阅读说明：本技术 一种无水氟化铝的生产方法 (Production method of anhydrous aluminum fluoride ) 是由 曹玉宽 于 2020-06-19 设计创作，主要内容包括：本发明公开了一种无水氟化铝的生产方法,包括如下步骤：S1、用萤石制备粗氟化氢气体；S2、将粗氟化氢气体冷凝得到氟化氢液体和废气；S3、氟化氢液体转入储槽中,加入氧化剂进行络合反应,然后转入精馏塔中进行精馏；S4、取精馏后的氟化氢蒸发成气体后与氢氧化铝反应制得无水氟化铝。本发明在氟化氢和氢氧化铝反应生产氟化铝之前,增设提纯工艺系统,充分利用萤石制取的氟化氢和其内含有的杂质在相同条件下沸点不同的特性,将氟化氢中的杂质予以除去获得高纯度的氟化氢；然后和氢氧化铝发生反应生产出更加符合市场质量标准要求的无水氟化铝高纯产品。(The invention discloses a production method of anhydrous aluminum fluoride, which comprises the following steps: s1, preparing crude hydrogen fluoride gas by fluorite; s2, condensing the crude hydrogen fluoride gas to obtain hydrogen fluoride liquid and waste gas; s3, transferring the hydrogen fluoride liquid into a storage tank, adding an oxidant to perform a complex reaction, and then transferring into a rectifying tower to perform rectification; s4, evaporating the rectified hydrogen fluoride into gas, and reacting the gas with aluminum hydroxide to obtain the anhydrous aluminum fluoride. Before the hydrogen fluoride and the aluminum hydroxide are reacted to produce the aluminum fluoride, a purification process system is additionally arranged, the characteristics that the hydrogen fluoride prepared from fluorite and impurities contained in the hydrogen fluoride have different boiling points under the same condition are fully utilized, and the impurities in the hydrogen fluoride are removed to obtain high-purity hydrogen fluoride; then the product reacts with aluminum hydroxide to produce the anhydrous aluminum fluoride high-purity product which better meets the requirements of market quality standards.)

1. A production method of anhydrous aluminum fluoride is characterized by comprising the following steps:

s1, preparing crude hydrogen fluoride gas by fluorite;

s2, condensing the crude hydrogen fluoride gas to obtain hydrogen fluoride liquid and waste gas;

s3, transferring the hydrogen fluoride liquid into a storage tank, adding an oxidant to perform a complex reaction, and then transferring into a rectifying tower to perform rectification;

s4, evaporating the rectified hydrogen fluoride into gas, and reacting the gas with aluminum hydroxide to obtain the anhydrous aluminum fluoride.

2. The method for purifying hydrogen fluoride according to claim 1, wherein the condensation temperature in S2 is 14 to 16 ℃.

3. The method of purifying hydrogen fluoride according to claim 1 or 2, wherein in S3, the temperature of the bottom of the rectifying column is 20 to 22 ℃, and the temperature of the top outlet of the rectifying column is 14 to 16 ℃.

4. The method for purifying hydrogen fluoride according to any one of claims 1 to 3, wherein the oxidizing agent is potassium permanganate in S3.

5. The method for purifying hydrogen fluoride according to any one of claims 1 to 4, wherein the weight ratio of the hydrogen fluoride liquid to the oxidizing agent in S3 is 1000:0.8 to 1.2.

6. The method for purifying hydrogen fluoride according to any one of claims 1 to 5, wherein the temperature of the complexation reaction in S3 is room temperature and the time is 20 to 28 hours.

7. The method of purifying hydrogen fluoride according to any one of claims 1 to 6, wherein the off gas is subjected to scrubbing absorption treatment in S2.

8. The method of purifying hydrogen fluoride according to any one of claims 1 to 7, wherein condensation is performed in a condenser in S2.

9. The method for purifying hydrogen fluoride according to any one of claims 1 to 8, wherein in S4, the rectified hydrogen fluoride is evaporated by an evaporator into a fluidized bed and reacted with aluminum hydroxide to produce anhydrous aluminum fluoride.

10. The method of purifying hydrogen fluoride according to any one of claims 1 to 9, wherein the reaction temperature in S4 is 550 to 650 ℃ and the reaction is carried out under negative pressure.

Technical Field

The invention relates to the technical field of aluminum fluoride preparation, in particular to a production method of anhydrous aluminum fluoride.

Background

With the development of electrolytic aluminum industry, the common dry-process aluminum fluoride can not meet the requirements of high-end aluminum industry, and the common dry-process aluminum fluoride puts forward the requirements of higher-standard and high-specification anhydrous aluminum fluoride quality standard. The high-standard and high-specification anhydrous aluminum fluoride has higher requirements on main components, has stricter standard requirements on impurity content, and provides stricter product requirements compared with the prior silicon and phosphorus, mainly expressed in the content requirements on heavy metal impurities and simultaneously provides nearly rigorous standards on ignition loss.

At present, the existing production technology cannot solve the influence of impurities contained in raw fluorite in the actual production process, and the impurities contained in the fluorite directly enter a final product through the existing process production line, so that the quality of the final product is influenced. The demand for the quality of aluminum fluoride products in the market is continuously increased, which presents a great challenge to the production enterprises.

