Influences of different degassing processes on refining effect and properties of 4004 Al alloy

In order to improve the plasticity of 4004 AI alloy and subsequently the productivity of 4004 AI foil, the research studied in detail the influence of the rotary impeller degassing process on the refining effect of 4004 AI alloy, in which the impacts of four major parameters： gas flow, rotational speed, refining time, and stewing time, on degassing rate of 4004 AI alloy was systematically studied by using an orthogonal experiment methodology. Results show that the rotational speed has the greatest impact on the degassing of 4004 AI alloy, followed by gas flow and refining time; stewing time has the least impact. The optimum purification parameters obtained by current orthogonal analysis were： rotor speed of 500 r.min1, inert gas flow of 0.4 mL.h-1, refining time of 15 min, and stewing time of 6 min. Degassing rate using the optimum parameters reaches 68%. In addition~ the comparison experiments among C2CI6 refining, rotary impeller degassing, and combined treatment of C2CI6 refining and rotary impeller degassing for 4004 AI alloy were performed. The experimental data indicated that the combined treatment of C2CI6 refining and rotary impeller degassing has the best degassing effect. Degassing rate of C2CI6 refining, rotary impeller degassing and combined refining treatment is 39%, 69.1% and 76.9%, respectively. The mechanical properties of the specimen refined by rotary impeller degassing were higher than those by C2CI6 refining, but lower than those by combined refining treatment.

A Straightforward Mathematical Model of Hot Metal Desulphurization

A straightforward kinetic model for the hot metal desulphurization process is presented. The model contains some of the most important parameters and variables that govern the process. The inputs, outputs and parameters of a desulphurization program employed at industry are discussed. The model is able to cope with different injection policies of desulphurizers such as mono- injection, co-injection or multi-injection. When compared to the rotary impeller method, results of this model shows that the weight of lime consumed in the lance injection method is lesser than that consumed in the rotary impeller method for the same conditions of the hot metal charge.