Mfg. composted agricultural fertiliser from domestic rubbish - by fermentation after sifting out glass and plastic material

摘要

Process includes the following steps:- (a) the coarse compost is sifted via a 6 mm mesh screen to separate an oversize fraction from the fines, (b) the oversize fraction is put into a mixer together with an oxygenated mineral acid, pref. H2SO4, H3PO4 or HNO3. The mixture is allowed to mature and is then neutralised, after which it is sifted mature and is then neutralised, after which it is sifted through a 5 mm. Mesh screen from which the oversize fraction is either recycled to stage (a) or neutralized with lime and discarded. (c) organic and/or mineral substances are added to the fines from the second screening to produce a rich fertiliser or manure. When H2SO4 is used, the concn. is pref. between 40% and 78% and the quantity (anhydrous) is between 4 and 8 kg per 100 kg of compost, the temp. being between ambient and about 80 degrees C in stage (b) the mixing operation pref. lasts for between 30 mins. and 4 hrs. maturation for between 10 and 60 days and the neutralisation is carried out with an ammonia base compound. Used in mfg. a rich manure or fertiliser from domestic rubbish. The prod. is partic. suitable for market gardens. The only particles of glass and plastic which remain in the prod. are to small to be harmful. The prod. can be enriched with organic and/or inorganic additives.