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1

Effect of Particle Sizes of Slag on Reduction Characteristics of Nickel Slag-Coal Composite Briquette

Li Xiaoming, Li Yi, Xing Xiangdong, Wang Yanjun, Wen Zhenyu, Yang Haibo

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 1

127--134

EN

Nickel slag has a high-content iron and is a secondary utilization resource with great development potential. The coal-based direct reduction is an innovative technology that can be used to utilize the iron resources in nickel slag. The effect of the particle size of nickel slag on the strength and the reduction of nickel slag-coal composite briquettes were investigated. Four samples with particle size of 75~106 μm, 106~150 μm, 150~270 μm, and >270 μm were selected. The drop strength increased 9.4 times and the compressive strength reached 281.1 N when the nickel slag particle size decreased from >270 μm to 75~106 μm. The reduction degree determined by the data from the thermogravimetric experiment indicated that its maximum was 79.545%. The reduction experiments performed at 1200°C for 45 minutes indicated that the nickel slag with particle sizes between 75~106 μm were appropriate for the reduction of the nickel slag-coal composite briquettes.

2

The effect of pellet technology on direct reduction of jarosite residues from zinc hydrometallurgy

Wang Yayun, Yang Huifen, Hou Xiaoqiang, Gao Wenjie, Gui Haiping, Liu Qian

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 3

802--811

EN

In this study, the coal-based direct reduction technique has been applied to recover the valuable metals lead, zinc and ions from powdery and pellet jarosites. The influence of coal dosage of powdery and pellet jarosite separately on the volatilization rates of lead and zinc and on the metallization rate of iron was investigated. Results showed that the lead and zinc in both powdery and pellet jarosite could be effectively reduced with the volatilization rates higher than 95% and 99%, respectively. However, the iron reduction efficiency of pellet jarosite is better than that of powdery jarosite. The concentration of CO and CO2 gas produced in the reduction process of two types of jarosite were detected and compared to investigate the difference of reduction mechanism between powdery and pellet jarosite. The result showed that the utilization of both CO and C during the reduction of pellet jarosite was higher than that of powdery jarosite. The theoretical analysis was carried out by gas analysis and scanning electron microscopy and energy dispersive spectrometer (SEM-EDS).

3

Study on recovery of lead, zinc, iron from jarosite residues and simultaneous sulfur fixation by direct reduction

Wang Y., Yang H., Zhang W., Song R., Jiang B.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 2

517--526

EN

Jarosite residues, which are generated in a zinc production plant by a hydrometallurgical process, contain a large amount of valuable metal components. In this study, a method was proposed for the recovery of lead, zinc and iron from the residues and simultaneous sulfur fixation through direct reduction followed by magnetic separation. The influences of the roasting temperature, roasting time and the concentration of SO2 gas in the direct reduction process were researched in detail. Results showed that the volatilization rates of lead, zinc and sulfur were 96.97%, 99.89% and 1.09%, respectively, and the iron metallization rate was 91.97% under optimal reduction conditions; roasting temperature 1523 K for 60 min. The magnetic concentrate with the iron content of 90.59% and recovery rate of 50.87% was obtained from the optimal reduction product by grinding and magnetic separation. The optimum fineness for separation 96.56% less than 37 μm accounted with magnetic field strength 24 kA/m. The theoretical analysis was carried out by thermodynamics, X-ray powder diffraction, gas analysis and scanning electron microscopy.

4

Recovery Of Nickel From Spent Nickel-Cadmium Batteries Using A Direct Reduction Process

Shin D. J., Joo S.-H., Wang J.-P., Shin S. M.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2B

1365--1370

EN

Most nickel is produced as Ferro-Nickel through a smelting process from Ni-bearing ore. However, these days, there have been some problems in nickel production due to exhaustion and the low-grade of Ni-bearing ore. Moreover, the smelting process results in a large amount of wastewater, slag and environmental risk. Therefore, in this research, spent Ni-Cd batteries were used as a base material instead of Ni-bearing ore for the recovery of Fe-Ni alloy through a direct reduction process. Spent Ni-Cd batteries contain 24wt% Ni, 18.5wt% Cd, 12.1% C and 27.5wt% polymers such as KOH. For pre-treatment, Cd was vaporized at 1024K. In order to evaluate the reduction conditions of nickel oxide and iron oxide, pre-treated spent Ni-Cd batteries were experimented on under various temperatures, gas-atmospheres and crucible materials. By a series of process, alloys containing 75 wt% Ni and 20 wt% Fe were produced. From the results, the reduction mechanism of nickel oxide and iron oxide were investigated.

5

Use of non-traditional alternative fuels, typical of the Moravian-Silesian region for Midrex technology, with a view to reducing the environmental burden

Pustejovska P., Jursova S., Bilik J.

Hutnik, Wiadomości Hutnicze

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2012

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Vol. 79, nr 12

885--887

EN

Metallurgical coke is becoming worldwide more deﬁcit and costly reducing mean and source of heat energy during traditional pig iron production in blast furnaces. In spite of the fact that up till now not every possibility of production of quality metallurgical coke from less caking coal and even non-caking kinds of coals has not been used, it is necessary to be concerned with problems of pig iron production without using coke sufﬁciently beforehand. Some alternative method of iron production could be a solution both from melting and/or direct reduction (for example Midrex). A lot of theoretic and practical knowledge from direct iron production will be also possible to use in connection with existing production of pig iron in blast furnaces aiming to replace a considerable part of metallurgical coke with more available and cheaper fuels and power sources.

