阅读说明：本技术 一种采用磷酸二氢铵分解重晶石制偏磷酸钡的方法 (Method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate ) 是由 周骏宏 唐尚金 何丹 马糯 文灿 刘严 张瑶 罗孝春 朱昌鸿 黄志强 于 2021-01-16 设计创作，主要内容包括：本发明公开了一种采用磷酸二氢铵分解重晶石制偏磷酸钡的方法,按照重晶石与磷酸二氢铵质量比为1:2.0——1:2.6进行备料,将两种原料均匀混合后,在500-800℃高温下煅烧2.5-3.5h,所得产物即为偏磷酸钡。本发明直接利用天然重晶石资源的思路,提出了一种直接采用重晶石为原料,不需要经过碳酸钡或者氢氧化钡制取阶段,直接由硫酸钡转化为偏磷酸钡的新方法。该方法通过将磷酸二氢铵和重晶石高温下混合煅烧,即可生产得到偏磷酸钡。整个方法较为简单,生产比较方便、快捷,降低了偏磷酸钡的生产成本。而且不会对环境产生污染。(The invention discloses a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate, which comprises the steps of preparing materials according to the mass ratio of 1: 2.0-1: 2.6 of barite to ammonium dihydrogen phosphate, uniformly mixing the two raw materials, and calcining for 2.5-3.5h at the high temperature of 500-800 ℃, wherein the obtained product is the barium metaphosphate. The invention provides a novel method for directly converting barium sulfate into barium metaphosphate by directly adopting barite as a raw material without a barium carbonate or barium hydroxide preparation stage by directly utilizing the thought of natural barite resources. The method is characterized in that ammonium dihydrogen phosphate and barite are mixed and calcined at a high temperature to produce barium metaphosphate. The whole method is simple, the production is convenient and quick, and the production cost of the barium metaphosphate is reduced. And no pollution to the environment.)

1. A method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate is characterized in that: the method comprises the steps of preparing barite and ammonium dihydrogen phosphate according to the mass ratio of 1: 2.0-1: 2.6, uniformly mixing the two raw materials, and calcining at the high temperature of 500-800 ℃ for 2.5-3.5h to obtain the product, namely barium metaphosphate.

2. The method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate according to claim 1, wherein: the preparation method comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.0, uniformly mixing the two materials, and calcining at the high temperature of 700 ℃ for 3.0h to obtain the product, namely barium metaphosphate.

3. The method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate according to claim 1 or 2, wherein: before the material preparation, barite and ammonium dihydrogen phosphate are ground and crushed.

Technical Field

The invention relates to a method for preparing barium metaphosphate, in particular to a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate.

Background

The barite is a non-metallic mineral with barium sulfate as a main component, the reserve of Chinese barite is the first world, the barite is the dominant mineral product in China, the barite mineral in Guizhou is good, the mineral resources are rich, the even barite reserve in Qiannan accounts for 8% of the whole province, and is far higher than 85% of BaSO in Guizhou province₄Average level of (d). But because most of the barite raw ore has low grade, the direct utilization channels are few, for example, the barite is mainly used for an oil and gas drilling weighting agent and accounts for about 85 percent of the total consumption; or as a filler in the paint industry. In addition, in the chemical field, barium carbonate, barium chloride, barium sulfate, barium nitrate, optical glass, ceramics, enamel, pesticides, organic resins, plastics, bleaches, and the like can be produced from barite by chemical processing. Because the barite is closely associated with other metal ores and non-metals to reduce the utilization value of the barite, the potential industrial value of the barite is not well developed and utilized.

Barium metaphosphate is a novel chemical, but the traditional production method for barium metaphosphate has three main production methods: firstly, calcining a mixture of barium hydrogen phosphate and barium carbonate at high temperature for 15 hours to prepare barium metaphosphate; secondly, reacting hydrogen peroxide with phosphoric acid to generate barium metaphosphate precipitate, and heating the precipitate to convert the barium metaphosphate precipitate into barium metaphosphate; thirdly, reacting barium hydroxide with phosphoric acid, and performing high-temperature spray drying and condensation in a centrifugal spray drying tower to obtain barium metaphosphate. The three methods have high production cost and complex production process, and the production process can cause environmental pollution and influence ecological environment.

Therefore, how to better improve the additional value of the barite mineral and better solve the demand of the current chemical industry on barium phosphate becomes a technical problem to be solved urgently.

