ATMOSPHERE CONTROLLED ROLLER HEARTH KILN FOR HIGH-PERFORMANCE MN-ZN FERRITES

A new roller hearth kiln(RHK) has been developed, which satisfies not only the highest quality of Mn-Zn ferrites, but also large quantity oi production. Using the RHK (the length is 50m), the total sintering ti me is reduced to less than 11 hours, that is shorter than the half of the case pi pusher kiln. Then the productive capacity of the RHK achie ved 100 ton per month. Moreover, the control of oxygen content during sintering and the subsequently cooling is performed precisely, so that two different types of Mn-Zn ferrite, i.e. high-permeability and low power loss materials, can be sintered simultaneously in the RHK. The e lectromagnetic properties oi these materials reach to the highest leve l in mass production. This paper describes the basic structure and the characteristics of the new RHK: and shows the magnetic properties of Mn-Zn ferrites which are sintered by the RHK.