BS EN 15875:2011 pdf download

BS EN 15875:2011 pdf download.Characterization of waste -Static test for determination of acid potential and neutralisation potential of sulfidic waste.
8 Test procedures
8.1 Determination of acid potential
8.1.1 General
The acid potential CAP) can either be based on the determination of total sulfur or on a species analysis where sulfide sulfur Is determined.
Analyses of total sulfur Is a well established method with a high potential of automatesatlon resulting wi short analysis times. Total sulfur determination can therefore be regarded as a default method which is described In
8.1.2.
If either through mineralogical or chemical analysis it is shown that substantial pacts of total sulfur is sulfate, then a more appropriate (realistic) APis obtained by analyzing sulfur species (see 8.1.3).
NOTE The main source for acidity Is the oiadation of sutfides. Total sulfur is used as a conservative approximation of sulbde content It a significant part of total sulfur Is sulfate this will lead to a significant overestimabon of AP. in which case a more realistic assessment will be adchieved it the AP determination is based on sulfide content
8,1.2 Total sulfur content
Total sulfur content is determined either by bomb combustion according EN 14582 or by high temperature combustion according ISO 15178.
The bomb combustion method described in EN 14582 usually gives high recoveries when inorganic salts are analysed. However, depending on the material to be analysed. suitable pure inorganic compounds with similar sulfur binding shall be used to test recovery rates
When using high temperature combustion techniques, appropriate operating conditions ol the analysis shall be chosen, to ensure the detection of all sulphur components, Induding temperature stable Inorganic sulphates (e.g. calcium sulfate). This can be achieved by Increasing the temperature (e.g. up to 1 500 C) or the use of tin capsules (which bum in an exothermic reaction resulting in high temperatures). Also measuring time may be increased as these stable compounds react slower. Calibration has to be made with cal.brants having the same range of sulfur concentration as the material to be analysed.
8.1.3 Determination of sulfur species
The main purpose of all species analyses is the determination of sulfides, mainly pynte. This can be done either by direct determination of pynte or by subtraction of the sulfate sulfur fraction froni the total sulfur content (assuming no other sulfur species like elemental sulfur is present). The choice of direct or Indirect approach depends on the mineralogical composition of the sample.
There are no CEN or ISO standards for the determination of sulfur species (sulfate-, sulfide-, disulfide-, sulfur) in waste described in this standard. However, guidance is given in the informative Annex C.
NOTE Some sulfides do not contrwute to AP, this can only be assessed through more detailed cheracteresation. such as nwwralogy.
8.1.4 CalculatIon
The acid potential (API is calculated based on the sulfur content (either total or sulfide sulfur) as follows:
NOTE I Calculation of acid potential assuwnes all sulfur to appear as pyrite
a) expressed as H content in mol/kg (Equation (3))
82 Determination of neutralisation potential
8.2.1 General
The amount of acid added for the test is crucial for the results obtamed. Therefore, the carbonate content is determined first to gve the carbonate rating. From this, the required hydrochloric acid addition is taken from Table 1.
8.2.2 Carbonate rating
Determine the carbonate content following the procedure in EN 13137:2001 method A.
The carbonate carbon content obtained from EN 13137:2001 (there named inorganic carbon) is expressed as mass fraction in percent, it is used as carbonate rating in 8.2.3 (for further explanation see Annex D).
8.2.3 Neutralisation potential
Weigh test portion M. corresponding to 2,00 g ± 0,10 g of dry mass (P4) into a test vessel or bottle (6.2.2).
Record the exact weight of the sample.
Add 90 ml ± 5 ml of demineralised water (6.1.1). Start mixwlg using an appropriate st%ring device (6.2.4).
Maintain the temperature at 20 °C ± 5 C during the whole test.
NOTE I Some matens may form gas en In contact with water m acidic conditions, Therefore, Es highly recolTwnended to allow possible gas exit by making a small hole Wi to the Ud of the vessel or botile.
Test portion and water are stirred for 15 mm ± 5 mm and the pH of the slurry is measured and recorded before the acid addition. If pH < 2 already, this sample cannot be characterised wtth this test. After IS mm ± 5 mm of stirring hydrochloric acid (6.1.2) is added based on the carbonate rating (8.2.2) of the test sample (see Table 1).