Li Ming

Bio: Li Ming is an academic researcher. The author has contributed to research in topics: Vanadium & Chromium. The author has an hindex of 3, co-authored 8 publications receiving 35 citations.

Effective Extraction of Vanadium and Chromium from High Chromium Content Vanadium Slag by Sodium Roasting and Water Leaching

Abstract: The extraction of vanadium and chromium from high chromium content vanadium slag by salt roasting and water leaching process has been investigated, which uses mixed sodium salts (Na2CO3 and NaOH) as additive agent in roasting process. The mineralogical morphology was prospected by TG-DSC, XRD, SEM and EDS. The oxidation of slag and transversion of V/Cr-containing phase and sodium salts have been discussed. It has been demonstrated that the presence of NaOH contributes to decompose spinel and olivine phases, which is beneficial to reduce the roasting temperature and elevate V, Cr leaching ratio. The roasting parameters have been studied as a function of roasting temperature, roasting time and ratio of alkali, in which the roasting temperature is the most effective factor on the leaching rate of vanadium and chromium. Under the optimum condition, the leaching rates of V and Cr reached 95.8% and 97.6%, respectively.

Method for magnetically separating and smelting chromium-iron alloy by vanadium extraction from vanadium-chromium slag and reduction of tailings

Abstract: The invention discloses a method for magnetically separating and smelting chromium-iron alloy by vanadium extraction from vanadium-chromium slag and reduction of tailings. The method includes: directly roasting and acid-leaching the vanadium-chromium slag to extract vanadium, adding an ammonium salt into vanadium-containing solution obtained by acid leaching so as to deposit vanadium, preparing vanadium pentoxide by using a product, using a reducing agent to reduce chromium-containing tailings obtained by acid leaching, performing grinding and screening, subjecting a screened product to low-intensity magnetic separation to obtain iron concentrate, subjecting the iron concentrate to high-intensity magnetic separation to obtain chromium-iron concentrate, returning the chromium-iron concentrate into a blast furnace for smelting, subjecting the chromium-iron concentrate to fusion smelting with a reducing agent and a slag former to obtain chromium-iron alloy and slag, and using the slag to produce cement or building materials. The method enables vanadium leaching yield to be up to 99%, with chromium barely leached (chromium leaching rate being less than 0.5%), and enables efficient separation of vanadium and chromium; the whole-course vanadium recovery rate is higher than 95%, chromium recovery rate is higher than 90%, efficient recycling and clean utilization of the vanadium and chromium are achieved, and harmless comprehensive utilization of the slag is also achieved.

Method for separating vanadium and chromium solution and recycling vanadium and chromium

Abstract: The invention discloses a method for separating a vanadium and chromium solution and recycling vanadium and chromium A reducing agent is added to the vanadium and chromium solution under the condition that the pH value ranges from 8 to 14, and the temperature ranges from 20 DEG C to 100 DEG C, and pentavalent vanadium and hexavalent chromium are reduced into tetravalent vanadium and trivalent chromium; the trivalent chromium forms chromic hydroxide precipitate in situ, and a chromic hydroxide filter cake and vanadium-containing filtrate are obtained through filtering; the chromic hydroxide filter cake is used for preparing chromic oxide; and the vanadium-containing filtrate is used for preparing hydration vanadium dioxide or vanadyl sulfate or vanadium pentoxide By means of the method, efficient separation and recovery of vanadium and chromium are achieved, the vanadium recovery rate reaches 96% or higher, the chromium recovery rate reaches 98% or higher, and the purity of vanadium and chromium products reaches 98% or higher The method has the beneficial effects that the technological processes are short, the separation efficiency is high, the cost of raw materials and auxiliary materials is low, operation is easy and convenient, and the method can be used for large-scale industrial production

Method for preparing mixture by synchronously grinding and mixing vanadium slag and limestone in vanadium slag calcification vanadium extraction process

Abstract: The invention discloses a method for preparing a mixture by synchronously grinding and mixing vanadium slag and limestone in a vanadium slag calcification vanadium extraction process, belongs to the technical field of metallurgy, and aims to solve the technical problems of low quality, unstable index and low vanadium yield of existing mixtures subjected to step-by-step ball milling and mixing. Themethod comprises the following steps: adding vanadium slag blocks and limestone blocks according to CaO/V2O5 requirements of the vanadium slag calcification vanadium extraction process at the feed end of a vanadium slag ball milling system, performing synchronous grinding and mixing operations through the ball milling system, and performing selection to obtain the mixture. According to the method, the vanadium slag blocks and the limestone blocks are treated simultaneously by a ball mill, grinding and mixing are completed in one step, and accordingly, the qualified mixture is prepared. Compared with the conventional process, the process method has the advantages of short flow, simple equipment, stable product quality, low cost, low flying loss and the like.

