Zinc-containing Dust Research Articles

Preparation of active zinc oxide from zinc-containing dust and synergistic recovery process of valuable elements

Zinc-containing dust generated from the iron and steel industry is enriched with a large amount of heavy metal substances and rare elements, which is a hazardous waste and a secondary resource. In this study, a new process for the preparation of active zinc oxide and synergistic recovery of valuable elements using zinc-containing dust was proposed. Firstly, a fire process was used to make the valuable components such as Zn, Cd, K, Na, Pb, Bi, In and Sn secondary enriched in the zinc-rich dust. Then the leaching and recovery of K (99.74 %) and Na (98.12 %) were realized by alkaline washing method taking advantage of the solubility difference. Thermodynamic analysis showed that controlling the pH of the leaching system could realize the selective separation of the valuable components. The experimental results showed that the leaching rates of Zn and Cd reached 86.95 % and 92.28 %, respectively, under the optimal experimental conditions, while Pb, Sn, Bi and In were enriched in the neutral leaching slag. Cd sponge (70.3 %) was obtained after the neutral leach solution was treated by Zn powder replacement process. The purified zinc sulfate solution was used to prepare active zinc oxide (97.04 %) by direct precipitation at a molar ratio of CO32–/Zn2+ of 1.15 and a temperature of 50 °C. The average particle size of the product was 21.95 nm, which was in accordance with the industry standard. Neutral leaching slag realized Bi (91.5 %), Sn (71.01 %) and In (94.0 %) in high acid leaching process, and Pb was enriched in slag in the form of PbSO4. The high acid leach solution is hydrolyzed, extracted and replaced to obtain BiOCl, crude tin and crude indium. This process realizes the comprehensive recovery and high-value utilization of various valuable elements in zinc-containing dust sludge, and has significant environmental, economic and social benefits.

Innovative deep eutectic solvent approaches in zinc electroplating for morphology enhancement, superior strength, and corrosion protection

The growing number of galvanized scrap due to the extensive application of galvanized products has led to a significant increase of the zinc content in the electric furnace dust, so how to realize high-value comprehensive utilization of zinc-containing dust has become a key issue for the sustainable development of the iron and steel industry. Based on the principle of recycling zinc resources, this study proposes an innovative full life cycle process for the preparation of electro-galvanized sheet using zinc-containing dust as raw material and deep eutectic solvents (DESs) as medium. Zinc plating was successfully prepared on duplex steel automobile plates using choline chloride-urea DES (Reline) as the electrolyte, and the modifying effects of different concentrations of nicotinic acid (NA) on the electrochemical system of the solution and the prepared plating were also investigated. The results show that the addition of 0.06 M NA to the system can modulate the deposition morphology of the plating layer, leading to the generation of ultrafine grains, and the surface densities and flatness are significantly improved. Besides, the addition of NA to the system increased the hardness value by 67.5 % and reduced the coefficient of friction by 38.8 % compared to the plating obtained in the system without additives; the corrosion rate decreased from 0.374 mm·a-1 to 0.023 mm·a-1, and the corrosion mechanism of the zinc layer was a direct dissolution process of zinc. This study realizes the morphology regulation of electroplated zinc plating, and greatly improves the aesthetics, mechanical properties and corrosion resistance of the plating at the same time, also the preparation process is in line with the requirements of the green development, which can provide a novel solution for the automotive high-quality plating.

Research on Biomass Waste Utilization for Synergetic Reduction of Stainless Steel Sludge and Zinc-Containing Dust

Research on Biomass Waste Utilization for Synergetic Reduction of Stainless Steel Sludge and Zinc-Containing Dust

Use of a Vortex Layer Apparatus for the Preparation of Oiled Scale and Zinc-Containing Dust and Sludge for Briquetting

Use of a Vortex Layer Apparatus for the Preparation of Oiled Scale and Zinc-Containing Dust and Sludge for Briquetting

Hydrogen reduction process for zinc-bearing dust treatment: Reduction kinetic mechanism and microstructure transformations in a novel and environmentally friendly metallurgical technique

