Kinetics of Reductive Leaching of Low-grade Pyrolusite with Molasses Alcohol Wastewater in H2SO4

Hydrometallurgical Process and Kinetics of Leaching Manganese from Semi-Oxidized Manganese Ores with Sucrose

“…This phenomenon reduced the leaching efficiency. The experimental research verified that the effect of external diffusion could be easily ignored when the agitation speed was over 500 r·min −1 [23]. Therefore, the agitation speed was kept constant at 500 r·min −1 in the following tests.…”

“…Likewise, the leaching equations for MnO 2 and MnCO 3 were lnk = −4882.4/T + 8.9721 and lnk = −6414/T + 13.94 with R 2 of 0.9710 and 0.9679, and the apparent activation energies were 40.59 and 53.33 kJ·mol −1 , respectively. The apparent activation energy of TMn, MnO 2 and MnCO 3 indicated that the leaching processes of semi-oxidized manganese ore were controlled by diffusion through the insoluble layer of the associated minerals [23,27]. The value clearly confirms that this process was controlled by chemical reaction and diffusion, simultaneously.…”

“…The morphology of reacted particles supported the appropriateness of using the shrinking core model (SCM) to describe the kinetics of leaching in semi-oxidized manganese ore. Generally speaking, the classical models could be concluded to three equations as follows [23,26,27]: surface chemical reaction controlled kinetic model (Equation (4)), internal diffusion controlled kinetic model (Equation (5)) and mixed-controlled kinetic model (Equation (6)). …”

Kinetic Study of the Leaching of Low-Grade Manganese Ores by Using Pretreated Sawdust as Reductant

“…There are a large number of reports about using organics as reductants to leach manganese oxide ores [9,10]. Su et al [9], on the reductive leaching of manganese ore in the presence of alcohol wastewater, showed that the leaching efficiency of manganese increases with the temperature, H 2 concentration, organic matter in alcohol wastewater, and decreasing ore particle size. Although using these organics has some advantages, there has been little application value in industry due to the high cost and consumption rate.…”

Reductive Leaching of Low-Grade Pyrolusite with Formic Acid

“…[13] For the low-or middle-grade pyrolusite, hydrometallurgy is extensively applied in the reduction of quadrivalence manganese because of its efficiency and economy. Generally, there are three kinds of hydrometallurgical reductants: organic materials including glucose, [14][15][16] sucrose, [17] cellulose, [18] and methanol [19] ; inorganic materials including pyrite, [20] hydrogen peroxide, [21] and sulfur dioxide [22] ; biomass including molasses [23] and molasses alcohol wastewater, [24] sawdust, [25] corncob, [26] dried leaves, [27] waste tea-leaves, [28] and so on. Although there have been many reductants reported on hydrometallurgy, few C 1 organic reductants have been investigated.…”