Manufacturing Potassium Carbonate in Bittern Factory

Abstract

We are investigating the method of manufacturing potassium carbonate from Engel salt by means of heat decomposition. The outline of this method of manufacturing fairly resembles the Engel-precht method. The chemical fundamental equation of Engel-precht method is as follows:
1. 2KCl+3 (MgCO3·4H₂O) +CO₂=2KHCO₃·4H₂O+MgCl₂.
2. 2 (KHCO₃·MgCO₃·4H₂O) =K₂CO₃+2MgCO₃·9H₂O+CO₂.
This well-known classical Enge1-precht method has been renovated and modified so as to be suitable and adoptable in a bittern factory. The points of innovation over the Engel-precht method are:
To use magnesium hydroxide, and to use the concentrated gas of CO₂ in place of waste dilute combustion gas.
The first step of the experiment is the design of the equilibrium diagram on oceanic salts.
In order to make, Na, K₂, Mg, Cl₂, HCO₃, each compartment change freely and perfectly, on condition in pretence of CO₂ gas, the author felt it necessary to make use of the diagram of ternary prism system. The author has drawn diagrams on ternary prism system. By way of graphical calculation, the distribution of the amount of materials, the yield of potassium, and the water equivalent have been determined. The next step of the experiment is the beaker test using the pure liquid CO₂ and magnesium hydroxide in potassium chloride solution. The data aquired in the laboratory has been applied to the actual production process on the same scale by using waste combustion gas.
The last step of the experiment is intermediate industrial experiment. This experiment of manufacturing Engel salt has been the most important aim of the whole attempt of the investigation.
The chemical composition of Engel salt and yield of potassium carbonate are as follows:
Engel salt% K Mg Cl SO₄ K yield
15.8 9.5 1.4 0.03 48.3
potassium carbonate %
K₂CO₃ KCl KHCO₃ K₂O K yield % from Engel salt
86.5 0.1 2.2 60.0 75.0
The result of the experiment has been nearly satisfactory.