A kind of method utilizing wet process phosphoric acid to prepare ferrous phosphate

Abstract

The invention relates to a method for preparing ferrous phosphate by using wet-process phosphoric acid, comprising the following steps: under the condition of 40-100°C, adding a basic magnesium compound to the phosphoric acid solution to adjust the pH to 3-6, and filtering to obtain a filter residue and a filtrate One; add ferrous sulfate in filtrate one and pass into carbon dioxide, add the pH of alkaline magnesium compound to adjust the solution to be 3-5, obtain product ferrous phosphate hydrate and filtrate two; The pressure of carbon dioxide above described filtrate one is 0.01 ‑1Mpa; add a basic magnesium compound to the filtrate two until the pH value of the solution is greater than 6, solid-liquid separation obtains the filter residue three and the filtrate three, and when the content of aluminum on a dry basis in the filter residue three is lower than 2%, the filter residue is used Substitute or partially replace the basic magnesium compound in step 2. Based on the method for preparing ferrous phosphate by wet-process phosphoric acid of the present invention, ferrous phosphate with relatively high purity can be prepared, and the preparation process is short, and the operation is simple, which reduces the cost of preparing ferrous phosphate by wet-process phosphoric acid.

Description

technical field [0001] The invention belongs to the field of ferrous phosphate preparation, and in particular relates to a method for preparing ferrous phosphate by using wet-process phosphoric acid. Background technique [0002] The production of phosphoric acid by wet method is the main way to manufacture phosphoric acid at present. The output of wet method phosphoric acid in the world has accounted for 85%-90% of the total output of phosphoric acid. The cost of wet method phosphoric acid is about 20%~25% lower than that of hot method phosphoric acid. The energy consumption is about 1 / 3 of that of thermal phosphoric acid, which has many advantages of low production cost and low energy consumption. Avoid entering into the finished phosphoric acid, the phosphoric acid produced has a low purity and cannot be directly used in the preparation of high-purity ferrous phosphate. The research and development of wet-process phosphoric acid purification technology enables it to reach...

AI Technical Summary

Problems solved by technology

[0004] The technical problem solved by the present invention is: to provide a method for preparing ferrous phosphate by using wet-process phosphoric acid to solve the technical problems of high investment cost, complicated process and long cycle in the production of ferrous phosphate by purifying phosphoric acid in the prior art