Studying the mechanical properties of iron ore concentrate briquettes

This paper studies the properties of metallurgical briquettes of iron ore concentrate with coke screenings and liquid glass as a binder. The briquettes are produced by one-sided pressing in a closed die mounted on the plates of a vertical press with a force of 100 kN. The studies were carried out in the laboratory of Spidermash LLC. The following properties of briquettes were determined: density, impact strength and compressive strength (for green and dry briquettes). The functional dependences of the mechanical properties on 4 parameters are plotted, namely on charge mixture composition (the content of iron ore concentrate and coke), binder (liquid glass) percentage in the mixture, moisture content in the mixture, and charge mixture compacting pressure. The obtained experimental data are approximated with the use of a multiplicative model, with the application of the least squares method. Various analytical models for describing the behavior of the material to be briquetted are studied. It is concluded that the multiplicative model provides a more adequate description of the mechanical properties. The quality of the multiple regression model is assessed by the adjusted coefficient of determination. The significance of the regression equation is evaluated by the Fisher criterion, and the significance of the regression coefficients is evaluated according to Student. The mechanical properties of briquettes from iron ore concentrate with coke screenings, presented in the form of analytical dependencies, are necessary to assess the strength of the briquettes when designing the briquetting process. For example, it is necessary to take into account the change in yield during briquette transportation after briquetting. These dependences are also necessary for formulating and solving problems of pressing/briquetting of finely dispersed materials, including iron ore concentrate with coke screenings.