Waelz Process: Most Up-to-Date Encyclopedia, News
As of 2000, the Waelz process was considered the "best available technology" for flue gas zinc recovery, and the process is used on an industrial scale worldwide. ... (August 1976), "Treatment of Zinc Silicate by the Walez Process" (PDF), South African Journal of Mining and Metallurgy: 11–14. Harris, William E. (1936), "The Waelz Process ...
(PDF) Purification of Zinc Containing Waelz Oxides from …
The Waelz oxides (WO) obtained upon processing of zinc containing semi products in Waelz kilns are rich in impurities such as alkalines, chlorides and fluorides. ... instance the fluoride ions content in the zinc electrolite Waelz Rotary Kiln Process has found its application cause problems with the removal of the metallic zinc for processing ...
Identification and Control of the Waelz Process Using …
The optimized automatic closed-loop control is finally demonstrated at an industrial Waelz kiln by using an automatic motion based slag detection and minimizing a cost functional. Today, the recycling of zinc from zinc-bearing residues is mostly done by the pyro-metallurgical Waelz process in a rotary kiln. The optimum recovery rate is only …
A review of the modified zincex® process from skorpion
A Waelz plant consists of normally two, sometimes three parts: the raw material preparation, the Waelz kiln with off-gas and slag treatment and eventually the washing of the crude ZnO dust for de ...
PURIFICATION OF ZINC CONTAINING WAELZ OXIDES
Ohridski, 1756, Sofia, Bulgaria E-mail: pkiliev@gmail Received 28 September 2016 Accepted 16 December 2016 ABSTRACT The Waelz oxides (WO) obtained upon processing of zinc containing semi products in Waelz kilns are rich in impurities such as alkalines, chlorides and fluorides. After acid leaching of the WO chlorine and fluorine …
(PDF) HOW TO WRITE YOUR MASTER THESIS: …
This handbook provides master's students the needed guide with practical examples to achieve their research works and overcome the problems they face before and while writing. In addition, this ...
MASTER THESIS
This diploma thesis presents the most important technological as well as economic aspects of a new recycling concept for Waelz slag that is being developed at the University of Leoben. Nowadays, a vast majority of the slag accumulating from recycling steel mill dust in the Waelz process is sent to landfill which generates costs.
Thermo-environmental evaluation of a modified Waelz process …
This work proposes a new configuration for the Waelz process to recycle the IETP sludge. Fig. 2 shows the flow diagram of a conventional Waelz kiln, modified with the addition of a slag cooling system (a grate-type cooler) for heat recovery from the slag through thermal integration, and a sludge drying system (both the additional systems are …
IMPROVEMENT OF THE WAELZ PROCESS FOR SLAG …
in implementing the Waelz process will make it possible to increase the yield of zinc oxide by 5–10% with an increase in unit productivity by 10–15% and a reduction in specifi c …
Minimizing dioxin and furan emissions during zinc dust
The Waelz process is a classic method for treating steel plant dusts containing zinc and lead. This process makes especially exacting demands on the off-gas cleaning system because, in most cases, the feed material is heavily contaminated with organic and inorganic components. As a result of the thermal treatment of the residues, dioxins and …
(PDF) Microstructural, thermochemistry and mechanical evaluation …
At the present time, the Waelz process treats more than 85% of the EAFD involved in recycling [15]. In the Waelz process, carbothermic reduction at 1250-1300 °C decomposes ZnFe 2 O 4, so zinc ...
Recupero dei metalli dalle polveri di aspirazione dei …
processo Waelz [6]. Table 1. Main zinc minerals used in the Waelz process [6]. Minerale Composizione Tenore teorico di Zn Calamina o Emimorfite Zn 4 Si 2 O 7 (OH) 2.H 2 O 54.28% Smithsonite ZnCO 3 ...
The effect of CaO and MgO addition and cooling rate on …
The Waelz process includes the reduction, the vaporization and oxidation of zinc and lead. The Zn/Pb materials are mixed with a reducing agent (coke) and flux (lime, quartz or
MASTER THESIS
This diploma thesis presents the most important technological as well as economic aspects of a new recycling concept for Waelz slag that is being developed at the University of …
(PDF) Hydrometallurgical processes for Waelz oxide valorisation …
The Waelz Kiln Technology is the most commonly used technology for this purpose, generating concentrates of Zn and Pb oxides (called Waelz oxides). The main component of Waelz oxides is zinc and ...
