Phosphates 2020: Meet the Glatt Experts and learn more about PHOS4green
08.03. - 10.03.2020
Paris Marriott Rive Gauche, Paris, France
This P-recovery process is market-ready: At 13th CRU Phosphates, the annual meeting for commercial and operational professionals in the fertilizer, feed and industrial phosphates industries, Glatt will present a waste-free process that recycles the phosphorus from sewage-sludge ash to produce ready-to-use, high-quality fertilizers. The market-ready process fulfils the legal obligation of the German fertilizer ordinance (DüMV), which requires waste-disposal companies to recover phosphorus, and can recover phosphorus from the ash of incinerated sewage sludge.
In the first step of the two-stage PHOS4green process, a suspension is produced from the phosphate-containing ash, a mineral acid (for example, phosphoric acid) and, depending on the objective, other components. This acid treatment macerates the ash, and converts insoluble phosphates into a form that can be absorbed by plants. In the second step, the suspension is sprayed into a fluidized-bed granulator, which is blown with hot air. As the water evaporates, the granules grow in size before being discharged. Product is screened to separate granules of the desired size from over- and undersized solids, which are recirculated to the granulator.
"The process recycles 100% of the ash," says Jan Kirchhof, Senior Sales Manager Process and Plant Engineering at Glatt. "By flexibly adapting the recipes, a wide variety of fertilizers, including complex varieties (NP, PK, NPK), can be produced, which can be placed on the market as new products," he says.
The process has been tested on various sludge ashes, from mono-incineration plants, in a pilot plant at Glatt's Technology Center in Weimar. The pilot unit can produce approximately 60 kg/h of standard fertilizer. Several engineering phases have already been completed for the first large-scale commercial plant, which is now under construction. The modular system can be configured for the desired capacity, with various configurations handling a capacity of 10,000–40,000 ton/yr of sludge ash. Nevertheless smaller and larger plant set-ups are possible.