Zinc Plant Research Articles

Pb Recycling Through Leaching, Precipitation, and Cementation from Zinc Plant Residue

This paper presents the hydrometallurgical methods used for the recovery of concentrate and metallic lead from zinc plant residue (ZPR). The ZPR mainly consisting of 9.5% Pb and 7.5% Zn was initially leached by sulfuric acid under the following conditions: leaching temperature 90 °C, leaching time 90 min., sulfuric acid concentration 200 g/l, and solid/liquid ratio 1/5. The zinc recovery obtained was 92.8%, which was finally directed to solvent extraction circuit to produce zinc cathode. Then acidic residue was subjected to alkaline leaching, using sodium hydroxide (NaOH). The lead recovery obtained was 92.58%. For precipitation method by using NaClO, the effects of three important factors including (NaClO/solution) ratio, temperature, and precipitation time were studied and reported. As a result, lead was precipitated in the form of PbO2 with concentrated grade of 72.03% and recovery of 92.31%. Furthermore, aluminum was used for cementation process to produce metallic Pb with grade of 96.11% and total recovery of 87.17%.

Identification and Metabolism of Naturally Prevailing Microorganisms in Zinc and Copper Mineral Processing

It has only recently been discovered that naturally prevailing microorganisms have a notable role in flotation in addition to chemical process parameters and overall water quality. This study’s aim was to assess the prevailing microbial communities in relation to process chemistry in a zinc and copper mineral flotation plant. Due to the limitations of cultivation-based microbial methods that detect only a fraction of the total microbial diversity, DNA-based methods were utilised. However, it was discovered that the DNA extraction methods need to be improved for these environments with high mineral particle content. Microbial communities and metabolism were studied with quantitative PCR and amplicon sequencing of bacterial, archaeal and fungal marker genes and shotgun sequencing. Bacteria dominated the microbial communities, but in addition, both archaea and fungi were present. The predominant bacterial metabolism included versatile sulfur compound oxidation. Putative Thiovirga sp. dominated in the zinc plant and the water circuit samples, whereas Thiobacillus spp. dominated the copper plant. Halothiobacillus spp. were also an apparent part of the community in all samples. Nitrogen metabolism was more related to assimilatory than dissimilatory nitrate and nitrite oxidation/reduction reactions. Abundance of heavy metal resistance genes emphasized the adaptation and competitive edge of the core microbiome in these extreme conditions compared to microorganisms freshly entering the process.

Fuzzy multi-criteria lead and zinc plant site location considering environmental criteria (A case study in Iran)

The aim of this study is to determine the location of the lead and zinc site considering environmental criteria. Within a radius of 5 km-10 km of the province under study, there are about 150 lead and zinc plants, which increase the pollution of the city and various diseases. If the plants are closed, about 3,500 people will be unemployed, with the industry mines, and national capital severely affected. Another option is to move these plants to a radius of 100 km in the province, which will cost a lot. Since the fuzzy sets theory method has been widely applied to uncertain decision-making problems in the real-world, in this study and for the first time, to select the appropriate option according to the criteria affecting environmental pollution, disease prevalence, income, unemployment rate, corruption, and cost, a multi-criteria decision-making technique with a hybrid fuzzy approach has been used. The proposed method is a hybrid of the TOPSIS fuzzy technique and a fuzzy hierarchical process that takes advantage of both of them. The results obtained in the case study show that using the proposed method, the best option is moving plants within a radius of 100 km from the city.

Metal citrate nanoparticles: a robust water-soluble plant micronutrient source.