Characteristics of PCDD/F Distributions in Vapor and Solid …
The Waelz process is a classic method used for recovering zinc from electric arc furnace (EAF) dusts containing relatively high concentrations of PCDD/Fs (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans) as well as volatile metals, such as Zn, Pb, and Cu, and chlorine. As a result of the operating temperature in …
Identification and Control of the Waelz Process Using …
Download chapter PDF. 1 Introduction. The most common technology, that is applied for the recycling of dusty steel mill residues and in particular of EAF (electric arc …
Recovery of Zinc Oxide from Secondary Raw Materials: New …
The residence time of materials in Waelz kiln is determined by bricklaying, kiln length and rotation speed, usually between 4 and 6 h (Mager et al., 2000). Suetens et al. (2014b), and Ruetten et ...
Theoretical and Practical Evaluation of the Feasibility of Zinc
The best available pyrometallurgical technology for zinc-bearing residue treatment is the Waelz process using a rotary kiln. The Waelz process is characterized by the volatilization of zinc from an oxidized solid mixture (zinc bearing waste) through reduction by coke or coal. The Waelz kiln operates at a rotational speed of …
Waelz Kiln Process
Protecting the enviroment Our way. We produce Waelz oxide in our rotary kiln plant. The zinc-containing input materials are enriched in our rotary kiln using the so-called Waelz process to form Waelz oxide with a zinc content of at least 56 %. For this purpose, the input materials are introduced into the 40 m long rotary kiln together with other additives …
Technical Support Document for the Zinc Production …
For the Waelz kiln process, the feed material is charged to an inclined rotary kiln together with petroleum coke, metallurgical coke, or anthracite coal. The zinc oxides in the gases from the kiln are then collected in a baghouse or electrostatic precipitator. The second recovery process used for EAF dust uses a
IMPROVEMENT OF THE WAELZ PROCESS FOR SLAG …
UDC 669.531.66. Drying, heating, and combustion of lumps of coke in a Waelz kiln produces gases released with active combustion of carbon in the oxidizing zone in a counterfl ow regime with air blast entering through the kiln discharge end. Under conditions of a charged layer of lumps of coke and materials with occurrence of them at a surface ...
Waelz Kiln Technology
The Waelz Kiln process is an established, energy-efficient and resilient technology used to treat zinc containing materials and residues. Although Waelz technology has been around for over 80 years, the design and technology surrounding the basic kiln has improved throughout this time. In fact, we believe, that GSD has advanced the design ...
Hydrometallurgical processes for Waelz oxide valorisation …
Waelz oxide is a solid mixture with a powdery appearance; it has a grey colour and its average particle size is d 50 = 5 μm. Thus, Waelz process is an in-between process in order to make possible (technological and economical feasible) to complete the zinc recycling cycle from a hazardous waste from steelmaking industry. 1.3.
Zinc Recovery of Low Grade Concentrate from Vazante Mine by the Waelz
The Waelz process is the most used route in the world for the treatment of electric arc furnace dust (EAFD) [].It is a pyrometallurgical process characterized by the volatilization of metals like zinc, cadmium, and lead in a rotary kiln from a solid mixture by means of reduction by coal or other reduction agent, generating a solid slag []. ...
(PDF) Hydrometallurgical processes for Waelz oxide …
Article PDF Available. Hydrometallurgical processes for Waelz oxide valorisation – An overview. July 2019. Process Safety and Environmental Protection …
Camera based Identification and Control of the Waelz Process
At the feed end Fig. 1. Scheme of a Waelz kiln for zinc recycling with SDHL-process air lance and infrared camera for slag temperature measurement [7] the solid charge enters the kiln, is first ...
(PDF) HOW TO WRITE YOUR MASTER THESIS: THE EASY HANDBOOK …
This handbook provides master's students the needed guide with practical examples to achieve their research works and overcome the problems they face before and while writing. In addition, this ...
Advanced Methods for Kiln-Shell Monitoring to Optimize the Waelz …
The recycling of zinc in the Waelz process is an important part of the efficient use of resources in the steel processing cycle. The pyro-metallurgical processing of zinc-containing wastes takes place in a Waelz rotary kiln. Various measured variables are available to monitor the process. The temperature of the kiln-shell is analyzed by an …
A new infrared camera-based technology for the …
The Waelz process is currently used to process EAFD and other metallurgical wastes containing zinc by reducing and volatilizing zinc metal at temperature usually higher than 1100°C [12, 13]. Also ...