Large Volume Inorganic Chemicals - Ammonia ... - ammk-rks.net

Chapter 55.5 BAT for phosphoric acidBAT is to apply the common BAT given in Section 1.5.BAT for storage is to apply BAT given in [5, European Commission, 2005].BAT for existing installations using a wet process is to achieve P 2 O 5 efficiencies of 94.0 –98.5 %, e.g. by applying one or a combination of the following techniques:• dihydrate process or improved dihydrate process (see Section 5.4.1)• increasing the residence time (see Section 5.4.1)• recrystallisation process (see Sections 5.4.3, 5.4.4 and 5.4.5)• repulping (see Section 5.4.6)• double-stage filtration (see Section 5.4.4 and 5.4.5)• recycling the water from the phosphogypsum pile (see Section 5.4.1)• selection of phosphate rock (see Sections 5.4.9 and 5.4.10).BAT for new installations is to achieve P 2 O 5 efficiencies of 98.0 % or higher, e.g. by applying arecrystallisation process with double-stage filtration (see Sections 5.4.4 and 5.4.5).BAT for the wet process is to minimise the emissions of P 2 O 5 by applying one or a combinationof the following techniques (see Section 5.4.12):• entrainment separators, where vacuum flash coolers and/or vacuum evaporators are used• liquid ring pumps with recycling of the ring liquid to the process• scrubbing with recycling of the scrubbing liquid.BAT is to reduce dust emissions from rock grinding, e.g. by application of fabric filters orceramic filters and to achieve dust emission levels of 2.5 – 10 mg/Nm 3 (see Section 5.4.8).BAT is to prevent dispersion of phosphate rock dust by using covered conveyor belts, indoorstorage, and frequently cleaning/sweeping the plant grounds and the quay (see Section 5.4.8).BAT is to reduce fluoride emissions by application of scrubbers with suitable scrubbing liquidsand to achieve fluoride emission levels of 1 – 5 mg/Nm 3 expressed as HF (see Section 5.4.7).BAT for wet processes is to market the generated phosphogypsum and fluosilicic acid, and, ifthere is no market, to dispose of it. For precautionary measures concerning phosphogypsum pileand recycling water from these piles (see Section 5.4.13).BAT for wet processes is to prevent fluoride emissions to water, e.g. by application of indirectcondensation system or by a scrubbing with recycling or marketing the scrubbing liquid (seeSection 5.4.7).BAT is to treat waste water by applying a combination of the following techniques (see Section5.4.7)• neutralisation with lime• filtration and optionally sedimentation• recycling of solids to the phosphogypsum pile.Large Volume Inorganic Chemicals – Ammonia, Acids and Fertilisers 255