The iron and steel sector generates 80 million tons of zinc-containing dust annually, traditionally treated using carbon-based pyrometallurgical processes, which have significant drawbacks, including large carbon emissions, high energy consumption, and low production value. To address the above issues, a green hydrogen reduction method was developed for zinc-bearing dust treatment. This study examined the thermodynamics, reduction kinetics, and phase transformation during the process, revealing that at 800 °C, the hydrogen partial pressure for zinc oxide reduction is only 45.56 %. The direct reduction of zinc-containing dust pellets with hydrogen reveals that the limiting step of iron oxide and zinc reductions both are interfacial chemical reaction control at the reduction temperature of 800–950 °C, with an apparent activation energy of 16.42 kJ/mol and 71.39 kJ/mol. The kinetic mechanism indicates that reducing iron and zinc oxides is more accessible in a hydrogen reduction system, with lower apparent activation energies than carbothermal reduction. Consequently, hydrogen reduction offers a more efficient and environmentally friendly solution for treating zinc-bearing dust.

Mineral Phase Reconstruction and Separation Behavior of Zinc and Iron from Zinc-Containing Dust.

Zinc-containing dust can be found in ironmaking and steelmaking, and it is an important secondary resource of zinc. Zinc-containing dust from an electric furnace was used as a raw material to study the phase transformation behavior of the dust using a calcification roasting process and the zinc-iron separation behavior by using ammonia leaching. The zinc-bearing dust was mixed with CaO and roasted to transform the zinc ferrite into zinc oxide. The results showed that increasing the calcium oxide to dust ratio could promote the conversion of zinc ferrite to zinc oxide. When the calcium oxide ratio reached 60%, the peak of zinc ferrite in the calcined-roasted product in the zinc-containing dust basically disappeared. As the temperature increased, the zinc oxide grains increased but were still smaller than 10 µm. The calcined-roasted product was crushed and ground, and the zinc was leached by ammonia. A zinc-iron recovery rate of 86.12% was achieved by the ammonia leaching. The leachate could be used for zinc extraction by electrolysis. The leaching residue was mainly calcium ferrate, which could be used in sintering production. The proposed process may achieve on-site recovery of zinc-containing dust in steel-making plants.

A review of processing methods for electric arc furnace dust

The work presents an analytical review of processing methods for industrial waste from the ferrous industry, namely, electric arc furnace dust. The annual emissions of this dust and the source of each dust component are determined. Scientific works on the topic of processing electric arc furnace dust published over the past 20 years are compared and analysed. The major methods for dust processing to recover iron, zinc and other metals include pyro - and hydrometallurgical techniques and their combinations. To date, several high-temperature technologies have been developed that allow zinc-containing dust to be efficiently processed (in particular, the Waelz process and secondary processes). However, many of these technologies have remained at the development stage for various reasons (either requiring considerable capital investments, or being unreliable, energy-intensive and inefficient). It is shown that hydrometallurgical processes are environmentally safe and selective to valuable components and allow technological parameters to be controlled. By selecting a suitable solvent (acidic or alkaline), the required metal can be selectively extracted from dust. In addition, such a technology will be cost-effective even under low contents of the extracted component. Approaches to processing metallurgical dust with inorganic and organic acids and ammonia-based solutions are described. Both conventional processing of electric arc furnace dust on an industrial scale and the laboratory developments recently introduced at zinc production plants (their features, advantages and disadvantages) are discussed. Technologies that allow valuable components in the dust to be extracted and returned to the production cycle are identified.

Control of Zinc-containing Dust Agglomerates in Basic Oxygen Furnace Flue Gas Cleaning System

Control of Zinc-containing Dust Agglomerates in Basic Oxygen Furnace Flue Gas Cleaning System

Influence of chloride ion on zinc electrodeposition from choline chloride based deep eutectic solvent

When deep eutectic solvent (DES) is used to recycle Zn from zinc-containing dusts, chlorine present in these dusts will enter into the resulting solution and inevitably affects subsequent electrodeposition of zinc. This paper investigated the effect of added chloride ions on the electrodeposition behavior of zinc from choline chloride-urea-ethylene glycol (ChCl-urea-EG) DES-containing zinc oxide. Compared with the blank ChCl-urea-EG DES, the addition of chloride ion is found to increase the current efficiency, reduce the energy consumption, and improve the compactness of Zn deposits. In addition, cyclic voltammetry results and kinetic parameters lead to the conclusion that the added chloride ions have an inhibiting effect on Zn(II) ion migration, but have a promoting effect on reduction reaction of Zn(II) ion. The results of X-ray diffraction analysis reveal that the addition of chloride ions affects the crystallographic orientation by enhancing the growth of (101), (102), and (103) planes.

