Beneficiation of Phosphate Ore examines various methods for processing phosphate rock, an important mineral commodity used in the production of phosphoric acid. The majority of phosphoric acid is produced by the wet process, in which phosphate rock is reacted with sulfuric acid to produce phosphoric acid and gypsum (calcium sulfate dihydrate). This wet process demands a phosphate rock feed that meets certain specifications to produce phosphoric acid efficiently and economically. Beneficiation of Phosphate Ore thoroughly explains the methods used in beneficiation of different types of phosphate ores for use in the wet process. The mineralogical properties of the two major types of phosphate deposits, sedimentary and igneous, are described along with the processing methods. The benefits and disadvantages of each process are discussed in detail.
Updating content from the author's 2001 book Coal Desulfurization, this new title focuses on CO2 sequestration and utilization. It includes information on the theory and practical approaches to CO2 capture and recent advances in the use of sequestered CO2. Avoiding these pollutants requires either forgetting about the 250 billion tons of coal reserves the United States possesses or capturing and utilizing the pollutants in a profitable and environmentally responsible fashion. The book covers postcombustion and precombustion capture approaches for coal, and postcombustion capture can be generalized to many other fuels. Recent practical implementations at full-scale power facilities around the world are discussed. The book covers sequestering CO2 via underground, oceanic, biological, and other long-term CO2 storage methods. It also includes recent advances in utilizing CO2 for enhanced oil recovery, advances in storage with depleted oil and gas reservoirs and deep saline aquifers, and additional topics. The book also examines specific applications of pure CO2 and covers chemical conversion of CO2 to useful compounds. It answers questions like Can we create methanol from coal? or Can we create ethanol from coal? It is found that methanol and ethanol cannot be sustainably produced from coal power alone. However, oxalic acid can be created at a much lower energy cost than methanol or ethanol. Oxalic acid can be used to extract rare earths, which are not currently produced anywhere in the United States, but are typically concentrated in coal ash. Aimed at researchers and industry professionals in chemical, environmental, and energy engineering, this book provides insight and inspiration into capturing CO2 not merely as a response to regulatory pressure and climate change but as an inherently profitable and valuable venture.
Advances in Comminution comes at a critical time. It focuses on the dilemma of needing to grind materials to ever-finer sizes while maintaining reasonable energy costs. The selection and sizing of stirred mills for regrinding and ultrafine grinding applications do not lend themselves to conventional methodologies; therefore, new approaches are being developed. There is a great deal of activity directed toward improving ore characterization to predict AG/SAG mill energy requirements, as well as developing improved models and instrumentation for optimization and control of comminution circuits. Instrumentation, modeling, and control functions in particular have benefited from rapidly advancing computer technology, with calculations that were formerly extremely time-consuming becoming rapid and routine. These advances will keep energy waste to a minimum and will provide the increased energy efficiency needed to maintain ongoing industry success. The 36 chapters are based on the 2006 SME symposium. Topics and contributors were carefully selected to provide a balance between academic and industrial practice so that the reader can readily find information on current best practices and evaluate future industry trends.