ANNEX BAT CONCLUSIONS FOR THE NON-FERROUS METALS INDUSTRIES

1.7. BAT CONCLUSIONS FOR FERRO-ALLOYS PRODUCTION

1.7.2. Air emissions

1.7.2.2. Channelled dust emissions
BAT 154. In order to reduce dust and metal emissions to air from the storage, handling and transport of solid materials, and from pretreatment operations such as metering, mixing, blending and degreasing, and from tapping, casting and packaging, BAT is to use a bag filter.
BAT-associated emission levels: See Table 46.
BAT 155. In order to reduce dust and metal emissions to air from crushing, briquetting, pelletising and sintering, BAT is to use a bag filter or a bag filter in combination with other techniques.

Applicability
The applicability of a bag filter may be limited in the case of low ambient temperatures (– 20 °C to – 40 °C) and high humidity of the off-gases, as well as for the crushing of CaSi due to safety concerns (i.e. explosivity).
BAT-associated emission levels: See Table 46.
BAT 156. In order to reduce dust and metal emissions to air from an open or a semi-closed submerged arc furnace, BAT is to use a bag filter.
BAT-associated emission levels: See Table 46.
BAT 157. In order to reduce dust and metal emissions to air from a closed submerged arc furnace or a closed plasma dust process, BAT is to use one of the techniques given below.
	Technique	Applicability
a	Wet scrubber in combination with an ESP	Generally applicable
b	Bag filter	Generally applicable unless safety concerns exist related to the CO and H2 content in the exhaust gases
Descriptions of the techniques are given in Section 1.10.		
BAT-associated emission levels: See Table 46.
BAT 158. In order to reduce dust and metal emissions to air from a refractory-lined crucible for the production of ferro-molybdenum and ferro-vanadium, BAT is to use a bag filter.
BAT-associated emission levels: See Table 46.

Table 46
BAT-associated emission levels for dust emissions to air from ferro-alloys production
Parameter	Process	BAT-AEL (mg/Nm3)
Dust	Storage, handling and transport of solid materials Pretreatment operations such as metering, mixing, blending and degreasing Tapping, casting and packaging	2-5
	Crushing, briquetting, pelletising and sintering	2-5
	Open or semi-closed submerged arc furnace	2-5
	Closed submerged arc furnace or closed plasma dust process Refractory-lined crucible for the production of ferro-molybdenum and ferro-vanadium	2-5
As an average over the sampling period.		
As a daily average or as an average over the sampling period.		
The upper end of the range can be up to 10 mg/Nm3 for cases where a bag filter cannot be used.		
The upper end of the range may be up to 15 mg/Nm3 for the production of FeMn, SiMn, CaSi due to the sticky nature of the dust (caused e.g. by its hygroscopic capacity or chemical characteristics) affecting the efficiency of the bag filter.		
Dust emissions are expected to be towards the lower end of the range when emissions of metals are above the following levels: 1 mg/Nm3 for lead, 0,05 mg/Nm3 for cadmium, 0,05 mg/Nm3 for chromiumVI, 0,05 mg/Nm3 for thallium.		
The associated monitoring is in BAT 10.