A feeding method for producing high-purity titanium sponge

Abstract

The application relates to a feeding method for producing high-purity titanium sponge, which comprises the following steps: S1, adding distillate obtained by a reduction method into a reactor; S2, adding liquid magnesium into the reactor, and sending electricity for constant temperature; S3, adding titanium tetrachloride for the first time; S4, sending electricity for constant temperature; S5, adding titanium tetrachloride for the second time; and S6, sending electricity for constant temperature. The application realizes material recycling, saves production cost, and utilizes the process of titanium sponge particles sinking to the bottom of the reactor after being generated to absorb metal impurities in the titanium liquid, so that the obtained titanium sponge product has Fe content below 0.002%, Mn content below 0.001%, and Al content below 0.001%.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metal smelting, and more specifically to a feeding method for producing high-purity sponge titanium. Background Technology

[0002] With the continuous improvement of the production process of sponge titanium, the impact of impurity content on the quality of sponge titanium products is also decreasing. However, my country's production of high-purity sponge titanium still lags behind the international advanced level.

[0003] The main technical indicators of sponge titanium iron quality standards are impurity content, Brinell hardness (HB), and particle size. Different countries' sponge titanium standards cover different impurity elements, and the requirements for Brinell hardness and particle size also differ. In my country, the main impurities in sponge titanium refer to Fe, Si, Cl, N, C, O, Mn, and Al, among others. The required content of different impurities varies. Fe, Mn, and Al are particularly difficult to remove during the production process of sponge titanium.

[0004] The Fe impurities partly originate from the raw magnesium ingots and the liquid magnesium produced in the multi-electrode tank. Additionally, the containers used in the magnesium melting process are made of steel, and at high temperatures, the liquid magnesium dissolves the iron walls. As the temperature increases, the solubility of Fe in magnesium increases. In actual production, the average Fe content in magnesium is 0.025%, which significantly affects the Fe impurity content in sponge titanium. Al mainly comes from the liquid magnesium produced in the multi-electrode tank. The refractory materials used in the multi-electrode tank are primarily alumina bricks and mullite. The multi-electrode tank process increases the Al content in the liquid magnesium, resulting in an average Al content in the liquid magnesium. The L content is 0.03%; the Mn in sponge titanium mainly comes from magnesium ingots, and the Mn content in magnesium ingots is usually 0.2%. In the process of producing sponge titanium, magnesium and titanium are basically in a 1:1 ratio, that is, 1 ton of magnesium is consumed to produce 1 ton of titanium. Therefore, all the impurity elements in magnesium usually enter the titanium. Al, Fe, and Mn are also harmful impurities to sponge titanium. When they enter the sponge titanium, they will lead to an excessively high content of impurity elements in the sponge titanium, which will affect the product grade of the sponge titanium. Therefore, the removal of the three impurity elements Al, Fe, and Mn is extremely important for the production of high-purity sponge titanium. Summary of the Invention

[0005] The purpose of this invention is to provide a feeding method that reduces the impact of impurities such as iron, manganese, and aluminum in sponge titanium on product quality, especially reducing the impact of raw material magnesium on the quality of produced sponge titanium. By improving the process, the content of iron, manganese, and aluminum impurities is significantly reduced, thereby producing high-purity sponge titanium.

[0006] The technical solution of this invention is:

[0007] A feeding method for producing high-purity sponge titanium includes the following steps:

[0008] S1 adds the distillate obtained during the thermal reduction of sponge titanium magnesium into the reactor, and then heats it with electricity to melt it at a temperature of 780-820℃ for 4-8 hours.

[0009] S2 adds liquid magnesium into the reactor, supplies power to maintain a constant temperature of 820-850℃, and the time is 2 hours.

[0010] For the first feeding of S3, titanium tetrachloride is added to the reactor at a weight of 6%-7% of the reactor's rated ton weight, with a feeding rate of 120-360 kg / h and a furnace bottom temperature set at 820-850℃.

