Method for preparing FexPO4 by electrolyzing ferrophosphorus

Abstract

The invention relates to a method for preparing FexPO4 by electrolyzing ferrophosphorus, which comprises the following steps: by using ferrophosphorus as the anode and providing an oxygen source by using oxygen in water as the product, electrolyzing to obtain a FexPO4 solution, wherein only ferrophosphorus and water are consumed in the reaction process; adding basic oxides to regulate the pH value of the solution so as to settle out FexPO4; and granulating, filtering and washing to obtain the finished FexPO4 product. In the method, cheap ferrophosphorus is converted into high-value FexPO4 by using the electrolytic reaction process; the source of ferrophosphorus is not limited; the influence of impurity elements on the product can be eliminated; the product can be granulated into controlled shape and particle size; the byproduct H2 can be recycled; the treated filtrate can be used cyclically; the obtained finished FexPO4 product has the advantages of high purity, small particle size, easily controlled shape, and low power consumption; the reaction process has low requirements for equipment and is easy to operate; and the preparation method has the advantages of simple technique, high resource utilization rate, low cost, low investment, good benefit, high cleanness and environmental protection, can be easily industrialized, and is suitable for high-value comprehensive utilization of byproducts in chemical industry and large-scale industrial low-cost clean production of high-end phosphates.

Description

technical field [0001] The invention relates to a method for preparing Fe by electrolysis of ferrophosphorus x PO 4 The method uses the reaction process to eliminate the influence of impurities in the raw materials on the product. The product has high purity, fine particle size, easy control of shape, and simple process. It can be applied to the high-value comprehensive utilization of chemical solid waste and the low cost of high-end phosphate materials. Clean manufacturing. Background technique [0002] Fe x PO 4 It is a kind of iron phosphate, which is widely used in energy materials, catalysts, ceramics, food additives and other fields. In the field of energy materials, Fe x PO 4 It can be used as an electrode material (its electrochemical performance is greatly affected by the crystal form of the material and the preparation method, among which amorphous FePO 4 The operating voltage is 3V), and can also be used as a preparation of LiFePO 4 , LiFeP 2 o 7 and Li ...

AI Technical Summary

Problems solved by technology

In our original special implementation process of preparing iron phosphate from iron phosphorus [Chinese patent CN101659406A], relying on iron phosphorus to be oxidized to Fe at high temperature in a dry oxygen-containing atmosphere 2 o 3 and P 2 o 5 Then react again to reduce the impact of impurity elements in ferrophosphorus on the product, and do not directly prepare ferric phosphate with controllable morphology by electrolytic dedoping of ferrophosphorus at room temperature, which is obviously different from the process and technology of this application

In addition, the types and contents of impurities in ferrophosphorus obtained by different processes in different regions are different, making it difficult to fully purify ferrophosphorus

However, these impurities will affect the performance of the product, and it needs to be purified to a certain extent

In addition, when preparing ferric phosphate directly from ferrophosphorus, it needs to be completed in a dry and oxidizing atmosphere at a relatively high temperature. The reaction process is complex and costly, and the requirements for equipment are relatively high. Greater impact

[0005] In order to overcome the current Fe x PO 4 The deficiencies in the production process solve the problem of preparing Fe by ferrophosphorus x PO 4 High temperature dry oxidizing atmosphere, uncertain types and contents of impurities in ferrophosphorus raw materials make it difficult to fully purify impurity elements and Fe x PO 4 The technical problem that the product particle size and shape are difficult to control, simplify the preparation process, reduce energy consumption, and reduce waste discharge, the present invention proposes a new process method completely different from the above invention: electrolysis of ferrophosphorus in aqueous solution to prepare Fe x PO 4 , apply a voltage of 1 to 20V, and a current density of 5 to 1500A m -2 , to obtain Fe by electrolysis x PO 4 solution, adding alkaline oxides, adjusting the pH value of the solution to 1-8, Fe x PO 4 Precipitated, filtered and washed to obtain Fe x PO 4 finished product

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