Two methods of producing lead oxide powder

Lead oxide powder is the main raw material for producing active substance of lead battery plate. Lead oxide powder manufacturing is an important step in battery production. The performance of lead oxide powder directly affects the quality of paste and plate, and then affects the battery capacity and life.

Lead oxide powder is not pure lead particles in powder form, but biphase granular powder of metallic lead covered with a layer of lead oxide (PbO). The color of lead oxide powder is determined by the content of lead oxide in particles, particle structure and size, etc. With the increase of oxidation degree, the powder gradually changes from black to yellowish green or grayish yellow.

The oxidation of lead oxide powder is too low, not only affects the change of acid absorption and water absorption, but also affects the quality of the plate and the initial capacity of the battery; Excessive oxidation of lead powder may affect the capacity stability and cycle life of lead battery.

At present, there are two main ways to manufacture lead oxide powder:

One is the ball milling method, is developed by the Japanese Shimadzu Genzo in 1924, so the equipment is also called shimadzu type lead powder machine, it is actually a drum type ball mill. Its production process is as follows: the shot put into the ball mill, due to the friction lead oxide and lead is oxidized to oxygen in the air when the heat that makes the temperature inside the cylinder, as long as reasonably control the shot put, blast volume, under the certain humidity of the air, can produce qualified lead powder (white is actually lead oxide parcel metallic lead particles).

Ball mill grinding manufacturing principle of lead powder is: when the ball mill work, in the drum of the lead ball by centrifugal force, with a rotary belt to a certain height, and under the action of gravity, falling and impact cylinder in the lead ball; At the same time, with the cylinder rotation, so that the lead ball in the cylinder friction with each other (and wall friction), at this time, the mechanical energy of the lead powder machine rotation into heat energy. Under the action of friction, the metal particles on the surface of the displacement, in under the action of high temperature air with a certain humidity, the surface of lead especially displacement of crystal edges are more susceptible to oxidation of the oxygen in the air, at the same time gives off heat, owing to the nature of the lead oxide and pure lead, under the influence of friction and impact, falls off from the lead surface, further grinding fine, Get the lead powder you need.

Another method is air phase oxidation method, also known as Barton process, the use of lead oxide powder machine called Barton type lead powder machine, is first published by the United States patent. It is the temperature up to 450 degrees of liquid lead and air into the gas phase oxidation chamber, indoor has a high-speed rotating impeller, the molten lead liquid will be stirred into fine fog drops, so that the liquid lead and air fully contact, oxidation generation is mostly lead oxide lead powder. The lead oxide powder is then blown into the cyclone settler to cool down and settle the coarser lead powder, and finally separated from the fine powder in the bag filter. Brief introduction is: molten lead for “liquid” – extract – lead liquid to pressure – air mixer – oxidation chamber – oxidation – lead powder.

Post time: Sep-27-2021