ISO 334-2020 pdf download

ISO 334-2020 pdf download.Coal and coke一Determination of total sulfur- Esch ka method. 8.3 IgnitIon 8.3.1 For coal Place the charged crucible (and any others up to the limit of the muffle furnace capacity) in the cold muffle furnace (6.3) and raise the temperature to 800 C a 2% 5C in about 1 h. maintaining this temperature for at least a further 1.5 h Withdraw the crucible (or crucibles) and allow to cool. NOTE The cracking of porcelain cn.ciblcscan be prevented if they are slowly cooled by iissertkm in supports of light porous Iirebrick on removal from the muffle furnace 8.3Z For coke Place the charged crucible (or crucibles) on the cold insulating flat plate (6.5) and insert into the mufllc furnace (6.3) at a temperature of 900 C * 25 C. maintaining this temper.lture for at least a further 1,5 h. Withdraw the crucible (or cruclbles) and allow to cool. See Note In &3.1. 8.4 Recovering the resIdue Transfer the ignited mixture from the crucible to a 400 ml beaker containing 25 ml to 30 ml of water. If unburnt particles are present. the determination shall be stopped and the test repeated. Wash the crucible thoroughly with about 54) ml of hot water and add the washings to the contents of the beaker. 8.5 Ixtractlon Place a watch glass on the beaker and then, while tilting the witch glass, carefully add vnough hydrochloric acid (5.2) to dissolve the solid matter (17 ml will normally be required), warming the contents of the beaker to effect solution. Boil for 5 mm to expel carbon dioxide and filter, collecting the filtrate in a 400 ml conical beaker. NOTE A medium-textured. doubly acul-wached filter paper or a filter-paper pad is recommended for speed of tiltratliaL To prepare the filter-paper pad, shake doubly acid-washed filter-paper clippings, in pieces with areas of approximately 1 cm2, with water In a bottle until the paper Is thoroughly dIsrntegrated. Place a porcelain fIlter cone of 25 mm In a 75 mm funnel, close the stem of the funnel with a finger, and add water until the cone Is immersed and the funnel stem Is full. Shake, onto the cone. sufficient paper pulp to form a pad 5 mm thick, and level it with a flat-ended g1ass rod. Allow the excess water to drain away by removing the finger from the stem and as drainage ceases, lightly tamp the pad...