Can anhydrous sodium sulfate be prepared by evaporation crystallization method? Today, I will briefly introduce how anhydrous sodium sulfate is prepared by evaporation crystallization.

一、無水硫酸鈉的應(yīng)用

1、 Application of anhydrous sodium sulfate

無水硫酸鈉又名元明粉，廣泛用于生產(chǎn)硫化鈉、水玻璃和群青等還可用于制造玻璃、造紙、洗滌﹒劑、肥皂、染料、合成纖維、制革、醫(yī)藥和陶瓷等行業(yè)，是一種重要的化工原料。

Anhydrous sodium sulfate, also known as Yuanming powder, is widely used in the production of sodium sulfide, water glass and ultramarine. It can also be used in the manufacturing of glass, paper, detergent, soap, dye, synthetic fiber, leather, medicine and ceramics. It is an important chemical raw material.

二、無水硫酸鈉的生產(chǎn)方法

2、 Production method of anhydrous sodium sulfate

常見的生產(chǎn)無水硫酸鈉的方法有芒硝脫水法、轉(zhuǎn)化法、副產(chǎn)法、鈣芒硝法等。芒硝脫水法又分為全溶蒸發(fā)脫水法、熱融脫水法以及熱融鹽析脫水法。

Common methods for producing anhydrous sodium sulfate include mirabilite dehydration method, conversion method, by-product method, calcium mirabilite method, etc. Mirabilite dehydration method can be divided into total solution evaporation dehydration method, hot melt dehydration method and hot melt salting out dehydration method.

三、無水硫酸鈉蒸發(fā)結(jié)晶設(shè)備選型

3、 Selection of evaporation crystallization equipment for anhydrous sodium sulfate

目前常見的無水硫酸鈉蒸發(fā)結(jié)晶設(shè)備，一般會采用DTB（導(dǎo)流筒—擋板）型結(jié)晶器并用真空蒸發(fā)結(jié)晶法直接從工業(yè)粗制芒硝中結(jié)晶出無水硫酸鈉。

At present, the common anhydrous sodium sulfate evaporation crystallization equipment generally uses DTB (draft tube baffle) crystallizer and uses vacuum evaporation crystallization method to directly crystallize anhydrous sodium sulfate from industrial crude mirabilite.

采用DTB型結(jié)晶器+真空蒸發(fā)結(jié)晶法，該方法具有流程短、設(shè)備少、投資小、產(chǎn)品粒度、純度易控制等優(yōu)點(diǎn)。

DTB crystallizer + vacuum evaporation crystallization method is adopted. This method has the advantages of short process, less equipment, small investment, easy control of product particle size and purity, etc.

DTB型結(jié)晶器的構(gòu)造如下：

The structure of DTB type crystallizer is as follows:

它的中部有一導(dǎo)流筒，在四周有一圓筒形擋板，在導(dǎo)流筒內(nèi)接近下端處有螺旋槳，以較低的轉(zhuǎn)速旋轉(zhuǎn)﹐懸浮液在螺旋槳的推動下，在筒內(nèi)上升至液體表層，然后轉(zhuǎn)向下方，沿導(dǎo)流筒與擋板之間的環(huán)行通道流至器底，重又被吸入導(dǎo)流筒的下端，如此往復(fù)循環(huán)，形成接近良好混合的條件．圓筒形擋板將結(jié)晶器分割為晶體生長區(qū)和澄清區(qū)，擋板與器壁間的環(huán)隙為澄清區(qū)，其攪拌的影響已經(jīng)消失。

There is a guide cylinder in the middle of the guide cylinder and a cylindrical baffle around it. There is a propeller near the lower end of the guide cylinder, which rotates at a lower speed. The suspension is pushed by the propeller, rises to the liquid surface layer in the cylinder, then turns downward, flows to the bottom of the device along the circular channel between the guide cylinder and the baffle, and is sucked into the lower end of the guide cylinder again. In this way, The cylindrical baffle divides the crystallizer into a crystal growth zone and a clarification zone. The annular gap between the baffle and the wall of the crystallizer is a clarification zone, and the influence of stirring has disappeared.

要使晶體得以從母液中沉降分離，只有過量的微晶可隨母液在澄清區(qū)的頂部排出器外，從而實(shí)現(xiàn)對微晶量的控制，結(jié)晶器的上部為氣液分離空間，用于防止霧沫夾帶，熱的濃物料加至導(dǎo)流筒的下方，晶漿由結(jié)晶器的底部排出.為了使所生產(chǎn)的晶體具有更窄的粒度分布，這種形式的結(jié)晶器在下部設(shè)有淘析腿。

In order to settle and separate the crystals from the mother liquor, only excess microcrystals can be discharged from the top of the clarifier along with the mother liquor, so as to control the amount of microcrystals. The upper part of the crystallizer is a gas-liquid separation space to prevent entrainment of mist. Hot concentrated materials are added to the lower part of the draft tube, and the crystal slurry is discharged from the bottom of the crystallizer In order to produce crystals with a narrower particle size distribution, this type of crystallizer is provided with elutriation legs at the lower part.

無水硫酸鈉可以采用蒸發(fā)結(jié)晶法制備是一種比較好的方式。

Anhydrous sodium sulfate can be prepared by evaporation crystallization method, which is a better way.