Modelling and Control Structure of a Phosphorite Sinter Process with Grey System Theory

International audienceThe sintering process of phosphorite ore occurs with a large amount of return caused by untimely process control. The control task of the phosphorite ore sintering is to regulate parameters of the process to obtain a high-quality sinter. The parameter clearly responsible for the sinter quality is the temperature in the wind box (also called burn through point (BTP)). Therefore, in order to solve the real-time control task, it is necessary to predict the BTP. In this paper, the grey system theory is used as a predictive approach, which makes it possible to obtain an adequate model that has the character of a "generalized energy system" and uses a small initial sample. Based on the grey model GMC(1,n), which is constructed in real-time by using real data at the beginning of the process, the temperature is well predicted at the end of the sintering process. When the temperature does not match the set value or to find out an optimal regulation, a control synthesis is carried out through an optimization of the prediction according to the "particle swarm" algorithm

Minimising Particulate Emissions From Sintering Operations

With the drive for manufacturing and foundation industries to move towards a circular economy, the steel industry is making step changes to its processes that aim to produce greener and cleaner products. The current work is focused on sintering, which can account for almost half of all particulate matter (PM) emissions produced during integrated steelmaking. Historic sintering data has been explored to understand the formation of particulate matter and has informed experimental trials, simulating the sintering process. It has shown that it is feasible to reduce PM emissions without incurring significant capital expenditures for a new end-of-line abatement. Prioritising trials was supported by an understanding of the main key levers from the historical data analysis of the sinter plant and a pilot-scale sinter rig that had been modified to capture PM emissions was commissioned and validated. To promote a more circular economy within the steel industry, experimental work showed that the use of new micropellets made from recycled materials would enhance sintering performance and reduce PM emissions. It was determined that the amount of chloride content emitted from PM emissions increased in the waste gas stream as well as decreasing the electrostatic precipitator (ESP) abatement efficiency and this influence can be reduced by washing recycled materials to remove undesirable volatile elements before sintering. It was also established that by manipulating the ratio of nuclei, adhering, and non-adhering particles in the sinter blend by controlling the size fractions, along with partially replacing raw materials, the particle size distribution can be optimised to reduce PM emissions

Advances in Pyrometallurgy

There are several major megatrends having an impact on pyrometallurgical metal processing. The steadily growing demand for all metals is strengthened by the emergence of electrical vehicles (EV), which brings a high need for battery metals, but additionally, a significant increase in copper consumption. Even if only moderate forecasts for the number of the EVs become true, production of the base metals must increase by tens of percentages, or even more than double. At the same time, pyrometallurgical processes have to produce fewer side products, such as slag, and maintain the quality level of the primary product, although raw material mixtures are increasingly complex and new elements are entering the processes in secondary raw materials. Therefore, it is imperative to continue the development of pyrometallurgical processes more efficiently and productively, while still improving their selectivity regarding slagging the unwanted material and recovering the desired elements. This Special Issue is for current advances in the pyrometallurgical processing of metals, including all aspects, namely, the basic unit processes and operations in a smelter, metallurgical engineering, furnace integrity, cooling systems, modelling, slag and offgas handling, to name a few. A collection of 13 papers deal with ferrous and ferroalloy development, and the processing of different raw materials for metal production

Advances in Energy Conservation of China Steel Industry

The course, technical progresses, and achievements of energy conservation of China steel industry (CSI) during 1980–2010 were summarized. Then, the paper adopted e-p method to analyze the variation law and influencing factors of energy consumptions of large- and medium-scale steel plants within different stages. It is pointed out that energy consumption per ton of crude steel has been almost one half lower in these thirty years, with 60% as direct energy conservation owing to the change of process energy consumption and 40% as indirect energy conservation attributed to the adjustment of production structure. Next, the latest research progress of some key common technologies in CSI was introduced. Also, the downtrend of energy consumption per ton of crude steel and the potential energy conservation for CSI during 2011–2025 were forecasted. Finally, it is indicated that the key topic of the next 15 years’ research on the energy conservation of CSI is the synergistic operation of material flow and energy flow. It could be achieved by the comprehensive study on energy flow network optimization, such as production, allocation, utilization, recovery, reuse, and resource, according to the energy quantity, quality, and user demand following the first and second laws of thermodynamics

Bureau of Mines publications and articles, 1992-1993 (with subject and author index)

The U.S. Bureau of Mines (USBM) was established in the public interest to conclude inquiries and scientific and technologic investigations on mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and prevent their waste; to further economic development; to increaseee efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting those industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the U.S. Bureau of Mines to "disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act."In accordance with this directive, USBM reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-USBM publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make this kind of list both necessary and valuable.This edition describes reports and articles published during calendar years 1992 and 1993. It supplements the 50-year list of Bureau publications from July 1, 1910, to January 1, 19602 ; and these 5-year lists of publications and articles: from January 1, 1965, to December 31, 1969 from January 1, 1970, to December 31, 1974, from January 1, 1975, to December 31, 197 , from January 1, 1980, to December 31,1984, and from January 1, 1985, to December 31, 1989.ISBN 0-16-045065-