Selective recovery of zinc from zinc oxide dust using choline chloride based deep eutectic solvents

Deep eutectic solvents (DESs) are a kind of potential lixiviant for selective metal processing due to their versatile complexation properties. In this study, we investigated the recovery of zinc from zinc oxide dust using choline chloride−urea− ethylene glycol (ChCl−urea−EG) DESs. The zinc extraction efficiency can be up to 85.2% when the slurry concentration is 50 g/L, leaching temperature is 80 °C and stirring speed is 600 r/min. The leaching process is controlled by the diffusion and the corresponding activation energy is 32.1 kJ/mol. The resultant solution was directly used for the electrodeposition of zinc. The pure zinc deposit is obtained with a current efficiency of 82.6%. Furthermore, the ChCl−urea−EG DESs can be recycled. This approach is shown to be promising for the recycling of zinc from the zinc-containing dust.

Hydrometallurgical Recycling of Electric Arc Furnace Dust

The current global primary zinc stocks are estimated to last for approximately 20 years. For this reason, the recycling and processing of waste (especially steelmaking dust) containing zinc are currently necessary, and this will remain the case in the future. The main objective, we deal with in this article is the experimental research on electric arc furnace dust (EAFD) compounds which may potentially result in the commercial manufacture of products in the electrotechnical industry. In our work we focus on the production of ZnO-based varistors used in surge protection devices (SPD), which are the current trend in the world. ZnO, a resultant product of hydrometallurgical recycling of zinc-containing dust produced by the remelting of steel waste in an EAF, was used for this research. From the resulting product containing 79.04% Zn, five varistor samples were prepared. Subsequently, their electrical characteristics were measured and calculated on these samples. From the measured electrical parameters, the non-linear characteristic typical of voltage-dependent resistors–varistors is evident. Based on the results of the electrical characteristics, we conclude that the ZnO product, which is the output of hydrometallurgical recycling of EAFD, is a potentially suitable material for use in the production of ZnO varistors in the future.

Development of the Metallurgical Waste Recovery Process

We have developed the process that enables receiving pellets from zinc-containing dust and recovering them in a Waelz kiln with practically total zinc distillation and its capture in bag filters. As this takes place, metallic iron, still present in the pellets, can be used in metallurgical treatment. We have elaborated the process instructions to obtain pellets from zinc-containing dust with an addition of solid fuel, magnesite, and bentonite. To simulate recovery of the carbon-containing pellets in production, bench tests have been performed. These allowed us to determine principal operating conditions of the technological procedure of metallurgical zinc-containing dust recovery and validate the unit for recovery of this dust. The data obtained from the production tests prove feasibility of implementation of this process and allow assessing economic efficiency of zinc-containing dust recovery.

Use of Electrolytic Zinc Powder for Cementation of Gold from Cyanide Solutions

Features of gold cementation from cyanide solutions with electrolytic zinc powder are studied. The test powders are prepared by electro-extraction of alkaline solutions after leaching zinc-containing dust. Cementation is conducted in two regimes: under pressure (Merrill–Crowe process) and a fluidized bed regime. It is established that with respect to degree of gold extraction and specific consumption of test dendritic powder it is no worse or surpasses powders prepared by vapor condensation used traditionally in the gold extraction industry. The features established may be explained by physical features of powders prepared by electro-extraction from alkaline solutions.

Prediction of Zinc and Lead Behavior During Steel Electric Smelting

The balance of zinc and lead is calculated during steel smelting in an electric arc furnace (EAF). It is shown that the main proportion of zinc and lead is removed from metal during charge melting in an EAF, and the remaining amount evaporates during steel degassing. With an increase in the proportion of galvanized steel in a charge, dust formation and zinc and lead contents in EAF discharges increase considerably. In order to determine a strategy for treating zinc-containing dust, it is necessary to monitor its content in all production stages.

