℃.

[0069] Environmental control: The carbonization reaction needs to be carried out in an oxygen-free or low-oxygen environment to avoid material combustion and reduce the pollution of emissions to the environment.

[0070] Time control: lasts 1 to 3 hours.

[0071] 4. Treatment and Refining of Carbonized Rice Husk

[0072] Cooling: After the carbonization process, the rice husk charcoal is at a high temperature and needs to be cooled before it can be safely handled. This can be done naturally or through specialized cooling equipment such as a rotating drum for rapid cooling.

[0073] Screening and grinding: The cooled rice husk charcoal is screened and ground to remove impurities and uncarbonized particles to obtain high-quality carbonized rice husk products with the required particle size and uniformity.

[0074] It should be noted that the component raw materials involved in the refining method of high-purity ferrosilicon provided by the embodiment of the present invention, unless otherwise specified or specifically explained, can be directly commercially available products or homemade using existing public preparation methods; at the same time, the steps and parameters involved, unless otherwise specified or specifically explained, can be carried out in accordance with the existing high-purity ferrosilicon refining process or directly using existing equipment, and the present invention document will not elaborate on them one by one.

[0075] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present invention only and are not intended to limit the scope of the invention. The experimental methods in the following examples where specific conditions are not specified are generally measured in accordance with national standards. If there are no corresponding national standards, then the methods are carried out in accordance with general international standards, conventional conditions, or the conditions recommended by the manufacturer.

[0076] Example 1

[0077] This example provides a high-purity ferrosilicon refining method, which includes the following steps:

[0078] (1) Prepare the refining agent. The ingredients are as follows: quartz sand: 1-6 mm, accounting for 52%; calcite: 1-6 mm, accounting for 32%; limestone: 1-6 mm, accounting for 16%; mix the materials evenly and store them for later use.

[0079] (2) Prepare the heat preservation agent - carbonized rice husk and store it for later use.

[0080] (3) Install the air bricks and vent pipe on the ladle.

[0081] (4) The ladle with the air bricks and vent pipe installed is hoisted to the ladle baking area for baking.

[0082] (5) Before tapping, transport the baked molten iron ladle to the tapping place by the molten iron ladle car, connect and adjust the vent pipe valve, and open the compressed air valve to let in compressed air.

[0083] (6) When tapping iron, switch the compressed air pressure to oxygen.

[0084] (7) When one third of the iron has been tapped, add the refining agent into the ladle at one time (calculated at about 50 kg of refining agent per ton of molten iron).

[0085] (8) After adding the refining agent, add the insulation agent into the molten iron ladle at one time (calculated at about 30 kg insulation agent per ton of molten iron), and continue blowing oxygen and stirring to refine.

[0086] (9) After the iron is tapped, continue oxygen blowing refining for about 20 minutes to end the oxidation stirring refining (turn off the oxygen).

[0087] (10) Take a sample of refined iron water for analysis.

[0088] (11) Conduct statistics, evaluation and next cycle.

[0089] Example 2

[0090] This example provides a method for refining high-purity ferrosilicon, which differs from Example 1 only in that the refining agent is composed of quartz sand, calcite, and limestone in a weight ratio of 50:30:13; the added weight of the refining agent is 45 kg per ton of molten iron; and the added weight of the insulation agent is 25 kg per ton of molten iron; the remaining steps and parameters are the same.

[0091] Example 3

[0092] This example provides a method for refining high-purity ferrosilicon. The only difference from Example 1 is that the refining agent is composed of quartz sand, calcite, and limestone in a weight ratio of 55:35:18; the added weight of the refining agent is 55 kg per ton of molten iron; and the added weight of the insulation agent is 35 kg per ton of molten iron. The remaining steps and parameters are the same.

[0093] In summary, the embodiments of the present invention provide a method for refining high-purity ferrosilicon. The entire refining process of the present invention is carried out in the gas collecting hood of the iron outlet, and the iron is tapped and refined at the same time, which greatly shortens the operation time from the completion of iron tapping to the completion of refining. The refining operation is convenient, safe, and environmentally friendly.

[0094] Various embodiments of the present invention may be presented in the form of a range; it should be understood that the description in a range format is only for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention; therefore, the range description should be considered to have specifically disclosed all possible subranges and single numerical values within the range. For example, the description of a range from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. In addition, whenever a numerical range is indicated herein, it is intended to include any cited numeral (fractional or integer) within the indicated range.

[0095] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but is intended to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for refining high-purity ferrosilicon, characterized in that: The refining method of described high-purity ferrosilicon comprises the following steps: Preparation of refining agents; When one third of the iron is tapped, the refining agent is added into the molten iron ladle at one time for oxygen blowing and stirring refining; After the refining agent is added, the heat preservation agent is added into the molten iron ladle at one time to continue the oxygen blowing and stirring refining; The oxygen blowing and stirring refining uses bottom blowing oxygen as the oxidizing and stirring gas, and the molten iron discharged from the furnace is directly injected into the ladle containing the refining agent, and the refining is carried out while the iron is being discharged.

2. The refining method of high-purity ferrosilicon according to claim 1, wherein The refining agent comprises quartz sand, calcite and limestone in a weight ratio of (50-55):(30-35):(13-18).

3. The refining method of high-purity ferrosilicon according to claim 1, wherein The refining agent includes quartz sand, calcite and limestone in a weight ratio of 52:32:

16.

4. The refining method of high-purity ferrosilicon according to claim 1, wherein The added weight of the refining agent is 45 to 55 kilograms per ton of molten iron.

5. The refining method of high-purity ferrosilicon according to claim 1, wherein The added weight of the refining agent is 50 kg per ton of molten iron.

6. The refining method of high-purity ferrosilicon according to claim 1, wherein The heat preservation agent is carbonized rice husk.

7. The refining method of high-purity ferrosilicon according to claim 1, characterized in that: The added weight of the heat preservation agent is 25 to 35 kilograms per ton of molten iron.

8. The method for refining high-purity ferrosilicon according to claim 1, wherein: The added weight of the heat preservation agent is 30 kg per ton of molten iron.

9. The method for refining high-purity ferrosilicon according to claim 1, wherein: The particle sizes of the quartz sand, calcite and limestone are all 1-6 mm.