A series of iron (Fe) and zinc (Zn) plant nanonutrients in citrate form were prepared by an eco-friendly solid-state grinding of the respective nitrates and citric acid. Ball-milling of the as-prepared Fe and Zn citrates resulted in nanosize particles. The as-prepared and ball-milled Fe and Zn citrates were characterized using Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis and differential thermal analysis (TGA/DTA), and powder X-ray diffraction (XRD). The particle size and morphology of the obtained samples were studied using a scanning electron microscope (SEM) and transmission electron microscope (TEM). The obtained nanosized Fe and Zn citrates were analyzed for their plant uptake in the test crop soybean (var. JS-335) using the white-sand technique. The concentration of nutrients was estimated by atomic absorption spectrometry (AAS). A significant increase in nutrient absorption was observed in 6 h ball-milled samples of both Fe (789.8 μg per g of dry weight) and Zn (443.8 μg per g of dry weight) citrates. Such an increased nutrient absorption is due to the high mobility of nanocitrates. Therefore, nanocitrates can serve as an excellent source of plant nutrients in agriculture.

Processing of Anthropogenic Waste of Smelters of the Ural Mining and Metallurgical Company


 
 
 The industrial sites of the smelters of the Ural Mining and Metallurgical Company have accumulated a lot of anthropogenic waste, the processing of which is currently economically impractical. These primarily include tailings and beneficiation tailings, as well as waste granulated and copper smelting slag. This article conducts studies on technologies for x-ray-radiometric/magnetic separation enrichment of discard slags of MMSK as well as using jigging machines. Slag and slag enrichment tailings are used for cement production and road construction. For complex processing of fine copper smelting dusts OJSC Chelyabinsk zinc plant developed, tested and implemented a special technology. After implementation of ”Actions to process industrial waste generated by UMMC enterprises at metallurgical enterprises of UMMC-Holding Corp.”, the following were noted: concentrators and special beneficiation facilities process slag; R&D on complete processing of concentrator’s tailings was conducted; smelting dust was not stored but processed in full; the technology of implementing Waelz process for processing of steel smelting dust has been developed and commercially tested; the technology for extraction of copper and precious metals from pyrite dross is to be improved.
 
 
 
 Keywords: anthropogenic waste, dust, tailings, slag, pyrite dross
 
 
 
 
 

Eco-City: Model Concept for Transforming Brownfield into Modern Urban District

Brownfields are undoubtedly a problem in many 21st century cities. Abandoned, degraded, dangerous, overgrown and degrading the image of cities, they also have many potentials and assets. In the context of contemporary urban development trends related to sustainable development and the idea of creating a compact city with a high quality of life, post-industrial areas, especially those located in city centers, are ideal areas for new investments. Polish cities still have a tendency to urban sprawl, which is why the purpose of this article is to draw attention to the transformation of brownfield areas into modern eco and healthy urban districts as a way of creating sustainable urban space. In addition, the article deals with the topic of pro-ecological solutions, including those related to adaptation to climate change. The study uses the case study method. Five significant examples of post-industrial area transformation from Germany, Spain and France were selected. During the analyzes compared masterplans, functional schemes and location of these areas, and then the basic parameters and relationships between them were distinguished in four main categories: general data, environment, land development and attractiveness assessment. The conclusions of the comparative analysis allowed for the definition of detailed guidelines for creating a model concept for land development of the brownfields located in the city structure. The chosen location is placed in Katowice in former areas of Silesia Zinc Plant. The proposed concept presents functional solutions for connecting residential, recreational, commercial office and industrial areas. It is a template solution for the process of spatial, social and economic development. The project proposes pro-ecological solutions and technologies, including: water recycling, use of solar energy, energy storage, intelligent control and monitoring systems, sustainable mobility, building development based on natural ventilation of the city, rain gardens, reducing heat islands, etc. The transformation methods based on modern pro-ecological technologies in the context of adaptation to climate change which were presented in the article may constitute guidelines for the implementation in similar cases of transforming brownfield areas into modern urban districts.

