Scientific and technical support for the devel-opment of sinter plant no. 5 of PJSC MMK

Abstract

The design characteristics of the sinter plant No. 5 of PJSC MMK, commissioned in 2019, are presented. The results of studies of the processes of homogenization, mixing, moistening and pelletizing of the burden, its burdening on the sintering machine, ignition, sintering and cooling of the sinter cake are presented. The erroneousness of the design solutions for installing the pelletizing drum at the zero level and the charge bunker with a volume of 60 m3 in the sintering body without an intermediate bunker is shown. Technical solutions are presented to prevent a discrete charge descent of the charge from the drum feeder of the loading unit and to form the profile of the charge layer on the sintering machine, which increases the uniformity of the process of its sintering along the width of the pallets. The operation of a multi-roll charge stacker, first used at sinter plants in the CIS, was studied. Industrial experiments were carried out on sintering a conditionally “dense” and loosened by a special device batch layer, the advantage of the latter in terms of the speed of the sintering process was established. A technical solution has been developed and accepted for implementation to reduce the length of the hearth by 40%, which will increase the sintering area of the sintering machine by 3%. The operation of the energy-consuming exhaust gas recirculation system based on their selection from eight vacuum chambers of the sinter machine out of twenty with the installation of a smoke exhauster with a drive capacity of 3.1 MW and gas cleaning from dust was stopped. Vacuum chambers of the recirculation system are connected to two parallel collectors of the sintering machine; an analysis of the impact of these measures on the operation of the sintering machines has been carried out. The possibility of using gas recirculation with the installation of a smoke exhauster with a drive power of 400 kW without additional purification of gases from dust is shown. In the future, it is proposed to increase the open section of the collectors by making them from three sections of different sections. It was found that the area of linear coolers was overestimated due to the use of “direct” loading of sinter on them, in which the cooling of the material is limited by its large lumps located in the upper part of the layer. A sinter back loading system was proposed and implemented in the project, which allows to reduce the cooling area by 30% (turn off two of the six blowers), it was decided to implement it. As a result of development of AF-5, for the first time in the practice of sintering plants in the CIS, the height of sintered charge layer of 700 mm was established. The specific productivity of sintering machines during the sintering of the charge based on the Sokolovsko-Sarbaisky concentrate was achieved, equal to 1.10 t/(m2•h); the cold strength of the sinter according to GOST 15137–77 for impact is on average 82.5%, for abrasion ‒ 4.5%.