A kind of method utilizing metal strontium slag to prepare strontium chloride

Abstract

The invention fully considers the characteristics of the slag produced by using the thermite method to prepare metal strontium, and provides a method for recovering strontium oxide to prepare strontium chloride under low-acid and low-temperature conditions. That is, strontium metal slag is pulverized to obtain strontium slag slurry, acidified with hydrochloric acid and barium removed with sulfuric acid, and the pH value of the solution is controlled to be greater than 3.5 during the reaction, which can inhibit the dissolution of aluminum, and then use hydrogen peroxide to oxidize ferrous ions; Strontium hydroxide adjusts the pH value of the solution so that aluminum and iron ions are flocculated, and finally the solution is filtered and then concentrated and crystallized to obtain the strontium chloride product. The pH value of the reaction solution is greater than 3.5, the reaction temperature does not exceed 50° C., and the operating environment is good. The production process is simplified. The waste slag generated by the method is mainly available alumina, which solves the pollution problem.

Description

Technical field [0001] The invention relates to a process for recovering strontium in metal strontium slag, in particular to a method for preparing strontium chloride using metal strontium slag. Background technique [0002] In the process of preparing metal strontium by the thermite method, strontium carbonate is decomposed into strontium oxide at high temperature, and strontium oxide and aluminum powder undergo oxidation-reduction reaction to produce strontium metal. The yield of metal strontium in this process is currently only 40-70%. A large amount of strontium remains in the slag in the form of strontium oxide and unreacted strontium carbonate. If this slag is not recycled, it will certainly cause serious pollution to the environment and waste valuable resources. [0003] The publication number is 1609242, and the patent application document of publication date 2005-04-27 discloses a method for preparing strontium salt by using metal strontium slag. The method uses exces...

AI Technical Summary

Problems solved by technology

In this patent, the separation of strontium salt and aluminum salt must be carried out under strong acidic conditions to avoid hydrolysis of aluminum ions. Therefore, the reaction temperature is high, the solution is highly acidic, and the operating environment is relatively harsh.

At the same time, strontium salts and aluminum salts may form double salts during the crystallization process, which requires repeated recrystallization and purification. The process is long, the total yield is low, and the cost is high.