The electrolysis process for the production of primary aluminum has been known for over a hundred years. In 1886, C. M. Hall and P. L. T. Héroult independently patented an electrowinning process, where aluminum oxide - alumina was dissolved in a molten cryolite. Although the basics of electrowinning process are already well researched, developments and optimizations are still underway.
For optimal process control it is important to conduct the electrolysis cells in a narrow temperature range. In the master’s thesis the problem of temperature control of the electrolysis cell, which comprises adding an aluminum fluoride, which is the main additive cryolite, which is the basic component of the electrolyte is presented. For a typical modern aluminum reduction cell an excess of aluminum fluoride between 10 -14 wt % AlF3 is required, since it decreases the melting point of the electrolyte to about 950 °C.
The purpose of the master's thesis is to examine the possibility of replacing aluminum fluoride from NORALF AS with the required minimum 89 wt.% AlF3, with an aluminum fluoride higher purity of PT PETROKIMIA GRESIK with a minimum requirement of 94.0 wt.% AlF3. As we indicated in the analysis of industrial research on electrolytic cells, the aluminum fluoride of NORALF AS does not differ significantly from the aluminum fluoride of the higher purity of the producer PET PETROKIMIA GRESIK, but the mass balance of consumption of AlF3 should also be included in further research.
The analysis of the laboratory conductivity study showed that the samples of the electrolyte with the aluminum fluoride additive of the manufacturer NORALF AS has higher conductivity than the samples, where the aluminum fluoride additive from manufacturer PT PETROKIMIA GRESIK was used.