Advances and Innovations in Ferronickel-making

The authors of this book and their research team have been wedded to innovating ferronickel-making for nearly twenty years from the aspects of development of new ferronickel production process, innovation of existing processes, value-added utilization of ferronickel slag, etc. For instance, they invented a process for preparing ferronickel from laterite ore by selective solid-state reduction-magnetic separation, allowing decrease of reduction temperature by 500 oC and cost saving of over 30% in comparison with the traditional RKEF process. They also developed a pioneering technology for regulating slag system of reductive smelting of laterite ore and a novel technology for controlling softening-melting performance of laterite ore, enabling decline of smelting temperature by 100 oC and electricity saving of 600 kWh per ton of ferronickel. Moreover, they proposed new methods for preparation of forsterite refractory materials and lightweight thermal insulation materials from ferronickel slag, realizing highly efficient value-added utilization of the solid waste.

内容简介

This book covers six chapters and is organized following the hierarchy of basic research, technological development, and industrial application. Chapter 1 introduces the basic properties and applications of nickel, laterite ore treatment, technological progress, existing problems, challenges, and development trend of ferronickel industry. Chapter 2 presents a novel ferronickel-making process via selective solid-state reduction-magnetic separation of laterite ore, featured by short process, high energy efficiency, and low cost, based on exploration of thermodynamic and kinetic laws of selective reduction and sulfidation of laterite ore with clarification of the growth behavior of ferronickel grains in the process of solid-state reductive roasting. With the much lower operating temperature in comparison with those in traditional ferronickel-making processes, it represents an exciting breakthrough in rational and optimal utilization of low-and medium-grade laterite ore resources for developing ferronickel and stainless-steel industry. Chapter 3 discusses the effects of calcium, magnesium, silicon, aluminum, and ferrous oxide on the properties of slag, from which a new low melting point slag type with diopside and mafic olivine as the main phases and a technology for slag system optimization and regulation centering on controlling FeO content and simultaneous adjustment of quaternary alkalinity are described with the purpose of reducing smelting temperature of electric arc furnace with less power consumption and higher metal recovery. Chapter 4 presents an original technical scheme of reducing the softening-melting temperature of laterite ore with promoted formation of liquid phase based on identification of the relationship between phase transformation and softening-melting property in the roasting process of laterite ore. It also clarifies the formation behavior of low melting point diopside phase during high-temperature roasting from which an innovative technology for regulating the softening-melting performance of laterite ore is presented. The findings denote efforts to improvement of the output and quality of laterite ore sinter and the smelting index of blast furnace, decrease of reduction temperature, acceleration of growth of ferronickel particles, and enhancement of separation of ferronickel in the Krupp–Renn process. Chapter 5 describes in detail the value-added utilization of ferronickel slag for preparing refractory materials and lightweight thermal insulation materials by comprehensively applying a series of techniques including biphasic design, particle gradation, and additive induction to optimize the phase composition, liquid phase generation, and volume/structure of product. Chapter 6 highlights a creative technical route of co-processing stainless-steel pickling sludge, which contains multiple valuable elements and sulfur that hinders its utilization and deteriorates the product quality when recycled as the feed for ferronickel production, with laterite ore via the RKEF process, based on analysis of desulfurization behaviors of the sludge, including thermodynamics, phase transformation, and off-gas emission characteristics during reduction.