Recovery of Cobalt from the Residues of an Industrial Zinc Refinery

The electrolytic production of metallic zinc from processing zinc sulfide concentrates generates a residue containing cadmium, copper, and cobalt that need to be removed from the electrolytic zinc solution because they are harmful to the zinc electro-winning process. This residue is commonly sent to other parties that partly recover the contained elements. These elements can generate revenues if recovered at the zinc plant site. A series of laboratory tests were conducted to evaluate a method to process a zinc plant residue with the objective of recovering cobalt into a salable product. The proposed process comprises washing, selective leaching, purifying and precipitation of cobalt following its oxidation. The process allows the production of a cobalt rich hydroxide precipitate assaying 45 ± 4% Co, 0.8 ± 0.2% Zn, 4.4 ± 0.7% Cu, and 0.120 ± 0.004% Cd at a 61 ± 14% Co recovery. Replicating the whole process with different feed samples allowed the identification of the critical steps in the production of the cobalt product; one of these critical steps being the control of the oxidation conditions for the selective precipitation step.

Use of temporary gas flow to improve the efficiency of metallurgical units operation

This paper presents the results of industrial tests on dust deposition due to the use of an unsteady gas flow. JSC SUMZ (Revda) applied the technology with the use of acoustic radiators to organize in-furnace dust deposition at Vanyukov furnace. The design of the radiator included a nozzle pipe, air nozzle, resonator and focusing surface. Based on the surface area of the furnace molten pool and recommended specific acoustic power values for in-furnace dust condensing, the total acoustic field sound power was calculated. The optimal number and location of acoustic radiators was determined. The analysis of the data of industrial tests of the use of the acoustic field energy in the working space of the PZhV, as well as the results of tests on the converter No. 2 of JSC ‘SUMZ’, the cyclone of the firing multi-hearth furnace of JSC ‘SVYATOGOR’, the dust chamber of the Waelz furnace and cleaning of the heat exchange surfaces of the boiler on waste gases (JSC ‘Chelyabinsk Zinc Plant’).

Study of the separation of mineral phases of Waelz clinker for its disposal

The article presents the results of technological studies on the enrichment of a sample of Waelz clinker from zinc cakes from the Chelyabinsk Zinc Plant by magnetic and flotation methods. The phase and chemical composition of the Waelz clinker of various enterprises is considered, the analysis of the main components of the clinker is carried out. Clinker is a large tonnage solid waste of the zinc sub-industry of non-ferrous metallurgy, has a complex multicomponent composition and is characterized by high contents of iron (36.41%), non-ferrous (Cu 5.28%, Zn 0.93%) and noble (Au 3.8 g / t, Ag 332.2 g / t) metals. Apart from that, there is noticeable content of waste rock, including free carbon (coke breeze), silicone dioxide, calcium oxide, magnesium oxide, alumina. It is shown that, in principle, Waelz-clinker can be separated according to the magnetic flotation scheme without recycle operations to produce four products: a non-magnetic carbon-containing product βC = 21.7%), copper middlings βCu = 11.39-11.69%), flotation coal product βC = 22%) and an iron-containing concentrate in the form of flotation tailings βFe = 60.23%).

Zinc, a micronutrient and its effect to performance of BARI gom30

To evaluate the effect of Zinc fertilizer on performance of wheat cv. BARI gom30, an experiment was carried out at Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, from November 2015 to March 2016. The experiment comprised four levels of Zinc (Zn) viz., 0, 1.5, 2 and 2.5 kg/ha. The experiment was laid out in a randomized complete block design with three replications. Application of Zinc (Zn) plant height, number of total tillers/plant, number of effective tillers/plant, spike length, number of fertile spikelets/spike numbers of sterile spikelets/spike number of grains/ spike, grain yield and straw yield were found significant. But there was no significant effect of the treatment on 1000-grain weight. The highest number of total tiller/plant (4.42), number of effective tillers/plant (3.92), number of grains/spike (47.70), 1000-grain weight (47.73 g), grain yield (5.06 t/ha), straw yield (6.21 t/ha) was obtained from 2 kg Zn/ha. The highest plant height (94.08 cm), spike length (9.92 cm), number of fertile spikelets/spike (19.59) and sterile spikelets/spike (3.22) and harvest index (46.16%) were recorded at 0 kg Zn/ha respectively. The control treatment indicated the lowest value for the yield attributing characters except the number of sterile spikelets/spike. Grain yield was found to be significantly and positively correlated with number of grains/spike and straw yield. It is recommended that application of 2 kg Zn/ha is the best for maximum yield of BARI gom30.  Â

