| Aimed at the currently existing problems in aluminum production in our country, that is, the effect of purification fluxes is unsatisfied, the pollution of environment is serious and the cost is high, the high performance aluminum alloy A356 and Al-Mn-Mg alloy are selected as the main research object. Based on the previous research work and the advanced analyses and testing techniques, such as OM,SEM and testing of harmful gas in the air, the thermodynamics and kinetics condition of the purification flux are analyzed and the purification flux and the melt-treatment of eliminating inclusions, which have notable effect of eliminating inclusions and low environmental load are designed and developed. The main results as follows: 1. The thermodynamics and kinetics condition are determined directly by the physical and chemical nature of the fluxes, which have decisive effect for the purification of melt-treatment of aluminum .The experiment shows that the proportion of the ingredients of the flux RJ2 is appropriate, which is advantageous to the thermodynamics and kinetics condition of purification. Therefore, the flux RJ2 has higher dissolving inclusions rate than other conventional fluxes, which reaches to 7.4750%, and the melting point of conventional fluxes are almost over 650℃,while the flux RJ2 is only 578.0℃。 2. The orthogonal experiments show that the technology parameters in the melting process have notable influence for the purification effect: (1) The component of the flux has the largest influence of the amount of the inclusions in the aluminum alloy, which is the decisive reason of the effect of purification; (2) The melting temperature is lower, which is bad for the display of flux, while the solubility of hydrogen is increased and the oxidation loss of the component is intensified if the melting temperature is higher, so the melting temperature will be appropriate; (3) As the increasing of the content of the flux, the effected time between the flux and the inclusions is lengthened, and the amount of the inclusions is decreased apparently, but when the content of the flux is over a certain amount, the effect is to a level, so the content of the flux will be appropriate; (4) The best purification technology of A356 alloy (B1)is: the flux RJ2, the content of the flux 1% and the melting temperature 680℃; The best purification technology of Al-Mn-Mg alloy (T1)is: the flux RJ2, the content of the flux 3% and the melting temperature 700℃. 3. The better way of putting the flux is when the temperature of the original materials reaches to the melting point, which can improve the contact condition of aluminum and the flux effectively, and the effect time and the function of eliminating inclusions of the flux will be better. 4. The best purification technologies (B1 and T1) show the smallest influence extent in every appraisal targets of the environmental load in contrast with conventional fluxes treatment technologies: (1)The best eliminating inclusions rate and mechanical properties, therefore the purification effect is the best; (2) They have the highest aluminum alloy net gain rate, and the percent of aluminum alloy pellets in the dregs of total original materials M are obviously lower than all the conventional fluxes treatment technologies, and the loss of the original materials is the lest; (3) There is little smog and irritant gas during melting process, and the amount of harmful gas during B1 technology is proved that it is not only lower than conventional flux treatment technology (B3), but also largely lower than national standard value. 5. The result of the computation of the environmental load appraisal during fluxes treatment technologies of A356 and Al-Mn-Mg alloy further show that: (1) Considering the extent of harmful gas, the total environmental influence factor of B1 and T1 are 1.20 and 1.35, which are obviously lower than conventional fluxes treatment technologies; (2) And the total environmental influence factor of the conventional flux treatment technology (B3) is 4.13, while the best flux melt-treatment technology (B1) is only 2.07 when adding the data of harmful gas to the computation. It is fully proved that the best flux treatment technology has the best purification effect, the lest resources consumption and the lowest environment pollution, therefore, it is of the lowest environmental load.
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