BS ISO 12739:2006 pdf download.Zinc sulfide concentrates ——Determination of zinc— lon-exchange/EDTA titrimetric method.
Heat to evaporate the combined filtrates to a volume of 60 ml to 80 ml, Cool and add 16 ml of hydrochloric acid (4.3). Dilute to 100 ml with water,
If the sample contains lead, damage to the platinum crucible may occur. In this case, acid-insoluble material should be treated as follows.
Rinse the Wsotuble residues into a polytetrafluoroethytene beaker with a fine jet of watec Place the filter in a porcelain crucible and gently ash the paper in the muffle furnace at 600 C to 700 C. Allow the crucible to cool to ambient temperature.
Rinse the material from the crucible by washing with a small quantity of water into the polytetrafluoroethylene beaker used above. Add 2 ml of dilute sulfuric acid (4.8). 2 ml of nitric acid (4.6) and 2 ml of hydroffuonc acid (4.10), and evaporate the solution nearly to dryness.
Cool and add water in sn’ial quantities to dissolve the soluble salts. Filter through a medium-speed cellulose filter paper and add the filtrate and washing solution to the initial solution ob(amed above.
Should it be confirmed that the fitter paper contains no zinc, the procedure of ashwg the filter paper may be omitted.
7.4 Preparation of the ion-exchange column
Examples of ion-exchange columns that are suitable for use are shown m Annex A. Pack water-soaked cotton or glass-wool pads into the bottom of the column to a thickness of about 5mm. This will retain resrn in the column during use.
Soak the resin overnight in distilled water to make a slurry. With the stopcock open, carefully transfer the slurry into the column to form a settled bed This resin bed is formed by about 16 ml of the swollen resin, Close the stopcock and put about a 5mm thickness of water-soaked glass wool or cotton wool on top of the resin.
If the sample contains lead, damage to the platinum crucible may occur. In this case, acid-insoluble material should be treated as follows.
Rinse the Wsotuble residues into a polytetrafluoroethytene beaker with a fine jet of watec Place the filter in a porcelain crucible and gently ash the paper in the muffle furnace at 600 C to 700 C. Allow the crucible to cool to ambient temperature.
Rinse the material from the crucible by washing with a small quantity of water into the polytetrafluoroethylene beaker used above. Add 2 ml of dilute sulfuric acid (4.8). 2 ml of nitric acid (4.6) and 2 ml of hydroffuonc acid (4.10), and evaporate the solution nearly to dryness.
Cool and add water in sn’ial quantities to dissolve the soluble salts. Filter through a medium-speed cellulose filter paper and add the filtrate and washing solution to the initial solution ob(amed above.
Should it be confirmed that the fitter paper contains no zinc, the procedure of ashwg the filter paper may be omitted.
7.4 Preparation of the ion-exchange column
Examples of ion-exchange columns that are suitable for use are shown m Annex A. Pack water-soaked cotton or glass-wool pads into the bottom of the column to a thickness of about 5mm. This will retain resrn in the column during use.
Soak the resin overnight in distilled water to make a slurry. With the stopcock open, carefully transfer the slurry into the column to form a settled bed This resin bed is formed by about 16 ml of the swollen resin, Close the stopcock and put about a 5mm thickness of water-soaked glass wool or cotton wool on top of the resin.
