Fusibility test

As a general rule flasks and similar vessels should be heated in an air bath (compare Fig. II, 5, 3). A glycerol bath may be employed for temperatures up to 140° the glycerol is subsequently removed from the outside of the vessel by washing with water. Medicinal liquid paraffin may be used for temperatures up to about 220° hard hydrogenated cotton seed oil, Silicone fluids or fusible metal may be employed when higher temperatures are required. Small test-tubes and centrifuge tubes... 

Free-swelling tests are commonly used to measure a coal s caking characteristics. A sample of coal is packed in a cmcible or tube, without compaction, and heated at a fixed rate to about 800°C. Infusible coals distill without changing appearance or state of agglomeration. The fusible coals soften, fuse, and usually sweU. The profile of the resultant coke is compared to a series of reference profiles so that a swelling index can be assigned. The profiles represent indexes between 0 and 9. The best cokes come from coals having indexes between 4 and 9. 

Is each receipt of material checked Yes. The supplier once sent a cylinder of phosgene. Since then, a test is performed by the maintenance staff. In addition, the fusible plugs are inspected for evidence of leakage, before a cylinder is hooked up. 

Acceptance testing of fusible link fire dampers should always include a random sample actual fusible link (melting) test of the installed assembly that causes the damper to close. Many times an improperly installed damper will not close correctly and the shutter louvers become hung up or twisted. An alternative sometimes available is a link assembly that can be temporary installed that is easily cut by a pair of clippers. The fusible link melting temperature can then be tested separately at a convenient location without subjecting the installation heat or flames for testing purposes. 

The potassium tantalum fluoride first precipitated is a fusible substance. Its aqueous solutions on being boiled predpitate a very insoluble potassium tantalum oxyfluoride, 4KF.Ta2Os.2TaFs or K4Ta4OfiFu, as a white powder. This reaction is stated to constitute a sensitive test for tantalum.1... 

Other important chemical and physical tests performed to characterize coal include (I) Heating value (Btu content) (2) sulfur forms (31 ash fusibility temperatures (4) ash analysis (5) trace elements (6) free swelling index and (7) hardgrove grindability. 

ASTM D-1757. Standard Test Method for Sulfate Sulfur in Ash from Coal and Coke. ASTM D-1857. Standard Test Method for Fusibility of Coal and Coke Ash. 

The test method for determining the fusibility of coal ash (ASTM D-1857) covers the observation of the temperatures at which triangular pyramids (cones) prepared from coal and coke ash attain and pass through certain defined stages of fusing and flow when heated at a specified rate in controlled, mildly reducing, and where desired, oxidizing atmospheres. 

In practice, types of burning equipment, rate of burning, temperature and thickness of the fire bed, distribution of ash-forming minerals in the coal, and viscosity of the molten ash may influence ash behavior more than do the laboratory-determined ash fusibility characteristics. The correlation of the laboratory test with the actual utilization of coal is only approximate, due to the relative homogeneity of the laboratory test sample compared to the heterogeneous mixture of ash that occurs when coal is burned. Conditions that exist during the combustion of coal are so complex that they are impossible to duplicate completely in a small-scale laboratory test. Therefore, the test should be considered only as an empirical one, and the data should be considered qualitative and should not be overinterpreted. 

ASTM D-1857. Standard Test Method for Fusibility of Coal and Coke Ash. 

Standard tests consisted of proximate, ultimate, higher heating value, ash composition, ash fusibility temperatures, Hardgrove grindability, and screen analyses. Special bench scale characterization tests consisted of micro-proximate analysis and micro-ultimate analysis (C, H, N) micro-proximate and micro-ultimate analyses were performed on particulate samples collected from varying stages of combustion in the DTFS and CMHF. In addition, selected samples of SRC and chars from partial combustion or pyrolysis of the SRC were submitted for Thermo-Gravimetric analyses. 

Ignition Temperature, This is usually determined by placing 0 1 g. of the explosive in a smalt test tube, which is then corlud and placed in a fusible metal bath at 100. The temperature is raised 5 per minute until inflammation or explosion occurs. The quantity and rate of heating difler m diffei t countries. 

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