Method for joint production of strontium nitrate and barium nitrate from high-calcium strontianite and witherite

Abstract

The invention discloses a method for joint production of strontium nitrate and barium nitrate from high-calcium strontianite and witherite. The method comprises the following steps: respectively crushing high-calcium strontianite and witherite, mixing with water to obtain strontianite pulp and witherite pulp, subsequently adding nitric acid into the strontianite pulp, reacting, filtering to obtain a nitrate solution and strontium sulfate filter residue, adding hydrogen peroxide and activated carbon into the nitrate solution to react and decontaminate, subsequently evaporating to crystallize the decontaminated nitrate solution, centrifuging to obtain strontium nitrate and a mother liquid containing calcium nitrate, adding the witherite pulp into the mother liquid, reacting and filtering to obtain a solution with barium nitrate and calcium carbonate filter residue, removing the nitrate solution from the solution with barium nitrate, adding hydrogen peroxide and activated carbon for reaction and decontamination, and subsequently evaporating to crystallize the decontaminated barium nitrate solution to obtain barium nitrate and a mother liquid which mainly contains strontium nitrate. The method adopts high-calcium strontianite and witherite for joint production of strontium nitrate and barium nitrate, the raw materials are low in cost, the materials can be recycled, and thus environment pollution is avoided.

Description

technical field [0001] The invention belongs to the field of strontium-barium salt synthesis, relates to a method for producing strontium nitrate and barium nitrate, in particular to a method for jointly producing strontium nitrate and barium nitrate by using high-calcium strontite and witherite. Background technique [0002] Strontium nitrate and barium nitrate are widely used in analytical reagents, electronic component materials, fireworks and medicine. At present, the production of strontium nitrate and barium nitrate mainly has the following two processes: [0003] (1) Carbonate method: After mixing industrial strontium carbonate or industrial barium carbonate, add concentrated nitric acid to react to obtain the corresponding nitrate raw material solution, and obtain strontium nitrate and barium nitrate after impurity removal, filtration, evaporation and crystallization, and drying Product: The quality of strontium nitrate and barium nitrate obtained by this method is b...

AI Technical Summary

Problems solved by technology

The method uses strontite or witherite as raw material, and the production cost is relatively reduced. However, due to the reduction of the grade of strontium ore, the presence of impurities such as more symbiotic calcium carbonate strontium sulfate in the strontium ore, the solution after acidolysis with nitric acid Contains a large amount of calcium nitrate, because the circulation method is not adopted, the degree of concentration is relatively high, so as to increase the yield of strontium as much as possible, but because strontium nitrate crystallizes in a higher concentration of calcium nitrate solution, phenomena such as isomorphic substitution will occur , not only affects the purity of the final product, but also affects the evaporative crystallization process of strontium nitrate, and the final strontium nitrate crystal grains are fine, difficult to dry and easy to agglomerate

In addition, the calcium nitrate mother liquor of this method evaporation crystallization contains part of strontium nitrate, which increases the recovery difficulty of calcium nitrate, and in the process of directly producing barium nitrate with witherite and nitric acid reaction, due to containing certain calcium carbonate and carbonic acid in the witherite Strontium, calcium carbonate and strontium carbonate will also react with nitric acid, resulting in the consumption of nitric acid, and the resulting calcium nitrate and strontium nitrate are difficult to use due to their small amount

At present, the direct discharge method is generally used for treatment, which not only causes low utilization of nitric acid raw materials, but also brings serious environmental pollution.

[0005] At present, there are fewer and fewer rich minerals of strontium ore, and the production of strontium salt by using low-grade and medium-grade strontium is technically immature and the cost is high; especially for high-calcium strontite (paragenetic ore of calcium carbonate and strontium carbonate) , it is difficult to select the calcium carbonate in it by ordinary beneficiation methods, resulting in a high consumption of nitric acid when the ore is used to produce strontium nitrate

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