Lead Recovery from a Lead Concentrate throughout Direct Smelting Reduction Process with Mixtures of Na2CO3 and SiC to 1000 °C

Abstract

Lead was recovered through a direct smelting reduction route from a lead concentrate by using mixtures of Na2CO3 and SiC to 1000 °C. The lead concentrate was obtained from the mining State of Zacatecas, México by traditional mineral processing and froth flotation. The experimental trials showed that 86 wt.% of lead with a purity up to 97% can be recovered from the lead concentrate by a single step reduction process when 40 wt.% Na2CO3 and 0.4 g SiC were used in the initial charge. The process was modeled in the thermodynamic software FactSage 7.3 to evaluate the effect of adding different amounts of Na2CO3 on the lead recovery rates while holding constant the SiC amount and temperature. The stability phase diagram obtained showed that an addition of 34 wt.% Na2CO3 was enough to reach the highest lead recovery. It was observed that the interaction of Na2CO3 and SiC at a high temperature promotes the formation of C and Na2O, and SiO2, respectively, where the Na2O partially bonds with silica and sulfur forming Na2S and sodium silicates which may decrease the SO2 emissions and increase the weather degradation of the slag. The PbS was mainly reduced by the produced C and CO formed by the interaction between Na2CO3 and SiC at 1000 °C. The predicted results reasonably match with those obtained experimentally in the lead recovery rates and compounds formation.

Processing of titanium-containing ores for the production of titanium products: A comprehensive review

“…In particular, soda is added to the reduction charge [ [50] , [51] , [52] ], which is both a reduction catalyst and a flux that reduces the viscosity of the slag. The introduction of sodium oxide (Na 2 O) into the mixture leads to the formation of low-melting sodium titanates (Na 2 TiO 3 with a melting point of 1030 °C, Na 2 Ti 2 O 5 –985 °C, and Na 2 Ti 3 O 7 –1128 °C).…”

“…The introduction of sodium oxide (Na 2 O) into the mixture leads to the formation of low-melting sodium titanates (Na 2 TiO 3 with a melting point of 1030 °C, Na 2 Ti 2 O 5 –985 °C, and Na 2 Ti 3 O 7 –1128 °C). The influence of soda additives (1.5–2.5 %) on phase transformations during the solid-phase reduction of a poor (3 % TiO 2 ) titanomagnetite concentrate with hydrogen (H 2 ) in the temperature range of 700–1200 °C was studied [ 52 ]. At the final stage of the process (i.e.…”

Lead (Pb) Pollution in Soil: A Systematic Review and Meta-Analysis of Contamination Grade and Health Risk in Mexico

“…Since Pb is malleable, ductile, and resistant to corrosion [11], it has been widely used in the battery industry, machinery manufacturing, and medicine, resulting in increased world Pb production [12]. Refined Pb has been obtained from mined ore since ancient times, but since the early 1980s, it has also been recovered from used Pb products (e.g., Pb-acid batteries) by secondary smelting [13].…”