Method for testing content of eutectic phosphorus in ardealite

Abstract

The invention provides a method for testing the content of eutectic phosphorus in ardealite. The method comprises the following steps of: mixing pretreated ardealite with an inorganic acid solution with the concentration of 0.0001-0.01 mol / L, and carrying out solid-liquid separation after reaction to obtain a pickling solution; testing the phosphorus content and the sulfate radical content of the obtained pickling solution; completely dissolving out phosphorus in the ardealite by adopting an acid dissolution method, and measuring the total phosphorus content of the ardealite; and setting the difference value between the total phosphorus content and the phosphorus content is the content of the eutectic phosphorus in the ardealite. According to the method, corresponding pickling process conditions are selected according to the types of phosphorus impurities in the ardealite to ensure that soluble phosphorus and insoluble phosphorus in the ardealite are completely dissolved out, and then the content of the eutectic phosphorus in the ardealite is quantitatively obtained by comparing the content with the total phosphorus content in the ardealite, so that the influence of the content of the eutectic phosphorus on the performance of the ardealite is conveniently researched; and the method is easy and convenient to operate, simple in process, low in cost and wide in application prospect.

Description

technical field [0001] The invention belongs to the technical field of comprehensive utilization of gypsum, and relates to a method for testing eutectic phosphorus content of phosphogypsum. Background technique [0002] Phosphogypsum is mainly derived from the production process of wet-process phosphoric acid. It is a kind of industrial by-product gypsum. Its output is large. Most of the phosphogypsum is still mainly stockpiled. Pollution will have an impact on the ecological environment and human life, so the recovery and resource utilization of phosphogypsum is essential. The main component of phosphogypsum is CaSO 4 2H 2 O, the rest belong to impurity components, the types of impurities are complex and the concentration range is wide, including phosphorus-containing, fluorine-containing impurities and organic impurities, which make the comprehensive utilization of phosphogypsum difficult to remove impurities, complex process, large investment, and economical feasibility...

AI Technical Summary

Problems solved by technology

The main component of phosphogypsum is CaSO4·2H2O, and the rest are impurity components with complex types and wide concentration ranges, including phosphorus-containing, fluorine-containing impurities and Organic impurities, etc., make the comprehensive utilization of phosphogypsum have disadvantages such as difficulty in removing impurities, complicated process flow, large investment, and poor economic feasibility.

[0003]Phosphogypsum contains a lot of phosphorus, which is the impurity that has the greatest impact on the physical properties of phosphogypsum. The existence forms of impurity phosphorus can be divided into soluble phosphorus, insoluble phosphorus and Three types of eutectic phosphorus, the presence of phosphorus-containing impurities will hinder the hydration of phosphogypsum, resulting in loose product structure and reduced strength

By studying the influence of various phosphorus impurities on the performance of phosphogypsum, it can provide a basis for effectively improving the performance of gypsum products. The key to studying the influence law is to quantitatively test the content of various phosphorus impurities. Currently, the testing and research on soluble phosphorus It is relatively mature, but there are few studies on eutectic phosphorus. Conventional washing, flotation and other impurity removal methods are difficult to dissolve eutectic phosphorus, so it is impossible to accurately explain the impact of different contents of eutectic phosphorus on gypsum cementitious materials. , so the quantitative detection of eutectic phosphorus content is an important research direction to realize the efficient utilization of phosphogypsum

[0004]CN 107244690A discloses a compound pretreatment method of phosphogypsum, the method first removes harmful substances in phosphogypsum by grinding and screening, and then crushes and ferments lemons, Obtain the fermentation filtrate rich in citric acid and microorganisms, mix and stack the fermentation filtrate and phosphogypsum, stand still and react to obtain the primary pretreatment phosphogypsum, then use water as the autoclaving medium, and steam at low pressure to obtain the secondary pretreatment phosphogypsum , continue frying and heating under high temperature conditions, and make slurry from the three pretreated phosphogypsum obtained after cooling down, add calcium oxide to adjust the pH to neutral, filter to obtain filter residue, and complete the pretreatment of phosphogypsum; The soluble impurities and eutectic phosphorus in phosphogypsum are removed by one-step operation, but the whereabouts of insoluble phosphorus is not clear, and the operation steps are relatively complicated, only the eutectic phosphorus is removed, and its content cannot be accurately determined

[0005] CN 101486536A discloses a sulfuric acid modification method of phosphogypsum, the method comprises: mixing sulfuric acid and phosphogypsum raw materials, at a reaction temperature of 10-90°C React for 0.5-24 hours; neutralize the reaction product to obtain modified phosphogypsum; this method removes the eutectic phosphorus in phosphogypsum by acid leaching and heating, but at the same time it also removes other types of phosphorus Impurities are dissolved out, and the range of process operating conditions is wide, and the degree of phosphorus removal is different, so it is impossible to accurately measure the total amount of phosphorus impurities and the content of various types of phosphorus in phosphogypsum