Vanadium precipitation method capable of reducing vanadium precipitation wastewater

Abstract: The invention relates to a vanadium precipitation method capable of reducing vanadium precipitation wastewater. The method comprises the following steps: a. carrying out acidic ammonium salt vanadium deposition on a conventional-concentration vanadium solution; b. after finishing adding the ammonium salt in the step a, regulating the pH value and carrying out vanadium precipitation reaction for some time, injecting the high-concentration vanadium solution into the reaction tank; c. adding acid to keep the pH value at 2-3, and continuing holding while stirring; and d. supplementing a certain amount of ammonium salt to continuously react until the precipitation product can not be easily stirred, and filtering to obtain more ammonium vanadate and less vanadium precipitation wastewater. The method provided by the invention can effectively lower the wastewater quantity, and has the advantages of simple technique, high vanadium precipitation rate and high product purity.

A review on the metallurgical recycling of vanadium from slags: towards a sustainable vanadium production

Abstract: The critical applications of vanadium in metallurgical field and the growth in commercialization of vanadium redox flow batteries (VRFB) have led to the increased demand of vanadium. It is thus important to ensure the sustainability of vanadium production. Vanadium bearing slags, the solid byproducts in iron- and steel-making plants, are the principal source of vanadium production, accounting for more than 69% of total vanadium in terms ofthe raw material types. Academic researches and engineering investigations have been addressed to develop such metallurgical processes for treating the vanadium bearing slags. This article presents a comprehensive review on the metallurgical treatments of vanadium bearing slags. The composition and phase/mineralogical characterization of vanadium bearing slags from various sources are given. Literature review shows that the vanadium bearing slags have been traditionally treated through the roasting-assisted leaching with the recent efforts of integrating the state-of-the arts technologies in extractive metallurgy and developing direct leaching methodologies. Some promising methods are worth discussing and quite encouraging, and expected to be the future focuses of this area. Discussion also highlights the separation of vanadium from silica, phosphorus and chromium as the major interfering elements/metal in the leach solutions of vanadium slags. Recommendation is made for taking up future works in order to develop a sustainable metallurgical process for vanadium bearing slag.

Roasting and leaching behaviors of vanadium and chromium in calcification roasting–acid leaching of high-chromium vanadium slag

Abstract: Calcification roasting–acid leaching of high-chromium vanadium slag (HCVS) was conducted to elucidate the roasting and leaching behaviors of vanadium and chromium. The effects of the purity of CaO, molar ratio between CaO and V2O5 (n(CaO)/n(V2O5)), roasting temperature, holding time, and the heating rate used in the oxidation–calcification processes were investigated. The roasting process and mechanism were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetry–differential scanning calorimetry (TG–DSC). The results show that most of vanadium reacted with CaO to generate calcium vanadates and transferred into the leaching liquid, whereas almost all of the chromium remained in the leaching residue in the form of (Fe0.6Cr0.4)2O3. Variation trends of the vanadium and chromium leaching ratios were always opposite because of the competitive reactions of oxidation and calcification between vanadium and chromium with CaO. Moreover, CaO was more likely to combine with vanadium, as further confirmed by thermodynamic analysis. When the HCVS with CaO added in an n(CaO)/n(V2O5) ratio of 0.5 was roasted in an air atmosphere at a heating rate of 10°C/min from room temperature to 950°C and maintained at this temperature for 60 min, the leaching ratios of vanadium and chromium reached 91.14% and 0.49%, respectively; thus, efficient extraction of vanadium from HCVS was achieved and the leaching residue could be used as a new raw material for the extraction of chromium. Furthermore, the oxidation and calcification reactions of the spinel phases occurred at 592 and 630°C for n(CaO)/n(V2O5) ratios of 0.5 and 5, respectively.