How to Purify High Impurity Sodium Tungstate Solution

With the development of tungsten ore raw materials towards low quality and high impurity, various companies have recovered and decomposed tungsten ore in different ways, resulting in high hetero tungsten in the market than sodium tungstate / tungsten ore. China's tungsten smelting is the mainstream of ion exchange. The biggest characteristic of ion exchange is strict demand for impurity content in the precursor fluid. Therefore, we must purify high hetero tungsten than sodium tungstate before exchanging, so as to get qualified pre liquid.

Methods for purifying high hetero tungsten ratio sodium tungstate include: high hetero tungsten, sodium tungstate solid and tungsten ore as raw materials, and purify through raw material comminution process, batching process, decomposition process and unloading process. It promotes the reaction of high hetero tungsten with high content of anions in tungsten tungstate and the metal ions in tungsten ore, and generates substances with small solubility products into the filter press residue. After filtration, purified sodium tungstate is obtained.

(1) In the raw material comminution process, the high hetero tungsten is placed in the crushing equipment than the sodium tungstate solid, and the particle size is less than 75 micron. The solid particles exceed 90%. The tungsten ore is placed in the crushing equipment, and the tungsten ore with less than 45 micron diameter is more than 96%.

(2) In the proportioning process, the quality ratio of sodium tungstate with the worn tungsten ore is 1/ (2~5), and the slurry is put into the slurry barrel according to the mass ratio.

(3) The decomposition process:
A. Adding the decomposition agent sodium hydroxide to the mixing pulping barrel, opening the mixer and adding the decomposing agent to add water, in order to prevent the excessive viscosity and make the stirring failure.

B. Open the exhaust valve at the top of the reaction kettle, pump the good solution into the reactor, and close the exhaust valve of the reaction kettle.

C. Open at the bottom of the reaction vessel and the surrounding electric heating or heat conduction oil heating device, the solution is heated to 120 ℃ ~200 ℃ in the reaction kettle, stop heating, insulation 1~5h;

(4) The unloading filtration process;
A. The reactor discharge valve connected to the dilution barrels, adding 1 to 5 m 3 water in the dilution barrels;

B. Open the blender dilution bucket, slowly open the reactor discharge valve until the slurry into the dilution bucket, the discharge valve open to 1/2; at this time the reactor slurry temperature exceeds 120 ℃, the formation of 5 ~ 12 Kgf / cm² of internal pressure, then the pulp temperature dropped until the pressure dropped to 5 Kgf / cm², the full open material valve;

C. Until the pulp temperature dropped to 50 ℃ ~ 100 ℃, the filtered product is purified high tungstate than sodium tungstate.

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