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CN-117430163-B - Method for preparing potassium fluotantalate from tantalum liquid

CN117430163BCN 117430163 BCN117430163 BCN 117430163BCN-117430163-B

Abstract

The invention relates to a method for preparing potassium fluotantalate from tantalum liquid, which comprises the following steps of liquid heating conversion, potassium fluotantalate crystallization solution transfer, potassium fluotantalate cooling crystallization, potassium fluotantalate crystallization mother liquor discharge, potassium fluotantalate crystal washing, potassium fluotantalate crystal discharging and potassium fluotantalate crystal drying. The method has the advantages that the method is suitable for preparing the potassium fluotantalate from the tantalum liquid with the concentration of tantalum oxide of 50-80 g/L, the tantalum liquid with high concentration does not need to be diluted by adding deionized water, conversion reaction materials are saved, before the potassium fluotantalate crystallization solution is added into the crystallization washing tank, hot water is introduced into a medium jacket to preheat the crystallization washing tank, the potassium fluotantalate crystallization solution is prevented from being excessively fast in cooling speed when being added into the crystallization washing tank, the formation of a large number of crystal nuclei or the generation of fine crystals are prevented, and meanwhile, enough time is provided for the crystal to grow.

Inventors

  • ZHAO MINGZHI
  • ZHENG HUIQUAN
  • ZHOU LI

Assignees

  • 广东广晟稀有金属光电新材料有限公司

Dates

Publication Date
20260505
Application Date
20231008

Claims (10)