[0011] S4 is powered on and kept at a constant temperature for 1 hour, with the temperature set at 670-700℃;

[0012] For the second feeding of S5, add the same amount of titanium tetrachloride as the first feeding into the reactor, with a feeding rate of 120-360 kg / h and a furnace bottom temperature set at 670-700℃.

[0013] S6 is powered on and kept at a constant temperature for 1 hour, with the temperature set at 780-820℃;

[0014] After the S7 constant temperature period ends, production continues with material feeding according to the normal process.

[0015] Preferably, the distillate in step S1 is a distillation condensate composed of magnesium and magnesium chloride.

[0016] Preferably, the liquid magnesium in step S2 is produced by electrolyzing magnesium chloride in a multi-electrode cell.

[0017] This invention is based on the mechanism of the reduction reaction of sponge titanium. When titanium tetrachloride is added to liquid magnesium during the first feeding, due to the high temperature of the liquid magnesium, a significant portion of the titanium tetrachloride does not directly contact the liquid magnesium but instead vaporizes into gaseous titanium tetrachloride. This gaseous titanium tetrachloride evenly diffuses and covers the entire surface of the liquid magnesium layer. The gaseous titanium tetrachloride reacts with magnesium at the gas-liquid interface to generate titanium particles. The initial sponge titanium particles are relatively small and, due to surface tension, float on the surface of the liquid magnesium. As the reaction proceeds, the titanium particles gradually grow. Maintaining a constant temperature inside the furnace, the titanium particles slowly settle to the bottom of the pile. During this process of titanium particle growth and sedimentation, impurities in the liquid magnesium are effectively adsorbed. The sponge titanium particles carry impurities to the bottom of the reactor, achieving the initial purification of the liquid magnesium. At this point, a second feeding is performed, with the furnace temperature slightly lower than the first feeding temperature, forming titanium particles of a different size than those in the first feeding, achieving a more thorough removal of impurities such as iron, manganese, and aluminum.

[0018] This invention combines the practical production of sponge titanium using the magnesothermic reduction method. In the initial stage of the reduction reaction, a distillation condensate composed of magnesium and magnesium chloride is used to achieve material recycling and save production costs. The sponge titanium particles adsorb metallic impurities in the titanium liquid during the process of settling to the bottom of the reactor after generation, and the impurities are well deposited at the bottom of the titanium mass to form a thin bottom layer, thereby achieving the effect of removing iron, manganese and aluminum from the sponge titanium, and thus obtaining high-purity sponge titanium.

[0019] This invention, through precise control and adjustment of technical parameters, without increasing other production costs, yields sponge titanium products with Fe content generally below 0.002%, Mn content below 0.001%, and Al content below 0.001%, thus solving the technical challenge of producing high-purity sponge titanium using the magnesothermic reduction method.

[0020] This invention is easy to operate, can significantly reduce the impurity content of sponge titanium, has obvious economic benefits, and is easy to promote and apply in the entire process of sponge titanium production. Detailed Implementation

[0021] Example 1: Implementing a charging process in a 3.5-ton furnace.

[0022] S1. Add 2.4 tons of distillate obtained during the thermal reduction of sponge titanium magnesium into the reactor, and heat it to melt at 820℃ for 4 hours. S2. Add 3.5 tons of liquid magnesium into the reactor, and maintain a constant temperature of 850℃ for 2 hours. S3. For the first feeding, add 240 kg of titanium tetrachloride to the reactor at a feed rate of 120 kg / h, with the furnace bottom temperature set at 850℃. S4. Maintain a constant temperature of 700℃ for 1 hour. S5. For the second feeding, add 240 kg of titanium tetrachloride to the reactor at a feed rate of 120 kg / h, with the furnace bottom temperature set at 700℃. S6. Maintain a constant temperature of 820℃ for 1 hour. S7. After the constant temperature period, continue feeding and production according to the normal process.

[0023] Using the method described in this embodiment, a total of 3.5 tons of sponge titanium was obtained. The average indicators of the product were all lower than the average indicators of the original 3.5-ton furnace product, and also lower than the national standard. A For product performance indicators, please refer to the table below for specific data:

[0024]

[0025] Example 2: Implementing a charging process in a 5.5-ton furnace.

