The pyrophosphate may be potassium pyrophosphate and/or sodium pyrophosphate.

An electrolyte containing an aqueous solution having potassium hydroxide and potassium pyrophosphate dissolved therein.

To this end, the method involves processing the humate-containing compound (turf, sapropel, lignite) in the presence of water using an alkaline agent that consists of potassium pyrophosphate, and carrying out a nitrogen enrichment.

If dilute nitric acid is still not washed, then with potassium pyrophosphate, sodium carbonate or borax melting melt.