  1. 1. The method for preparing potassium fluotantalate from tantalum liquid is characterized by comprising the following steps of: step 1, heating and converting feed liquid, namely adding tantalum liquid with the concentration of tantalum oxide of 50-80 g/L into a potassium fluotantalate crystallization heating tank, starting a stirring motor on the potassium fluotantalate crystallization heating tank to stir the tantalum liquid in the potassium fluotantalate crystallization heating tank at a stirring frequency of 30Hz, conveying steam into the potassium fluotantalate crystallization heating tank to heat the tantalum liquid internally, adding hydrofluoric acid to perform acid preparation when the temperature of the tantalum liquid in the potassium fluotantalate crystallization heating tank is increased to 95-100 ℃, heating again to 95-100 ℃, adding solid potassium chloride into the potassium fluotantalate crystallization heating tank, and continuing to stir for 5 minutes to react to form a potassium fluotantalate crystallization solution; Step2, transferring potassium fluotantalate crystallization solution, adding hot water into a medium jacket of a crystallization washing tank to preheat the crystallization washing tank for 5 minutes, placing a plurality of crystallization panels in the crystallization washing tank, opening a discharge hole at the bottom of a potassium fluotantalate crystallization heating tank, discharging the potassium fluotantalate crystallization solution into the crystallization washing tank, and standing; Step 3, cooling and crystallizing potassium fluotantalate, namely when the temperature of potassium fluotantalate crystallization solution in the crystallization washing tank is reduced to 60 ℃, introducing cooling water into a medium jacket of the crystallization washing tank to forcedly cool the potassium fluotantalate crystallization solution in the crystallization washing tank until the temperature of the potassium fluotantalate crystallization solution in the crystallization washing tank is reduced to room temperature; Step 4, discharging potassium fluotantalate crystallization mother liquor, opening an upper mother liquor discharge port of the crystallization washing tank, discharging the upper layer crystallization mother liquor in the crystallization washing tank to a mother liquor pond, slowly opening a lower mother liquor discharge port of the crystallization washing tank when no crystallization mother liquor is discharged from the upper mother liquor discharge port until the crystallization mother liquor in the crystallization washing tank is discharged, and closing the lower mother liquor discharge port of the crystallization washing tank; Washing potassium fluotantalate crystals, namely flushing the inner wall of the crystallization washing tank and the potassium fluotantalate crystals on the crystallization panel into the crystallization washing tank by using deionized water, continuously adding deionized water, slowly pushing the potassium fluotantalate crystals at the bottom of the crystallization washing tank by using a push plate, standing for 5 minutes after stopping pushing, and opening a lower mother liquor discharge port of the crystallization washing tank to discharge clear liquid of washing water in the crystallization washing tank into a mother liquor tank; Step 6, discharging and drying potassium fluotantalate crystals, opening a potassium fluotantalate discharge port of a crystallization washing tank, discharging the potassium fluotantalate crystals in the crystallization washing tank into a vacuum suction filter by using deionized water, starting the vacuum suction filter for filtering, discharging filtrate to a mother liquor pond, and transferring the suction-filtered potassium fluotantalate crystals to a drying box for drying; the crystallization washing tank comprises a rectangular box-shaped second tank body, a rectangular second tank cover and a plurality of T-shaped crystallization panels, wherein a rectangular box-shaped outer jacket is fixedly connected to the outside of the second tank body, a square inner jacket which is arranged along the long axis direction of the second tank body is fixedly connected in the second tank body, the inner jacket is communicated with the outer jacket to form a medium jacket, and lugs on two sides of the top of the crystallization panels are respectively placed on the inner jacket and the second tank body.
  2. 2. The method of claim 1, wherein the concentration of tantalum oxide in the tantalum solution in step 1 is 78g/L.
  3. 3. The method according to claim 1, wherein the hydrofluoric acid in the step 1 is AR grade hydrofluoric acid and the potassium chloride is CP grade potassium chloride.
  4. 4. The method according to claim 1, wherein the temperature of the hot water fed into the medium jacket of the crystallization washing tank in the step 2 is 80-85 ℃.
  5. 5. The method according to claim 1, wherein the crystallization panel in the crystallization washing tank is taken out or moved to an end of the crystallization washing tank away from the lower mother liquor discharge port before pushing the potassium fluorotantalate crystals in the step 5.
  6. 6. The method of claim 1, wherein potassium fluorotantalate crystals in front of the lower mother liquor discharge port of the crystallization washing tank are pushed away before the lower mother liquor discharge port of the crystallization washing tank is opened in the step 5.
  7. 7. The method of claim 1, wherein the potassium fluotantalate crystallization heating tank comprises a cylindrical first tank body, the bottom of the first tank body is conical, a first tank cover is arranged on an opening at the top end of the first tank body, a speed reducing motor is arranged at the top of the first tank cover, a motor shaft of the speed reducing motor is connected with stirring slurry which stretches into the first tank body, a potassium chloride feeding port, a heating pipe, a tantalum liquid feeding port, a hydrofluoric acid feeding port and a deionized water feeding port are arranged on the first tank cover, the heating pipe is externally connected with a steam conveying pipe, and a discharging port is arranged at the bottom of the first tank body.
  8. 8. The method of claim 1, wherein one side of the outer jacket is provided with a medium inlet and a medium outlet which are communicated with the outer jacket, the medium inlet is positioned below the medium outlet, one side of the second tank body is provided with a potassium fluocarbonate crystallization solution inlet which is communicated with the second tank body and is higher than the top end of the outer jacket, the other side of the second tank body is provided with an upper mother liquor discharge port, a lower mother liquor discharge port and a potassium fluotantalate discharge port, the upper mother liquor discharge port is positioned above the lower mother liquor discharge port, and the lower mother liquor discharge port and the potassium fluotantalate discharge port are positioned at the same level.
  9. 9. The method according to claim 8, wherein the difference in height between the bottom end of the inner jacket and the bottom end of the inner side of the second tank is 20 cm, and the difference in height between the upper mother liquor discharge port and the bottom end of the inner side of the second tank is 15 cm.
  10. 10. The method of claim 8, wherein an intermediate support plate perpendicular to the top end of the inner jacket is fixedly connected to the top end of the inner jacket, and the top end of the intermediate support plate is flush with the top end of the second groove body.

