Xuewen Wang

Removal of impurities from copper electrolyte with adsorbent containing antimony

Abstract A new adsorbent was synthesized with antimony oxide and barium sulfate to be used in the purification of copper electrolyte. The adsorbent possesses not only the properties of common adsorbents, but also special merits of its own. It can adsorb antimony from copper electrolyte, which then becomes adsorbent itself after regeneration; so the more the use-times, the more the amount of the adsorbent. Under the conditions of fixed contents of Cu and H 2 SO 4 in copper electrolyte, the adsorbent can adsorb 90% of Bi, 80% of Sb, as well as parts of As. The paper presents the results of adsorbent synthesis, characterization, regeneration, and metal ion separation. The feasibility of utilizing this adsorbent for copper electrolyte purification has been examined.

Extraction of molybdenum and nickel from roasted Ni–Mo ore by hydrochloric acid leaching, sulphation roasting and water leaching

Abstract To extract molybdenum and nickel from the roasted Ni–Mo ore, a process of hydrochloric acid leaching, sulphation roasting and water leaching was investigated. The results showed that this process could get a high leaching rate of Mo and Ni. Under the optimum conditions of hydrochloric acid leaching (roasted Ni–Mo ore leached with 0.219 mL/g hydrochloric acid addition at 65 °C for 30 min with a L / S ratio of 3 mL/g), sulphation roasting (51.9% sulfuric acid addition, roasting temperature 240 °C for 1 h), followed by leaching with the first stage hydrochloric acid leaching solution at 95 °C for 2 h, the leaching rates of Mo and Ni reached 95.8% and 91.3%, respectively.

Existing form of Mo(VI) in acidic sulfate solution

The existing form of molybdenum in acidic sulfate solution was studied by means of ion exchange, infrared (IR) spectra and X-ray photoelectron spectroscopy (XPS). The results indicate that the anionic molybdenum species are predominant in acidic sulfate solution, and Mo(VI) can combine with sulfate radical to form heteropoly acid anions [Mo2O5(SO4)2]2− and [MoO2(HSO4)4]2−. With the decrease in solution pH from 1.92 to 0.06, the existing form of Mo(VI) changes from Mo7O21(OH)33− to [Mo2O5(SO4)2]2− and then becomes [MoO2(HSO4)4]2−, which results in the decrease in the resin adsorption capacity for molybdenum.

Extraction of molybdenum from acidic leach solution of Ni–Mo ore by solvent extraction using tertiary amine N235

ABSTRACT Tertiary amine N235 diluted with sulphonated kerosene containing sec-octyl alcohol as a phase modifier was used to directly extract molybdenum from the acidic leach solution of Ni–Mo ore. The results indicated that the extraction of molybdenum can reach more than 88% using a solvent extraction system consisting of 10u2005vol.-% N235 and 10u2005vol.-% sec-octyl alcohol in sulphonated kerosene with an O/A ratio of 1:2 at room temperature for 20u2005min. The extracted molybdenum species of Mo7O21(OH)33–, MoO2(SO4)22– and MoO2(HSO4)42– in loaded organic phase were identified, and the predominant species was Mo7O21(OH)33–. Molybdenum in the loaded organic phase can be stripped with ammonia solution, and the stripping of molybdenum can reach 95.8% at an O/A ratio of 7:1, phase contact time of 10u2005min, and the ammonia concentration of 6u2005molu2005L−1.

Extraction of Vanadium and Chromium from the Material Containing Chromium, Titanium and Vanadium

To recover iron, titanium, vanadium and chromium from vanadium bearing titanomagnetite, a process of direct reduction has been proposed. After magnetic separation, a material containing titanium, vanadium and chromium was obtained. In this paper, a salt-roasting process was proposed to extract vanadium and chromium from the material containing titanium, vanadium and chromium. The effects of the several parameters that included roasting temperature, roasting time and the addition of sodium carbonate were investigated. Under the most suitable conditions including a roasting temperature of 900 °C, roasting time of 2 h and sodium carbonate addition of 33 wt%, the leaching of vanadium and chromium reached 91.2 and 68.4%, respectively. After leaching, the leach residue can be used as the raw material for extraction of titanium.