Fundamentals of Applied Smouldering Combustion

Smouldering combustion is defined as a flameless oxidation reaction occurring on the surface of the condensed phase (i.e., solid or liquid). Traditional research on smouldering was related to economic damages, fire risk, and death, due to the release of toxic gases and slow propagation rates. Recently, smouldering has been applied as an intentional, engineering technology (e.g., waste and contaminant destruction). Smouldering involves the transport of heat, mass, and momentum in the solid and fluid phases along with different chemical reactions. Therefore, numerical models are essential for the fundamental understanding of the process. Smouldering models either neglected heat transfer between phases (i.e., assumed local thermal equilibrium) or employed heat transfer correlations (i.e., under local thermal non-equilibrium conditions) not appropriate for smouldering. Thus, the first step of this thesis was to develop and validate a new heat transfer correlation for air flowing through hot sand at conditions appropriated to smouldering. The new correlation was reliable and predicted well heat transfer between phases. The second step was to apply the new correlation along with appropriate chemistry into a one-dimensional model. The model was calibrated to a smouldering experiment of an organic liquid fuel embedded in sand and then confidence in the model was gained by independent simulations of additional experiments. Local thermal non-equilibrium demonstrated to be essential to correctly simulate smouldering of organic liquid fuels embedded in sand. Moreover, a two-step kinetic mechanism showed to be sufficient to simulate the smouldering chemistry. The third step was to use the one-dimensional model to understand the conditions that lead to self-sustaining smouldering and smouldering extinction. A global energy balance was developed, revealing that self-sustaining and extinction conditions occurred when the net energy balance was positive and negative, respectively. The last step was to use the one-dimensional model to conduct a sensitivity analysis of the key practical model parameters. Moreover, a local energy balance was developed and compared with the global energy balance; both were used to explain the physics of the process. It was found that the local energy balance described the moment of extinction, whereas the global energy balance predicted extinction in advance. Overall, this thesis presented new insights into the interplay between heat transfer and chemical reactions along with the understanding of the conditions that lead to self-sustaining smouldering and smouldering extinction

List of Bureau of Mines publications and articles, January 1, 1965, to December 31, 1969, with subject and author index

"This compilation supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960; the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960; and the 5-year list of Bureau publications and articles published from January 1, 1960, to December 31, 1964. It includes all the material in the four annual lists of Bureau publications and articles for January 1, 1965, to December 31, 1968, as well as the Bureau publications and articles for 1969. More than 2,500 publications by Bureau authors published in the regular Bureau of Mines series, in scientific, technical, or trade journals, or in other media are listed and summarized; those available from the Bureau of Mines are indicated. Libraries which maintain files of Bureau publications are listed. Cooperative publications issued by organizations with which the Bureau conducted joint research are described. Patents issued to Bureau personnel are also listed, and instructions are given on how to apply for permission to use them. One of the outstanding features of this special publication is an exhaustive subject and author index." - NIOSHTIC-2NIOSHTIC no. 1000888719701171

Process Modeling in Pyrometallurgical Engineering

The Special Issue presents almost 40 papers on recent research in modeling of pyrometallurgical systems, including physical models, first-principles models, detailed CFD and DEM models as well as statistical models or models based on machine learning. The models cover the whole production chain from raw materials processing through the reduction and conversion unit processes to ladle treatment, casting, and rolling. The papers illustrate how models can be used for shedding light on complex and inaccessible processes characterized by high temperatures and hostile environment, in order to improve process performance, product quality, or yield and to reduce the requirements of virgin raw materials and to suppress harmful emissions

Advanced Technology of Waste Treatment

The protection of human health and the environment (representing the main reason for waste management), as well as the sustainable use of natural resources, requires chemical, biological, physical and thermal treatment of wastes. This refers to the conditioning (e.g., drying, washing, comminution, rotting, stabilization, neutralization, agglomeration, homogenization), conversion (e.g., incineration, pyrolysis, gasification, dissolution, evaporation), and separation (classification, direct and indirect (i.e., sensor-based) sorting) of all types of wastes to follow the principles of the waste hierarchy (i.e., prevention (not addressed by this issue), preparation for re-use, recycling, other recovery, and disposal). Longstanding challenges include the increase of yield and purity of recyclable fractions and the sustainable removal or destruction of contaminants from the circular economy.This Special Issue on “Advanced Technology of Waste Treatment” of Processes collects high-quality research studies addressing challenges on the broad area of chemical, biological, physical and thermal treatment of wastes