Coldry technology for low rank coal drying Aug19

Coldry technology for low rank coal drying...

Coldry technology for low rank coal drying Coldry technology is being developed by Environmental Clean Technologies (ECT) Limited, Australia. The technology consists of expelling of water from a wide range of low rank coals (lignite coals and sub-bituminous coals) containing up to 70 % moisture into high calorific value (CV) black coal equivalent (BCE) pellets with a moisture content of around 10 %. The BCE means that the net energy value of the Coldry pellets is similar in range to that of many black coals. Coldry technology is a patented process which changes the naturally porous form of low rank coals to produce a dry and dense pellets by a process which is called as ‘brown coal densification’(BCD). The technology is based on research initially conducted by CRA and University of Melbourne in the early 1980s. The technology has been demonstrated at pilot plant scale at Bacchus Marsh Coldry plant. This plant was commissioned in 2004, enhanced with a water recovery system in 2007, and upgraded in 2011 so that it can produce up to 20,000 tons per annum of Coldry BCE pellets. The process has been tested and proven successful on a wide range of low rank coals. Principle of the process The Coldry process combines two unique aspects namely (i) brown coal densification, and (ii) waste heat utilization. The process stimulates a natural chemical reaction within the coal. This reaction polymerizes active sites in the coal compounds and expels chemically bound water. The polymerization of the active sites collapses the coal pore structure and expels the physically trapped water. The ejected water migrates to the surface of the coal pellets. The surface water is evaporated by the utilization of waste heat from an adjacent power plant (PP). BCD is a natural phenomenon whereby the physical structure...

Metal Forming Processes...

Metal Forming Processes Metal forming processes consists of deformation processes in which a metal work piece (billet, bloom, or blank) is shaped by tools or dies. The design and control of such processes depend on the characteristics of the material of the work piece, the requirements of the finished product, the conditions at the interface of the tool and the work piece, the mechanics of plastic deformation (metal flow), and the equipment used. These factors influence the selection of geometry and material of the tool as well as processing conditions (examples are temperatures of die and work piece and lubrication). Since many of the metalworking operations are rather complex, models of various types, such as analytical, physical, or numerical models, are often used to design these processes. A brief historical view, a classification of metalworking processes and equipment, and a summary of some of the more recent developments in the field are described below. Historical view Metalworking technology is one of three major technologies used for the fabrication of the metal products. The other two are casting process and powder metallurgy (P/M) technology. It is possibly the oldest and most established of the three technologies. The earliest records of metalworking show that the simple hammering of gold (Au) and copper (Cu) was practiced in various regions of the Middle East around 8000 BCE. The forming of these metals was crude since the skill of refining by smelting was not known and since the ability to work the material was limited by impurities that remained after the metal had been separated from its ore. With the start of Cu smelting around 4000 BCE, a useful method became available for purifying metals through chemical reactions in the liquid state. Later, in the Cu age, it was...