Method for preparing rare earth oxalate precipitation

Abstract

The invention belongs to the field of rare earth preparation and especially relates to a method for preparing a rare earth oxalate precipitation. The method includes following steps: mixing a rare earth chloride and an oxalic acid solution; performing precipitation, filtering and washing the precipitation, collecting wash water and performing a vaccumizing process for removing water. The precipitation is filtered and washed in a self-made filter barrel, wherein the washing process is divided into a plurality of steps, wherein water, except in a first washing step, in the other steps are all collected for washing the follow-up precipitation while the water in the first washing step is discharged out, so that utilization rate of water resource can be greatly increased and waste water discharge is reduced. By means of a vacuumizing process after the washing process, moisture in the precipitations can be effectively removed for reducing volume of the rare earth oxalate precipitations, so that a subsequent burning time can be shortened, energy required in burning is saved, a production period of a rare earth oxide is reduced and a production cost is reduced. In addition, rare earth loss during spin-dry in a centrifugal machine, thereby increasing product yield.

Description

technical field [0001] The invention belongs to the field of rare earth preparation, in particular to a method for preparing rare earth oxalate precipitation. Background technique [0002] China is the country with the largest reserves of rare earths in the world, and the distribution of elements is comprehensive. After nearly 40 years of development, the country has established the world's largest rare earth industry, and has become the world's largest rare earth producer, largest rare earth consumer and largest rare earth supplier. In the rare earth production process, it is generally necessary to convert rare earth ores into rare earth salt precipitation, such as rare earth oxalate, rare earth ammonium bicarbonate, etc., and then burn the rare earth salt to obtain rare earth oxides. Washing after precipitation is a key step in the preparation of pure rare earth products. The traditional washing method is often to extract the mother liquor in the precipitation tank, reinj...

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Problems solved by technology

Although this method can remove the impurities attached to the sediment to a certain extent, the water after each washing is discharged, which seriously wastes water resources and increases the discharge of waste water; and it is difficult to remove the water in the sediment after washing. It is extracted and cleaned, thereby prolonging the subsequent burning time, which not only prolongs the production cycle, but also wastes the energy consumed during burning, which increases the production cost and reduces the economic benefits of the enterprise

[0003] In response to the above problems, some manufacturers also use centrifuges to dry the sediment, but the centrifuges work at a high speed. If the operation is improper, it will cause serious bodily injury to the operator and increase safety hazards; and the centrifuge drying process In the middle, it is easy to throw the rare earth precipitation out of the machine, thus wasting rare earth resources and affecting the product yield

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