阅读说明：本技术 一种磷石膏的中和与固磷固氟方法及得到的磷石膏 (Method for neutralizing phosphogypsum, fixing phosphorus and fixing fluorine and obtained phosphogypsum ) 是由 朱清玮 张晓菲 王丽 李帆 王霞 陈红霞 武发德 宫丽伟 肖文韬 于 2018-06-06 设计创作，主要内容包括：本申请公开了一种磷石膏的中和与固磷固氟方法及得到的磷石膏,所述方法包括：将磷石膏与电石渣混合均匀,陈化一段时间,所述磷石膏与所述电石渣的重量比可以为75:1-90:1,所述陈化的时间可以为陈化12-24小时。本申请选用资源丰富的电石渣对磷石膏进行中和以及固磷固氟处理,有效降低了磷石膏的酸性以及可溶性磷和氟的含量,实现了电石渣和磷石膏两种固体废弃物的有效协同处理和资源化利用。(The application discloses a method for neutralizing phosphogypsum, fixing phosphorus and fixing fluorine and the obtained phosphogypsum, wherein the method comprises the following steps: uniformly mixing phosphogypsum and carbide slag, and aging for a period of time, wherein the weight ratio of the phosphogypsum to the carbide slag can be 75:1-90:1, and the aging time can be 12-24 hours. According to the method, the phosphogypsum is neutralized, phosphorus-fixing and fluorine-fixing are carried out on the phosphogypsum by using the carbide slag with rich resources, so that the acidity of the phosphogypsum and the content of soluble phosphorus and fluorine are effectively reduced, and the effective synergistic treatment and resource utilization of the carbide slag and the phosphogypsum are realized.)

1. A method for neutralizing phosphogypsum and fixing phosphorus and fluorine, comprising the following steps: mixing the phosphogypsum and the carbide slag uniformly, and aging for a period of time.

2. A process according to claim 1, wherein the weight ratio of phosphogypsum to carbide slag is from 75:1 to 90: 1.

3. A process according to claim 2, wherein the weight ratio of phosphogypsum to carbide slag is 80:1 to 85: 1.

4. The process according to any one of claims 1-3, wherein the aging period of time is 12-24 hours of aging.

5. An phosphogypsum obtained by the process according to any one of claims 1-4.

Technical Field

The application relates to but is not limited to comprehensive utilization technology of solid waste, in particular to but not limited to a method for neutralizing phosphogypsum, fixing phosphorus and fixing fluorine and obtaining the phosphogypsum.

Background

Phosphogypsum is a byproduct in the production of phosphoric acid in a phosphating plant, the main component of the phosphogypsum is calcium sulfate dihydrate, and 5t of phosphogypsum is produced every 1t of phosphoric acid. Phosphogypsum usually contains water-soluble P₂O₅(0.3-3.0 wt.%) and water-soluble F^-(0.1 to 0.7 wt.%) and the like, and the pH is usually not more than 2.0, so that the comprehensive utilization thereof is extremely limited. The realization of economic and effective pretreatment to eliminate the harmful influence of acidic substances on the performance of the phosphogypsum is the key to realize the reutilization of the phosphogypsum.

The existence of soluble phosphorus and soluble fluorine in the phosphogypsum can prolong the setting time, loosen the structure, coarsen the crystal and reduce the strength in the hydration process of the phosphogypsum. Meanwhile, too low pH value seriously affects the application of the phosphogypsum in gypsum building materials. Therefore, it is necessary to modify phosphogypsum accordingly in order to control its pH and its soluble phosphorus and fluorine contents.

At present, the water washing and lime neutralization method is an effective method for the neutralization of phosphogypsum and the treatment of solid phosphorus and solid fluorine, but the large use of lime can cause the exploitation of a large amount of natural mineral limestone and the consumption of energy.

Disclosure of Invention

The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

The carbide slag is the waste slag generated by preparing acetylene gas by hydrolyzing calcium carbide, and the main component of the carbide slag is Ca (OH)₂The particles are very fine. The pH value of common carbide slag liquid is 12-14. Ca (OH) in carbide slag₂The mass fraction of the lime reaches more than 90 percent, while the domestic slaked lime contains Ca (OH)₂Has an average mass fraction of only 65%, and thus, the carbide slag is likely to be an ideal substitute for lime. China is the biggest calcium carbide producing and consuming country in the world at present. By the end of 2016, the productivity of the calcium carbide in China reaches 3800 ten thousand t/a, the actual yield in 2016 is 2588 ten thousand t, and the total amount of the discharged calcium carbide slag is nearly 3000 ten thousand t/a. A large amount of carbide slag is discharged, which not only occupies a large area of land, but also seriously pollutes the surrounding environment and water area.

The application creatively adopts the carbide slag to replace lime for neutralization and phosphorus and fluorine fixation treatment of the phosphogypsum, so that the pH value of the phosphogypsum is effectively reduced, and the content of soluble phosphorus and fluorine in the phosphogypsum is reduced.

Specifically, the application provides a method for neutralizing and fixing phosphorus and fluorine of phosphogypsum, which comprises the following steps: mixing the phosphogypsum and the carbide slag uniformly, and aging for a period of time.

In some embodiments, the weight ratio of the phosphogypsum to the carbide slag may be from 75:1 to 90: 1.

In some embodiments, the weight ratio of the phosphogypsum to the carbide slag may be 80:1 to 85: 1.

In some embodiments, the aging period of time may be from 12 to 24 hours of aging.

The application also provides phosphogypsum obtained by the neutralization and phosphorus and fluorine fixation method.

According to the method, the strong acidity of the phosphogypsum is neutralized by selecting the carbide slag with rich resources to replace lime, and the soluble phosphorus and fluorine in the phosphogypsum are cured and controlled, so that the advantages are made up for the disadvantages, the effective synergistic treatment and resource utilization of the carbide slag and the phosphogypsum are realized, the environmental pressure of the carbide slag and the phosphogypsum is relieved, the wastes are made of the wastes, and the comprehensive utilization is realized.

In particular, the application utilizes Ca (OH) rich in carbide slag₂And high alkalinity, which replaces lime to react with soluble phosphorus and fluorine in the phosphogypsum to generate stable calcium phosphate and calcium fluoride precipitates, neutralizes the acidity of the phosphogypsum, and carries out curing modification treatment on harmful impurities in the phosphogypsum.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the application. The objectives and other advantages of the application may be realized and attained by the structure particularly pointed out in the written description and claims hereof.

Detailed Description

Hereinafter, embodiments of the present application will be described in detail to make objects, technical solutions and advantages of the present application more apparent. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.