Société des Fonderies de Plomb de Zellidja

Objective of the smelter
Process lead ores into metal lead with 99.99% content and various by-products.

Charge preparation
All products are sulphides and contain metals in various proportions.
The charge is balanced by the proportioning of ores and the addition of flux by means of automatic constant-weight feeders.
All this is mixed and then nodulized.

Sinterization
The roasting machine has a 48m² active surface area.
It processes PbS into PbO and agglomerates the charge for a smooth operation of the reduction furnace.
The machine is in continuous operation.

Shaft furnace
It is a Water-Jacket furnace of 11.7 m² whose walls are cooled with water in closed circuit.
Charges of coke and agglomerates are alternatively fed into the top of the furnace.
Air is blown at the bottom of the furnace.
These charges go down continuously according to the speed of reactions.
The main reactions are:
C + O2 -> CO2
C + CO2 -> 2 CO
CO + PbO -> CO2 + Pb
and all slagging reactions.
The molten charge comes out of the furnace into a settler where lead is separated from slags.
The chemical composition of slags, balanced during charge preparation, makes it possible to have a fusible product containing a minimum of lead.
The content of lead, called base bullion at this stage, is around 98%. It is conveyed in liquid form to the refinery.

Refining
The plant runs with 150 tons batches.
Various metals are successively removed: