QSL process

Process. The QSL process (14) is a continuous single-step process having great flexibiUty in regard to the composition of the raw materials. In this process the highly exothermic complete oxidation, ie, the roasting reaction, can be avoided to some extent in favor of a weakly exothermic partial oxidation directly producing metallic lead. However, the yield of lead as metal is incomplete due to partial oxidation of lead to lead oxide. 

The entire QSL process takes place in a single reactor as shown in Figure 6 (15). The reactor consists of an almost horizontal, refractory-lined cylinder, which can be tilted by 90° when operation is intermpted. Concentrates, fluxes, recirculated flue dust, and normally a small amount of coal, depending on the type of concentrate, are pelletized. The pelletizer ensures that the raw materials are mixed to the required degree of uniformity. 

Two processes, developed for the direct processing of lead sulfide concentrates to metallic lead (qv), have reached commercial scale. The Kivcet process combines flash smelting features and carbon reduction. The QSL process is a bath-smelting reactor having an oxidation 2one and a reduction 2one. Both processes use industrial oxygen. The chemistry can be shown as follows ... 

Boliden s Kaldo process of, 14 742-743 Isasmelt process of, 14 743-745 Kivcet process of, 14 739-740 Outokumpu process of, 14 745 QSL process of, 14 740-742 Lead stabilizers, for PVC polymers, 25 671 Lead storage battery, 14 783. See also Lead-acid batteries Lead-calcium alloy batteries... 

Both of the operating QSL plants participated in the survey. The current ratio of primary to secondary materi at the smelter in Onsan is 64.5 35.5 and in Stolberg it is 80 20. Both operations, however, rqxrrted a high flexibility of the process in terms of feed composition. The QSL process can deal with a wide variety of feeds, and much higher rates of secondary materials have been charged in the past. Lead scrap materials can be directly charged into the converter. 

Smelting Updraught Sinter Machine / Blast Furnace Updraught Sin Machine / Blast Furnace Updraught Sinter Machine / Imperial Smelting Furnace QSL-Process Short Rotary Furnace Sinter Machine / Blast Furnace Dross Rovorberatory... 

Smelting KIVCET Updrau Sinter Machine/ Blast Furnace UpdraugM Sinter Machine/ Blast Furnace Updraught Sintor Machine/ Blast Furnace QSL-Process... 

The QSL process has significant advantages over sinter plant-blast furnace technologies. It is a single step smelting process, is well contained with low emissions and can accept a wide range of feed materials. It does not require dry feed as with the Kivcet process however, in its early stages it did not prove to be as robust or as flexible as the Kivcet process, particularly with attempts to use natural gas for reduction and in its ability to handle quantities of zinc plant residues. 

Direct smelting processes provide alternatives to the sinter plant-blast furnace above, up to the stage of crude bullion production, but still require the addition of refining operations to produce high-grade lead. Three alternatives have been evaluated - the Kivcet process, the QSL process and the Isasmelt process - as typical of the top submerged lance slag bath reactor. Evaluations are based on comparable feeds, predominantly lead concentrates with low residue inputs. 

Operating parameters for the QSL process have been assumed as follows per tonne of product lead oxygen requirements... 

Summary of energy inputs for the Queneau-Schuhmann-Lurgi (QSL) process. 

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