Foliar sources of boron and manganese in soybean and zinc plants in corn plants complexed with polyols in nutritional status and in production

Foliar sources of boron and manganese in soybean and zinc plants in corn plants complexed with polyols in nutritional status and in production

Detoxification of lead-bearing zinc plant leach residues from Kabwe, Zambia by coupled extraction-cementation method

Zinc plant leach residues (ZPLRs) are hazardous solid wastes generated from zinc metal production owing to their substantial contents of lead (Pb), a toxic heavy metal. This study investigated the detoxification of historic ZPLRs from Kabwe, Zambia by removing Pb using a coupled extraction-cementation method in chloride media. For the coupled extraction-cementation method, micro-scale zero-valent iron (mZVI) was added during ZPLRs leaching in acidified chloride solution. Cemented Pb on the surface of mZVI was recovered easily from the leaching pulp by magnetic separation. Pb removal was evaluated in different solution compositions (NaCl:1–5.13 M, HCl: 0–0.1 M) with and without the addition of mZVI. The addition of mZVI during ZPLRs leaching (i.e., coupled extraction-cementation) increased Pb removal from 3% to 24%, 1.3% to 27.5%, 5.2% to 34.9%, and 6.5% to 55.8% when NaCl concentration was fixed at 0.86 M and HCl concentrations were 0 M, 0.01 M, 0.05 M and 0.1 M, respectively. When NaCl concentration was increased above 3.42 M and HCl maintained at 0.1 M HCl, Pb removal increased to 80%. Analysis of the Pb-loaded mZVI (magnetic fraction) by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and X-ray photoelectron spectroscopy (XPS) revealed that Pb was recovered during leaching via cementation as Pb°. The toxicity characteristic leaching procedure (TCLP) and in vitro solubility and bioavailability research consortium gastric phase (SBRC-G) tests for Pb of ZPLRs before and after treatment decreased drastically from 11.3 to 3.5 mg/L (below 5 mg/L threshold) and 12 300 to 2 840 mg/Kg, respectively.

Construction of Belovskii Zinc Plant in 1928-1932

The history of Belovsky distillation zinc plant in 1928–1932 — the first child of non-ferrous metallurgy of Soviet Siberia, the scale of construction of which at that time in Kuzbass was inferior only to Kuznetskstroi is considered. The stages of selecting the site of the future enterprise, its economic justification, design and creation of a raw material base in Salair in the form of mines and a enrichment factory have been studied. The difficulties that prevented the construction of production facilities are shown: repeated revision of the cover lists, lack of qualified construction personnel and metal specialists, shortage of construction materials, months of delay in the supply of metal structures and equipment, lag in the development of the social sphere in comparison with the production sector. The measures that mobilized the first initiative and labor enthusiasm of workers and engineers for commissioning of the plant in the scheduled time frame were considered. It was concluded that the organization of the design and construction of the Belovsky zinc plant did not go beyond the culture of inter-economic relations and intra-production relations characteristic in the USSR for the period of the I five-year plan.