PL

W tradycyjnym procesie wytwarzania surówki w wielkim pieca koks metalurgiczny jest coraz bardziej deficytowym reduktorem í źródłem energii cieplnej. Do tej pory nie opracowano technologii wytwarzania koksu metalurgicznego spełniającego odpowiednie wymagania jakościowe z węgli nie spiekających się. Dlatego konieczne jest już teraz opracowanie technologii produkcji surówki żelaza bez stosowania koksu. Rozwiązaniem mogą być alternatywne metody produkcji żelaza (np. metoda MIDREX). Niektóre z rozwiązań teoretycznych i praktycznych dotyczących redukcji bezpośredniej mogą znaleźć zastosowanie w procesie wielkopiecowym. Pozwoli to na częściowe ograniczenie zużycia koksu metalurgicznego poprzez zastąpienie go bardziej dostępnymi i tańszymi źródłami paliw i energii.

6

Short Route - Long-Term Success, Integrated Mini-Mill Solutions by Midrex and SMS Demag

Kempken J., Kleinschmidt G., Schmale K., Thiedemann U., Gaines H. P., Kopfle J. T.

Archives of Metallurgy and Materials

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2008

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Vol. 53, iss. 2

331-336

EN

SMS Demag and Midrex Technologies formed a strategic alliance and have teamed up to offer an integrated mini-mill concept for the production of high-quality hot rolled coils based on direct reduced iron (DRI). The cooperation of the market leaders in the fields of direct reduction, electric steelmaking and combined continuous casting/hot rolling enables steelmakers to profit from the shortest route from iron ore to hot rolled coils (HRC). Customers benefit from unique and well-proven technology: MIDREXr Plant, ARCCESSr EAF (electric arc furnace), CSPr technology (compact strip production) The direct reduced iron produced by the MIDREX Plant features a high metallic iron content, but almost no nonferrous metal impurities which are undesired in steel. In combination with SMS Demag’s clean-steel technology, it is possible to achieve ambitious metallurgical results and to reliably produce sophisticated steel grades. The optimally tuned plant components are designed for maximum energy-efficiency over the whole process route and hence result in a fast return-on-investment.

PL

Firmy SMS Demag i Midrex Technologies połączyły razem siły, wspólnie opracowały i przedstawiły projekt mini walcowni znajdujących zastosowania w produkcji wysokiej jakości gorąco walcowanych kręgów, w oparciu o proces redukcji bezpośredniej żelaza (DRI). Współpraca liderów z dziedziny redukcji bezpośredniej, elektrometalurgii oraz nowoczesnych metod ciągłego odlewania/walcowania na gorąco pozwoliła metalurgom uzyskać korzyści ze skróconej linii technologicznej od rudy żelaza do kręgów walcowanych na gorąco (HRC). Uzyskano korzyści z unikalnej i dobrze sprawdzonej technologii: MIDREXr Plant, ARCCESSr EAF (piece łukowe), CSPr technology (produkcja kompaktowa). W bezpośrednio zredukowanym żelazie według technologii w MIDREX Plant uzyskuje się wysoką zawartość żelaza metalicznego, przy praktycznie braku zawartości wtrąceń nieżelaznych, niepożądanych w stali. W połączeniu z technologią "clean-steel" firmy SMS Demag możliwe jest osiągnięcie bardzo dobrych rezultatów w procesach elektrometalurgicznych oraz produkcja specjalnych gatunków stali. Głównym celem optymalizacji jest uzyskanie jak najwyższej wydajności energetycznej podczas całego procesu, aby uzyskać szybki zwrot kosztów poniesionych na inwestycje.

7

Rotary hearth furnace technologies for iron ore and recycling applications

Ishikawa H., Kopfle J., Mcclelland J., Ripke J.

Archives of Metallurgy and Materials

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2008

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Vol. 53, iss. 2

541-545

EN

Midrex Technologies and Kobe Steel offer the FASTMET, FASTMELT, and ITmk3 Technologies for processing iron ore and iron-containing by-products to produce DRI and pig iron products. These processes offer steelmakers methods for economically producing high quality iron products and recovering valuable mineral resources using fine ores, by-products, and coal. Several commercial FASTMET Plants have been operating successfully for a number of years, confirming the basic process concept. A number of new projects are under development worldwide for the three technologies. This paper provides technical details of the processes, reviews promising applications, and discusses current commercial developments.

PL

Midrex Technologies i Kobe Steel posiadają w swojej ofercie następujące technologie: FASTMET, FASTMELT i ITmk3. Znajdują one zastosowanie w procesach przeróbki rud żelaza oraz półproduktów zawierających żelazo, które następnie wykorzystywane jest w procesie DRI oraz wytwarzania surówki. Wykorzystanie tych technologii przez producentów stali stwarza możliwość bardziej ekonomicznej produkcji wytwarzania żelaza wysokiej jakości oraz odzysku wartościowych materiałów mineralnych takich jak drobna ruda, materiały odpadowe oraz węgiel. Różne komercyjne instalacje FASTMET pracują z powodzeniem od wielu lat, wykorzystując proste założenia technologii. Obecnie na świecie realizowanych jest wiele projektów związanych z wprowadzeniem tych trzech technologii. W artykule opisano techniczne detale procesów, omówiono najnowsze rozwiązania rynkowe oraz przedstawiono obiecujące perspektywy zastosowania nowych technologii.