Division 42

United Kingdom

BAT is to reduce HCl and HF 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 1.10.4 and 1.10.6.
(i) Selection of raw materials for the batch formulation with a low content of chlorine and fluorine	The applicability may be limited by the constraints of the batch formulation for the type of glass produced at the installation and the availability of raw materials
(ii) Minimisation of the fluorine content in the batch formulation and optimisation of the fluorine mass balance The minimisation of fluorine emissions from the melting process may be achieved by minimising/reducing the quantity of fluorine compounds (e.g. fluorspar) used in the batch formulation to the minimum commensurate with the quality of the final product. Fluorine compounds are added to the batch formulation to give an opaque or cloudy appearance to the glass	The technique is generally applicable within the constraints of the quality requirements for the final product
(iii) Dry or semi-dry scrubbing, in combination with a filtration system	The technique is generally applicable
(iv) Wet scrubbing	The technique is generally applicable within technical constraints; i.e. need for a specific waste water treatment plant. High costs, waste water treatment aspects, including restrictions in the recycle of sludge or solid residues from the water treatment, may limit the applicability of this technique

Table 32

BAT-AELs for HCl and HF emissions from the melting furnace in the domestic glass sector

Parameter	BAT-AEL
A conversion factor of 3 × 10^–3 has been applied (see Table 2). However, a case-by-case conversion factor may have to be applied for specific productions.
The lower levels are associated with the use of electric melting.
In cases where KCl or NaCl are used as a refining agents, the BAT-AEL is < 30 mg/Nm³ or < 0,09 kg/tonne melted glass.
The lower levels are associated with the use of electric melting. The higher levels are associated with the production of opal glass, the recycling of filter dust or where high levels of external cullet are used in the batch formulation.
Parameter	mg/Nm³	kg/tonne melted glass^f2
Hydrogen chloride, expressed as HCl^f3 ^f4	< 10 – 20	< 0,03 – 0,06
Hydrogen fluoride, expressed as HF^f5	< 1 – 5	< 0,003 – 0,015

Annotations

f1: A description of the techniques is given in Sections 1.10.4 and 1.10.6.
f2: A conversion factor of 3 × 10^–3 has been applied (see Table 2). However, a case-by-case conversion factor may have to be applied for specific productions.
f3: The lower levels are associated with the use of electric melting.
f4: In cases where KCl or NaCl are used as a refining agents, the BAT-AEL is < 30 mg/Nm³ or < 0,09 kg/tonne melted glass.
f5: The lower levels are associated with the use of electric melting. The higher levels are associated with the production of opal glass, the recycling of filter dust or where high levels of external cullet are used in the batch formulation.