Disclosure of Invention

The invention aims to provide a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate. The application provides a new method for directly converting barium sulfate into barium metaphosphate by directly adopting barite as a raw material without a barium carbonate or barium hydroxide preparation stage based on the idea of directly utilizing natural barite resources.

The technical scheme of the invention is as follows: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1: 2.0-1: 2.6, uniformly mixing the two materials, and calcining at the high temperature of 500-800 ℃ for 2.5-3.5 hours to obtain a product, namely the barium metaphosphate.

In the method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate, the barite and the ammonium dihydrogen phosphate are prepared according to the mass ratio of 1:2.0, and the barium metaphosphate is obtained by uniformly mixing the two raw materials and calcining the mixture at the high temperature of 700 ℃ for 3.0 h.

In the method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate, before preparing materials, barite and ammonium dihydrogen phosphate are ground and crushed.

The invention has the beneficial effects that: compared with the prior art, the invention directly utilizes the idea of natural barite resources, and provides a novel method for directly converting barium sulfate into barium metaphosphate by directly adopting barite as a raw material without a barium carbonate or barium hydroxide preparation stage. The method is characterized in that ammonium dihydrogen phosphate and barite are mixed and calcined at a high temperature to produce barium metaphosphate. The whole method is simple, the production is convenient and quick, and the production cost of the barium metaphosphate is reduced. And no pollution to the environment.

In order to convert barium sulfate in barite into barium phosphate or barium metaphosphate, a phosphorus-containing raw material is added. In consideration of the difficulty of raw material acquisition, disodium hydrogen phosphate, ammonium dihydrogen phosphate, anhydrous disodium hydrogen phosphate, anhydrous ammonium dihydrogen phosphate and reaction of phosphoric acid and barium sulfate are used in the initial research of the method, and the experimental results of barium sulfate and different phosphorus-containing raw materials show that barium sulfate, anhydrous disodium hydrogen phosphate, disodium hydrogen phosphate and anhydrous ammonium dihydrogen phosphate cannot react in the whole firing process. Only ammonium dihydrogen phosphate and phosphoric acid can generate double decomposition reaction with barium sulfate, because the reaction product can volatilize in the form of gas and escape from the system, so that the reaction is carried out in the positive reaction direction. However, phosphoric acid can generate a large amount of black smoke in the firing process and has pungent smell, a layer of black objects is arranged on the surface of a fired product, and finally barium sulfate and ammonium dihydrogen phosphate are selected as raw materials for the reaction preparation of barium metaphosphate in consideration of environmental pollution and purification process cost in industrial production.

In the calcining process, the material proportion, the temperature and the time all influence the product, so that the reaction conversion rate of barium sulfate and ammonium dihydrogen phosphate under the conditions of different proportions, calcining temperatures and calcining times is intensively studied by adopting a single-factor method. The mixture ratio is 1: 2-1: 2.6, the temperature is lower than 500 ℃, or higher than 800, the conversion effect is not good, the temperature is 500-800, 700 ℃ is a better calcining condition, the calcining time is more than 1 hour, and the barium metaphosphate can be efficiently prepared.

When the mixing and calcining proportion of the barium sulfate and the ammonium dihydrogen phosphate is 1:2.0, 700 ℃ and 3 hours, the product can be dissolved in a mixed solution of sodium hydroxide, hydrogen peroxide and hydrochloric acid by 99.5 percent, and the conversion rate of barium metaphosphate is proved to reach 99.5 percent.

Drawings

FIG. 1 is a graph showing barium sulfate, sodium dihydrogen phosphate, disodium hydrogen phosphate, and phosphoric acid (1: 1, 700 ℃ C., 1.5 hours) calcined;

FIG. 2 is a graph showing the detection of phosphoric acid and barium sulfate at different ratios under the calcination condition of 700 ℃;

FIG. 3 is ammonium dihydrogen phosphate and barium sulfate 1: 1. the graph is detected under the condition of calcining at 700 ℃ for 1.5 h;

FIG. 4 is a graph showing the examination of ammonium dihydrogen phosphate and barium sulfate at different ratios and calcination temperatures of 500 ℃.

Detailed Description

The invention is further illustrated by the following figures and examples, which are not to be construed as limiting the invention.

The following are examples of the present invention.

