Potassium hydroxide is a kind of strong alkali, which is often used as chemical raw materials. However, if the main content of the main products fails to meet the requirements, it will also affect the subsequent use effect. How to solve it when the main content of the products is low? Let's take a look.

主含量是指成品中KOH的质量分数，这是确定产品质量主要的参数之一，一般要求含量大于90%。这个过程中控制好碱液的温度是关键。1.148%碱液浓度在经过一效、二效蒸发器蒸发只有，碱液浓度需要达到或大于48%，为后面进行的工序质量合格做好准备。

The main content refers to the mass fraction of KOH in the finished product, which is one of the main parameters to determine the product quality. Generally, the content is required to be greater than 90%. In this process, the key is to control the temperature of alkali liquor. 1.148% of the alkali liquor concentration needs to reach or exceed 48% after being evaporated by the first effect evaporator and the second effect evaporator, so as to prepare for the quality qualification of the subsequent processes.

这个过程主要是通过蒸气冷凝产生的热量用来蒸发碱液中的水分从而提高浓度，因此需要能够保证蒸气的压力和温度达到相应的要求：真空状态下可以降低碱液沸点，所以为了节约能源和提升效率，蒸发器中的真空度要尽量保持一个比较高的状态。二效蒸发器碱液真空度处于0.085~0.094MPa，温度在75~85摄氏度之间，效果是比较好的。

This process mainly uses the heat generated by steam condensation to evaporate the water in the alkali liquor, so as to improve the concentration. Therefore, it is necessary to ensure that the pressure and temperature of the steam meet the corresponding requirements: the boiling point of the alkali liquor can be reduced in the vacuum state. Therefore, in order to save energy and improve efficiency, the vacuum degree in the evaporator should be kept as high as possible. The vacuum degree of alkali liquor in the two-effect evaporator is 0.085 ~ 0.094mpa, and the temperature is between 75 ~ 85 ℃.

1、提高高压蒸气的压力和温度

1. Increase the pressure and temperature of high-pressure steam

升膜蒸发器以高压蒸气为加热介质，可以继续提高碱液的浓度，氢氧化钾碱液温度一般在190~210摄氏度之间比较适宜。

The rising film evaporator takes high-pressure steam as the heating medium, which can continue to improve the concentration of alkali liquor. The temperature of potassium hydroxide alkali liquor is generally between 190 ~ 210 ℃.

2、氢气燃烧炉及熔盐系统

2. Hydrogen combustion furnace and molten salt system

浓缩制片过程需要使用熔融盐HTS为加热介质，而加热BTS是使用氢气燃烧炉来提供热源的。燃烧炉提供的热量要保证稳定，这样才能确保熔盐温度和流量的稳定，才能生成足够量的稳定热量来加热碱液，使经过浓缩器后的碱液温度达到标准要求，一般在380-400摄氏度之间。

Molten salt HTS is used as the heating medium in the concentration and production process, and hydrogen combustion furnace is used to provide heat source for heating BTS. The heat provided by the combustion furnace shall be stable, so as to ensure the stability of molten salt temperature and flow, generate sufficient stable heat to heat the alkali liquor, and make the alkali liquor temperature after passing through the concentrator meet the standard requirements, generally between 380-400 ℃.

3、保持系统密闭

3. Keep the system closed

为了避免碱液温度降低和发生潮解，降低其中的K0H含量，碱液在从浓缩器片碱机的流动过程中需要尽量保持密闭状态，避免和空气进行接触。

In order to avoid the decrease of alkali liquor temperature and deliquescence and reduce the k0h content, the alkali liquor needs to be kept in a closed state as far as possible during the flow from the concentrator to the flake alkali machine to avoid contact with air.

上面介绍的四种就是氢氧化钾主含量低的解决方法，通过上面的方法处理之后可以有用的提高产品的纯度。

The four methods described above are the solutions to the low main content of potassium hydroxide. After treatment by the above methods, the purity of the product can be effectively improved.