[0026] S1. Add 3.9 tons of distillate obtained during the thermal reduction of sponge titanium magnesium into the reactor, and heat it to melt it at 800℃ for 6 hours. S2. Add 5.5 tons of liquid magnesium into the reactor, and heat it to maintain a constant temperature of 835℃ for 2 hours. S3. For the first feeding, add 360 kg of titanium tetrachloride to the reactor at a feed rate of 240 kg / h, with the furnace bottom temperature set at 835℃. S4. Heat it to maintain a constant temperature for 1 hour, with the temperature set at 685℃. S5. For the second feeding, add 360 kg of titanium tetrachloride to the reactor at a feed rate of 240 kg / h, with the furnace bottom temperature set at 685℃. S6. Heat it to maintain a constant temperature for 1 hour, with the temperature set at 800℃. S7. After the temperature maintenance period, continue feeding and production according to the normal process.

[0027] Using the method described in this embodiment, a total of 5.5 tons of sponge titanium was obtained. The average indicators of the product were all lower than the average indicators of the original 5.5-ton furnace product, and also lower than the national standard. A For product performance indicators, please refer to the table below for specific data:

[0028]

[0029] Example 3: Implementing a charging process in a 7.5-ton furnace.

[0030] S1. Add 5.3 tons of distillate obtained during the thermal reduction of sponge titanium magnesium into the reactor, and heat it to melt it at 780℃ for 8 hours. S2. Add 7.5 tons of liquid magnesium into the reactor, and heat it to maintain a constant temperature of 820℃ for 2 hours. S3. For the first feeding, add 480 kg of titanium tetrachloride to the reactor at a feed rate of 360 kg / h, with the furnace bottom temperature set at 820℃. S4. Heat it to maintain a constant temperature for 1 hour at 670℃. S5. For the second feeding, add 480 kg of titanium tetrachloride to the reactor at a feed rate of 360 kg / h, with the furnace bottom temperature set at 670℃. S6. Heat it to maintain a constant temperature for 1 hour at 780℃. S7. After the temperature maintenance period, continue feeding and production according to the normal process.

[0031] Using the method described in this embodiment, a total of 7.5 tons of sponge titanium was obtained. The average indicators of the product were all lower than the average indicators of the original 7.5-ton furnace product, and also lower than the national standard. A For product performance indicators, please refer to the table below for specific data:

[0032]

[0033] The above embodiments are merely examples to clearly illustrate the present invention and are not intended to limit the implementation. Those skilled in the art of sponge titanium production will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to list all possible embodiments here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A feeding method for producing high-purity sponge titanium, characterized in that, Includes the following steps: S1 adds the distillate obtained during the thermal reduction of sponge titanium magnesium to the reactor, and then heats it with electricity to melt it at a temperature of 780-820℃ for 4-8 hours. The distillate is a distillation condensate composed of magnesium and magnesium chloride; S2 adds liquid magnesium into the reactor, supplies power to maintain a constant temperature of 820-850℃, and the time is 2 hours. For the first feeding of S3, titanium tetrachloride is added to the reactor at a weight of 6%-7% of the reactor's rated ton weight, with a feeding rate of 120-360 kg / h and a furnace bottom temperature set at 820-850℃. S4 is powered on and kept at a constant temperature for 1 hour, with the temperature set at 670-700℃; For the second feeding of S5, add the same amount of titanium tetrachloride as the first feeding into the reactor, with a feeding rate of 120-360 kg / h and a furnace bottom temperature set at 670-700℃. S6 is powered on and kept at a constant temperature for 1 hour, with the temperature set at 780-820℃; After the S7 constant temperature period ends, production continues with material feeding according to the normal process.

2. The feeding method according to claim 1, characterized in that: The liquid magnesium mentioned in step S2 is produced by electrolyzing magnesium chloride in a multi-electrode cell.

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