Example 1: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.0, uniformly mixing the two materials, and calcining at the high temperature of 500 ℃ for 3.0 hours to obtain a product, namely barium metaphosphate.

Example 2: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.0, uniformly mixing the two materials, and calcining at the high temperature of 600 ℃ for 2.5 hours to obtain a product, namely barium metaphosphate.

Example 3: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.0, uniformly mixing the two materials, and calcining at the high temperature of 700 ℃ for 2.5 hours to obtain a product, namely the barium metaphosphate.

Example 4: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.0, uniformly mixing the two materials, and calcining at the high temperature of 700 ℃ for 3.0h to obtain a product, namely barium metaphosphate.

Example 5: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.0, uniformly mixing the two materials, and calcining at 800 ℃ for 3.0h to obtain a product, namely barium metaphosphate.

Example 6: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.2, uniformly mixing the two materials, and calcining at the high temperature of 500 ℃ for 2.5 hours to obtain a product, namely barium metaphosphate.

Example 7: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.2, uniformly mixing the two materials, and calcining at the high temperature of 500 ℃ for 3.0h to obtain a product, namely barium metaphosphate.

Example 8: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.2, uniformly mixing the two materials, and calcining at the high temperature of 700 ℃ for 2.5 hours to obtain a product, namely the barium metaphosphate.

Example 9: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.2, uniformly mixing the two materials, and calcining at the high temperature of 700 ℃ for 3.0h to obtain a product, namely barium metaphosphate.

Example 10: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.4, uniformly mixing the two materials, and calcining at the high temperature of 600 ℃ for 3.0h to obtain a product, namely barium metaphosphate.

Example 11: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.4, uniformly mixing the two materials, and calcining at the high temperature of 700 ℃ for 3.0h to obtain a product, namely barium metaphosphate.

Example 12: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.4, uniformly mixing the two materials, and calcining at 800 ℃ for 3.0h to obtain a product, namely barium metaphosphate.

Example 13: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.6, uniformly mixing the two materials, and calcining at the high temperature of 600 ℃ for 3.0h to obtain a product, namely barium metaphosphate.

Example 14: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.6, uniformly mixing the two materials, and calcining at the high temperature of 700 ℃ for 2.5 hours to obtain a product, namely the barium metaphosphate.

Example 15: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.6, uniformly mixing the two materials, and calcining at the high temperature of 700 ℃ for 3.0h to obtain a product, namely barium metaphosphate.

Example 16: a method for preparing barium metaphosphate by decomposing barite with ammonium dihydrogen phosphate comprises the steps of preparing materials according to the mass ratio of barite to ammonium dihydrogen phosphate of 1:2.6, uniformly mixing the two materials, and calcining at 800 ℃ for 3.0h to obtain a product, namely barium metaphosphate.

Before the materials are prepared in the above embodiments, the barite and the ammonium dihydrogen phosphate are ground and crushed, so that the barite and the ammonium dihydrogen phosphate can fully react.

The method directly adopts barite as a raw material, and directly converts the barite into barium metaphosphate without a barium carbonate or barium hydroxide preparation stage. Therefore, before the method is put into industrial application, the process conditions of the novel method are firstly explored in a laboratory, and the influence of phosphorus-containing raw materials, calcination temperature, calcination time and the like on the reaction is mainly studied.

In order to convert barium sulfate in barite into barium phosphate or barium metaphosphate, a phosphorus-containing raw material is added. In consideration of the difficulty of raw material acquisition, disodium hydrogen phosphate, ammonium dihydrogen phosphate, anhydrous disodium hydrogen phosphate, anhydrous ammonium dihydrogen phosphate and reaction of phosphoric acid and barium sulfate are used in the initial research of the method, and the experimental results of barium sulfate and different phosphorus-containing raw materials show that barium sulfate, anhydrous disodium hydrogen phosphate, disodium hydrogen phosphate and anhydrous ammonium dihydrogen phosphate cannot react in the whole firing process. Only ammonium dihydrogen phosphate and phosphoric acid can generate double decomposition reaction with barium sulfate, because the reaction product can volatilize in the form of gas and escape from the system, so that the reaction is carried out in the positive reaction direction. However, phosphoric acid can generate a large amount of black smoke in the firing process and has pungent smell, a layer of black objects is arranged on the surface of a fired product, and finally barium sulfate and ammonium dihydrogen phosphate are selected as raw materials for the reaction preparation of barium metaphosphate in consideration of environmental pollution and purification process cost in industrial production.

