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、无水硫酸钠的应用

1、 Application of anhydrous sodium sulfate

无水硫酸钠又名元明粉，广泛用于生产硫化钠、水玻璃和群青等还可用于制造玻璃、造纸、洗涤﹒剂、肥皂、染料、合成纤维、制革、医药和陶瓷等行业，是一种重要的化工原料。

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、无水硫酸钠的生产方法

2、 Production method of anhydrous sodium sulfate

常见的生产无水硫酸钠的方法有芒硝脱水法、转化法、副产法、钙芒硝法等。芒硝脱水法又分为全溶蒸发脱水法、热融脱水法以及热融盐析脱水法。

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、无水硫酸钠蒸发结晶设备选型

3、 Selection of evaporation crystallization equipment for anhydrous sodium sulfate

目前常见的无水硫酸钠蒸发结晶设备，一般会采用DTB（导流筒—挡板）型结晶器并用真空蒸发结晶法直接从工业粗制芒硝中结晶出无水硫酸钠。

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型结晶器+真空蒸发结晶法，该方法具有流程短、设备少、投资小、产品粒度、纯度易控制等优点。

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型结晶器的构造如下：

The structure of DTB type crystallizer is as follows:

它的中部有一导流筒，在四周有一圆筒形挡板，在导流筒内接近下端处有螺旋桨，以较低的转速旋转﹐悬浮液在螺旋桨的推动下，在筒内上升至液体表层，然后转向下方，沿导流筒与挡板之间的环行通道流至器底，重又被吸入导流筒的下端，如此往复循环，形成接近良好混合的条件．圆筒形挡板将结晶器分割为晶体生长区和澄清区，挡板与器壁间的环隙为澄清区，其搅拌的影响已经消失。

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.

要使晶体得以从母液中沉降分离，只有过量的微晶可随母液在澄清区的顶部排出器外，从而实现对微晶量的控制，结晶器的上部为气液分离空间，用于防止雾沫夹带，热的浓物料加至导流筒的下方，晶浆由结晶器的底部排出.为了使所生产的晶体具有更窄的粒度分布，这种形式的结晶器在下部设有淘析腿。

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.

无水硫酸钠可以采用蒸发结晶法制备是一种比较好的方式。

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