High-purity In0000 (6N5) indium production technology development at Chelyabinsk Zinc Plant, PJSC

High-purity In0000 (6N5) indium production technology development at Chelyabinsk Zinc Plant, PJSC

Waelz process adopted by Chelyabinsk Zinc Plant to process copper plant dusts

Waelz process adopted by Chelyabinsk Zinc Plant to process copper plant dusts

Ecological optimization of Chelyabinsk Zinc Plant operations

Ecological optimization of Chelyabinsk Zinc Plant operations

Waelz oxide calcination process adopted by Chelyabinsk Zinc Plant

Waelz oxide calcination process adopted by Chelyabinsk Zinc Plant

Microwave assisted chloride leaching of zinc plant residues

Microwave (MW) assisted chloride leaching was studied to remove valuable and heavy metals from two zinc plant residues, i.e. goethite sludge and Zn-leach product.For both materials, NaCl leaching parameters, such as temperature, NaCl concentration, leaching time and addition of acid, were optimized. For goethite sludge, the best efficiencies for Cu (45–47 %), Pb (83–90 %), and Zn (47–58 %) extraction, with a minimal dissolution of matrix elements, were obtained at 200 °C, 300 g/L NaCl and L/S 10. At short leaching times (5 min) the maximal leachability of Cu and Zn was reached, while at longer leaching time (60 min) the Pb extraction increased to 90 ± 1%. Zn leaching was limited due to the presence of stable franklinite (ZnFe2O4).NaCl (280 g/L) leaching of Zn-leach product required the addition of 1 M HCl to improve metal leaching to Ag 52 ± 3 %, Bi 83 ± 1 %, Cd 82 ± 4 %, Sb 39 ± 1 %, Zn 71 ± 2 % at 200 °C, L/S 10 for 30 min. Consequently, matrix dissolution was enhanced. Metal associations in Zn-leach product were statistically investigated. The environmental impact of the MW leached materials was evaluated by a one stage leaching test, which showed a significant overall reduction in heavy metal leachability compared to untreated materials.

Recovery of Metal Values from Ni-Cd Cake Waste Residue of an Iranian Zinc Plant by Hydrometallurgical Route

This paper concerns the development of an environment-friendly hydrometallurgical flowsheet dedicated to the recovery of zinc and nickel from a waste residue collected from an Iranian zinc plant. In particular, valuable metals from Ni-Cd cake waste generated at this plant were recovered by a simple hydrometallurgical process using minimum acid for leaching, and solvent extraction step was designed such that addition of sodium hydroxide was not required and the effluent generated is safe to dispose off. The waste was leached with a mixture of hydrochloric acid and sulfuric acid in the presence of hydrogen peroxide in order to achieve a good selectivity towards iron and calcium. Afterwards, cementation was performed at pH 5 in order to remove cadmium. Liquid–liquid extraction was then implemented to produce high-purity solutions of zinc and nickel. Zinc-nickel separation was obtained at pH 2 by using a mixture of bis-(2-ehtyl-hexyl)-phosphoric acid (HDEHP) and tris-2-ethylhexyl amine (TEHA) diluted in an aliphatic kerosene. TEHA did not directly participate but helped in the extraction of zinc by scavenging the protons released by HDEHP. Therefore, no alkaline solution was necessary for maintaining the equilibrium pH during liquid–liquid extraction. Finally, this flowsheet allowed to recover more than 95% of zinc and nickel from the residue with more than 99% purity.

Study of Sulphatizing Roasting Process Using Iron Sulphates for the Treatment of Zinc Leach Residue

The paper presents the results of the investigation of zinc leach residue (ZLR) processing by sulphatizing roasting with iron sulphates FeSO4 and Fe2(SO4)3 followed by water leaching. The elemental and phase compositions of ZLR of JSC "Chelyabinsk Zinc Plant" were studied. Based on the thermodynamic calculations using HSC Chemistry 9.9 software, the temperature ranges of the sulphatizing roasting and the required amounts of iron sulphate additives for the sulphation of zinc and copper were determined. Subsequent experiments showed that recovery rates of zinc and copper reached 99.5% and 89.1% respectively, while iron remained in the leached residue. The results have indicated a high efficiency of sulphatizing roasting to transform zinc and copper contained in ZLR from ferrite to water-soluble sulphate.