Research of selective leaching of zinc from metallurgical dust

This article discusses the process of liquid-phase extraction of zinc from metallurgical dust and sludges. The main purpose of this study is to investigate the efficacy and selectivity of the transition of zinc and iron from the solid phase into the liquid in the process of dissolution of zinc-containing material. To obtain data on selectivity of acid leaching of zinc were conducted experimental kinetic studies, the reaction products were analyzed by photocolorimetry. As the zinc-containing material were used samples of EAF dust with a high content of zinc oxide.As a result of research we obtained the data on the effectiveness and the selectivity of zinc extraction using an acid of different concentrations, as well as with increasing temperature. It was discovered that the process proceeds in two stages. We associate it with a complex chemical composition of the dust. The speed of zinc extraction in the first stage is much higher than the speed of the further course of process. The selectivity value increases during the dissolution process using a solution of sulfuric acid at a concentration of 0,05-0,1 mol/l. Increasing the concentration of the acid solution, as well as the increase of temperature reduces the selectivity of the zinc extraction.The research results can be used to improve industrial technologies for the utilization metallurgical zinc-containing dust and sludges. Carrying out the process at a low concentration of the acid solution for a longer period of time will allow to achieve high recovery of zinc, while maintaining high selectivity.

Physicochemical properties of the zinc-containing dusts of electric furnace steelmaking

The properties of the dusts of electric-arc melting in the Severstal’ metallurgical works are studied by X-ray diffraction, Mossbauer spectroscopy, and electron microscopy. The elemental compositions of dust particles of various sizes are determined, and the complex structural composition of iron-containing oxide phases is revealed. It is shown that, in these systems, the carbon reduction of zinc from zincite is possible in the solid state in the temperature range 600–1000°C. In this case, zinc passes into a gaseous phase and iron oxides are reduced to form metallic iron.

Replacement of reserves zinc based on the recycling of technogenic raw materials

In the article, the perspective trends of the expansion of the mineral-ore base of the Russian producers of zinc by recycling of technogenic raw materials are considered. The important role of recycling of resources for sustainable development of society and improve the environmental safety is justified. The main structural and dynamic characteristics of the use of mineral resource base for the production of zinc in Russia are considered. Raw materials opportunities and constraints for the development of zinc production are analyzed. In the paper, the structure and dynamics of the use of recycled materials by the largest producer of zinc in Russia are investigated. The methodical approach to the estimation of effectiveness of the industrial processing of technogenic metallurgical raw materials with the strategic flexibility of the implementation of projects is proposed and approved. The estimation of the effectiveness of a complex industrial processing of metallurgical zinc-containing dusts in a real production is carried out. The value of the strategic flexibility of the project of the industrial processing of the zinc-containing technogenic raw material is determined on the basis of the developed systematic approach. The value of the processes of recycling for sustainable production of zinc in Russia is revealed.

Transport and subcellular distribution of intranasally administered zinc in the olfactory system of rats and pikes.

Zinc is an essential element, which can act as a neuromodulator and also is bound in zinc proteins in the brain. The olfactory bulb contains high concentrations of zinc. In the present study, 65Zn(2+) was applied on the olfactory epithelium of rats and pikes and the transport of the metal in the olfactory system was then examined. Administration of 65Zn(2+) in the nasal cavity of rats or the olfactory chambers in pikes resulted in an uptake of the metal in the olfactory epithelium and a transport of the metal along the primary olfactory neurons to their terminations in the olfactory bulbs. Low levels of 65Zn(2+) passed these terminals and continued into the interior of the bulbs. In the rats 65Zn(2+) was also detected in the anterior parts of the olfactory cortex. Subcellular fractionations of the olfactory mucosa and olfactory bulb of rats given 65Zn(2+) intranasally showed that the metal is bound both to particulate cellular constituents and to cytosolic components in these tissues. Gel chromatography indicated that some of the zinc in the cytosol is bound to metallothionein in the olfactory mucosa and bulb. Inhalation of zinc-containing dusts or fumes occurs in some work-places and may imply high exposure of the nasal tissues. It is not known whether neurotoxicity may be related to uptake of zinc in the olfactory system. However, this is an issue which deserves attention, since zinc dysregulation has been implied to play a role in Alzheimer's disease. In addition, impairment of the sense of smell and degenerative changes of the olfactory tissues have been seen in early stages of some neurodegenerative disorders.

Fundamental study on recycling technology of zinc-containing dusts in steel works

In order to solve environmental problems in steel works, an effective recycling process of zinc containing dusts has been studied. After pelletizing the dust with binder and fine coke, these pellets were charged into hot metal in an experimental electric furnace. As a result of the charging tests, it was clarified that the zinc oxide is reduced and recovered as zinc vapour. The result was verified by charging them into 200 tons of hot metal produced from commercial blast furnace.

The effect of zinc-containing dusts and sprays on the yield of potatoes

The effect of zinc-containing dusts and sprays on the yield of potatoes