BS EN 15875:2011 pdf download – Characterization of waste — Static test for determination of acid potential and neutralisation potential of sulfidic waste
This test method consists of four steps:
Determination of total sulfur by bomb (EN 14582) or high temperature combustion (ISO 15178) andcalculation of acid potential (AP). Instead of total sulfur,sulfides may be determined using techniquesdescribed in the informative Annex c.
Determination of carbonate content by dry combustion(EN 13137:2001, method A) to give the carbonaterating (CR).
Determination of the neutralisation potential (NP) by hydrochloric acid addition to reach pH =2 to 2,5 andback titration with sodium hydroxide to reach pH = 8,3 after reaction time of 24 h.
Calculations of the net neutralisation potential (NNP) and the neutralisation potential ratio(NPR) basedon AP and NP.
AP and NP are expressed as H* content in molkg.The conversion factor is given for expression as carbonateequivalents (CacO3) in kg/t.
6 Reagents and laboratory devices6.1 Reagents
6.1.1 Distilled or demineralised water
6.1.2 Hydrochloric acid(analysis grade), c(HCI) = 1 mol/l6.1.3 Sodium hydroxide (analysis grade),c(NaOH)= 0,1 mol/l6.2 Laboratory devices
6.2.1 Analytical balance, with an accuracy of 0,05 g
6.2.2 Bottles or vessels (250 ml) made of inert material such as glass or high density polyethylene (HDPE)or polypropylene (PP) and supplied with a lid of inert material (e.g.PTFE).Rinsing is compuisory.When usingmagnetic bar in stirring (see 6.2.4) it is crucial to use a test vessel or bottle with flat bottom in order toguarantee good mixing.
6.2.3 Size reducing equipment, e.g. a jaw crusher, rotary swing mill, ball mill or similar device.
6.2.4 Stirring device or magnetic strring device with magnetic bar coated with PTFE. The parts in contactwith the sample and reagents shall be made of materials not affecting the outcome of the test like glass, PTFE.
6.2.5pH meter with a measurement accuracy of at least ± 0,05 pH units.
6.2.6Sample dividers (e.g. rotary splitter or riffle divider)
6.2.7 Sieves, conforming to the requirements of lSO 3310-1, with screen size of 0,125 mm.
7 Sampling and sample preparation
7.1 Laboratory sample
Perform sampling in accordance with EN 14899 in order to obtain a representative laboratory sample.The laboratory sample shall have a mass of at least 1 kg (dry mass).
NOTE The mass of the laboratory sample is dependent on its maximum particle size and homogeneity. Further information on sample masses can be obtained from EN 15002.
7.2 Test sample The test sample shall have a particle size of 95 % less than 0,125 mm. For material with larger particle sizes the following shall apply: Crush the laboratory sample to < 2 mm following the procedures given in EN 15002. Take a subsample from the crushed material by using a suitable divider (6.2.6) or by coning and quartering. The subsample of approximately 100 g is then milled to a particle size of 95 % less than 0,125 mm. Moist material that is not possible to sieve is dried prior to sieving and/or crushing. The drying temperature shall not exceed 40 °C in order to avoid unwanted reactions. Alternatively, freeze drying according to ISO 16720 can be used. The crushed material can change upon storage due to ageing of fresh surfaces. It is therefore recommended to test the material as soon as possible after crushing. If short-term storage is needed, crushed material should be stored cold and dark. For long-term storage material should be dried (at temperatures not exceeding 40 °C) prior to storage to prevent acid generating reactions. 7.3 Determination of dry residue of the sample The whole test sample, complying with the size criteria in 7.2 shall not be dried any further. The dry residue (w dr ) of the test sample shall be determined on a separate test portion according to EN 14346. The dry residue of the sample shall be determined at 105 °C ± 5 °C according to EN 14346. The dry residue expressed as mass fraction in percent is calculated according to Equation (1): where w dr is the dry residue of the sample expressed as mass fraction in percent;