The manufacturing process of lead anode plates for copper refining is sophisticated, involving raw material smelting, casting, rolling, machining, surface treatment, and other links, with strict control over each process to ensure product quality. The mainstream manufacturing process is mainly divided into the following key steps:
First, raw material preparation and smelting. High-purity lead ingots (purity ≥99.994%) are used as the base material, and alloying elements such as silver, tin, bismuth, and calcium are added in a certain proportion to improve the corrosion resistance and mechanical strength of the anode plate. The smelting is carried out in an intermediate frequency furnace, with the temperature controlled at around 500℃; after the lead is completely melted, the preheated intermediate alloy is added in sequence, and mechanical stirring is performed for 30 minutes to ensure uniform composition. A grain refiner (such as Al-5Ti-1B) is added to refine the grain structure and reduce internal defects.
Second, casting forming. The vertical casting method is adopted, which helps the oxides and slag to float upward quickly, avoiding the generation of bubbles, pores, inclusions, and cold shuts. The casting mold is precisely designed to ensure the dimensional accuracy of the anode plate blank, and the casting speed and cooling rate are strictly controlled to prevent deformation and cracks of the blank.
Third, rolling and machining. The cast anode blank is subjected to multiple cold rolling and calendering processes to improve the mechanical properties of the alloy, make the internal grain structure more dense and uniform, and enhance the compressive strength and corrosion resistance. After rolling, precision machining is performed, including edge deburring, chamfering, drilling of diversion holes, and processing of conductive lugs. The diversion holes on the plate surface help the uniform flow of electrolyte, reduce concentration polarization, and improve the quality of cathode copper crystallization.
Finally, surface treatment and inspection. The surface of the processed lead anode plate is cleaned and passivated to form a uniform passive film, further enhancing corrosion resistance. Strict quality inspection is carried out on the finished product, including dimensional inspection, mechanical performance test, conductivity test, and corrosion resistance test, to ensure that the product meets the industry standards and user requirements.
