Yaxin Yu

Thermo-electric field analysis on heat recovery aluminum reduction cell

The distribution of the electricity and the thermal field directly affects the stability, current efficiency and energy consumption of electrolysis cells. In this paper, by using finite element software ANSYS, the thermoelectric field of 2000 A heat recovery aluminum reduction cell model was built. Through the use of APDL, a parametric model was established and then the thermoelectric field was simulated. The results indicate that the model is accurate. On the basis of the established model, the thermoelectric field was further analyzed.

Research on electro-deposition of carbon from LiF-NaF-Na 2 CO 3 molten salt system

This paper studied electro-deposition of carbon from LiF-NaF-Na2CO3 molten salt system. By using a cyclic voltammetry technique, the electrochemical behavior on a tungsten wire was researched in 46.2wt.%LiF-49.8wt.%NaF-4wt.%Na2CO3 molten salt at 700 ºC, with two platinum wires used as a counter electrode and a reference electrode, respectively. The results show that carbon is reduced at the potential of −1.77V (vs. Pt, at a scan rate of 0.4V/s). The electro-deposition experiment of carbon was conducted in the same molten salt system in a see-through cell with a platinum wire and a nickel rod used as the anode and cathode, respectively. The cathode current density is 0.215A/cm2. During the electro-deposition course, evolving of a gas bubble from the anode was found. The Raman spectra analysis result shows that carbon is electrochemically deposited on the cathode.

Effect of the addition of ZrO 2 on the liquidus temperature of nNaF·AlF 3 -Al 2 O 3 molten salt system

In this paper, the liquidus temperature of nNaF·AlF<inf>3</inf>-Al<inf>2</inf>O<inf>3</inf>-ZrO<inf>2</inf> molten salt system was determined by thermal analysis method. The effects of molar ratio of NaF and AlF<inf>3</inf>, and ZrO<inf>2</inf> concentration on the liquidus temperature were studied by orthogonal regression experimental design method. The results show that the trends of liquidus temperatures of melts with five different molar ratios of NaF and AlF<inf>3</inf> are similar when ZrO<inf>2</inf> is added in the melts. The liquidus temperature at a certain molar ratio of NaF and AlF<inf>3</inf> is decreased effectively while ZrO<inf>2</inf> in a mass fraction range of 0∼2% is added. However, when the mass fraction of ZrO<inf>2</inf> is more than 2%, it has little effect. Therefore, it is thought that the optimum mass fraction of ZrO<inf>2</inf> addition is 2%. At last, the following equation is obtained by quadratic regression: T = 920.2–16n −1.36w<inf>(ZrO2)</inf>–1.8n • w<inf>(ZrO2)</inf> +15n² +0.58 w<inf>(ZrO2)</inf>², where T is the liquidus temperature; CR is molar ratio of NaF and AlF<inf>3</inf>; w<inf>(ZrO2)</inf> is the weight percentage of ZrO<inf>2</inf>.

Dissolution behavior of alumina in molten aluminum electrolyte

Alumina is the raw material in the aluminum electrolysis industry. The dissolution property of alumina is an important index. Generally, faster dissolution rate and higher solubility are required. In this paper, the dissolution behavior of six types of industrial alumina samples in cryolite-based melts was studied by using a quartz transparent cell. Furthermore, the influencing factors on the dissolution rate and solubility of alumina are analyzed and discussed. It is found that the dissolution phenomena of the fluorinated alumina is quite different from the other industrial alumina, and the dissolution rate and solubility of the fluorinated alumina are approximately twice that of the other industrial alumina.