Because of their low heat resistance fired plates crack after teeming of a single heat and become unsuitable for teeming of a second heat. To eliminate these disadvantages a method for unfired periclase plates with a phosphate binder has been developed. Powdered lignosulfonate is used as the organic plasticizer and inhibitor reducing the rate of interaction of the polyphosphate with MgO and CaO in the stage of preparation of the mixture and the hardening green compact in pressing. To increase the strength of the freshly pressed compact, caustic magnesite powder is also added.