A review of processing technologies for vanadium extraction from stone coal

ABSTRACT Due to the poor vanadium recovery of mineral processing, the extraction of vanadium from stone coal is directly carried out by metallurgical processes. Salt process, acid process and alkali process three types of stone coal leaching including nine technologies are introduced. However, all of these nine leaching technologies have serious disadvantages and up to now the stone coal has not been efficiently utilised. Chemical precipitation, ion exchange and solvent extraction all can be used to extract vanadium from stone coal leach solutions. Due to the low extraction of vanadium, Chemical precipitation method is rarely used. Ion exchange is only used for the extracting of V(V) from the leach solution. For the extraction of low valence, P204 is one of effective extraction agent. The lately developed technology, LTSRWL, is characterised by high recovery of vanadium, comprehensive recovery of other valuable elements and environmental friendliness, which make it become the best option.

Extraction of vanadium from V-Cr bearing reduced residue by selective oxidation combined with alkaline leaching

ABSTRACT The extraction of vanadium from the V-Cr-bearing reduced residue formed from the waste water by reduction and neutralization in the process of extracting vanadium from vanadium slag was investigated by selective oxidation combined with alkaline leaching. Vanadium pentoxide is used as the selective oxidant. The effects of leaching temperature, leaching time, solution pH and vanadium pentoxide addition were studied. Under the most suitable conditions including a leaching temperature of 95°C, leaching time of 3u2005h, solution pH 13.0 and vanadium pentoxide addition of 4.55u2005wt-%, the leaching of vanadium reached 93.4% and the leaching of chromium was 17.1%.

Kinetics of Extracting Vanadium from Stonecoal by Alkali Leaching

Vanadium was leached from roasted stone coal by NaOH solution, and the effect of leaching temperature, leaching time, addition of NaOH liquid to solid ratio, the grinding fineness of stone coal, and stirring speed on the vanadium leaching rate was studied. The kinetics analysis for the process is presented by the shrinking core model. The results show that the vanadium leaching ratio of roasted stone coal can be beyond 75% at the 6% NaOH addition, leaching temperature of 95°C, leaching time of 7h, liquid to solid ratio of 1.2mL/g, and grinding fineness of 0.111mm. The leaching process is controlled by interfacial reaction kinetics and the apparent activation energy was 59.36kJ/mol.

Selective Removal of the Impurity Silicon and Aluminum in Titanium Concentrate

The Panzhihua titanium concentrate contains high contents impurity of Mg and Al, and it is difficult to prepare high grade titanium slag. To solve this problem, a sodium salt roasting-acid leaching process was proposed for removing the impurities in titanium concentrate. Na2CO3 and titanium concentrate were mixed with the proportion of 1:4, and then the mixture was roasted at 700 °C for 2h. After roasting, the calcine was leached with HCl solution. The experimental results showed that the removal rate of silicon and aluminum can reach more than 85% and 80%, respectively, at leaching temperature of 70°C, leaching time of 4h, HCl addition of 5ml and liquid-solid ratio of 4:1.

STRIPPING OF Fe(III) FROM P204 BY OXALIC ACID

In the process of extracting vanadium from stone coal by sulfuric acid leaching — P204 solvent extraction, Fe(III) can accumulate in the organic phase which reduces the extraction of vanadium. In order to eliminate the effects of the accumulation of iron, oxalic acid was used as the stripping agent to strip the Fe(III). The effects of oxalic acid concentration, phase ratio O/A, stripping time and shake velocity on the stripping of Fe(III) were studied. The results showed that the Fe(III) stripping rate can reach beyond 96% at the room temperature with 70g/L oxalic acid using an O/A of 2 at 160 rpm shake velocity for 20min. After 2-stage stripping, the concentration of Fe(III) in organic phase was 0.008g/L.