Processing mixed nickel‑cobalt hydroxide precipitate by sulfuric acid leaching followed by selective oxidative precipitation of cobalt and manganese

Use of O3 and O3/H2O2 for degradation of organic matter from Bayer liquor towards new resource management: Kinetic and mechanism

“…Moreover, the results presented here demonstrate that oxidative techniques here by ozone may be applied even in extremely alkaline conditions, even though AOPs are commonly applied in milder conditions (pH around 6, for instance), such as the degradation of medicines in urban wastewater, [ 28,62 ] removal of surfactants from mining tailings, [ 63 ] and precipitation of metals from metallurgical processes. [ 60,64 ]…”

“…Also, as demonstrated by Ichlas et al, [ 64 ] the energy requirement for ozone production to be applied in the metallurgical process might be helpful to consider the industrial application. Based on the most optimized condition found in this study, 5.5 g of ozone was consumed per litre of Bayer liquor, assuming that each mole of organic carbon consumed 0.65 mol of ozone.…”

“…[6] Moreover, the results presented here demonstrate that oxidative techniques here by ozone may be applied even in extremely alkaline conditions, even though AOPs are commonly applied in milder conditions (pH around 6, for instance), such as the degradation of medicines in urban wastewater, [28,62] removal of surfactants from mining tailings, [63] and precipitation of metals from metallurgical processes. [60,64] The importance of studies for organic matter removal from Bayer liquor is getting more crucial since the quality of bauxite ores in Brazil and around the world has been decreasing. As a result, the amount of organic matter of bauxites for alumina production has increased, directly impacting the product's quality.…”

“…Moreover, most modern equipment would require less than 20 kWh, decreasing the energy consumption for ozone production. [40,45,60,64] Indeed, 99% was used for ozone generation, and future applications using oxygen-enriched air may require more energy; on the other hand, the technology has been advancing, and new generators are launched from which less energy is consumed. These analyses and the process efficiency depicted that using an AOP is technically and economically feasible for application in the Bayer process for organic matter removal.…”

Iron Removal Process From Nickel Pregnant Leach Solution Using Sodium Hydroxide

“…The PLS from the leaching process could also be processed before the precipitation process via a solvent extraction route to separate the dissolved metal into a different solution to produce higher-purity PLS [5]- [6]. MHP is a commercially proven technique [7]; MHP has a nickel content of around 3,8%-34%, while MSP is about 55%. MHP has received a lot of attention because it has several advantages over the MSP method, such as easier precipitation to obtain nickel and cobalt as concentrates and a more accessible nickel and cobalt extraction process [8]- [9].…”