Analiza dodatka aluminijevega fluorida višje čistosti na obratovanje elektrolizne celice

Urlep, Peter (avtor), Medved, Jožef (mentor)

Elektrolizni postopek pridobivanja primarnega aluminija je znan že več kot sto let. Leta 1886 sta C. M. Hall in P. L. T. Héroult neodvisno drug od drugega patentirala elektrolizni proces, kjer sta aluminijev oksid – glinico, raztopila v staljenem kriolitu. Čeprav so osnove elektroliznega procesa že zelo raziskane, še vedno poteka razvoj in optimizacija. Za optimalno vodenje procesa je pomembno vodenje elektroliznih celic v ozkem temperaturnem območju. V magistrskem delu je predstavljena problematika temperaturne regulacije elektroliznih celic, ki obsega dodajanje aluminijevega fluorida, ki je glavni dodatek kriolitu, ta pa je osnovna sestavina elektrolita. Pri sodobnih celicah je zahtevan prebitek aluminijevega fluorida med 10–14 mas.%, saj ta znižuje tališče elektrolita na okrog 950 °C. Namen tega magistrskega dela je bil preučiti možnost zamenjave aluminijevega fluorida proizvajalca NORALF AS z zahtevanim minimalnim deležem 89,0 mas.% AlF3, z aluminijevim fluoridom višje čistosti proizvajalca PT PETROKIMIA GRESIK z zahtevanim minimalnim deležem 94,0 mas.% AlF3. Kot je pokazala analiza industrijske raziskave, se po primerjanih parametrih aluminijev fluorid proizvajalca NORALF AS ne razlikuje bistveno od aluminijevega fluorida višje čistosti proizvajalca PT PETROKIMIA GRESIK, vendar bi morali v nadaljnje raziskave vključiti tudi masno bilanco porabe AlF3. Analiza laboratorijske raziskave električne prevodnosti pa je pokazala, da so vzorci elektrolita s prebitkom aluminijevega fluorida proizvajalca NORALF AS pokazali višje prevodnosti od vzorcev, kjer se je kot dodatek uporabil aluminijev fluorid proizvajalca PT PETROKIMIA GRESIK.

• Jezik: Slovenski jezik
• Ključne besede: aluminij, elektrolizna redukcija, elektrolit, prebitek aluminijevega fluorida, električna prevodnost elektrolita
• Vrsta gradiva: Magistrsko delo/naloga
• Organizacija: NTF - Naravoslovnotehniška fakulteta
• Leto izida: 2018
• PID: 20.500.12556/RUL-101674
• COBISS.SI-ID: 1735263
• Datum objave v RUL: 24.06.2018

URLEP, Peter, 2018, Analiza dodatka aluminijevega fluorida višje čistosti na obratovanje elektrolizne celice [na spletu]. Magistrsko delo. [Dostopano 9 april 2025]. Pridobljeno s: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=slv&id=101674

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Analysis of high purity aluminium fluoride addition on electrolytic cell operation

Izvleček

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.

• Ključne besede: aluminium, aluminium electrolysis, electrolyte, excess aluminum fluoride, electrical conductivity of electrolyte