Tungsten-Containing Waste Recycling Guidelines

At present, the main method of decomposition of tungsten containing materials is "sodium carbonate decomposition". Sodium carbonate is decomposed with sodium carbonate, which is corrosive to iron equipment, and its operating environment is general, and its scope of application is narrow (only for dissolving scheelite). The decomposition agent is expensive and extremely uneconomical. In the market, we need a process to treat tungsten containing materials without corrosive equipment, good operation environment, low cost and high tungsten recovery.

Some scholars have provided a method for processing tungsten-containing waste. The process includes ore blending, pulping, decomposition, and unloading processes to obtain a low-impurity sodium tungstate solution and directly exchange the original solution as a strong basic anion exchange resin. Expand the preparation of ammonium paratungstate raw materials, reducing the cost of making ammonium tungstate solution.

1.Blending: m (SiO₂) = 0.5 * m (WO₃) ^0.5, m (SiO₂), complete with ore, containing silica mass fraction material (%); m (WO₃) complete with ore, tungsten trioxide containing mass fraction of material (%). The tungsten containing materials are placed in the grinding machine (preferably ball mill) and grinded to less than 95% of the particle size less than 75 microns.

2. Add the decomposition agent sodium hydroxide or sodium hydroxide solution to the pulping barrel, and its addition amount is 2.5 times as much as the theoretical value. Open the agitation and add a small amount of water to the decomposition agent to prevent excessive viscosity and make the stirring fail. The final volume of 1m³ is 0.9m³.

2.Decomposition

(1) Open the exhaust valve of the reaction kettle, pump the good solution into the reaction kettle, and close the emptying valve of the reaction kettle.

(2)Turn on the heating equipment, heated to 120 ℃. Stop heating, insulation 2h.

4. Unloading filtration
(1) add 2m³ water in the diluting bucket in advance. After opening the dilution bucket agitator, open the discharge valve slowly and open the discharge valve to the 1/2; when the pressure is reduced to 5Kgf/cm², the discharge valve is fully opened. The temperature of the dilute bucket is controlled at 60 - 100 ℃. Filtering and washing, with a solution of cinchonine solution into washing filter residue without white precipitate, washing end point, discharging slag filter plate.

Using these methods to treat tungsten containing materials, a low content of sodium tungstate solution can be obtained. It can be used as a strong basic anion exchange resin to exchange original solution, and tungsten containing materials can also get good recovery rate.

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