• Resources Recycling
• /
• v.17 no.3
• /
• pp.42-47
• /
• 2008

In this work, the dissolution behavior of Pb from the complex sulphide concentrates containing Galena and Arsenopyrite by alkaline oxidative leaching was studied. The influences of leaching temperature, oxygen partial pressure, leaching time and NaOH concentration of leaching solution were examined at the leaching conditions in the range of $100^{\circ}C{\sim}140^{\circ}C$ temperature, $40psi{\sim}100psi\;PO_2$ and $0.5M{\sim}2M$ NaOH concentration. The optimum result was obtained at the leaching condition of leaching temperature $120^{\circ}C$, 100psi $PO_2$, leaching time 30min. and 2M NaOH concentration of leaching solution.

• Applied Chemistry for Engineering
• /
• v.7 no.3
• /
• pp.453-463
• /
• 1996

The chlorination of reagent PbS and natural ore galena with $NH_4Cl$ was investigated to find a new extraction metallurgical process of lead. The proper conditions for the chlorination of galena were that reaction temperature ; $425^{\circ}C$, $NH_4Cl$ weight ratio to galena ; 4.0 and reaction time ; 2hrs. Under these conditions, PbS was successfully chlorinated to $PbCl_2$ and the conversion was 90%. And also $NH_4Cl$ was effectively decomposed and was separated $NH_3$ and HCl. HCl was a chlorinating agent and 90% of $NH_3$ was recovered through this chlorination reaction.

• Resources Recycling
• /
• v.19 no.3
• /
• pp.9-15
• /
• 2010

Domestic gold mine tailings, generally, contain a lot of non-metallic silica and clay minerals. These minerals can be separated from the tailings by various physical separation methods and used as raw materials for cements and ceramic products. In these physical separation procedures, metallic complex sulfides, in which Au and metallic constituents such as Pb, As and Fe were concentrated, were obtained as a by-product. These metallic constituents should be removed or separated from the by-product to extract Au efficiently. In this work, removal and separation processes of Pb, As, and Fe from the by-product were investigated. Pb was removed to under 3% by using alkaline oxidative leaching at the leaching condition of $120^{\circ}C$, 2M NaOH, 100psi $Po_2$, 250r.p.m., 4 wt.% solid and 30 min. leaching time. The leached residue was roasted and separated magnetically to obtain a non-magnetic product contained <0.2% As, <3% Fe and high concentrated Au more than 8,000 ppm.

• Economic and Environmental Geology
• /
• v.17 no.2
• /
• pp.115-139
• /
• 1984

The Cu-Pb-Zn-Ag hydrothermal vein-type deposits which comprise the Sambong mine occur within calc-alkaline volcanics of the Cretaceous Gyeongsang Basin. The ore mineralization took place through three distinct stages of quartz (I and II stages) and calcite veins (III stage) which fill the pre-existing fault breccia zones. These stages were separated in time by tectonic fracturing and brecciation events. The reflection variations of one mineral depending on mineralization sequence are considered to be resulted from variation in its chemical composition due to different physico-chemical conditions in the hydrothermal system. The reflection power of sphalerite increases with the content of Fe substituted for Zn. Reflectances of the sphalerite grain are lower on (111) than on (100) surface. The spectral profiles depend on the internal reflection color. Sphalerite, showing green, yellow and reddish brown internal reflection, have the highest reflection power at $544m{\mu}$ (green), $593m{\mu}$ (yellow) and $615m{\mu}$ (red) wavelength, respectively. Chalcopyrite is recognized as biaxial negative from the reflectivity data of randomly oriented grains measured at the most sensitivity at $544m{\mu}$. The microindentation hardness against the Fe content (wt. %) for the sphalerite increases to 8.05% Fe and then decreases toward 9.5% Fe content. Vickers hardness of the sphalerite is considerably higher on surface of (100) than on (111). The relationship between Vickers hardness and crystal orientation of the galena was determined to be $VHN_{(111)}$ > $VHN_{(210)}$ > $VHN_{(100)}$. The softer sulfides have the wider variation of the diagonal length in the indentation. Diagonal length in the indentation is pyrite