Introduction to smelting and classification of lead

01. Smelting of lead

Lead smelting raw materials are mainly lead sulfide concentrate and a small amount of block ore. There are two smelting methods of lead: fire method and wet method. At present, fire method is the main one in the world, and wet process is still in the experimental research stage. Lead smelting by fire process basically adopts sintering roasting-blast furnace smelting process, accounting for 85-90% of total lead production; Second is the reaction smelting method, its equipment can be chamber furnace, short kiln, electric furnace or vortex furnace; Precipitation smelting is rarely used. Lead is mainly refined by fire, followed by electrolysis, but electrolysis is not widely used in China due to customary reasons.

The mixed concentrate of lead and zinc sulfide which is difficult to separate is generally treated by closed blast furnace smelting process which produces lead and zinc simultaneously.

For extremely difficult separation of mixed oxide lead-zinc ore, after long-term research has formed a unique treatment methods in our country, which is lead and zinc oxide mixed ore enrichment of ore or its product, after sintering or briquetting in blast furnace melting, in order to get the crude lead and molten slag containing lead and zinc, further in fuming fuming furnace slag, zinc oxide products, electrolytic zinc and wet zinc smelting. In addition, the product of zinc oxide can also be obtained by direct fumigation in a rotary kiln.

02. Classification of lead

Classification of lead alloys

Lead alloys ARE mainly divided into corrosion resistant alloys, battery alloys, solder alloys, printing alloys, bearing alloys and die alloys according to their properties and uses.

Classification of lead ingot

Lead ingots are generally divided into small ingots and large ingots

The ingot is rectangular trapezoidal, with bundling grooves at the bottom and protruding ears at both ends. The single weight can be: 48kg±3kg, 42kg±2kg, 40kg±2kg, 24kg±1kg.

The large ingot is trapezoidal, with t-shaped convex block at the bottom, and a grasping groove on both sides. The single weight can be: 950 kg±50kg, 500 kg±25kg.

Quality standard for lead ingots

According to GB/T 469-2005, domestic lead ingot is divided into 5 grades according to chemical composition: Pb99.994, Pb99.990, Pb99.985, Pb99.970, Pb99.940.