Reclaiming Rubidium from Rubidium Tungsten Ore

Rubidium (Rb) is a dilute chemical substance, very soft silver white wax metal. It is soft and light, and its chemical properties are more active than potassium. It can be used for the production of special glass, micro high energy battery and crystal scintillation counter. The minerals containing rubidium are mica and potash feldspar, mainly in wolframite and scheelite.

The extraction of rubidium resources in China is usually lithium ore or Saline Lake water. Lithium is the extraction of lithium and the by-product rubidium, while the salt lake water is generally comprehensive extraction of rubidium, cesium and potassium. The yield of the general rubidium is low and the price is high. The reserves of tungsten resources in China are abundant, but with the consumption of tungsten ores with high content of tungsten, the recovery and utilization of tungsten in low concentration tungsten ores is also essential. The associated ores of tungsten ores contain a variety of valuable metals, including rubidium. How to extract rubidium from rubidium tungsten ores in a comprehensive way is of great significance.

For example, the associated rubidium is in the scheelite mine of a large tungsten mine in Hunan. A process of sulphuric acid roasting, leaching, ion exchange, concentration crystallization and extraction has been put forward, which effectively extracts rubidium, tungsten and potassium in the mineral, and forms a complete technological route. The separation and recovery process is as follows:

1)By drying, crushing and grinding, the raw materials containing rubidium and tungsten are crushed to the size of less than 0.074 mm and 98% to - 0.048 mm.

2)100 weight of dry mineral powder combined with 110 to 150% concentrated sulfuric acid, after mixing and loading into rotary kiln, in the roasting equipment, roasting temperature 200~350 degrees C, baking time 2 ~ 5h, flue gas absorption production of hydrofluoric acid products, fluorine recovery rate 96%, baking material cooling to normal temperature, feed ball mill grinding, get roasted ore powder, In the roasting process, wolframite and scheelite containing tungsten are decomposed into insoluble tungstic acid by sulfuric acid, and rubidium is converted into rubidium sulfate soluble in water. The separation and collection of low concentration valuable metals tungsten, rubidium and potassium from ore powder are carried out by roasting ores.

3)In accordance with the liquid solid ratio of 1.5 to 2.5:1, the leaching agent is added, the leaching agent is the first leaching of water, and the leaching is heated to 2 ~ 3.0h at 70~90 C in the stirring soaking tank, and the leaching solution and the leaching residue are produced by the pulp filtration. The leaching residue is treated by slurry washing, the solid ratio of washing liquid is 1.2:1, and the leaching solution enters the comprehensive rubidium extraction and tungsten extraction process. The leaching residue added ammonium carbonate + ammonia water, liquid solid ratio 2 ~ 4:1, temperature to 30~40 C, leaching residue after three leaching of ammonium tungstate solution and leaching residue, of which the rubidium leaching rate of 96%, tungsten leaching rate of 89.5%.

4)Neutralize the leaching solution in caustic soda solution to pH value of 2 to 2.5, and then continue stirring 0.5h to obtain ion exchange material. The macroporous strongly basic anion exchange resin type 1299 was used. The contact time of the liquid ion exchange is 1 ~ 4H. After the resin is saturated, it is first washed with a small amount of water, and then the solution is analyzed with a mixture of 2 mole / liter ammonia water +5 mole / liter ammonium chloride, and the solution is concentrated and crystallized to produce ammonium para tungstate. The adsorbed tail liquid is entered into the production process of rubidium chloride.

5)The pH value of the adsorbed tail liquid is slowly added to the lime to adjust the value to 7. After the filtration, the leaching residue is used in two times of slurry and one leaching, and the leaching residue after washing can not only get the crude calcium sulfate from the by-product. After mixing the Neutralization Solution and washing water, the soda powder was gradually added to the calcium removal according to the theoretical consumption of 1.1 times. After adding the soda, the 0.5h was continuously stirred, and the calcium removal and calcium slag were obtained.

6)The solubility of calcium sulfate with potassium sulfate varies with the temperature, when the material is heated to the potassium sulfate near saturation, the concentration is terminated, and the centrifuge is used to separate the crystallized potassium sulfate and the mother liquor. The concentration of rubidium sulfate in mother liquor reaches 10 ~ 15g/ L. Potassium sulfate is obtained by washing potassium sulfate. Using the difference of solubility between potassium sulfate and rubidium sulfate, the separation of rubidium and potassium was realized by concentrated crystallization, and the concentration of rubidium in solution was increased.

7)Crude rubidium chloride is recrystallized and purified. The rubidium chloride is dissolved in hot water to ensure that the rubidium chloride is saturated and the crystal is cooled to produce high purity rubidium chloride. 3~5 times are needed for recrystallization, and the purity of rubidium chloride is more than 99.5%.

The recovery of tungsten, rubidium and potassium is realized through the process of sulphuric acid roasting, leaching, ion exchange, concentration and extraction. The recovery of tungsten, rubidium and potassium is 90.23%, 80.35%, 96.45%, and the comprehensive recovery rate of rubidium, potassium and tungsten is high, the product value is high, and the cost of production is low. Good economic benefits have been achieved.

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