Determination and characterization of the calcined product

Method for measuring conversion rate

In order to determine the content of barium metaphosphate in the calcined product, it was converted into barium orthophosphate by the reaction with a strong base in the presence of hydrogen peroxide, and the barium orthophosphate was soluble in an acid. Reacting alkali liquor with the calcined product, reacting with hydrochloric acid, and filtering to obtain insoluble substances, namely the reacted barite. And (4) carrying out suction filtration and drying on the reacted filter residue, weighing the filter residue after the temperature is up to room temperature, and calculating the conversion rate according to the mass difference between the front and the back. The method is adopted to measure the residual unreacted barium sulfate with different proportions, and the conversion rate is calculated, and the result is shown in table 1.

TABLE 1 influence of the matching ratio on the conversion

As can be seen from Table 1, the conversion rate increases with the proportion, and the calcined product is almost completely dissolved when the calcination time and the proportion reach the proper conditions.

Determination of calcination products at different temperatures

For the calcined product of the above experiment, the remaining unreacted barium sulfate was measured in the same manner and the conversion was calculated, and the results are shown in Table 2.

TABLE 2 calcination product dissolution of barium sulfate and ammonium dihydrogen phosphate at different calcination temperatures and the same ratio and calcination time

As can be seen from Table 2, when the temperature is 400-500 ℃, the dissolution rate of the calcined product tends to decrease, but when the temperature is 700-500 ℃, the dissolution rate tends to increase along with the increase of the temperature, and when the temperature is 800 ℃ after 700 ℃, the dissolution rate tends to decrease again, so that the dissolution rate of the calcined product reaches the highest value around 700 ℃.

Determination of calcination products at various times

For the calcined product of the above experiment, the remaining unreacted barium sulfate was measured in the same manner and the conversion was calculated, and the results are shown in Table 3.

TABLE 3 dissolution of the calcined barium sulfate and ammonium dihydrogen phosphate products at the same ratio and at different calcining temperatures and different calcining times

As shown in Table 3, the conversion experiment that the calcined product of barium sulfate and ammonium dihydrogen phosphate is dissolved with sodium hydroxide first and then with hydrogen peroxide and finally dissolved with hydrochloric acid shows that the dissolution rate of the calcined product increases with the ratio of barium sulfate to ammonium dihydrogen phosphate, increases with the increase of the calcining temperature and increases with the increase of the calcining time, and most of the dissolution rate increases.

X-ray powder diffraction analysis of the product

To further understand the conversion of barium sulfate to barium metaphosphate, particularly the phase change before and after the reaction, we selected a representative product for X-ray powder diffraction analysis. The XRD patterns are shown in attached figures 1-4, and the peak values and the sealing areas of the four figures of attached figures 1-4 are taken as the basis for judging that the product of the calcination of the barium sulfate and the ammonium dihydrogen phosphate is the barium metaphosphate. According to the diffraction peak pattern in the XRD pattern, the diffraction peak of barium sulfate is basically not seen in the product of mixed calcination of barium sulfate and ammonium dihydrogen phosphate, which indicates that the conversion of the reaction is complete.

The experimental results of barium sulfate and different phosphorus-containing raw materials show that barium sulfate can not react with anhydrous disodium hydrogen phosphate, disodium hydrogen phosphate and anhydrous sodium dihydrogen phosphate. Only ammonium dihydrogen phosphate and phosphoric acid can generate double decomposition reaction with barium sulfate, and the reaction product can volatilize in a gas form and escape from the system, so that the reaction is carried out in the positive reaction direction.

The calcination proportion, temperature and time can influence the product, the calcination proportion is too low or too high, the loss on ignition and the dissolution rate are not high, and the proportion is 1: 2-1: 2.6, the temperature is lower than 500 ℃, or higher than 800, the conversion effect is not good, the temperature is 500-800, 700 ℃ is a better calcining condition, the calcining time is more than 1 hour, and the barium metaphosphate can be efficiently prepared.

When the mixing and calcining proportion of the barium sulfate and the ammonium dihydrogen phosphate is 1: 20, the product with the temperature of 700 ℃ and the time of 3 hours can be dissolved in 99.5 percent of the mixed solution of sodium hydroxide, hydrogen peroxide and hydrochloric acid, and the conversion rate of barium metaphosphate is proved to be 99.5 percent.