Composite refining method for decreasing various impurity elements of brass alloy

Abstract

The invention discloses a composite refining method for decreasing various impurity elements of a brass alloy, and belongs to the technical field of purifying of regenerated copper melts. The method comprises the main processes of preparing raw materials, crushing, sorting, melting, purifying and casting, wherein yellow brass like wastes are selected from wasted scrap copper material and then is crushed into small blocks being less than 50mm; impurities are sorted by ways such as a way of magnetic separating; a mixture of calcium hexaboride, dolomite, calcium carbonate, calcium fluoride and sodium fluoride are added after the yellow brass is molten in an induction furnace; the temperature is maintained for 15-30min; slag is removed; and then an ingot is obtained by casting. According to the method, lead, tin, iron and nickel contents in the ingot brass copper are correspondingly decreased by 10-60%, so that the contents of impurity elements in the regenerated brass alloy can be controlled; and the problem of difficulty in control of the impurity elements in the scrap copper material can be solved.

Description

technical field [0001] The invention belongs to the technical field of purification of recycled copper melts, in particular to a method for reducing various impurity elements of brass alloys. [0002] technical background [0003] In recent years, China's copper consumption has approached 50% of the world's total consumption, but China's copper resources are only 4.35% of the world's. The huge contradiction between mining and consumption has stimulated the rapid development of the recycled copper industry, especially after 2000. China's recycled copper Copper has maintained an average annual growth rate of more than 15%. At present, the proportion of secondary copper in China is much higher than the world level, close to 40% in 2010, and has declined in recent years, but it has remained above 25%. [0004] China's secondary copper is highly dependent on imports. Before 2012, imported secondary copper accounted for about 90% of the total secondary copper, which has declined i...

AI Technical Summary

Problems solved by technology

In comparison, China’s miscellaneous copper scrap has not yet formulated a more detailed classification standard for miscellaneous copper scrap, and the classification degree and level are low, resulting in large fluctuations in the raw material composition of miscellaneous copper scrap in China and high content of impurity elements, which will have a negative impact on the smelting of miscellaneous copper scrap. , melt purification and casting process have a greater impact

[0005] In the regeneration process of scrap brass, Pb, Sn, Fe and Ni are the four most common elements, which have an important impact on the performance of recycled brass. When the content of impurity elements is too high, cracks, hard spots, Defects such as surface variations affect product quality

However, due to the high impurity content, complex composition and many limiting factors in scrap brass, the commonly used general refining agents cannot remove the impurity elements very effectively.