Description

Method for preparing potassium fluotantalate from tantalum liquid Technical Field The invention relates to the field of potassium fluotantalate preparation, in particular to a method for preparing potassium fluotantalate from tantalum liquid. Background The potassium fluotantalate is mainly used for preparing metal tantalum and other tantalum compounds, and a typical potassium fluotantalate production process is that tantalum-niobium ore is decomposed by mixed acid of hydrofluoric acid and sulfuric acid, tantalum liquid obtained after extraction, acid washing, niobium and tantalum reversing in a hydrofluoric acid-sulfuric acid-sec-octanol or methyl isobutyl ketone system is heated to 85 ℃ in a heating tank, hydrofluoric acid is added, potassium chloride is added, and a crystallization solution obtained after uniform stirring is carried out is transferred into a crystallization container, and is naturally cooled for 4-6 hours, then forced cooling is carried out for 12-16 hours, thus the whole potassium fluotantalate crystallization process is completed, then the crystallization mother liquor is extracted, and potassium fluotantalate crystals are transferred into a washing and suction filtration tank for washing, suction filtration, drying and packaging. The tantalum oxide content of the tantalum liquid after extraction, separation and purification is generally 30-100g/L according to different ore types. At present, in the production process of potassium fluotantalate, the crystallization concentration of the potassium fluotantalate solution after heating, synthesizing and converting is generally controlled to be 25-45g/L, because the crystallization concentration is too low, the yield is low, the production cost is high, the crystallization concentration is too high, a large amount of ultrafine powder is generated at the bottom of a crystallization container, a certain yield is affected as the washing liquid flows away in the washing process, the potassium fluotantalate crystals on the inner wall surface of the peripheral container and the deposition bottom grow a plurality of layers of irregular coarse particles, and a large amount of impurities are entrained or coated by the coarse particles, so that the product quality is affected. Therefore, when tantalum liquid with the concentration higher than 50g/L is used for heating synthesis, deionized water is needed to be added as a diluent, and the added deionized water is needed to be supplemented with hydrofluoric acid to improve acidity, so that the cost of production materials is increased, the yield is low, and meanwhile, the low-concentration crystallization ratio is higher than that of high-concentration crystallization, and the consumption of hydrofluoric acid per unit yield is also high. Meanwhile, in the selection of the crystallization container, each manufacturer has different choices, for example, each enterprise in the south is biased towards a small crystallization container, so that on one hand, the cooling is facilitated, the yield is improved, on the other hand, the production of finer particles with uniform granularity is facilitated, the product quality is good, but the operation is too complicated, the product is easy to be polluted, and the northern enterprise adopts a large container crystallization tank with a jacket and stirring, so that the stirring speed is controlled in the cooling crystallization process, on the one hand, the uniform cooling of the temperature is facilitated, and on the other hand, the fine particles with uniform granularity are also obtained. However, these crystallization vessels are limited to lower crystallization concentrations and have a limitation in improving the yield. Therefore, there is a need for appropriate improvements in the production process and crystallization equipment based on the existing conventional potassium fluorotantalate production process to solve the current problems. Disclosure of Invention The invention aims to overcome the problems existing in the prior art and provides a method for preparing potassium fluotantalate by tantalum liquid. In order to achieve the technical purpose and the technical effect, the invention is realized by the following technical scheme: A method for preparing potassium fluotantalate from tantalum liquid comprises the following steps: step 1, heating and converting feed liquid, namely adding tantalum liquid with the concentration of tantalum oxide of 50-80 g/L into a potassium fluotantalate crystallization heating tank, starting a stirring motor on the potassium fluotantalate crystallization heating tank to stir the tantalum liquid in the potassium fluotantalate crystallization heating tank at a stirring frequency of 30Hz, conveying steam into the potassium fluotantalate crystallization heating tank to heat the tantalum liquid internally, adding hydrofluoric acid to perform acid preparation when the temperature of the tantalum liquid in the potassium fluotanta