Roga test

The agglomerating for agglutinating) tendency of coal may also be determined by the Roga test (ISO 335), and the Roga index (calculated from the abrasion properties when a mixture of a specific coal and anthracite is heated) is used as an indicator of the agglomerating tendencies of coals (Table 7.4). 

ISO 335. Determination of Coking Power of Hard Coal Roga Test. 

The expression of results in analytical chemistry is mostly in SI units (all base units except the candela and many derived units). The principles to be followed to achieve the comparability and traceability of measurements to the SI have been clearly stated [1,2]. However, certain types of measurements are expressed in conventional units. Turbidity evaluation in water quality analysis, determination of soluble content of fruit and vegetable products by the refractometric method, measurement of caking power of hard coal by the Roga test, determination of the octane number of fuel and seric protein analysis are some examples. 

The FSl of coal is a measure of the increase in volume of a coal when it is heated (without restriction) under prescribed conditions (ASTM, 2011g ISO, 2011a). The ISO test (ISO, 2011a), Roga test, measures mechanical strength rather than size profiles of coke buttons another ISO test (ISO, 2011b) gives a CSN of coal. 

ISO. 2011a. Hard Coal—Determination of Coking Power, Roga Test (ISO 335). International Standards Organization, Geneva, Switzerland. 

Eor the free swelling index which is also known as the cmcible swelling number (ASTM D720), a coal sample is rapidly heated to 820°C in a covered cmcible. Then the profile of the resulting char is compared to a series of standard numbered profiles (18). Eor the Roga index weighed amounts of coal and standard anthracite are mixed and carbonized, and the product coke is tested in a Roga dmm for its resistance to abrasion (89). 

The only small-scale methods that have stood the test of time and have been accepted as standard plasticity tests are the crucible swelling number, Gray-King coke type, dilatation characteristics, Gieseler plasticity, and, in some countries, the Rogas index. All of these are essentially empirical in nature and many are subjective, at least to some degree. 

The Roga index provides information on the caking properties of the coal. The index itself is derived from the strength or cohesion of the coke produced in the crucible, as evaluated by a subsequent tnmbler test. 

Some of the most common methods to evaluate the suitability of a coal or coal blend for coke production are the free-swelling index test, Gray-King assay, Roga assay, various dilatometer tests, and Gieseler plastometer test. In addition, research using larger amount of coal sample is also performed by means of a pilot coke oven. 

Meniscus-coated composite films of SPPO (lEC value =2.2) on porous polypropylene (MST-110) were tested as a 1 x 3 inch flat sheet in the ROGA unit having a hydraulic diameter of 0.0126 ft, and a flow rate of 2.2 gpm. Tests were performed on secondary sewage from the treatment plant at Selam, NH. 

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