Overview

This document has been developed primarily to support the implementation of the Directive 2006/21/EC of the European Parliament and of the council on the Management of waste from the extractive industries, especially relating to technical requirements for waste characterization as sulfide bearing materials may generate sulfuric acid when subjected to weathering. Test methods for the determination of acid generation behaviour can be divided in static and kinetic tests. A static test is usually fast to perform, but gives only indicative information based on total composition of the waste material. The kinetic test gives more detailed information on behaviour based on reaction rates under specified conditions. This standard only covers static testing. The application of this method alone may not be sufficient to determine the actual potential in the field for the formation of acidic drainage as site specific conditions will affect the behaviour in the field and require a more detailed assessment. To carry out a more precise assessment of the acid generation potential and buffering capacity mineralogical information is required. A number of special cases can be identified, for example, presence of sulfate (for example, gypsum), nonacid producing sulfides or carbonates with no buffering capacity. Acid neutralisation behaviour as obtained by other methods can provide additional information in circumstances of uncertainty. This European Standard specifies methods to determine the potential of sulfide bearing materials for the formation of acidic drainage. Specified are methods for determining both the acid potential (AP) and the neutralisation potential (NP) of the material. From these results, the net neutralisation potential (NNP) and the neutralisation potential ratio (NPR) are calculated. This European standard is applicable to all sulfide bearing wastes from the extractive industries excluding wastes which will have pH < 2 in the initial step of the procedure described in 8.2.3. This test method consists of four parts: Determination of total sulfur by bomb (in accordance with EN 14582) or high temperature combustion (in accordance with ISO 15178) and calculation of acid potential (AP). Instead of total sulfur, sulfides may be determined using techniques described in the informative Annex C. Determination of carbonate content by dry combustion (in accordance with EN 13137, method A) to give the carbonate rating (CR). Determination of the neutralisation potential (NP) by hydrochloric acid addition to reach pH = 2 to pH = 2,5 and back titration with sodium hydroxide to reach pH = 8,3 after reaction time of 24 hours. Calculations of the net neutralisation potential (NNP) and the neutralisation potential ratio (NPR) based on AP and NP. AP and NP are expressed as H⁺ content in mol/kg. A conversion factor is given for expression as carbonate equivalents (CaCO₃) in kg/t. The committee responsible for this standard is NA 119-01-02-02 UA "Chemische und physikalische Verfahren" ("Chemical and physical methods").

Document: references other documents

Responsible national committee

NA 119-01-02-02 UA - Chemical and physical methods  

Responsible european committee

CEN/TC 444/WG 6 - Cross cutting issues