Separation of galena and chalcopyrite using the difference in their surface acid corrosion characteristics

Galena(PbS)and chalcopyrite(CuFeS_(2))are sulfide minerals that exhibit good floatability characteristics.Thus,efficiently separating them via common flotation is challenging.Herein,a new method of surface sulfuric acid corrosion in conjunction with flotation separation was proposed,and the efficient separation of galena and chalcopyrite was successfully realized.Contact angle test results showed a substantial decrease in surface contact angle and a selective inhibition of surface floatability for corroded galena.Meanwhile,the contact angle and floatability of corroded chalcopyrite remained almost unaffected.Scanning electron microscope results confirmed that sulfuric acid corrosion led to the formation of a dense oxide layer on the galena surface,whereas the chalcopyrite surface remained unaltered.X-ray photoelectron spectroscopy results showed that the chemical state of S^(2-)on the surface of corroded galena was oxidized to SO_(4)^(2-).A layer of hydrophilic PbSO4was formed on the surface,leading to a sharp decrease in galena floatability.Meanwhile,new hydrophobic CuS_(2),CuS,and Cu_(1-x)Fe_(1-y)S_(2-z)species exhibiting good floatability were generated on the chalcopyrite surface.Finally,theoretical analysis results were further verified by corrosion–flotation separation experiments.The galena–chalcopyrite mixture was completely separated via flotation separation under appropriate corrosion acidity,corrosion temperature,and corrosion time.A novel approach has been outlined in this study,providing potential applications in the efficient separation of refractory copper–lead sulfide ore.

Recovery of scandium from silicate minerals by high-pressure leaching in sulfuric acid

This study investigated the leaching of scandium from a Sc-bearing silicate ore.The Sc concentrate obtained by beneficiation pre-enrichment has 1.03×10^(−4) wt%Sc and 14.66 wt%Fe.The main Sc-bearing minerals are limonite,chlorite,sericite,and hornblende,in the form of isomorphism.High-pressure leaching(HPL)with sulfuric acid(98 wt%)and NaF was used to dispose this samples.The Sc leaching efficiency of 91.82%was obtained under the optimum conditions,which are pressure of 5.0×10^(5) Pa,A/O value of 1.1,L/S value of 1.8,NaF dosage of 2 wt%,at 130℃ for 6 h.The X-ray diffraction(XRD)and scanning electron microscopy(SEM)results show that the residue is mainly quartz phase in the multihole shape.Compared with ordinary leaching for silicate,high-pressure leaching has significant advantages in saving acid and energy consumption.

钛磁铁矿的旋流离心连续分级实验

分析了旋流离心连续分选机的作用原理并用其对攀枝花钛磁铁矿进行分级实验.结果表明,旋流离心连续分选机的给矿浓度、给矿压力、反冲水压力、溢流口压力和沉砂口压力等操作条件对沉砂的粒度分布均有明显影响,在给矿浓度5%、给矿压力70-72 k Pa、反冲水压力5 k Pa、溢流口压力40-50 k Pa、沉砂口压力45-55 k Pa的操作条件下,钛磁铁矿分级后0.15-2.00和0.074-0.15 mm粒级的颗粒分别占80%-83%和60%-65%,小于0.074 mm的颗粒仅占22%-28%.

Bioinspired C/TiO_2 photocatalyst for rhodamine B degradation under visible light irradiation

Papilio paris butterfly wings were replicated by a sol-gel method and a calcination process, which could take advantage of the spatial features of the wing to enhance their photocatalytic properties. Hierarchical structures of P. paris-carbon-TiO_2(PP-C-TiO_2) were confirmed by SEM observations. By applying the Brunauer-Emmett-Teller method, it was concluded that in the presence of wings the product shows higher surface area with respect to the pure TiO_2 made in the absence of the wings. The higher specific surface area is also beneficial for the improvement of photocatalytic property.Furthermore, the conduction and valence bands of the PPC-TiO_2 are more negative than the corresponding bands of pure TiO_2, allowing the electrons to migrate from the valence band to the conduction band upon absorbing visible light. That is, the presence of C originating from wings in the PP-C-TiO_2 could extend the photoresponsiveness to visible light. This strategy provides a simple method to fabricate a high-performance photocatalyst,which enables the simultaneous control of the morphology and carbon element doping.