Method for predicting strength characteristics of briquettes obtained from dry fine-grained materials

Abstract

In this paper, the authors studied the mechanisms of interphase interactions in bulk media to further develop results obtained earlier in Z.I. Nekrasov Iron & Steel Institute of National Academy of Sciences of Ukraine that are aimed to establish analytical methods for predicting strength during pressing of fine fractions. That allowed formulating theoretical ideas about strength bonds formation in briquettes due to adhesion bond and proposing local models of adhesive processes for two basic schemes of interparticle interaction: “particle + particle”, “particle + liquid phase + particle”. Types of adhesion processes occurring simultaneously, as well as their nature and combination, were established for each local model. That provided substantiation for selecting factors that determine the occurrence of adhesion linkage and indicators that determine the strength intensity of the bond formation. Experimental studies were conducted in the laboratory facilities of Z.I. Nekrasov Iron & Steel Institute of National Academy of Sciences of Ukraine, which allowed assessing the nature and degree of influence of selected factors on the strength of compacts. According to the results of experimental studies for the scheme of interparticle interaction “particle + particle”, the dependence of compressive strength on the integral indicators of adhesive bond formation were established and described by analytical expressions taking into account the briquetting pressure. These dependencies formed the basis of the proposed method for predicting the strength of briquettes obtained from fine-grained materials with zero humidity in the technological range of briquetting pressure from 50 to 220 MPa. The proposed computational and analytical method allows determining with high accuracy the strength of briquettes. Thus, it can be successfully used to develop the briquettes and press equipment production technology. A further development of the proposed method might be an expansion of its features by predicting the strength of pressed samples, considering the introduction of liquid bonding additives into the charge.