Process and equipment for upward-drawing continuous casting
This article introduces the process characteristics and equipment of upward-drawing continuous casting machine. In order to further develop the market and enhance the competitiveness of domestic up-drawing equipment in international trade, it is necessary to continuously improve the upward-drawing process equipment. At the same time, this move can further open up the application of upward-drawing in other industrial fields.
Overview With the vigorous development of the electrical industry, the quality requirements for wire and cable products have also increased. Upward-drawing equipment needs to use more high-purity copper with less impurity content and low oxygen content. The characteristics of high-purity copper are high Electrical conductivity, high density, excellent plasticity and good fatigue strength.
At present, the methods for producing high-purity copper commonly used in the world include continuous casting and rolling of copper, dipforming and upward-drawing (UP-Casting). Compared with the continuous casting and rolling and dip coating methods, the upward -drawing method is characterized by:
1. Since the drawing and rolling process is not continuous, the drawing and rolling process is performed at normal temperature, no gas protection is required, and the copper material will not be oxidized. Therefore, the equipment investment is small and the plant layout is flexible.
2. The single machine output has a wide range of changes, and the annual output can be from several hundred tons to several tens of thousands of tons. Manufacturers of different sizes can choose different types of upward-drawing units. In addition, because the continuous casting machine is multi-headed, the production volume per unit time can be easily changed by changing the casting specifications (rod diameter), so its output can be determined according to the supply of raw materials and product demand, which is convenient Organize production and save energy.
3. You only need to change the mold and change the shape of the graphite mold, you can produce special-shaped copper materials such as copper pipes, copper bars, etc., and you can produce different specifications and varieties of copper materials on the same machine, which is flexible and can be said to be upward -drawing features.
4. If a split furnace is used, that is, melting and thermal insulation are performed in two induction furnaces, it is relatively easy to achieve upward-drawing production of alloy copper.
2. Principle of process The basic feature of the upward-drawing continuous casting copper rod is “oxygen-free”, that is, the oxygen content is below 10ppm. During the entire process of electrolytic copper melting, copper liquid transfer, and crystallization, wood charcoal is used to restore the source. And flake graphite cover, oxygen barrier and other measures. Oxygen exists in the form of copper oxide (CuO) and cuprous oxide (CuO2) in the molten copper solution. Wood carbon (C) reacts with it at high temperatures to deoxidize it to less than 10 ppm oxygen. The reaction equation is as follows:
CuO + CuO2 + C → Cu + CuO + CO → 2Cu + CO2 ↑ The CO protective atmosphere generated during the reaction and the oxygen barrier effect of the flake graphite make the copper liquid transfer from the melting chamber to the heat preservation chamber and the crystallization process. The liquid is no longer oxidized.
Post time: Jan-20-2020