ABSTRACT
The spontaneous combustion of the sulfur concentrate is the main hazard faced in ore storage bins. To understand the thermodynamic characteristics of spontaneous combustion of the sulfur concentrate and test whether the kinetic compensation effects are present in the spontaneous combustion process of the sulfur concentrate, typical sulfur concentrate samples were selected as the research object, and thermogravimetric experiments were carried out under an air atmosphere at heating rates of 5, 10, and 15 K/min. On this basis, the contributions of different reaction models to the mass change during the spontaneous combustion of the sulfur concentrate, as well as the thermodynamic model and kinetic compensation effect, are analyzed. The results show that solid-phase combustion contributes the most to mass loss among different mechanisms of the reaction between the sulfur concentrate and oxygen. The contributions of reaction models to mass loss are affected by the different heating rates, and the contribution of solid-phase combustion to mass loss increases with increasing heating rates. The Malek method is used to obtain the kinetic model of the spontaneous combustion of the sulfur concentrate, and its mechanism function changes from a chemical reaction model to a three-dimensional diffusion model. There is a kinetic compensation effect in the spontaneous combustion process of the sulfur concentrate, and the level of the kinetic compensation line may be one of the bases for distinguishing the spontaneous combustion tendency of the sulfur concentrate.
ABSTRACT
The oxidation of sulfide ores is a common phenomenon. To better understand the current development and status of oxidation studies of sulfide ores (OSSO), a bibliometric analysis of OSSO was conducted by mapping the spatiotemporal distribution of the knowledge domain and the research focus using VOSviewer and Citespace tools. The data were derived from the Web of Science (WOS) core collection database from 2000 to 2018. Study emphases covered publication outputs, countries/regions, organizations, top journals, research focus and keyword co-occurrence network, and theme development. The results include the following findings: (1) The line of the 3-year moving average of publications (3-year MAP), h-index (3-year MAH), and authors (3-year MAA) increased from 2001 to 2018. Conversely, the h-index continuously declined. (2) Asia had the most publications, with 1052, followed by Europe, with 923, and America, with 767. China, the USA, and Australia are the most active countries. (3) The top 10 organizations with the most publications are five Chinese organizations and one organization from each of the following countries: Russia, Australia, France, and India. (4) Hydrometallurgy, Minerals Engineering, Ore Geology Reviews, Geochimica Et Cosmochimica Acta, and Economic Geology are among the top 10 journals that researchers are most concerned about. (5) Cooperation among different organization or different countries is the most effective way to produce the most influential papers. (6) The OSSO is still focused on the process of oxidation by using different methods and techniques. In future work, it is necessary to progress new methods to understand the process of self-heating and prevent spontaneous combustion disaster of sulfide ore which result from OSSO.
