Production process of potassium hydroxide by mercury electrolysis

In the chemical industry, there are three common production methods of potassium hydroxide, i.e., diaphragm method, mercury electrolysis method and ion-exchange membrane electrolysis method. When we choose mercury electrolysis method for production, the risk is relatively high, because Mercury is a heavy metal, which has a great toxicity. When we operate it, we must correctly regulate the operation. The following section will introduce the production process of potassium hydroxide by mercury electrolysis, as follows.

(1) Purification of potassium chloride solution:

The raw material potassium chloride is dissolved in the salt bath, potassium carbide is added, and barium chloride is used to remove impurities such as calcium, magnesium, and sulfate, and then enters the clarification tank. The clear solution overflows. The slightly suspended substance is filtered out by the sand filter and sent to the neutralization tank, acidified with hydrochloric acid, and then flows into the refined saltwater storage tank. The refined salt water is pumped to the brine high-level tank by the brine preheater and then flows into the mercury electricity Sloughing. Clear the salt mud at the bottom of the tank, then filter and recycle the salt water in it, and then drain the mud.

(2) Electrolysis:

Mercury electrolyzer is divided into two parts: electrolysis chamber and pump chamber. In the electrolysis chamber, graphite or metal is used as the positive end and mercury as the negative end. The chlorine produced after power on is sent to the chlorine drying process, and the potassium produced by electrolysis is pumped into the pump chamber. Most of the unreacted potassium chloride is treated as light brine and returned to brine process. In the pump chamber, the potassium pump reacts with the end water to form potassium hydroxide solution and flows into the electrolyte storage tank. The hydrogen generated by the pump chamber is sent to the hydrogen delivery station.

(3) Solid base:

The alkali solution containing 45-50% KOH produced from the dissolving pump room of mercury electrolytic cell is made into solid alkali by boiling alkali or into products by making machine-made slices.

The mercury electrolysis method described above can generally produce two forms of potassium hydroxide products, liquid alkali, and solid alkali. Both can be used and sold, and the benefits will be higher, so now it has also been more frequently used. For the selection of different production methods, we can comprehensively consider the quality of finished products, production costs, equipment costs and other aspects, and hope you can understand.