Division 59

United Kingdom

BAT is to reduce SO_X emissions from the melting furnace by using one or a combination of the following techniques:

Technique^f1	Applicability
A description of the techniques is given in Sections 1.10.3 and 1.10.6.
(i) Minimisation of the sulphur content in the batch formulation and optimisation of the sulphur balance	In glass wool production, the technique is generally applicable within the constraints of the availability of low-sulphur raw materials, in particular external cullet. High levels of external cullet in the batch formulation limit the possibility of optimising the sulphur balance due to a variable sulphur content. In the stone wool production, the optimisation of the sulphur balance may require a trade-off approach between the removal of SO_X emissions from the flue-gases and the management of the solid waste, deriving from the treatment of the flue-gases (filter dust) and/or from the fiberising process, which may be recycled into the batch formulation (cement briquettes) or may need to be disposed of
(ii) Use of low sulphur content fuels	The applicability may be limited by the constraints associated with the availability of low sulphur fuels, which may be impacted by the energy policy of the Member State
(iii) Dry or semi-dry scrubbing, in combination with a filtration system	Electrostatic precipitators are not applicable to cupola furnaces for stone wool production (see BAT 56)
(iv) Use of wet scrubbing	The technique is generally applicable within technical constraints; i.e. need for a specific waste water treatment plant

Table 49

BAT-AELs for SO_X emissions from the melting furnace in the mineral wool sector

Parameter	Product/conditions	BAT-AEL
The conversion factors of 2 × 10^–3 for glass wool and 2,5 × 10^–3 for stone wool have been used (see Table 2).
The lower levels of the ranges are associated with the use of electric melting. The higher levels are associated with high levels of cullet recycling.
The BAT-AEL is associated with conditions where the reduction of SO_X emissions has a high priority over a lower production of solid waste.
When reduction of waste has a high priority over SO_X emissions, higher emission values may be expected. The achievable levels should be based on a sulphur balance.
Parameter	Product/conditions	mg/Nm³	kg/tonne melted glass^f2
SO_X expressed as SO₂	*Glass wool*
	Gas-fired and electric furnaces^f3	< 50 – 150	< 0,1 – 0,3
	*Stone wool*
	Gas-fired and electric furnaces	< 350	< 0,9
	Cupola furnaces, no briquettes or slag recycling^f4	< 400	< 1,0
	Cupola furnaces, with cement briquettes or slag recycling^f5	< 1 400	< 3,5

Annotations

f1: A description of the techniques is given in Sections 1.10.3 and 1.10.6.
f2: The conversion factors of 2 × 10^–3 for glass wool and 2,5 × 10^–3 for stone wool have been used (see Table 2).
f3: The lower levels of the ranges are associated with the use of electric melting. The higher levels are associated with high levels of cullet recycling.
f4: The BAT-AEL is associated with conditions where the reduction of SO_X emissions has a high priority over a lower production of solid waste.
f5: When reduction of waste has a high priority over SO_X emissions, higher emission values may be expected. The achievable levels should be based on a sulphur balance.