Disclosure of Invention

Based on the technical problems existing in the background technology, the invention provides a production method of anhydrous aluminum fluoride, which is characterized in that a purification process system is additionally arranged before the hydrogen fluoride and aluminum hydroxide react to produce the aluminum fluoride, the characteristics of different boiling points of the hydrogen fluoride prepared from fluorite and impurities contained in the hydrogen fluoride under the same condition are fully utilized, the impurities in the hydrogen fluoride are removed, and meanwhile, the heavy metal in the hydrogen fluoride is removed through the action of an intermediate complex compound by combining the characteristic of heavy metal complex reaction, so that the high-purity hydrogen fluoride is obtained; then the existing aluminum fluoride production technology is adopted to react with aluminum hydroxide to produce an anhydrous aluminum fluoride high-purity product which meets the requirements of market quality standards better, so as to ensure the market demands.

The invention provides a production method of anhydrous aluminum fluoride, which comprises the following steps:

s1, preparing crude hydrogen fluoride gas by fluorite;

s2, condensing the crude hydrogen fluoride gas to obtain hydrogen fluoride liquid and waste gas;

s3, transferring the hydrogen fluoride liquid into a storage tank, adding an oxidant to perform a complex reaction, and then transferring into a rectifying tower to perform rectification;

s4, evaporating the rectified hydrogen fluoride into gas, and reacting the gas with aluminum hydroxide to obtain the anhydrous aluminum fluoride.

Preferably, in S2, the condensation temperature is 14-16 ℃.

Preferably, in S3, the temperature of the bottom of the rectifying tower is 20-22 ℃, and the temperature of the top outlet of the rectifying tower is 14-16 ℃.

The rectification process is a continuous process, and the time for rectifying the hydrofluoric acid in the rectification tower is 8-12 min.

Preferably, in S3, the oxidizing agent is potassium permanganate.

Preferably, in S3, the weight ratio of the hydrogen fluoride liquid to the oxidant is 1000: 0.8-1.2.

Preferably, in S3, the temperature of the complexation reaction is room temperature, and the time is 20-28 h.

Preferably, in S2, the exhaust gas is subjected to scrubbing absorption treatment.

The waste gas mainly contains silicon tetrafluoride, sulfur dioxide and the like, the environment pollution is avoided through washing and absorption treatment, and the fluosilicic acid by-product can be prepared through washing and absorption treatment.

Preferably, in S2, condensation is performed in a condenser.

Preferably, in S4, the rectified hydrogen fluoride is evaporated by an evaporator into a fluidized bed and reacted with aluminum hydroxide to produce anhydrous aluminum fluoride.

Preferably, in S4, the reaction temperature is 550 to 650 ℃, and the reaction is performed under a negative pressure.

The preparation of the crude hydrogen fluoride gas by using fluorite and the preparation of the anhydrous aluminum fluoride by reacting the hydrogen fluoride with the aluminum hydroxide are all conventional methods in the field.

Has the advantages that:

1. the gasification temperature of the hydrogen fluoride under normal pressure is lower, and is 19.5 ℃; firstly, condensing hydrogen fluoride gas into hydrogen fluoride liquid by using a condenser at 14-16 ℃, and enabling non-condensable waste gas (mainly gases such as silicon tetrafluoride, sulfur dioxide and the like) to enter a subsequent washing and absorbing system to prepare a fluosilicic acid byproduct in the system; hydrogen fluoride liquid enters a storage tank, and an oxidant and heavy metal contained in the hydrogen fluoride liquid are added to carry out a complex reaction; then the hydrogen fluoride enters a rectifying tower, heavy metal components are removed through the rectifying action, different temperatures are set for a tower kettle and the tower top, so that hydrogen fluoride presents different phase states in the tower, the temperature of the tower kettle is controlled to be 20-22 ℃, the hydrogen fluoride liquid can be evaporated to be in a gaseous state, heavy components in the hydrogen fluoride are further separated, the temperature of an outlet of the tower top is controlled to be 14-16 ℃, the hydrogen fluoride gas is condensed to be in a liquid state, and light components in the hydrogen fluoride are further separated; thereby greatly reducing the content of impurities (mainly silicon dioxide, phosphorus pentoxide, silicon tetrafluoride, sulfur dioxide, heavy metals and the like) and obtaining purer hydrogen fluoride, wherein the content of HF is more than 99.99 percent, and the content of impurity components is less than 0.01 percent;

2. in the whole purification process, the process temperature is 14-22 ℃, the temperature is moderate, the consumption of external heat sources and cold energy is low, the temperature is easy to control, and the requirement on equipment is low; the process of removing heavy metal by complex reaction can ensure the safe production only by providing less cold energy;

3. the purified hydrogen fluoride is volatilized into a gas state under the action of an external heat source of the evaporator, enters the existing fluidized bed and reacts with aluminum hydroxide, so that the whole reaction process is more thorough due to the high purity of the hydrogen fluoride gas, the effective HF component contained in the tail gas of the subsequent reaction is further reduced, and a good condition is created for the treatment of the subsequent tail gas; in the fluidized bed, hydrogen fluoride and aluminum hydroxide react at a high temperature of about 600 ℃, and heat released in the reaction process can provide heat for the subsequent reaction of new materials continuously, so that the whole reaction is normally carried out; the reaction is carried out in a negative pressure state, so that better safety production is ensured; the prepared anhydrous aluminum fluoride has higher content and lower impurity content.

Detailed Description

The technical solution of the present invention will be described in detail below with reference to specific examples.