ABSTRACT
The effluent streams from the capacitor manufacturing processes contain ceramic particulate and dissolved lead, nickel, and zinc at quantities above the allowable discharge limits. The ceramic particulate contains various metals such as barium, lead, and magnesium, and due to its sub-micron size, it passes through a filter whose pore diameter is 0.45 micron. As a result, ceramic particulate system metals are subject to Environmental Protection Agency (EPA) regulations as dissolved metals. Two Kyocera plants manufacture multilayer ceramic chip capacitors, and their effluent streams are successfully treated to Japanese standards. Kyocera top management in Japan wanted to transfer the Japanese waste treatment process to its US subsidiary with necessary modifications. Wastewater treatment process control consists of regulating the feed of lime slurry, dilute sulfuric acid, ferric chloride, and polymer in response to variations in pH and wastewater flow at various points in the process.
