Investigation of the sintering process productivity factors

The process of sintering is characterized by the circulation load - the return, which is both a production intensifier and a production fault. The return mode influences upon productivity of a sintering plant and the quality of the sinter. In production conditions the output of the return is self-balanced because of the product’s strength and the way of sinter cake processing. So it is required to try to reach balanced return in order to get objective results in laboratory conditions. Various factors of the sintering process productivity determined from wet charge, from charge with return, from finished sinter cake from standard stabilized sinter cake under closed cycle of return were analyzed in this article. In laboratory conditions a comparative evaluation of the sintering process productivity by raw charge and finished sinter cake output under a closed balanced cycle of return is most objective. Evaluation of productivity without any regard to the amount of the return in charge materials leads to biased results of investigations. A stabilized balance of return is supposed to take place under production conditions. The existing method of a sintering plant productivity evaluation is based on the shipped finished sinter cake output, without consideration for the quantity of the fine fraction, removed before charging into blast furnaces (secondary return), which is also added into sinter charge. Hence, a comparative evaluation of specific productivity of the sintering process must be made with due regard of the aggregate output of return or the strength of the sinter cake. Evaluation of specific productivity by stabilized sinter cake makes it possible to predict the output of finished sinter cake of high strength. An intensifying action upon the sintering process also depends upon the size of the return. In further investigations it is necessary to analyze the possibilities of controlling the return mode by means of preliminary granulation of its small fractions