empty flow charcterizations

Question

I am trying to model the impact of a mining tailing pond, where elementary flows are expected to be stored long term. I have averaged the composition of the mine tailings based on this paper and the head assay https://encyclopedia.pub/entry/40229 so I know exactly how much (per ton) and which elements I can expect to flow back to water or soil.

When I built the model I saw my elementary flows had no calculated impact. For example K2O was put in as potassium/ emissions/ emission to soil/ emissions to non agricultural soil, but the characterizaiton page is blank for me. I dug deeper and found all my elementary flows for potassium have no characterizaiton factors. Is this true for all datasets, or am I missing some LCIA download? I have transfered this model between computers several times, so maybe some previously linked or mapped data set got lost?

My last resort would be somehow adding the blank flows to a impact category, but this seems more in the relm of geotechnical analysis.

Answer 1

It's not possible to answer this without knowing which methods packages you use and which databases. In general, the impact methods that are directly integrated in the databases have to be used, and/or the openLCA methods package has to be imported which is compatible to more than one database like e.g. ecoinvent, agrifootprint, agribalyse, and not only compatible to one database.

What you describe often happens when datasets are taken from one database or a random source and impact methods are taken from a completely different source, so that the same elementary flows will not "know each other" by having the same unique identifier.

You can download the free openLCA methods package and have a look in which impact categories potassium has characterisation factors.