Abstract: The disclosure relates to a method for purifying yellow phosphorus including bringing yellow phosphorus and wood-based activated carbon into contact with each other. The disclosure also relates to a method for producing high-purity phosphoric acid including generating a gas of phosphorus pentoxide by burning yellow phosphorus obtained by the purifying method and then hydrating the gas.

Abstract: In a flatness measurement apparatus, a sensor unit having a flatness-detection sensor is slidable along the linear guide rail. A support system supports the linear guide rail such that the linear guide rail is rotatable in a horizontal plane, whereby a surface of a wafer stage to be measured is scanned all over with the sensor unit having the flatness-detection sensor so as to ensure a flatness measurement of the whole surface of the wafer stage.

Abstract: In a flatness measurement apparatus, a sensor unit having a flatness-detection sensor is slidable along the linear guide rail. A support system supports the linear guide rail such that the linear guide rail is rotatable in a horizontal plane, whereby a surface of a wafer stage to be measured is scanned all over with the sensor unit having the flatness-detection sensor so as to ensure a flatness measurement of the whole surface of the wafer stage.

Abstract: A method of manufacturing blast furnace coke wherein said coke is obtained by a process in which coal to be used for making briquettes is mixed with a caking substance having a softening point of 40.degree.-250.degree. C. with or without a solvent having fluidity at the mixing temperature and dissolvable to said caking substance, the resultant mixture being mixed by means of a powerful mixer capable of applying mixing energy of 0.01KW/Kg or more at a temperature of 40.degree.-250.degree. C. for 1-10 minutes, while a heating medium such as steam is passed therethrough and is then subjected to briquetting with a roll press. The briquette obtained is either carbonized directly or after blending with coal ready for coke oven charging.

Abstract: A process for preparing a briquette is disclosed. The process comprises a coal with a caking substance having a softening point of 20.degree.-40.degree. C. or with a caking substance having a softening point of above 40.degree. C. and a solvent which has fluidity at normal temperature and is compatible with the caking substance to a coal for making briquettes, powerfully mixing at a temperature of above 10.degree. C., preferably of 20.degree.-50.degree. C., for 1-10 minutes, by using a mixer provided with a mixing tool which is rotated at a speed of more than 5m/sec. peripheral velocity and/or a mixer provided with a mixing tool which applies a pressure of more than 45kg/cm.sup.2 ; and briquetting by using a roll press, whereby a briquette is obtained having a shutter strength of more than 80 and a trommel strength of more than 90.